JPH10200583A - Network connection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a network connection device in which by connecting between different networks (e.g. connecting between 1394 networks, and connecting two 1394 networks through another network), data are easily transferred between terminal equipment which are connected to the respective networks. SOLUTION: Topology of a 1st network 201 is recognized to prepare 1st topology information, the 1st topology information and topology information of a 3rd network 203 are exchanged via a 2nd network 300. The 1st topology information and topology information of the 3rd network are stored, and new topology information sharing them based on the 1st topology information and the topology information of the 3rd topology information is prepared to recognize the topology of the 1st network 201.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interconnecting apparatus and a connecting method for connecting between networks for transferring data between remotely interconnected networks, and more particularly, to standardizing an IEEE 1394 committee. The present invention relates to an interconnecting device and a connection method for interconnecting a recommended 1394 network.

[0002]

2. Description of the Related Art With the advance of network technology in recent years, the so-called Internet technology for speeding up a private network such as a public network or a corporate LAN and performing communication by interconnecting these different networks has been widely used. It is being used. This trend of networking is also spreading to homes, and in particular, users who purchase a personal computer connect the personal computer to the Internet and communicate with other external users via the network. It has become.

[0003] Further, there has been a viewpoint of a network in a home, and in particular, as a home network targeted at home security, CEBus is used.
Standards such as LON and LON have already been proposed. Furthermore, an analog AV cable (usually using white, red, and yellow cables) connecting AV (Audio Visual) devices can be regarded as a kind of home network. As described above, it is thought that there is a potential demand for networking even in a conventional home. However, in the current situation, there has been almost no widespread use other than an AV cable for connecting AV devices. It can be said that networking within has not advanced at all. This is because conventional AV cables use analog signals to transfer data, and cannot be connected to other home networks or personal computers, and conventional home networks such as CEBus and LON use narrowband data. This was due to the problem that only the transfer was possible. In addition, since the conventional home network could not connect to networks outside the home,
It seems that the lack of sufficient benefits for users by networking at home was a major factor that hindered the spread.

[0004] In response to such a problem, in recent years, an interface specification called 1394, which has been studied in IEEE, has come into the spotlight as a next-generation version of SCSI of personal computers. This 139
In the four interfaces, a plurality of terminals are connected in a daisy chain or a star type, so that data of a wide band exceeding 100 Mbps can be transferred. The most significant feature is that Asynchronous is used on the same cable.
s: Asynchronous transfer) data and isochronous (Isoch)
(Ronous) data. For this reason, SCSI
Consideration has begun as a next-generation version of 1394
There has been an increasing movement to use a cable as a cable connecting AV devices. Conventionally, large-capacity data such as image information and audio information transferred between AV devices is transferred by analog transmission, but is transferred by digital signals using the 1394 isochronous data transfer function. It is intended to be able to connect not only to the connection between AV devices up to this point, but also to digital devices such as personal computers.

[0005] In such a movement, Microsoft has been working on a next-generation Windows machine in 1394.
With the announcement of supporting an interface, 1394 has attracted attention as an interface for connecting a personal computer terminal and an AV terminal.

[0006]

Although the 1394 interface solves the problems of the conventional home network such as the analog transmission system and the narrow band communication, the 1394 interface has a problem of network connection outside the home. The problem remains. That is, 139
Terminals that can only communicate using the four protocols are 1394
If different types of networks other than 1394 exist between networks, communication between these 1394 networks cannot be performed.

[0007] In connection with a network outside the home, an external connection method using the Internet is currently mainly used. The Internet has the feature that communication can be performed between terminals connected to different networks without being aware of differences in data link layer types and transmission rates, and in recent years the number of users has increased rapidly. At the same time, the services provided are becoming more sophisticated.

However, in order to use the Internet, the terminal must obtain an Internet address such as an IP address, and a function of executing an Internet protocol together with a data link function to which the terminal is connected is implemented. Have to do it. In addition, router function in the Internet,
It is required for each household, and requires very expensive functions for use by ordinary household users. In particular, in the home network, it is expected that AV devices such as televisions and videos will mainly be used. Therefore, using the Internet technology developed mainly for personal computers as it is for connection between AV devices causes many problems. Will be.

In view of the above problems, the present invention provides a method for connecting different networks (for example, connecting between 1394 networks and connecting two 1394 networks via other networks). It is an object of the present invention to provide a network connection device capable of easily transferring data between terminals. That is, for example, by exchanging topology information held in each network between remote 1394 networks and emulating each other as one 1394 network, communication is performed only by the 1394 protocol. It is an object of the present invention to provide a network connection device capable of performing communication even with a terminal that cannot perform communication through another network. The network connection device according to the present invention may be used, for example, to connect home networks, to connect home networks to networks outside the home, and to connect home networks to each other via home networks. It can be used in cases such as:

[0010]

[Means for Solving the Problems]

(1) Claims 1 to 5 A network connection device (Claim 1) of the present invention is a network connection device for connecting a first network and a second network, the network connection device recognizing the topology of the first network. Create the first topology information
Automatic configuration recognizing means for recognizing the topology of the second network and generating second topology information
Automatic configuration recognition means, topology information storage means for storing the first topology information and the second topology information, based on the first and second topology information stored in the topology information storage means, And topology information creating means for creating new topology information for sharing these, even when the first and second networks operate independently of each other, share the topology information with each other. Therefore, even if the first and second networks operate independently, communication can be performed in an environment where the networks are connected.

Further, the network connection device of the present invention (claim 2) further comprises the first topology information based on the new topology information created by the topology information creation means.
Automatic configuration recognizing means for recognizing the topology of the second network and generating third topology information, and recognizing the topology of the second network based on the new topology information generated by the topology information generating means. And a fourth automatic configuration recognizing means for generating the fourth topology information by using the third and fourth automatic configuration recognizing means.
The topology information created by the automatic configuration recognizing means can be notified to each terminal in the first and second networks.

Further, the network connection device of the present invention (claim 3) further stores a topology information storing the third topology information and the fourth topology information together with the first and second topology information. Means,
A second topology information creating unit that creates new topology information sharing the third and fourth topology information based on the third and fourth topology information stored in the topology information storage unit. By exchanging the third and fourth topology information newly created by the second automatic configuration recognizing means between the first and second networks again, the topology recognized by each other's networks is exchanged. A network connection function that also takes into account information can be provided.

(2) Claims 6 to 12 A network connecting device according to the present invention (claim 6) is a network connecting device for connecting a first network to a third network via a second network. Automatic configuration recognizing means for recognizing the topology of one network and creating first topology information;
Topology information exchanging means for exchanging the topology information of the third network with the topology information of the third network via the second network, and the third network received by the first topology information and the topology information exchanging means. Topology information storage means for storing topology information, and a topology for creating new topology information sharing these based on the first topology information and the third network topology information stored in the topology information storage means And information creating means, even if the first and third networks are not directly connected via the second network and each network operates independently, Since each other's topology information can be shared, the first and third Ttowaku is, it is possible to communicate in an environment connected to the network even remains operated independently.

[0014] When the topology information exchanging means exchanges the first topology information and the topology information of the third network via the second network, the topology information exchanging means transmits the topology information via the second network. By using a connection setting function for setting a connection with the third network, a broadcast function for the second network, and the like,
And a function of exchanging topology information of the third network.

Further, the network connection apparatus of the present invention further recognizes the topology of the first network based on the topology information newly created by the topology information creating means, and further recognizes the second topology. And a second automatic configuration recognizing means for generating information, the topology recognizing process in each network using the topology information generated by the automatic configuration recognizing means for each of the first and third networks. In particular, in the first network, the second topology information created by the second automatic configuration recognizing means can be notified to each terminal in the first network.

Further, the network connection device of the present invention further comprises a second topology for exchanging the second topology information and the topology information of the third network via the second network. Information exchange means, topology information storage means for storing the second topology information and topology information of the third network received by the second topology information exchange means,
A second topology information creating unit that creates new topological information sharing these based on the second topology information and the third network topology information stored in the topology information storage unit. Thus, the topology information of the first and third networks newly created by the topology information creation function is exchanged between the first and third networks again, and is recognized by each other's networks. A network connection function that also takes into account existing topology information can be provided.

Further, according to the network connection device of the present invention (claim 9), the first and third networks are defined by the IEEE1394 committee and are defined by IEEE.
By using the 1394-1995 network, so-called real-time data communication can be performed together with data communication between the first and third networks, and multimedia communication via different networks can be realized. become.

(Claim 12) The first network uses IEEE1394-1995, and the topology information creating means creates the topology information of the first network by using the second or third network. The Capability information in the 1EE1394 protocol of the terminal belonging to
topology information is created by converting the topology information into ty information. topology information exchange for notifying the third network of the topology information of the first network using a broadcast function to the second network. Means.

A topology information exchange means for notifying the third network of the topology information of the first network by using a communication resource reserved in advance in the second network.

Topology information receiving / storing means for receiving / storing topology information of a plurality of networks connected by the second network when connecting two or more networks via the second network; And topology information notifying means for notifying topology information of each network stored in the topology receiving / storing means in response to a request from a network connected to the second network.

(3) Claims 13 to 20 The network connection device of the present invention (claims 13 and 1)
4) is the first topology information included in the first topology information.
A terminal address assigned to a terminal in the third network, a terminal address assigned to a terminal in the third network included in the topology information of the third network, and the terminal address included in the second topology information. An address conversion table that stores a correspondence relationship between terminal addresses assigned to terminals in the first and third networks, or an address translation table that is included in the second topology information. A terminal address assigned to a terminal; and the first and third terminals included in the topology information of the third network.
An address exchange table for storing a correspondence between terminal addresses assigned to terminals in the first network, and a destination terminal address and transmission of a packet received from the first network with reference to the address conversion table. First address translation means for rewriting at least one of a source terminal address, and at least one of a destination terminal address and a source terminal address of a packet received from the second network with reference to the address translation table A second address translation unit that rewrites, a first packet translation unit that refers to the address translation table and encapsulates a packet received from the first network into a packet to be transmitted to the second network; With reference to the address conversion table A second packet converter for extracting a packet to be sent to the first network from a packet received from the second network, the topology information storage means includes: The correspondence between the topology information recognized by the terminal of the third network and the topology information stored by the terminal in the third network is stored, and the address conversion table is set in the first network. Since the correspondence between the channel or connection for real-time data transfer and the channel or connection set in the second network is stored, the correspondence is transmitted from the first network with reference to these. The source terminal address and destination terminal address of the packet are stored in the third network. It is possible to convert the terminal address in over click. Also, it is possible to know to which connection in the second network the real-time data transmitted from an appropriate channel in the first network should be transferred only by reading its channel number. Therefore, real-time data such as image data can also be transferred to and from the third network via the second network.

Specifically, (claim 15) first resource acquisition means for acquiring communication resources in the first network, and second resource acquisition means for acquiring communication resources in the second network.
At least one of the resource acquisition means.

(Claim 16) A first resource for acquiring a communication resource in the first network based on request information described in a packet sent from a terminal in the second network Acquisition means, and second resource acquisition means for acquiring communication resources in the second network based on request information described in a packet sent from a terminal in the first network. It has at least one.

(Claim 17) Resource acquisition means for acquiring communication resources in the second network based on request information described in a packet sent from a terminal in the first network. And a packet sent from a terminal in the first network is IE
The packet conforms to the C1883 protocol, and
When a data transmission or reception request is sent to a terminal in a network other than the first network, the IEC
The resource acquisition means is activated based on request information described in a packet conforming to the 1883 protocol.

(Claim 18) A first resource acquiring means for acquiring a communication resource in the first network, and a communication resource in the first network acquired by the first resource acquiring means is used. Data transmission / reception request transmitting means for transmitting a request to a terminal in the first network according to the IEC1883 protocol so as to transmit or receive data.

(Claim 19) A first resource acquiring means for acquiring a first communication resource in the first network, and a second resource acquiring means for acquiring a second communication resource in the second network. A resource acquisition unit, a correspondence relationship between the first communication resource and the second communication resource that uses the first communication resource, and a method that uses the first communication resource and the first communication resource. First connection correspondence storage means for storing at least one correspondence relation among terminal address correspondence relations in a second network, the second communication resource and the second communication resource;
At least one of the correspondence relationship of the first communication resource using the communication resource of the first embodiment and the correspondence relationship of the terminal address in the first network using the second communication resource and the second communication resource. And second connection correspondence storage means for storing one of the correspondence relations.

(Claim 20) A first resource acquiring means for acquiring a first communication resource in the first network, and a second resource acquiring means for acquiring a second communication resource in the second network. A resource acquisition unit, a correspondence relationship between the first communication resource and the second communication resource that uses the first communication resource, and a method that uses the first communication resource and the first communication resource. First connection correspondence storage means for storing at least one correspondence relation among terminal address correspondence relations in a second network, the second communication resource and the second communication resource;
At least one of the correspondence relationship of the first communication resource using the communication resource of the first embodiment and the correspondence relationship of the terminal address in the first network using the second communication resource and the second communication resource. A second connection correspondence storage unit for storing one correspondence relationship, and a second connection correspondence storage unit based on a source terminal address or a connection number described in a packet received from the first network. First packet transfer means for searching for one communication resource and transferring the received packet to a terminal address or connection in the second network corresponding to the searched first communication resource; Source terminal address or connection number described in the packet received from the network Searching for a second communication resource from the second connection correspondence storage means on the basis of the above, and storing the received packet in a terminal address or connection in the first network corresponding to the searched second communication resource. And second packet transfer means for transferring.

(4) Recognition of packet type The network connection device of the present invention has an interface function to the first and second networks to which the network connection device is connected, and is set in the first network. And a packet identification function for identifying a specific packet requesting the transfer of real-time information using the real-time data transfer channel.

Specific means of this packet identification function include: a destination terminal address of the packet received from the first network together with the destination terminal offset information of the packet, and a packet received from the first network. Is provided.

Referring to a tcode field of a packet received from the first network, the first
The packet processing determining means for determining the processing of the packet received from the network.

With reference to a header field of a data portion of a packet received from the first network,
And a packet processing determining means for determining processing of a packet received from the first network.

In the packet processing determining means,
It is characterized by starting EC1883 protocol processing.

[0033] By using at least one of these, it is determined whether the packet sent from the first network is a packet for performing normal data transfer to a terminal in the third network. It is possible to identify whether the packet requests the start or end of the transfer. Conversely, by performing the same packet identification processing on the packet sent from the third network, it is determined whether the packet received from the second network is a normal data packet or not. This makes it possible to identify whether the packet is a packet requesting start or end of transfer, or whether the packet is topology information sent from the third network via the second network.

(5) Ack Pending The network connection device of the present invention has an interface function to the first and second networks to which the network connection device is connected, and is transmitted from the first network. When transferring a packet to a third network via the second network,
Sending an Ack signal for the received packet to the sending terminal that sent the packet in the first network without waiting for a regular Ack signal from a destination terminal in the third network; When sending an Ack signal instead of the destination terminal, sending a pseudo Ack signal sending an Ack waiting signal instead of a normal Ack signal and sending a pseudo Ack signal to the source terminal Has functions.

Specific functions of these functions are as follows: When a packet is received from the first network, a packet transfer process to the second network is performed, and a transmission source described in the received packet is transmitted. There is provided a packet transfer end notification waiting means for sending a waiting packet for temporarily waiting for a data transfer end notification to the terminal.

The packet transfer completion notification waiting means, and the transmission described in the received packet when receiving the packet transfer completion notification waiting from the packet transfer completion notification waiting means from the second network. A packet transfer end notifying unit for sending the waiting data transfer end notification packet to the former terminal is provided.

Thus, an Ack signal from the destination terminal is transmitted until a packet transmitted from the first network is transferred to the third network via the second network. , The first network from the third network via the second network.
The network connection device transmits the pseudo Ack signal to the network even if it takes a long time to arrive at the network of the transmission source terminal and becomes longer than the allowable Ack signal waiting time at the source terminal. Since the packet is transmitted to the terminal, the packet communication between the first network and the third network is executed even in an environment where the transfer delay time is long over a plurality of networks. You can do it.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a network connection device according to the present invention will be described in detail with reference to the drawings. In the following description, for example, a plurality of IEEE 1394 high performance serial
A description will be given of an example in which a bus (hereinafter, referred to as 1394) network is connected.

IEEE 1394 TA (Trade A
ssociation), a data transfer method on a 1394 network, a method of setting a synchronization channel for transferring real-time data, and the like are defined.
P1394 Standards for a Hig
h Performance Serial Bus
(Hereinafter, referred to as 1394 Specification)
Has been created. As a control protocol for transferring image data using a synchronization channel, a specification of Digit is used.
al Interface for Consumer
Electronic Audio / Video E
A specification called “quipment” (hereinafter referred to as IEC1883) defined by ISO / IEC is adopted. Data and packets used in the IEC1883 protocol (for example, packets having a format shown in FIGS. 11 and 18) can be easily converted to IEC188.
3 data or IEC1883 packet.

In the 1394TA, a plurality of 1
A method of connecting a 394 network via a bridging function called a 1394 bridge is also being studied.

In this embodiment, a method will be described in which a plurality of 1394 networks can be recognized as one 1394 network, thereby connecting the 1394 networks even through different types of networks.

(First Embodiment) 1.1 Procedure for Initializing Topology Information FIG. 1 shows three 1394 networks X, Y, and Z in a home.
(201, 202, and 203: hereinafter referred to as 1394 networks X, Y, and Z), and shows an example of a home network in which these networks are connected by the backbone network 300.

In the home network shown in FIG. 1, each of the 1394 networks X, Y, and Z and the backbone network 300 are connected to the network connection devices A, B, and C (110, 120, 130) of the present invention. A, B, and C). In addition, each of these network connection devices has one
394 networks are emulated to perform communication between 1394 networks.

FIG. 2 shows a home network in which each 1394 network is connected by a backbone network 300 as an example of a specific configuration of the home network having the configuration shown in FIG.

In FIG. 2, 1 is stored in the 1394 network X.
394 terminals 111, 112, and 113 exist, and are further connected to the backbone network 300 via the network connection device A. At this time, the 1394 Spec
According to the information, an initialization procedure called a bus reset is executed when the network is started up, whereby an automatic configuration recognition process of the topology of each 1394 network is executed.

In FIG. 2, the 1394 network X
1394 terminal 111 becomes the root (Root) terminal and the 1394 terminal 113 becomes the isochronous resource manager (Isochronous).
(Resource Manager) terminal. Details of the root terminal and the isochronous resource manager terminal will be described later.

Similarly, a case where the network connection device 120 becomes the root terminal and the 1394 terminal 123 becomes the isochronous resource manager terminal due to the bus reset in the 1394 network Y is shown.
The case where the 1394 terminal 132 becomes the root terminal and the 1394 terminal 131 becomes the isochronous resource manager terminal due to the bus reset in the network Z is shown.

Further, in the example of FIG.
Each bus reset in the network
As a value of the physical ID allocated to the four terminals, a physical ID of A0 [X0] is allocated to the network connection device A, and A1 [X0], A2 [X0], A3 are allocated to each 1394 terminal in the 1394 network X. This shows a case where a physical ID of [X0] is assigned. The physical IDs of these 1394 terminals are similarly assigned in the 1394 networks Y and Z.

Here, the value (X0, X0 in FIG. 2) used in the notation of the physical ID of each 1394 terminal in this embodiment is used.
Y0, Z0) indicate the type of topology information of each 1394 network in which those physical IDs are stored. Details will be described later.

As described above, in the following embodiments including this embodiment, when representing the physical ID of each 1394 terminal, the type of this topology information (topology X, Y, Z) is used to indicate the 1394 terminal. If the physical ID of the terminal is 13
It is possible to identify whether it is assigned in the 94 network (X, Y, Z). Specifically, when representing the physical ID assigned in the 1394 network X, A0 [X] or A0 [X0]
To represent the physical ID assigned in the 1394 network Y, B0 [Y] or B0 [Y
0]. Such a physical ID assigned 1
As a method for identifying the 394 network, not only the method using the type of topology information described above, but also, for example, 1
A method using Bus-ID defined in 394 Specification is also conceivable.

In the network connection devices A, B, and C according to the present invention shown in FIG.
The topology information of the 394 network (the topologies X0, Y0, and Z0 in FIG. 2) are exchanged with each other via the backbone network 300. As a method of exchanging the topology information, there are the following methods.

1. A method of broadcasting the topology information held by each network connection device to the backbone network 300 at the end of the bus reset in each 1394 network.

At this time, the backbone network 300
Is a connection-type network such as an ATM network, a separate connection (PVC: Perm) is previously established between each network connection device.
anent Virtual Channel), a method of setting a new connection and transferring topology information each time Flooding (described later) is executed, a multipoint-multipoint connection between all network connection devices. May be set in advance and used for broadcasting the topology information.

2. A method in which addresses of network connection devices are stored with each other, and when the bus reset in each 1394 network is completed, topology information newly created by the bus reset is notified to the stored network connection devices.

At this time, if the backbone network 300 is Ethernet, the address of each network connection device will have a method using the Ethernet address of each network connection device, or each network connection device will have an address. A method using an IP address can be considered. Backbone network 3
If 00 is an ATM network, a method using an ATM address of each network connection device, or a method that each network connection device will have. For example, a method using 164 addresses can be considered.

3. A network connection server for connecting each 1394 network is arranged in the backbone network 300, and the topology information of each 1394 network stored in each network connection device is transmitted to the network connection device at an appropriate timing. A method of writing to the connection server and reading the topology information of the other 1394 networks written in the network connection server at an appropriate timing, such as after each network connection device has completed the bus reset.

At this time, as a method of transferring the topology information between each network connection device and the network connection server, the backbone network 300 as described above is used.
Is an Ethernet network, an ATM network, or the like.

Here, the backbone network shown in FIGS. 1 and 2 is a shared network such as Ethernet.
d Media type network may be used.
A connection-type network such as a TM network or a shared network such as IEEE 1394 may be used.
A network in which the media type and the connection type are mixed may be used.

Hereinafter, referring to FIGS. 3 to 8, each of the network connection devices A, B, and C stores the topology information of each 1394 network stored therein (the topology X in FIG. 2).
0, Y0, Z0) to the backbone network 300
(Hereinafter referred to as "Flooding") and a method of notifying the other network connection device via
The topology information created as a result of the ing will be described in detail. In the procedure described below, topology information when each of the 1394 networks X, Y, and Z perform a bus reset independently to automatically recognize the topology is represented as topology X0, Y0, and Z0 (in the case of FIG. 2). Is assumed). Further, the topology X0, Y0, Z0 of each 1394 network is a
After that, the bus reset including the topology information is performed, and the topology information when a new topology recognition process is performed is stored in the topology X,
Expressed as Y and Z.

1.2 Topology Recognition Method (Part 1) FIG. 3 shows a first topology recognition method. First, each one
A bus reset is generated in the 394 networks X, Y, and Z, and a topology automatic configuration recognition process is executed for each 1394 network. The procedure for automatic topology configuration recognition is Tree. ID process, Se
Two processes, called If_ID processes,
94 Specification.

The Tree_ID process is a process for defining the mutual relationship between the connected 1394 terminals, whereby one of the terminals connected to both ends of each link is set as a parent (Parent) terminal and the other is set as a parent (Parent) terminal. It is determined whether the terminal is defined as a child terminal. The relationship between the parent terminal and the child terminal is used to determine a root terminal in the 1394 network. Specifically, all 1394 terminals connected to the own 1394 terminal are
A terminal whose terminal is defined as a child terminal is a root terminal.

In the Self_ID process, Tr
139 to which the root terminal belongs based on the instruction from the root terminal defined by the ee_ID process.
For all 1394 terminals in the four networks, physical IDs as terminal identifiers in the 1394 network
Is assigned. Therefore, this physical ID
As described above, a value corresponding to each topology information of each 1394 network is assigned.

These two processes (Tree_I
D, Self_ID).
94, all terminals belonging to the network
Network topology information can be automatically recognized, and all terminals have topology information (topology X0, Y0, Z0) common to each 1394 network (step S1 in FIG. 3).

Next, each of the network connection devices A, B, C
Is the 1394 created by executing the above process
Topology information for each network (topology X0, Y
0, Z0) between each network connection device.
ooding. First, the network connection device A of the 1394 network X floods the topology information X0 to the network connection devices B and C (step S2 in FIG. 3). At this time, several methods described above can be used as the Flooding method.
Network connection devices B and C that have received topology X0
May or may not generate a bus reset at this point (no bus reset is generated in FIG. 3).

Hereinafter, similarly, the topology information Y0,
Flood Z0 (steps S3 and S4 in FIG. 3), and the Flo between all the network connection devices.
The odding process ends.

When these processes are completed, each network connection device is provided with the 1394 networks X, Y, and Z.
(Topology X0, Y0, Z0) are all held.

Next, each piece of topology information (topology X
0, Y0, Z0).
B and C generate a new bus reset for each of the 1394 networks X, Y and Z, execute the Tree_ID process and the Self_ID process again, and perform an automatic configuration recognition process for a new topology (step S in FIG. 3).
5). As a result, as the topology information in each 1394 network, a topology as if a group of terminals in each 1394 network were connected to each network connection device via another network connection device is recognized. Using the topology, the network connection device performs emulation processing of another 1394 network).

Tree executed at the time of this bus reset
In the ID process, for example, the network connection device A is a 1394 terminal in which the other network connection devices B and C are connected to different ports of the own terminal, respectively. A process for recognizing the child terminal of the device A is performed. By doing so, a terminal existing in the 1394 network X can be always assigned to a root terminal in the topology information (topology X) created by a new bus reset in the 1394 network X. Become like However, in the newly created topology information (topology X), the value of the physical ID assigned to each 1394 terminal is 1
394 network topology information (topology X0,
Y0, Z0), which is different from the value assigned to each 1394 terminal.

The topology information (topologies X0, Y0, Z0) for each 1394 network created during the above-described topology recognition processing, and each 1394 network finally created by the above-described topology recognition processing. Topology information (topologies X, Y,
One example of Z) is shown in FIG.

As can be seen from FIG. 4, the topology information X, Y, and Z finally recognized by the above-described topology recognition processing have a configuration in which the network connection information A, B, and C are directly connected. Thus, the three networks X, Y, and Z appear to each terminal as if they were one 1394 network.

As a result of executing the topology recognition processing shown in FIG. 3, the network connection apparatus A obtains the topology information of the 1394 network X newly created by the above-described topology recognition processing (topology X) in the topology information of FIG. ) Together with the topology information (topologies X0, Y0, Z0) created for each of the 1394 networks X, Y, Z.
These pieces of topology information are used for, for example, address conversion when executing data communication (for example, data communication from the 1394 terminal 112 to the 1394 terminal 132) over each 1394 network. Details will be described later.

FIG. 5 shows an example of detailed contents of topology information (topologies X0, Y0, Z0) unique to each 1394 network stored in each network connection device.
FIG. 6 shows an example of the detailed contents of the topology information (topology X) of the 1394 network X in the newly created topology information of each 1394 network. However, since the examples shown in FIGS. 5 and 6 are topology information stored in each network connection device, as will be described later, each topology information includes an address of each network connection device in the backbone network and other information. Information on the 1394 terminal address in the 1394 network is also described.

However, information on the addresses of the respective network connection devices in such a backbone network and the addresses of the 1394 terminals in other 1394 networks are stored in the normal 1394 terminals in the respective 1394 networks X, Y and Z (see FIG. 2). 1394 terminal 111 in
To 113, 121 to 123, 131 to 133, etc.) are unnecessary information and are not notified even in the present embodiment. Therefore, the topology information held by each 1394 terminal includes: It is not necessary to describe the topology information on the backbone network and other 1394 networks as described above.

FIG. 5 shows, as topology information for each 1394 network, the physical ID assigned to each 1394 terminal and the 1394 terminal in advance (at the time of manufacture).
The assigned unique ID, the attribute of each 1394 terminal assigned as a result of the automatic configuration recognition (State: information on a root terminal, an isochronous resource manager terminal, and the like), and the data processing capability of each 1394 terminal ( Capability) and port information indicating whether the 1394 terminal connected to the port of each 1394 terminal has been recognized as a parent or a child.

These information are stored in the 1394 Specif
As described above, the root terminal is a terminal that has recognized all 1394 terminals connected to the end of its own port as children, and the isochronous resource manager terminal is a topology terminal. Is a terminal assigned as a node that manages isochronous data transfer processing as a result of the automatic configuration recognition processing. In addition, the data processing capability of the terminal (Capabilit
y) indicates the level of the data processing capability of each terminal, and indicates the 1394 Specificatio.
In n, the six types of processing capabilities shown in FIGS. That is, a repeater
Capability), Transaction (Tran)
action Capability, Isochronous Capability
y), Cycle Master
Capability), isochronous resources
Manager (Isochronous Resource)
e Manager Capability), bus
Master (Bus Master Capabilit)
Each processing capacity of y).

Each of these processing capacities is assigned a level. The bus master processing capacity (Bus Master C) is assigned to the top level.
capability), and a terminal having this processing capability has all of the above processing capabilities. Isochronous resource manager processing capacity (Isochronous R) assigned to the next level
resource Manager Capabilit
y) has all processing capabilities other than the bus master processing capability, and only terminals having a processing capability equal to or greater than the isochronous resource manager processing capability can become the isochronous resource manager.

Further, the cycle master processing capacity (Cy
cle Master Capability) is 1
It indicates a level at which a cycle time for creating a periodic frame on the 394 bus can be defined, and a terminal having a processing capability higher than this level can be a root terminal. Conversely, cycle
A 1394 terminal having only a lower processing capability than the master processing capability cannot be a root terminal or an isochronous resource manager terminal on the bus.

Hereinafter, similarly, an isochronous processing capability (Isochronous Capability),
Transaction processing capability (Transaction
Capability), Repeater processing capacity (Repe
Levels are assigned in the order of “a.

In the topology information shown in FIG. 5, the address information (BB address information) of each of the network connection devices A, B, and C in the backbone network 300 is shown.
Is also described. For example, an address A [B] is assigned to the network connection device A, an address B [B] is assigned to the network connection device B, and an address C [B] is assigned to the network connection device C. The address information in the backbone network 300 does not particularly need to be described in the topology information X0, Y0, Z0. However, for example, Flo
If the odding process is executed by a process that is only broadcasted to the entire backbone network 300, it becomes necessary to newly acquire the address of each network connection device when transferring an actual data packet. . Therefore, as shown in FIG. 5, a method is also conceivable in which the address of each network connection device in the backbone network 300 is also described in the topology information of each 1394 network, and is notified in advance.

In addition to this, naturally, the topology information of each 1394 network may include not only the above information but also much more information.

First, in the topology X0, the physical I
D A0 [X0], A1 [X0], A2 [X0], A3
[X0] is assigned to each terminal, and the physical ID therein
The terminal of A1 [X0] becomes the root terminal, and the physical ID A
The terminal 3 [X0] is an isochronous resource manager terminal.

The processing capability of each terminal is as shown in FIG.

Similarly, the processing capacities of the root terminal, the isochronous resource manager terminal, and each terminal in each 1394 network are shown in the topologies Y0 and Z0.

Based on such topology information, 139 which is new topology information created after executing the second automatic configuration recognition process (step S5 in FIG. 3).
4 shows an example of topology information (topology X) recognized in the network X.

As can be seen from FIG. 6, since the physical ID of each 1394 terminal belonging to the 1394 networks X, Y, and Z has been replaced by the physical ID in the topology X, A0 [X0] becomes A0 [X], B1 [Y0] is rewritten as B1 [X], and C2 [Z0] is rewritten as C2 [X]. Also, the topology information (topology X0, Y
0, Z0), the physical I of each terminal
D is described in the “other 1394” field.
Further, each one belonging to the 1394 networks Y and Z
All of the processing capabilities of the 394 terminal have been rewritten to a processing capability at a level equal to or lower than the isochronous processing capability (Isochronous Capability). this is,
New automatic configuration recognition enables 1394 network X
This is to prevent a 1394 terminal belonging to a 1394 network other than the 1394 network X from becoming a root terminal or an isochronous resource manager terminal in the topology.

Here, in FIGS. 5 and 6, the same 1394 terminal is assigned to both the root terminal and the isochronous resource manager terminal in the 1394 network X in the topology X0 and the topology X. In the embodiment, it is not always necessary to match them, and it is sufficient that the terminal in the 1394 network X is assigned to the root terminal or the isochronous resource manager terminal in the topology X.

In the actual data transfer described in the second and subsequent embodiments, in the topology X shown in FIG.
Topology X described in the "physical ID" field
And the physical ID of each 1394 terminal in
4), the physical IDs of the respective 1394 terminals in the topologies X0, Y0, and Z0 independently created in the respective 1394 networks, and the address information in the backbone network 300 of each network connection device ( BB address information) becomes important.

1.3 Topology Recognition Method (Part 2) FIG. 7 shows a conceptual diagram of the second topology recognition method. In this topology recognition method, after the topology recognition method shown in FIG. 3 is executed, the newly created topologies X, Y, and Z are again transferred between each network connection device by Flood.
(step S11 in FIG. 7,
Step S12, Step S13).

By adding such a topology notification process, each network connection device can obtain another 139 network together with the topology information created in each 1394 network.
Since the topology information created in the four networks can also be held, the address rewriting process in the actual data transfer between the networks, which will be described later, can be easily performed.

FIG. 8 shows an example of the topology information held in the network connection device A after executing the flooding process of the newly created topology information (topologies X, Y, Z). The difference between FIG. 8 and FIG. 6 is that topology information (topologies Y and Z) recognized by the other 1394 networks in the topology X shown in FIG. 1394Z "field. Other root terminals and isochronous resources
The setting of the processing capability of the manager terminal and each terminal is the same as in FIG.

Here, in FIGS. 5 and 8, the same 1394 terminal is assigned to both the root terminal and the isochronous resource manager terminal in the 1394 network X in the topology X0 and the topology X. However, also in the present embodiment, it is not always necessary to match them, and it is sufficient that the terminal in the 1394 network X is assigned to the root terminal or the isochronous resource manager terminal in the topology X.

In the actual data transfer described in the second and subsequent embodiments, in the topology X shown in FIG.
Topology X described in the "physical ID" field
And the physical ID of each 1394 terminal in
Y "and" 1394Z "fields, the physical I of each 1394 terminal in the topology information (topology Y, Z) used in each 1394 network.
The correspondence between D and the address information (BB address information) in the backbone network 300 that each network connection device has becomes important.

Even after the above-described topology recognition processing is performed, a bus reset occurs in any one of the 1394 networks X, Y, and Z, and the topology information is rewritten. Conceivable. In this case, the topology information newly created by the bus reset is again flooded to each network connection device, so that the newly created topology information can be notified to other network connection devices. it can. Each network connection device that has received the newly created topology information by the Floodding process uses the unique ID of each 1394 terminal described in the topology information to obtain the newly created / received topology information. The relationship between the physical ID information of each 1394 terminal and the physical ID information of each 1394 terminal in the topology information stored before can be known.

After updating such new topology information, a new bus reset is executed in each 1394 network, and the topology information is stored in the local network.
The notification may be made to all 1394 terminals in the 94 network, or if not necessary, the topology information in the network connection device may be updated without performing a bus reset.

(Second Embodiment) 2.1 Asynchronous Data Transfer The following is a description of the 13
The transfer of asynchronous data between 94 terminals will be described in detail.

FIG. 9 shows 1394 terminals 112 to 1394 in the home network configured as shown in FIG.
Data transfer request packet to the terminal 133 (Requests)
t packet) and the corresponding 1394 terminal 1
33 to the 1394 terminal 112 (C)
FIG. 10 shows a simple conceptual diagram of transfer of an “complete packet”, and FIG. 10 shows a detailed transfer procedure of asynchronous data.

FIG. 9 shows a case where Ethernet is used for the backbone network 300 in the home. Packet 901 shown in FIGS.
906 represent packets being transferred in the data transfer procedure within / between the networks.

FIG. 11 shows 1394 Specifica.
This indicates an asynchronous packet format defined by "tion".

Here, all the 1394 terminals in the 1394 network X are determined from the topology information (topology X) shown in FIG. 6 or FIG. It is assumed that topology information excluding address information in the backbone network 300 is shared. Similarly, all the 1394 terminals in the 1394 network Z exclude the physical IDs of the 1394 terminals in the other 1394 networks and the address information of the network connection device Z in the backbone network 300 from the same topology information (topology Z). It is assumed that the shared topology information is shared.

Thus, each of the 1394 terminals can operate in the same manner when performing communication across different 1394 networks and when performing communication within the same 1394 network. However, the network connection devices A and C hold the topology information (topologies X and Z) shown in FIGS. 6 and 8 and play a role of absorbing (emulating) the difference in the topology information between the respective 1394 networks. Running.

2.2 Transmission of Request Packet (Request Packet) First, according to the 1394 protocol, arbitration (Arbitra) for acquiring the right to use the connected bus when transferring asynchronous data.
) is executed. In this arbitration procedure, a 1394 terminal that wishes to perform data transfer transfers a bus acquisition request (arbitration request) to a root terminal in the same bus, and when the request is accepted by the root terminal, gives the bus usage right to the requesting terminal. Running by returning.

Therefore, in the configuration of FIG. 9, first, the 1394 terminal 112, which is the data transmission terminal, issues an arbitration request to the root terminal 111 in order to acquire the right to use the bus in the 1394 network X.
The process of acquiring the right to use the bus from the root terminal 111 is performed (step S31 in FIG. 10).

Data transmission terminal 1 that has acquired the right to use the bus
Reference numeral 12 denotes a data transfer (Write.Request) packet 9 to the 1394 terminal 133 in accordance with the asynchronous packet format (see FIG. 11) defined by the 1394 Specification.
01 is transmitted (step S32 in FIG. 10). At this time, the asynchronous packet 901 transferred from the 1394 terminal 112 to the network connection device A includes FIG.
Destination ID in the format of (Destination
n ID) field, the 1394 terminal 133 1394
The physical ID (C3 [X]) in the network X is written, and the physical ID (A2 [X]) in the 1394 network X of the 1394 terminal 112 is written in the source ID (Source ID) field. In the 1394 specification, the data itself for actually performing the write processing to the 1394 terminal 133 is also transferred by a data transfer (Write.Request) packet, so that the data block of the asynchronous packet 901 in FIG. Describes data to be written.

Next, the network connection device A, which has received the packet 910 from the 1394 terminal 112, stores the destination address and the source address of the packet 901 and the destination address of the packet 901 because the destination terminal of the packet 901 is not a terminal in the 1394 network X. With reference to the topology information (topology X), the transfer destination of the packet 901 is 1
In the 394 network Z, the physical ID of the destination terminal 133 and the physical ID of the source terminal 112 are rewritten.

First, when the topology information stored in the network connection device A is the topology information shown in FIG. 6, the physical ID of the destination terminal of the packet 901 is set to C
The process of rewriting 3 [X] to C3 [Z0] and rewriting the physical ID of the source terminal of the packet 901 from A2 [X] to A2 [X0] is executed.

When the topology information stored in the network connection device A is the topology information shown in FIG. 8, the physical ID of the destination terminal of the packet 901 is set to C
3 [X] is rewritten to C3 [Z], and the physical ID (A2 [X]) of the source terminal of the packet 901 is not rewritten.

FIG. 9 describes the latter case (the case where the topology information is FIG. 8) as an example.

As described above, the network connection device A in which the destination information of the packet to be transferred is rewritten, the packet 901 is encapsulated in the Ethernet packet in order to execute the data transfer process using Ethernet in addition to the above process. Is also performed. In the encapsulation into the Ethernet packet, the protocol field of the Ethernet packet and the SNAP (Subnetwork) are used.
Access Point) "139
4 interconnect packets "
The 1394 packet 901 to be transferred to the Ethernet packet may be directly encapsulated, or the 1394 packet 901 to be transferred may be once encapsulated into an IP packet and then further encapsulated into an Ethernet packet. In any case, by performing such processing, the 1394 packet 901 is encapsulated in a packet transferred on the Ethernet 300, and FIG.
And the packet 902 in FIG. 10 is created.

Normally, the Ethernet connecting a plurality of 1394 networks is considered to be a single cable, so that the transfer destination network at this time is identified by the MAC address of each network connection device. Shall be. In addition, such a network identification method is not limited to a method using a MAC address, but is, of course, an IP address or an E.E. A case where a layer 3 address such as a 164 address is used is also conceivable.

For example, in the examples of FIGS. 9 and 10, the address A [B] of the network connection device A in the backbone network 300 is written in the source address of the Ethernet packet 902, and the backbone of the network connection device B is written in the destination address. The address B [B] in the network 300 is written and transferred.

The packet 902 created by such a method is transferred from the network connection device A to the network connection device C (step S33 in FIG. 10), and is encapsulated in the Ethernet packet 902 in the network connection device A on the transmission side. The asynchronous packet 901 of the 1394 is taken out.

[0112] The network connection device C
Since the source terminal of the 394 packet is not a terminal in the own 1394 network Z, the destination address and the source address described in the received packet 902 and the stored topology information (topology Z) are referred to. A rewriting process of the physical ID of the terminal 133 and the physical ID of the transmission source terminal 112 is performed.

First, when the topology information stored in the network connection device C is the topology information shown in FIG. 6, the physical ID of the destination terminal of the packet 901 is set as
Rewrite from C3 [Z0] to C3 [Z] and change the physical ID of the source terminal of the packet 901 to A2 [X0]
A2 [Z] is rewritten.

When the topology information stored in the network connection device C is the topology information shown in FIG. 8, the physical ID of the source terminal of the packet 901 is
The packet 901 is rewritten from A2 [X] to A2 [Z].
The rewriting process of the physical ID (C3 [Z]) of the destination terminal is not performed.

As described above, the packet 903 in which the destination address and the source address of the packet have been rewritten is
After the arbitration process in the N.94 network Z (step S34 in FIG. 10), the data is transferred to the final destination terminal 1394 terminal 133 (step S34 in FIG. 10).
35).

In this case, the transfer of the asynchronous packet from the network connection device C to the 1394 terminal 133 is executed in the same manner as the transfer of the asynchronous packet on the network X.

2.3 Transmission of Data Transfer Completion Notification Packet (Ack.Complete Packet) In the 1394 network, if any processing requested from the transmission source terminal can be executed in the destination terminal, then the transmission from the destination terminal is performed. A data transfer end notification packet (Ack.Complete) packet for notifying that the process has been completed is sent back to the former terminal.

The transfer of the data transfer end notification packet can be executed in the same manner as the transfer of the request packet (Request packet).

First, an arbitration process for acquiring the right to use the bus for transmitting the data transfer end notification packet 904 from the destination 1394 terminal 133 is executed (step S36 in FIG. 10).

When the 1394 terminal 133 acquires the right to use the bus, the 1394 terminal 133 sends a data transfer end notification packet 904 (step S3 in FIG. 10).
7) The packet 904 is transferred to the network connection device C on the receiving side.

Next, the network connection device C receiving the packet 904 sets the destination terminal of the packet 904 to 13
Since the terminal is not a terminal in the 94 network Z, the packet 9
04, referring to the stored topology information (topology Z) and the physical ID of the destination terminal 112 and the physical ID of the source terminal 133 in the 1394 network X to which the packet 904 is transferred. An ID rewriting process is executed.

Specifically, if the topology information stored in the network connection device C is the topology information as shown in FIG. 6, the physical ID of the destination terminal of the packet 904 is changed from A2 [Z] to A2 [X0] and change the physical ID of the source terminal of the packet 904 to C
A process of rewriting from 3 [Z] to C3 [Z0] is executed. When the topology information stored in the network connection device C is the topology information as shown in FIG. 8, the physical ID of the destination terminal of the packet 904 is set to A2
[Z] is rewritten to A2 [X], and the physical ID (C3 [Z]) of the source terminal of the packet 904 is not rewritten.

Further, the network connection device C having rewritten the destination information of the packet to be transferred, in addition to the above processing,
In order to execute a data transfer process using Ethernet, a process of encapsulating the packet 904 into an Ethernet packet is also performed. The encapsulation processing into the Ethernet packet executes the same processing as that executed by the network connection device A in the transmission processing of the request packet.

The packet 905 created by such a method is transferred from the network connection device C to the network connection device A (step S38 in FIG. 10), and is converted into the Ethernet packet 905 in the network connection device A on the transmitting side. The encapsulated 1394 asynchronous packet 906 is taken out.

[0125] The network connection device A
Since the source terminal of the 394 packet is not a terminal in the own 1394 network X, the destination address and the source address described in the received packet 905 and the stored topology information (topology X) are referred to. A rewriting process of the physical ID of the terminal 133 and the physical ID of the transmission source terminal 112 is performed.

First, when the topology information stored in the network connection device A is the topology information shown in FIG. 6, the physical ID of the destination terminal of the packet 906 is
While rewriting from C3 [Z0] to C3 [X], the physical ID of the source terminal of the packet 906 is changed to A2 [X0]
A2 [X] is rewritten.

If the topology information stored in the network connection device A is the topology information shown in FIG. 8, the physical ID of the source terminal of the packet 906 is
The packet 906 is rewritten from C3 [Z] to C3 [X].
The rewriting process of the physical ID (A2 [X]) of the destination terminal is not performed.

As described above, after the destination address and the source address are rewritten, the packet 906 is subjected to arbitration processing in the 1394 network X (step S39 in FIG. 10), and then to the final destination terminal 1394.
The data is transferred to the terminal 112 (step S40 in FIG. 10).

In this case, the transfer of the asynchronous packet from the network connection device A to the 1394 terminal 112 is executed in the same manner as the transfer of the asynchronous packet on the network X.

By performing the above-described processing, transfer of asynchronous packets between terminals in different 1394 networks interconnected by Ethernet can be realized.

2.4 Data transfer end notification packet (A
ck. Until the Complete Packet) Returns Here, in the 1394 Specification, a request packet (Request packet) for transmitting the asynchronous packet is transmitted, and then the data transfer end notification packet (Ack.Complete packet) returns. It is supposed to keep the time until a certain time. However, if it is determined that it takes time to send the data transfer end notification packet (Ack.Complete packet), Ac
k. Pending packet or Ack. A Busy packet is sent back to notify that processing is delayed.

Therefore, as in the present embodiment, a request packet (Request packet) or a data transfer end notification packet (Ack.Comp.) Is transmitted via another network.
When the network connection device transmits the Ack. Pending packet or Ack. A method of sending back a busy packet may be considered.

More specifically, in FIG.
Write. At an appropriate timing when the network connection device A that has received the Request packet is performing the packet transfer process to the 1394 terminal 133 that is the actual destination terminal (in FIG. 9,
At an appropriate timing after the transmission processing of the Ethernet packet 902), Ack. Pending packet or Ack. The Busy packet is transmitted to the 1394 terminal 1 on the transmission side.
I will send it back to 12. Then, the network connection device A (step S3 in FIG. 10) receives the data transfer end notification packet (Ack.Complete packet) from the 1394 terminal 133 which is the actual destination terminal.
8) is the data transfer end notification packet (Ack.C).
complete packet) on the transmitting side as it is
By transmitting the packet to the terminal 112, the transfer of the asynchronous packet can be completed.

2.5 Internal Configuration of Network Connection Device FIG. 12 shows the network connection device A110 shown in FIG.
1 shows an example of the internal configuration of the device.

In the network connection device A, the backbone network Ethernet (Ethernet) is used.
t) Ethernet for performing data transfer with 300
139 for performing data transfer between the et / MAC processing unit 1203 and the 1394 terminal in the 1394 network X
A four-bus control processing unit 1206 and a 1394 protocol processing unit 1207 exist.

The 1394 protocol processing unit 1207 includes
394 Specification,
This function performs so-called physical layer processing, link layer processing, and transaction layer processing.

Also, 139 via the Ethernet 300
As functions for connecting the four networks, a topology information exchange processing unit 1202, a topology storage unit 120
1. Address conversion processing unit 1204, Ethernet /
A 1394 bridging unit 1205 exists.

First, the topology information (topology Y, Z or topology Y) of another network received in the procedure as in the first embodiment when the network is started up.
0, Z0) are transferred from the topology exchange processing unit 1202 to the topology storage unit 1201.

When a packet containing topology information of each 1394 network is received, first, the Ether / MAC processing unit 1203 refers to the protocol ID and SNAP header of the header of the Ethernet packet received by , The information about the received topology information to the topology exchange processing unit 12.
02 can be transferred. In the topology exchange processing unit 1202, the initialization processing of the topology information shown in the first embodiment is executed. In addition, when the 1394 network starts up (when a bus reset occurs), the topology recognition processing (Tree) is performed. ID, Se
if ID), and the topology information of the 1394 network 201 is stored in the 1394 bus control processing unit 1206, so that the topology information is also transferred to the topology storage unit 1201.

As a result, the topology storage unit 1201
Means that all the topology information (topology X0, Y0, Z0 or topology X, Y, Z) of the 1394 network X, Y, Z can be obtained.

Next, the processing at the time of transferring an asynchronous packet from the 1394 network X will be described. First, an asynchronous packet sent from the 1394 network X is received by the 1394 protocol processing unit 1207. Here, in the network connection device A, 1
13 belonging to a network other than the 394 network X
If the 94 terminal is the destination terminal, the 1394 packet is transferred to the Ethernet / 1394 bridging processing unit 1205.

In the Ethernet / 1394 bridging processing unit 1205, the physical IDs of the destination terminal and the source terminal of the 1394 packet are determined based on the topology information (topology X) stored in the topology storage unit 1201.
Rewrite to the physical ID in the 1394 network to which the destination terminal belongs. Also, the 1394 packet in which the physical ID of the destination terminal or the source terminal is rewritten is encapsulated in an Ethernet packet, and for example, the MAC address of the network connection device A110 is described in the source address,
The MAC address of the network connection device belonging to the 1394 network to which the destination terminal is connected is described in the destination address, and the created Ethernet packet is transmitted to the Ethernet 300.

When the Ethernet packet received from the Ethernet 300 is from another network connection device, the received Ethernet packet is transferred to the Ethernet / 1394 bridging processing unit 1205. Here, when the 1394 asynchronous packet is encapsulated in the received Ethernet packet, similar to the above-described processing,
Based on the topology information (topology X) stored in the topology storage unit 1201, the physical ID of the source terminal or destination terminal is converted to a physical ID in the 1394 network X, and the packet is transmitted to the 1394 network X.

By such processing, the address conversion / packet conversion processing in the network connection device A of the present invention can be executed.

(Third Embodiment) Next, referring to FIG. 13 to FIG. 19, isochronous data is transferred using a connection type network such as an ATM network as a backbone network connecting each 1394 network. The case will be described.

In the present configuration, the 1394 network X and the 1394 network Z at home are connected by the ATM network 500. The ATM network 500 includes an ATM switch 13.
50, which allows 1394 networks X and 1
394 network Z is connected.

FIG. 13 is a conceptual diagram showing an example of data transfer when data is transferred from the 1394 terminal 112 to the 1394 terminal 133 using isochronous packets in the home network having the configuration shown in FIG.

In this example, a channel for 1394 isochronous data transfer (Ch a) is set, and the network connection devices A and C are set.
In the meantime, the ATM connection (VC a, VC c) is set, and a channel for 1394 isochronous data transfer (Ch c) is set.

In the following, the procedure for setting up these 1394 isochronous data transfer channels and ATM connections, and the procedure for actually transferring isochronous data using these channels / connections will be described.

Here, all the 1394 terminals in the 1394 network X are determined from the topology information (topology X) shown in FIG. 6 or 8 by the physical IDs of the 1394 terminals in the other 1394 network and the backbone of the network connection device A. Topology information excluding address information and the like in the network 300 is shared. Similarly, all 1394 terminals in the 1394 network Z are:
From the same topology information (topology Z), other 139
The topology information excluding the physical ID of the 1394 terminal in the four networks and the address information in the backbone network 300 of the network connection device Z is shared. Accordingly, each of the 1394 terminals can operate in the same manner when performing communication across different 1394 networks or when performing communication within the same 1394 network. However, the network connection devices A and C hold the topology information (topologies X and Z) shown in FIGS. 6 and 8 and play a role of absorbing (emulating) the difference in the topology information between the respective 1394 networks. Running.

3.1 Channel Setting Procedure Isochronous data is transmitted from the 1394 terminals 112 to 133.
When transferring the 1394 network, as shown in FIG.
Channel 1310 (Ch Set a)
And an ATM connection within the ATM network 500.
1320 (VC a) and the ATM connection 1330 (V
C c) is set and the channel is set in the 1394 network C.
1340 (Ch c) must be set. This
Here, the ATM connection 1320 (VC a) and
ATM connection 1330 (VC c) meanwhile
Since the ATM switch 1350 exists, the VPI / VC
Although the value of I will be rewritten, logically one
This is equivalent to setting a connection.

The following is a description of the case in the 1394 network X.
94 terminal 112 to 139 in 1394 network Z
A procedure for setting a channel / connection for performing isochronous packet transfer to the four terminals 133 and a procedure for handling transmission / reception requests for isochronous data will be described.

The 1394 Specification defines a method of setting an isochronous channel in a 1394 network, but does not show a procedure for actually starting / ending the transfer of isochronous data on the set channel. . The procedure for transferring the transfer start / end request of the isochronous data is described in IEC1883 (Specification o).
f DigitalInterface for C
onsumer Electronic Audio /
Video Equipment). Specifically, the 1394 terminal that has set the isochronous channel on the 1394 network is IEC18.
By using the 83 protocol, a transfer request of an isochronous packet to another 1394 terminal on the same 1394 network and a reception request of an isochronous packet from another 1394 terminal can be transmitted using the isochronous channel. ing.

Therefore, in this embodiment, the setting procedure of the isochronous channel in each 1394 network follows the procedure of 1394 Specification, and the exchange of the data transmission / reception request signal on the isochronous channel follows the procedure of IEC1883. .

The call setting procedure in the ATM network 500 connecting each 1394 network is based on I
Q. stipulated by TU-T 2931, and a detailed description of these procedures themselves will be omitted.

The procedure for setting the isochronous channel will be described below with reference to FIGS.

First, the 1394 terminal 112 attempting to start the transfer or reception of the isochronous packet,
In order to set an isochronous channel on the 394 network X, a request to acquire a band and a channel number on the 1394 bus is sent to the 1394 terminal 113 which is an isochronous resource manager in the 1394 network X. The method of transferring the bandwidth / channel number request information on the 1394 bus is described in 1394 Spec.
According to the rules in the Lock.
An isochronous packet called a Request (Compared Swap) packet is used. Therefore, before the transfer of the band / channel number request information, the arbitration process for acquiring the right to use the bus is executed (in FIG. 14, the arbitration process is omitted and described). There).

[0158] Also, 1394 Specificati
According to On, the sending terminal 112
Describes and sends both the band information to be used and the channel number to be used. The procedure for acquiring each channel number and the procedure for acquiring a band are as described above.
It is not described in detail here as it conforms to the specification. If the requested channel number and bandwidth can be assigned to such a request, the isochronous resource manager 113
4 terminal 112 is informed that the requested isochronous channel can be set in Lock. Responc
notification using an e-packet (defined in 1394 Specification) (step S in FIG. 14).
41).

When the setting of the isochronous channel is completed, the 1394 terminal 112
The data transmission / reception request packet 1401 is transferred to the server 33 (step S42 in FIG. 14). The above-mentioned IEC1883 protocol defines the packet transfer method. This data transmission / reception request packet 14
01 is an asynchronous packet as described above, so that the transmission destination ID (D
The destination ID field is 1394
Physical ID of terminal 133 in 1394 network X
(C3 [X]) is written, and the transmission source ID (Source)
e ID) field contains 139 of the 1394 terminal 112.
4 The physical ID (A2 [X]) in the network X is written.

The transmitted data transmission / reception request packet 1
401 is received by the network connection device A;
The physical ID (C3 [X]) of the destination terminal is not a terminal in the 1394 network X, but a 1394 network Z
Since the terminal is within the terminal, the processing for transferring the data transmission / reception request packet 1401 to the network connection device C of the 1394 network Z is started. Here, the network connection apparatus A determines that the received packet 1401 is not a normal asynchronous packet but IEC1883.
, It is necessary to recognize that the packet requests isochronous data transmission / reception. As a method for this, there are several methods described below.

1. First, according to IEC1883, in order to control transfer of isochronous data in each terminal, a CSR (Command and S) of each terminal is required.
INPU that exists in the status register)
T MASTER PLUG register, OUTPUT
MASTER PLUG register, INPUT PLU
G CONTROL register, OUTPUT PLUG
Four registers of the CONTROL register are used.

[0162] These four registers have a CSR.
Are assigned (specified) addresses. Therefore, in each network connection device, the received asynchronous packet is Lock. Request
Packet and the physical ID of the destination terminal is 139.
4 is a physical ID other than the terminal belonging to the network, the packet identification information (offset value) of the received asynchronous packet is checked, and the offset value is set in the INPUT in the CSR of each terminal. MASTER PL
UG register, OUTPUT MASTER PLUG
Register, INPUT PLUG CONTROL register, OUTPUT PLUG If the offset value is assigned to the four registers of the CONTROL register, the received packet is set to IEC188.
It recognizes that it is based on three protocols.

2. Identification is performed using tcode (see FIG. 11) allocated in the asynchronous packet. Specifically, a value that can be defined by the user in the packet type by tcode is defined in advance, and an asynchronous packet having the defined value of tcode, in particular, Lock. When a Request packet is received, the received packet is IEC1
It recognizes that it is based on the 883 protocol.

[0164] 3. Reading up to the data field of the asynchronous packet, if the content is the content specified by IEC1883, it recognizes that the received packet is based on the IEC1883 protocol. A method of performing a so-called gateway process.

[0165] 4. The automatic configuration recognition process is executed so that the network connection device always becomes the isochronous resource manager, and all the setting request packets of the band / channel number in the 1394 network to which the network connection device belongs are stored. L sent from the terminal that has made the bandwidth / channel number setting request
ock. Physical ID of the destination terminal of the Request packet
Is the physical I other than the terminal belonging to the own 1394 network.
D, the received packet is IEC18
It recognizes that it is based on the 83 protocol.

5. The above 1. ~ 4. Any combination of methods.

The above 1. ~ 5. The network connection device A that recognizes that the transmission / reception request of the isochronous data has been transmitted by the method as described above includes the destination terminal 133 of the received data transmission / reception request packet 13
A signaling process for setting up an ATM connection is performed between the network connection devices C in the 94 network Z (step S43 in FIG. 14).

As the bandwidth information requested in the signaling process, a value corresponding to the used bandwidth information described in the received data transmission / reception request packet is requested.
As a result of such signaling processing, in the present embodiment,
VC as an identifier of the ATM connection between the network connection device A and the ATM switch 1350 a is AT
VC as a connection identifier between the M switch 1350 and the network connection device C This shows a case where c is given.

Packet 140 from 1394 Terminal 112
1 receives the packet 4
01 is not a terminal in the 1394 network X, the destination address and the source address of the packet 1401 are compared with the stored topology information (topology X), and the destination of the packet 1401
It is possible to know the physical IDs of the destination terminal and the source terminal in the 394 network Z.

Specifically, when the topology information (topology X) stored in the network connection device A is the topology information having the configuration shown in FIG. 6, the network connection device A transmits the destination of the received packet 1401. Rewriting the physical ID of the terminal from C3 [X] to C3 [Z0], and rewriting the physical ID of the source terminal from A2 [X] to A2 [X0],
If the topology information (topology X) stored in the network connection device A is the topology information having the configuration shown in FIG. 8, the network connection device A sets the physical ID of the destination terminal of the received packet 1401 to C3 [X ] To C3 [Z].

As described above, the network connection device A in which the destination information of the packet to be transferred has been rewritten performs a packet conversion process for transferring data to the ATM network 500 in addition to the above process. Here, it is assumed that the transferred packet 1401 is recognized as a layer 2 packet, SNAP encapsulation or the like is performed, an appropriate ATM adaptation layer process is performed, and then the cell is converted into an ATM cell and transferred in the ATM network 500. . Here, the ATM connection to be used is the connection (VC a), or such an IE in advance
A method of setting an ATM connection for transferring C1883 data between network connection devices may be used.

Here, the packet 1401 is transferred to an appropriate ATM.
The packet length after the adaptation layer processing is
The SAR packet (cell division / assembly sublayer (Segmentat in the ATM adaptation layer)
If the length of the packet 1401 is longer than the length of the packet 1401, the packet 1401 has a plurality of ATMs.
The cell is divided into cells 1402 and transferred to the network connection device C.

The ATM cell 1402 which is converted into an ATM cell and transferred is subjected to switching / header rewriting processing in the ATM switch 1350, and the value of the connection identifier is changed to VC. a to VC c and transferred to the network connection device C (step S4 in FIG. 14).
4. Step S45).

ATM connection VC The data transmission / reception request packet 1403 transferred by (c) is received by the network connection device C and is converted into ATM decells.

In the network connection device C,
The address of the destination terminal or source terminal of the 1394 packet in the 1394 packet assembled after the ATM deceleration is compared with the stored topology information (topology Z), and the 1394 packet is transferred to the 1394 network Z at the transfer destination. The physical ID of the destination terminal or the source terminal is rewritten.

Specifically, when the topology information (topology Z) stored in the network connection device C is the topology information having the configuration shown in FIG. 6, the network connection device C transmits the destination of the received 1394 packet. Rewriting the physical ID of the terminal from C3 [Z0] to C3 [Z], and rewriting the physical ID of the source terminal from A2 [X0] to A2 [Z],
If the topology information (topology Z) stored in the network connection device C is the topology information having the configuration shown in FIG. 8, the network connection device C receives the received 1
The physical ID of the source terminal of the 394 packet is rewritten from A2 [X] to A2 [Z].

Further, the network connection device C transmits the received packet to the IEC 18 by the method described above.
It recognizes that the packet is an 83-packet, and as described above, sends the 1394 packet to the isochronous resource manager 131 in the 1394 network Z based on the bandwidth information described in the 1394 packet 1404 whose physical ID has been rewritten. A request to acquire a band and a channel number on the network Z is sent (step S46 in FIG. 14). The transfer procedure of the band / channel number acquisition request can be executed by the same procedure as that performed in the 1394 network X.

When the setting of the isochronous channel on the 1394 network Z is completed, the network connection device C transmits / receives data to / from the 1394 terminal 133.
The received packet request 1404 is transferred (step S47 in FIG. 14).

With the above processing, Lock. Requ
The est packet transfer process ends. In a normal asynchronous packet transfer process, a response confirmation packet (Ack packet) is always returned. Therefore, in this embodiment, the Lock. Requ
The Ack packet is transferred from the 1394 terminal 133 to the 1394 terminal 112 in response to the transmission of the est packet (see the second embodiment).
Here, the transfer process of the Ack packet is omitted.
Similarly, the Lock. At the end of the response packet transfer process, the transfer process of the Ack packet from the 1394 terminal 112 to the 1394 terminal 133 is executed, but this is also omitted in FIG.

If the 1394 terminal 133 determines that the data transmission / reception request can be accepted, the data transmission / reception ACK (Lock. Response) packet 140
5 is transferred to the previous 1394 terminal 112 of the transmission source. This transfer procedure is performed by the above-described transmission source terminal 112 to destination terminal 1
This is almost the same as the transfer method of the asynchronous packet to the C.33.

The data transmission / reception request Ack packet 1405 transmitted from the 1394 terminal 133 (step S48 in FIG. 14) is transmitted to the network connection device C together with the rewriting of the physical IDs of the destination terminal and the transmission source terminal.
An ATM cell processing is performed. In this case, the rewriting process of the physical ID also includes the topology information (topology Z) stored in the network connection device C, as in the case described above.
Is the topology information of the configuration shown in FIG. 6, the network connection device C changes the physical ID of the destination terminal of the received packet 1405 from A2 [Z] to A2 [X0] and the physical ID of the transmission source terminal to C3. Rewriting from [Z] to C3 [Z0], if the topology information (topology Z) stored in the network connection device C is the topology information of the configuration shown in FIG. The physical ID of the source terminal of 1405 is C3
Rewrite from [Z] to C3 [X].

When the data transmission / reception request Ack packet 1405 is transferred to the network connection device A through the ATM connection set previously, the API set in the VPI / VCI field of the created ATM cell is used.
Connection identifier VC of TM connection c will be written.

The data transmission / transformation made into the ATM cell as described above
The reception request Ack packet 1406 is transferred from the network connection device C to the network connection device A via the ATM switch 1350 (step S49 in FIG. 14,
Step S50).

The processing in the network connection apparatus A is the same as described above. After performing the ATM deceleration processing, the physical ID of the destination terminal or the transmission source terminal of the received data transmission / reception request Ack packet is rewritten. Is done. In this case, the rewriting process of the physical ID is also performed in the same manner as in the above case.
When the topology information (topology X) stored in the network connection device A is the topology information having the configuration shown in FIG.
The physical ID of the destination terminal of the 94 packet is rewritten from A2 [X0] to A2 [X], and the physical ID of the source terminal is rewritten from C3 [Z0] to C3 [X], and the topology information stored in the network connection device A is stored. If (topology X) is the topology information having the configuration shown in FIG. 8, the network connection device A rewrites the physical ID of the destination terminal of the received 1394 packet from A2 [Z] to A2 [X].

Finally, the created data transmission / reception request Ack packet 1408 is transmitted to the 1394 terminal 112 of the transmission source.
(Step S51 in FIG. 14),
The transfer processing of the data transmission / reception request defined by 1883 is completed.

Since the above-described data transfer processing is realized by the transfer of the asynchronous packet, the request packet (Request packet) for transferring the asynchronous packet is transmitted in the same manner as in the second embodiment. After sending, Ack. The time until the complete packet returns must be kept within a certain time. Therefore, as in the case of the second embodiment, Lock. R
request packet or Lock. When the response packet is transferred, the network connection device transmits the Ack. Pendi
ng packet or Ack. A method of sending back a busy packet may be considered.

[0187] Specifically, in FIG.
Lock. At an appropriate timing when the network connection device A that has received the Request packet is performing the packet transfer process to the 1394 terminal 133 that is the actual destination terminal (in FIG. 14,
At an appropriate timing after the processing in step S43), Ack. Pending packet or Ack. Bus
The y packet is sent back to the 1394 terminal 112 on the transmitting side.

Conversely, 1394 terminal 1 which is the destination terminal
Lock. At an appropriate timing when the network connection device C that has received the Response packet performs a process of transferring the packet to the 1394 terminal 112, which is the actual destination terminal (step S4 in FIG. 14).
9) at an appropriate timing after the processing of Ack. P
ending packet or Ack. The Busy packet is sent back to the 1394 terminal 133 on the transmission side.

By performing such processing, 1
Lock. 394 between terminals 112 and 113. Requ
est packet and Lock. The response packet transfer process can be completed.

By the above processing, for example, the isochronous packet transmitted to Ch_a on the 1394 network X is referred to the VC_a in the ATM network 500 as the backbone network by referring to the connection table in the network connection device A. Encapsulation and ATM cell processing are performed and input. Further, in the network connection device C belonging to the 1394 network Z, the VC on the ATM network 500
c by referring to the connection table in the network connection device C.
Ch on 94 Network Z The packet is transmitted after c is converted into a 1394 isochronous packet.

Also, the backbone network A
TM network 500, 1394 network Z
In the case where the band or channel for transferring the isochronous packet cannot be secured, a Nack (rejection response) signal in the IEC1883 protocol notifying the fact is transmitted from the network connection device C or A to the transmission source 1394. This will be transmitted to the terminal 112.

3.2 Actual Isochronous Data Transfer According to the setting of the isochronous channel described above, the network connection devices A and C are set to 13
A connection table indicating the relationship between the 94 isochronous channel and the ATM connection is created / stored. FIG. 15 shows an example of a connection table held by each of the network connection devices A and C.

The network connection device A shown in FIG.
In each connection table of C, the channel number (Iso.Ch) of each isochronous channel, the set bandwidth, the combination of the terminal (source) requesting the connection setting and the terminal (destination) requesting the connection setting, and 6, physical IDs (source physical IDs, destination physical IDs) obtained from the topology information of FIG. 6 or FIG. 8 and recognized by each network of the terminal that has requested / set the isochronous channel. The connection table also describes the VPI / VCI values of the ATM connection corresponding to each isochronous channel.

In the example of FIG. 15, the information (Iso.Ch) of the isochronous channel set by each of the network connection devices A and C with the terminal in the own 1394 network is also shown. However, the information of the isochronous channel set up with the terminal in the own 1394 network may or may not be described in this connection table.

In FIG. 15, four isochronous channels are set on the 1394 network X.
An example in which three isochronous channels are set on the 1394 network Z is shown. On the 1394 network X side, the channel number of the isochronous channel in the 1394 network X newly set by the above procedure is “9” and the set band is 15
Mbps, and the network connection device A and the ATM switch 1 set corresponding to the isochronous channel.
ATM connection between 350 (VC a) VPI
The case where the value of / VCI is VPI = b and VCI = q is shown.

Further, on the 1394 network Z side, the channel number of the isochronous channel in the 1394 network X newly set by the above procedure is “4”, and the set band is 15 Mbps, which corresponds to this isochronous channel. Connection (VC) between the network connection device C and the ATM switch 1350 c) VPI / VCI value is VPI
= A, VCI = p.

Assuming that each network connection device holds the connection table as described above, an actual transmission / reception method of isochronous data will be described below.

First, the procedure for transmitting isochronous data when transmitting an isochronous packet from the 1394 terminal 112 that has issued the isochronous channel setting request to the 1394 terminal 133 will be described with reference to FIG.
In this case, in the transfer of the transmission / reception request packet of the isochronous data in the IEC1883 protocol shown in FIG. 1, the transmission of the isochronous data after the transmission of the transmission request of the isochronous data is performed.

1394 for sending isochronous data
The terminal 112 does not describe the address of the destination terminal or the like,
However, the set isochronous channel Ch a
= 9 only an isochronous packet is transmitted.

FIG. 18 shows the 1394 Specificat.
An example of the format of an isochronous packet specified by the ION is shown. However, 1394 Speci
According to the faction, arbitration processing for acquiring the right to use the bus is required even when transmitting the isochronous packet.
The 1394 terminal 112 that sends data first performs arbitration for isochronous data transmission (step S61 in FIG. 16), and then sends an isochronous packet 1301 onto the bus (step S6 in FIG. 16).
2).

Next, the network connection device A will be described with reference to FIG.
Of the isochronous channel Ch on the 1394 network X a = 9 is ATM
Connection VC a (VPI = b, VCI = q), the isochronous channel Ch The isochronous packet 1301 to which a = 9 is sent is converted into an ATM cell, and the packet 1302 converted into the ATM cell is converted into an ATM connection VC. Transfer to a.

Here, the above processing is performed only by referring to the channel number on the 1394 network and the connection number on the ATM network, which are the identifiers of the data link layer. Therefore, in the following description, such processing using only the identifier of the data link layer will be referred to as data link switching.

This ATM cellized packet 1302
Is an ATM connection VC in the ATM network.
a, and the switching / cell header rewriting process is performed in the ATM switch 1350.
After being converted to an M cell 1303, the ATM connection VC c (VPI = a, VCI = p) is transferred from the ATM switch 1350 to the network connection device C (steps S63 and S64 in FIG. 16).

ATM connection VC The ATM cell transferred by c is arriving at the network connection device C and is de-cellulated into ATM cells, and an isochronous packet 1394 is extracted. The network connection device C uses this connection table shown in FIG. The isochronous channel in the 1394 network Z corresponding to c (VPI = a, VCI = p) is Ch Since it is known that c = 4, the arbitration process in the 1394 network Z for transmitting the extracted isochronous packet 1394 to the isochronous channel is performed (step S65 in FIG. 16).
4 is the isochronous channel Ch It is transmitted to c = 4 (step S66 in FIG. 16).

According to such a series of procedures, the isochronous data is transferred from the 1394 terminal 112 to the 1394 terminal 1.
31.

On the other hand, when it is desired to receive isochronous data from the 1394 terminal 131 to the 1394 terminal 112, this can be realized by transmitting a request for receiving isochronous data according to the IEC1883 protocol described above. The transfer of the IEC1883 packet at this time is as follows.
This can be performed in the same manner as in the case shown in FIG. The 1394 terminal 112 that has transmitted the isochronous data reception request is
As a result, the isochronous packet transmitted from the 1394 terminal 133 can be received by the procedure shown in FIG. The procedure shown in FIG. 17 can be basically realized in the same manner as the procedure for transmitting the isochronous packet in FIG.

That is, the 1394 terminal 133 transmitting the isochronous data does not write the address of the destination terminal, but simply sets the set isochronous channel Ch. It merely sends out isochronous packets on c = 4. However, 1394 Specificat
According to Ion, arbitration processing for acquiring the right to use the bus is also required at the time of transmitting the isochronous packet. Therefore, the 1394 terminal 112 which transmits the data first transmits the isochronous data. As in the case of arbitration (step S71 in FIG. 17), the isochronous packet 1394 is transmitted onto the bus (step S72 in FIG. 17).

Next, the network connection device C
Of the isochronous channel Ch on the 1394 network Z c = 4 is ATM
Connection VC c (VPI = a, VCI = p), the isochronous channel Ch The isochronous packet 1394 transmitted at c = 4 is converted into an ATM cell, and the packet 1303 converted into the ATM cell is converted to an ATM connection VC. c by data link switching.

The packet 1303 converted into an ATM cell
Is an ATM connection VC in the ATM network.
c, and is subjected to switching / cell header rewriting processing in the ATM switch 1350.
After being converted to an M cell 1302, the ATM connection VC a (VPI = b, VCI = q) is transferred from the ATM switch 1350 to the network connection device A (steps S73 and S74 in FIG. 17).
ATM Connection VC A transferred by a
After arriving at the network connection device A, the TM cell
The packet is converted into a TM decell, and an isochronous packet 1301 is extracted.

The network connection device A uses the ATM connection VC according to the connection table shown in FIG.
a (VPI = b, VCI = q), the isochronous channel in the 1394 network X is Ch a =
9, after performing an arbitration process in the 1394 network X to send the extracted isochronous packet 1301 to the isochronous channel (step S75 in FIG. 17), the isochronous packet 1301 The above isochronous channel Ch a = 9 (FIG. 17
Step S76).

[0211] The 1394 Specificati
According to the on, according to the transfer of the isochronous packet, unlike the transfer of the asynchronous packet, even when the receiving terminal can receive the data packet transmitted from the transmitting terminal, the response confirmation is performed. There is no need to return a packet (Ack packet).

3.3 Internal Configuration of Network Connection Device FIG. 19 shows an example of the internal configuration of the network connection device A used in this embodiment. In the network connection device A, an ATM layer processing unit 1909, a signaling processing unit 1908, and 139 for performing data transfer with the ATM network 500 as a backbone network.
1394 for data transfer with network X
Bus control processing unit 1906, 1394 protocol processing unit 1
907 are present.

The 1394 protocol processing unit 1907 has
394 Specification,
This is a function of executing a so-called physical layer process, link layer process, and transaction layer process.

The functions for transferring isochronous data between the 1394 networks via the ATM network 500 include a topology information exchange processing section 1902, a topology storage section 1901, an address / connection conversion processing section 1910, and an ATM / 1394 bridge. A processing unit 1911 exists.

Further, in this embodiment, a data link switching processing section 1912 for executing data link switching processing of ATM connection and isochronous channel is provided so that high-speed switching processing of isochronous data can be executed.

The connection table shown in FIG. 15 is stored in the topology storage
Although a method of storing the data in the TM / 1394 bridging processing unit 1911 is conceivable, in order to execute the above data link switching processing, in the present embodiment, the 1394 protocol, which is an interface processing unit of each network connection device, is used. It is stored in the processing unit 1907 and the ATM layer processing unit 1909.

First, the topology information (here, topology Y0, Z0 or topology Y, Z) of another network received at the time of starting the network is received via the ATM network 500, and the topology exchange processing unit 1902 stores the topology information. It is transferred to the unit 1901. In the topology exchange processing unit 1902, the initialization processing of the topology information shown in the first embodiment is executed.

When the 1394 network starts up (at the time of bus reset), the topology recognition processing (Tree) is performed.
ID, Self ID), and the topology information of the 1394 network X is stored in the 1394 bus control processing unit 190.
6 is transferred to the topology storage unit 1901. This means that the topology storage unit 1901 has obtained all the topology information (topology X0, Y0, Z0 or topology X, Y, Z) of the 1394 network X, Y, Z. Here, since the ATM connection for exchanging the topology information is set by a request from the topology information exchange processing unit 1902, the ATM connection set for isochronous data transfer, which will be described later,
It can be identified by the ATM signaling processing unit 1908.

Next, the process of transferring an isochronous packet from the 1394 network X will be described. First one
When an attempt is made to start transmission / reception of isochronous data from a 1394 terminal in the 394 network X, the 1394 terminal acquires a band in the 1394 network X and a channel for transferring the isochronous data from the isochronous resource manager. After that, a transmission / reception request signal for isochronous data is transmitted to the partner 1394 terminal. Therefore, in the network connection device A, the transmission / reception request packet of the isochronous data is detected by the above-described means, and the network connection device A belongs to a different 1394 network.
An ATM connection for isochronous data transfer is set with the four terminals.

First, the network connection device A that has received the asynchronous packet from the 1394 network X
Reads the 1394 terminal address of the request destination described in the data transmission / reception request when the packet is the above-mentioned data transmission / reception request packet, and reads the address of the 1394 terminal other than the 1394 network X. If the terminal is a 1394 terminal belonging to
The reception request packet is transferred to the ATM / 1394 bridging processing unit 1911.

ATM / 1394 bridging processing unit 19
At 11, the physical IDs of the destination terminal and the source terminal of the request packet are sent to the address / connection conversion processing unit 1910, where the destination node determines the destination node based on the topology information (topology X) stored in the topology storage unit 1901. Rewrite to the physical ID in the 1394 network to which it belongs. The ATM / 1394 bridging processing unit 1911 also executes an ATM cell processing of the data transmission / reception request packet in which the destination node address is rewritten. Further, the ATM / 1394 bridging processing unit 19
11 judges the network connection device belonging to the 1394 network of the connection request destination from the destination node address of the read data transmission / reception request packet, and transfers the ATM address of the network connection device to the signaling processing unit 1908. .

The ATM signaling processing unit 1908 performs a signaling process for setting up an ATM connection for the notified ATM address of the network device. Here, the ATM address of each network connection device is stored in the topology storage unit 1901 (may be described in topology X),
M in the M signaling processing unit 1908,
A method is also conceivable in which the M / 1394 bridging unit notifies the 1394 address of the network connection device. This ATM signaling processing unit 1908
The signaling process in A method using 2931 is also conceivable, and a method is also conceivable in which a PVC is previously set between network connection devices, and an ATM cell is transmitted to the PVC after converting a data transmission / reception request packet into an ATM cell. .

When the ATM connection is set by the signaling process, the data obtained by converting the data transmission / reception request packet into an ATM cell using the ATM connection belongs to the 1394 network to which the destination 1394 terminal belongs. ATM for network connection equipment
The data is transferred via the layer processing unit 1909. Also, AT
The relationship between the ATM connection set by the M signaling process and the isochronous channel in the 1394 network X (see FIG. 15) is based on the 1394 protocol processing unit 1 which executes the data transfer process of each network.
907 and the ATM layer processing unit 1909. Using this connection table, an isochronous packet to be transferred to another 1394 network via the network connection device A among the isochronous packets sent to the 1394 protocol processing unit after this is converted to the data link switching processing unit 1912.
Can be transferred to

[0224] Next, the network connection device A, which has received the ATM cellized data via the ATM network 500, transfers the ATM cell to the ATM signaling processing unit 1908 if the ATM cell is signaling data. Then, execute a signaling process. This A
In the TM signaling data, it is possible to describe information for identifying whether the ATM connection is a connection used for topology information exchange processing or a connection used for transferring isochronous data. Specifically, a method of giving a specific value to an ESI field in an address field of the NSAP format defined by ISO (International Standard), a method of using a RESERVE field, and signaling information include: A method of describing the type of the ATM connection is also conceivable. Therefore, when an ATM connection is set up and the ATM layer processing unit 1909 transfers an ATM cell via the ATM connection for isochronous data transfer, the ATM cell is transferred to the ATM / 1394 bridging processing unit 1909.
911, and when an ATM cell is transferred via an ATM connection for topology information exchange,
The ATM cell can be transferred to the topology information exchange processing unit 1902.

ATM / 1394 bridging processor 19
In step 11, the 1394 packet is assembled from the ATM cell. If the received 1394 packet is an asynchronous packet, the physical ID of the source terminal or destination terminal of the packet is read, and the read physical ID is read. To the address / connection conversion processing unit 1910, where the topology storage unit 1901
Based on the topology information (topology X) stored in the
Rewrite to the physical ID of the source terminal or destination terminal in the own 1394 network.

When it is determined that the asynchronous packet received by the above method is a transmission / reception request packet for isochronous data, the requested band information is read from the data transmission / reception request packet. , Via the 1394 protocol processing unit 1907 to execute a channel acquisition process for securing an isochronous channel having the read band in the 1394 network X. If an isochronous channel can be set in the 1394 network by this channel acquisition processing, the ATM connection that has transferred the data transmission / reception request packet and the newly set 139
Information that four isochronous channels correspond (FIG. 15)
) Is stored in both the 1394 protocol processing unit 1907 and the ATM layer processing unit 1909 which execute the data transfer processing of each network.

By using this connection table, among the ATM cells transmitted to the ATM layer processing unit 1909, the ATM cells for transferring data to the isochronous channel in the 1394 network X are directly subjected to data link switching. The data can be transferred to the processing unit 1912.

As will be described in a fourth embodiment described later, the network serving as the backbone network may be a public network. In this case, a 1394 network existing in each remote home or office is replaced with a single 1394 network.
The network can be emulated.

(Fourth Embodiment) Next, referring to FIGS. 20 to 23, when communication is performed between 1394 terminals belonging to a 1394 network which exists in a remotely distant home, each 1394 network Are connected by a public network such as a telephone network.

In this embodiment, there is a network connection device between each 1394 network and the public network, and this network connection device executes a data transfer process between the public network and each 1394 network. State. Here, each 1394 in the remote home is
It is assumed that the networks are connected by a telephone line, the Internet, or the like.

FIG. 20 shows an example of a connection mode when different homes are connected via the network connection device of the present embodiment. Here, 1394 network X20
40 and a home having a 1394 network Y2050, respectively.
020 via a public network 2030. Specifically, the network connection device A20
10 and B2020 also have a public network interface (for example, a telephone line), and the 1394 network X2040 and the 1394 network Y2050 are connected via the public network interface.

The following describes two embodiments (first asynchronous data transfer and second asynchronous data transfer) for transferring asynchronous data from the 1394 terminal 2011 in the 1394 network X to the 1394 terminal 2022 in the 1394 network Y in FIG. Will be described in detail.

4.1 First Asynchronous Data Transfer A data transfer procedure of the first asynchronous data transfer will be described in detail with reference to FIG.

First, 139 in the 1394 network X
4 From terminal 2011, 13 in 1394 network Y
139 wanted to transfer data to 94 terminal 2022
4 The user on the network X side has the 1394 terminal 1
The processing is performed on the network connection apparatus A instead of the network connection apparatus 12, and a communication request is transmitted from the network connection apparatus A to the network connection apparatus B of the 1394 network Y.

In FIG. 21, assuming that a telephone network is used as the public network, a process of making a call (signaling) from the network connection device A to the network connection device B is executed (step S8 in FIG. 21).
1). 20 and 21, the network connection devices A and B correspond to the telephone numbers A [T] and B [T], respectively.
This shows a case where the address has the address [T].

Next, if the signaling process is successful and the telephone line between the network connection devices can be set, the topology information stored in each of the network connection devices A and B is exchanged via the telephone line. (Step S82 in FIG. 21).

As a result of this topology exchange processing, each of the network connection devices A and B holds the topology information of the other 1394 network. in this case,
Thereafter, new topology information may or may not be constructed by a new bus reset.

Next, the network connection apparatus A sends a read request packet (Read.Req) for reading out desired data to the 1394 terminal 2011 that sends out the data.
send packet (Read packet) 2101 (step S83 in FIG. 21) and a read response packet (Read.Complete packet) 2102 from the 1394 terminal 2011
Desired data can be read out (FIG. 21).
Step S84).

In FIG. 21, an arbitration process for acquiring the right to use the 1394 bus is required before each of the above-mentioned processes, but is omitted in FIG.

The network connection device A transfers the data read using the set telephone line to the network connection device B in accordance with the public network data transfer method (using the packet 2103 in FIG. 21). The destination terminal (the 1394 terminal 20) that transfers the read data
The physical ID of 22) is also notified (step S85 in FIG. 21). This transfer destination terminal (1394 terminal 20)
The physical ID of 22) corresponds to the topology exchange processing (FIG. 21).
Is the physical ID of the 1394 terminal 2022 in the 1394 network Y read in step S82). Specifically, in FIGS. 20 and 21, the terminal B2 [Y] in the 1394 network Y is notified.

Here, in FIG. 21, 139
4 Since the data transfer to the 1394 network Y received from the network X is performed, the physical ID of the destination terminal is to be notified. Conversely, the 1394 network X that made the call makes the call. When it is desired to receive the data from the received 1394 network Y, the physical ID of the 1394 terminal requesting the data transmission is notified from the network connection device A to the network connection device B.
20 and 21, the terminal ID to be notified in this case also notifies the physical ID of the 1394 terminal in the 1394 network Y, that is, B2 [Y].

The data transmitted in this way and the physical I / O of the destination terminal (1394 terminal 2022) of the data are
Network connection apparatus B that has received D transmits the received data to 1394 terminal 2022 via a write request packet (Write. Request packet) 2104 for 1394 terminal 2022 (step S86 in FIG. 21).

Finally, a write response packet (Write.Com) from the 1394 terminal 2022 that received the data
(Plete packet) 2105 via the network connection device B (step S87 in FIG. 21) to the network connection device A in accordance with the public steel data transfer method (in FIG. 21, using the packet 2106). When the data is transferred, this data transfer process ends (FIG. 21).
Step S88).

It is noted that such data transfer processing can be similarly performed for the transfer of isochronous packets.
It is obvious from the embodiment.

4.2 Second Asynchronous Data Transfer Referring to FIG. 22, data of the second asynchronous data transfer will be described. The Sou procedure will be described in detail.

First, 139 in the 1394 network X
4 terminal 2011 is 139 in the 1394 network Y.
1394 wanted to transfer data to terminal 2022
The user on the network X side is the 1394 terminal 2011
139 exists a destination 1394 terminal 2022
Home in which 4 networks exist Request packet (Requ for notifying the ID (for example, telephone number)
est packet) 2201 (step S91 in FIG. 22).

As a method of recognizing this packet in the network connection device A, the above-described IEC18
Several schemes are conceivable, such as a scheme for viewing the packet header and a scheme for reading the data portion of the packet, such as an 83-packet identification scheme.

[0248] Also, the home of another home is stored in the 1394 network Y. The method of notifying the ID may be a method of notifying from the network connection device via the 1394 network, or the method of notifying the user of the Home
A method of writing the ID to the 1394 terminal 2011 and notifying it may be used.

Next, the network connection device A, which has received the connection request for the 1394 network Y, sends the received Home Refers to the ID and recognizes that it is the home where the network connection device B exists,
The communication request is transmitted to the network connection device B of the 94 network Y. In FIG. 22, since it is assumed that a telephone network is used as the public network, a process of making a call (signaling) from the network connection device A to the network connection device B is performed (step in FIG. 22). S92).

Here, in FIGS. 20 and 21, the network connection devices A and B have A
This shows a case where the addresses [T] and B [T] are provided.

Next, if the signaling process is successful and the telephone line between the network connection devices can be set, the topology information stored in each of the network connection devices A and B is exchanged via the telephone line. (Fig. 22
Step S93). Further, network connection device A,
B includes 139 each including the received topology information.
A new bus reset as shown in the first embodiment is generated in the four networks, and the topology automatic configuration recognition process is executed (step S94 in FIG. 22).

FIG. 23 is a conceptual diagram of the topology information that each network connection device holds as a result of the new topology automatic configuration recognition processing. The conceptual diagram of this topology information is similar to the conceptual diagram shown in FIG. That is, the transfer of the asynchronous packet and the transfer of the isochronous packet after the automatic configuration recognition processing of the new topology can be executed in the same manner as in the second and third embodiments.

(Fifth Embodiment) Next, referring to FIGS. 24 to 27, when image data is received by an in-home 1394 terminal from an image server existing in a public network, the network of the present invention is used. The details of the processing executed by the connection device will be described.

This method can be basically performed in the same manner as in the third and fourth embodiments. However, when the image server in the public network does not have the 1394 address, Special processing for that is required.

The following is a detailed description of a case where a channel (connection) that guarantees a band between the 1394 terminal and the image server when the home 1394 terminal receives image data from an image server that does not have a 1394 address. Will be described.

FIG. 24 shows an image server 2 in a public network via the network connection device of this embodiment.
An example of a connection mode when a 1394 terminal in a home having a 420 and a 1394 network X2440 is connected is shown. Specifically, the network connection device A 2410 in the 1394 network X 2440 and the image server 24
20 are connected by an ATM network 2430.

Referring to FIG. 25, a detailed procedure for connection setting when image data is transferred from image server 2420 to 1394 terminal 2411 in 1394 network X 2440 in the configuration of FIG. 24 will be described. Also, with reference to FIG. 27, a description will be given of a procedure for actually transferring image data from the image server 2420 to the 1394 terminal 2411 in the 1394 network X2440 in the configuration of FIG.

First, the network connection device A collects addresses of various servers existing in the public network 2430 (step S101 in FIG. 25). This is to check in advance the services that can be enjoyed by the 1394 terminals in the 1394 network X2440 and to notify the information to each 1394 terminal. Of course, without performing such data collection, the 1394 terminal 2411 that wants to receive image data sends the address of the desired image server to the network connection device 2.
A method of notifying 410 (the method of the fourth embodiment) is also conceivable.

FIG. 25 shows a case where the ATM address [S] of the image server 2420 is notified as the notified image server address.

Next, a physical ID is given to the collected various servers as a 1394 terminal in the 1394 network X, and further, the network connection device is used to notify the physical ID to all the terminals in the 1394 network X. A executes a bus reset for the 1394 network X (step S102 in FIG. 25). This allows all terminals in the 1394 network X to know what server exists in the public network 2430. At this time, the various servers existing in the public network need not have the 1394 address.
The real addresses of the various servers (ATM address [S] in FIG. 25) and the physical ID addresses in the 1394 network X assigned to the various servers (As in FIG. 25)
[X]) may be maintained.

By such a topology process, 13
Since the 1394 terminal 2411 in the 94 network X can recognize the existence of the image server 2420 in the public network, the 1394 terminal 2411 can directly issue an image transmission request to the image server 2420. Become like However, actually, the image transmission request data is received by the network connection device A, and is transferred from the network connection device A to the image server 2420 via the public network 2430.

First, the 1394 terminal 2411 sets the isochronous channel for transferring image data in the 1394 network X.
The required bandwidth and channel number are requested to the isochronous manager 2413 in the server (step S1 in FIG. 25).
03).

In FIG. 25, as a result of this request, the fact that the channel can be set by the isochronous manager 2413 and the assigned channel number Ch
This shows a case where a has been notified.

Next, the 1394 terminal 2411 recognizes that an isochronous channel has been set between the terminal itself and the image server 2420.
With respect to Lock. For requesting isochronous transmitter transmission / reception shown in the third embodiment. A request packet 2502 (based on IEC 1883) is transmitted (step S104 in FIG. 25). This Lock. Req
The physical ID of the destination terminal in the east packet is As [X] given by the network connection device A. Therefore, the network connection device A receives the physical ID (A
s [X]), it is possible to know that the server of the connection request destination is the image server 2420, and it is also possible to obtain necessary information such as the required bandwidth by reading the contents of the request packet. Based on the information thus obtained, the network connection device A executes a signaling process from the network connection device A to the image server 2420 (step S105 in FIG. 25).

In this embodiment, since an ATM network is assumed as the public network, an ATM signaling process is executed here, and the notified required bandwidth can be set between the network connection device A and the image server 2420. If, ATM connection VC a is set. Further, if the signaling is successful, the network connection device A transmits a Lock. No. for notifying the 1394 terminal 2411 that the image data transmission / reception request has been accepted. A response packet 2503 is transmitted (step S106 in FIG. 25).

[0266] Through these series of processing, a connection / channel for transferring image data has been set between the 1394 terminal 2411 and the image server 2420.

Here, the signaling information between the network connection device A and the image server 2420 is normally performed using a connection for signaling processing. In particular, in the case of a VOD service, for example, A control connection may be set. Therefore, in the above-described signaling process in the present embodiment, a case may be considered in which the control connection assigned to the image server is performed instead of the normal ATM signaling process.

Further, by the above processing, the network connection device A establishes the isochronous channel number Ch in the 1394 network X. a and an ATM connection VC in an ATM network which is a public network a
Can be recognized as corresponding.

FIG. 26 shows an example of a conceptual diagram of the topology information recognized by the network connection device A at the time when the above-described series of procedures is completed. FIG. 27 shows the connection / connection information set by the above-described procedure. 4 shows an actual image data transfer procedure using a channel.

As shown in FIG. 26, the network connection device A
Is connected to the own 1394 network X by the image server 2420, the ATM address of which is [S], and 13
It recognizes that the value of As [X] is given as the physical ID of the 94 terminal.

[0271] Also, it is set on the 1394 network X side.
Isochronous channel Ch a and ATM network
ATM connection VC set in the connection a is the correspondence
We recognize that there is.

When the 1394 terminal 2411 receives image data while holding such topology information, first, a packet for requesting the image server to start data transfer from the 1394 terminal 2411 is received. 2601 is transmitted (step S111 in FIG. 27). Such a packet requesting the start of transfer is not shown in the third embodiment, but can be used in the third embodiment. The data request packet 2601 may be transferred using a newly set isochronous channel, or may be transmitted using an asynchronous packet.

Next, the network connection device A that has received the data transfer request packet sends the data transfer request packet to the image server 242.
This image data transfer request is notified by using an ATM connection or control connection to 0 (step S112 in FIG. 27).

The image server 2420 that has received the image data transmission request transmits a predetermined ATM connection VC
The requested image data is sent to a (step S113 in FIG. 27).

Further, the network connection device A transmits the received image data to the 1394 terminal 2411 via the arbitration process (step S114 in FIG. 27) for isochronous data transfer on the 1394 network. The transmission is performed using a (step S115 in FIG. 27).

(Sixth Embodiment) Next, FIGS.
A description will be given of an embodiment in which two 1394 networks X and Y are connected by a single network connection device C by using FIG.

In this case, the two 1394 networks are connected by the network connection device C without any intervening other networks.
Of the topology as shown in the embodiment of FIG.
The g processing becomes unnecessary.

FIG. 28 shows an example of a network configuration diagram when two 1394 networks X and Y are connected by the network connection device C of the present embodiment.

According to FIG. 28, network connection device C
1394 network X including four 1394 terminals 2811 to 2814, and three 1394 terminals 28
A 1394 network Y including 21 to 2823 is connected.

Each 1394 network is a 1394 S
A series of automatic configuration recognition processes (Tree ID process, Self ID process) to create topology information (topology X0, Y0) for each 1394 network.

Further, the network connection device C of this embodiment executes a new automatic configuration recognition process in each of the 1394 networks X and Y using the topology information, and shares the above-mentioned topologies X0 and Y0. Create topology information (topologies X and Y). An example of the topology information created in this manner (topology X
0, Y0, X, Y) are shown in FIG.

In FIG. 29, a 1394 terminal 2812 (A2 [X
0]) is selected and the 1394 terminal 2814 (A4 [X0]) is used as the isochronous resource manager terminal.
Has been selected. Similarly, in FIG.
13 as the root terminal in the 1394 network Y
The figure shows a case where the 94 terminal 2821 (B1 [Y0]) is selected and the 1394 terminal 2823 (B3 [Y0]) is selected as the isochronous resource manager terminal.

As described above, the network connection device C
Two 1394 connected to own network connection device
Since the topology information of each network can be held, the same topology information as that shown in FIG. 6 or FIG. 8 can be held based on this information.

[0284] 1 held by the network connection device C
An example of the topology information of the 394 networks X and Y is shown in FIGS. Here, the topology information shown in FIG. 30 is used when data is transferred from the 1394 network X to the 1394 network Y, and the topology information shown in FIG. 31 is used for transferring data from the 1394 network Y to the 1394 network X. This is information used when performing.

The topology information shown in FIGS. 30 and 31 has basically the same configuration as the topology information shown in FIGS. That is, in the topology information of FIG. 30, the terminal in the 1394 network X becomes the root terminal or the isochronous resource manager terminal,
1 in the 1394 network Y
Terminals in the table are root terminals and isochronous resource manager terminals.

The processing capacity (Cap) of each 1394 terminal
availability) is set in the topology information of the 1394 network X (FIG. 30) in the same manner as in the case of the topology information shown in FIG.
The processing capacity of the 394 terminal is the isochronous processing capacity (Is
ochronous Capability) and the topology information of the 1394 network Y (FIG. 3).
In 1), the processing capacity of the 1394 terminal in the 1394 network X is changed to the isochronous processing capacity (Isochron processing capacity).
ous Capability).

In FIG. 30 and FIG. 31, the same 1394 terminal is assigned to the root terminal and the isochronous resource manager terminal in the 1394 network X in the topology X0 and the topology X. However, in the present embodiment, it is not always necessary to match them as described above.
It is only necessary that the terminals in are assigned to the root terminal and the isochronous resource manager terminal in the topology X.

As described above, the network connection device C holding the topology information as shown in FIGS.
When an actual synchronous packet or isochronous packet is transferred, the processing in the network connection device shown in the above-described second and third embodiments, which exists for every two 1394 networks, is performed by one. By performing the processing in the network connection device, a packet transfer process between two 1394 networks connected as shown in FIG. 28 is executed. However, in the present embodiment, since the network connection device C directly connects the two 1394 networks, the stored address information and the like can be reduced, and each of the 13
There is no need to perform packet conversion processing on packets transmitted from the 94 network, and a network connection function can be provided only by rewriting the values of the destination terminal address and the source terminal address.

6.1 Asynchronous Data Transfer With reference to FIG. 32, an asynchronous packet transfer procedure in the case of using the network connection device of the present embodiment will be described in detail.

In FIG. 32, a write from the 1394 terminal 2813 in the 1394 network X to the 1394 terminal 2822 in the 1394 network Y shown in FIG.
e. Request packet transfer and the corresponding
A from 1394 terminal 2822 to 1394 terminal 2813
ck. The details of the transfer of the Complete packet are shown. Also, packets 3201 to 3201 shown in FIG.
Reference numeral 3204 denotes a packet being transferred in each network.

Here, all of the 1394 terminals in the 1394 network X are obtained from the topology information (topology X) shown in FIG.
Topology information excluding the physical ID of the terminal is shared. Similarly, all 13 in the 1394 network Y
The 94 terminals share topology information obtained by removing the physical ID of the 1394 terminal in the 1394 network X from the topology information (topology Y) shown in FIG. This allows each 1394 terminal to operate in the same manner when performing communication between different 1394 networks and when performing communication within the same 1394 network. However, if the network connection device C is
0 and the topology information (topologies X and Y) shown in FIG. 31 and serves to absorb (emulate) differences in topology information between 1394 networks.

First, as described above, in the 1394 protocol, when transferring asynchronous data, arbitration processing for acquiring the right to use the connected bus is executed. In the present embodiment, since the 1394 terminal 2812 is the root terminal of the 1394 network X, the 1394 terminal 2813 first executes the arbitration process on the 1394 terminal 2812 which is the root terminal (step S121 in FIG. 32). .

Then, the 1394 which has acquired the right to use the bus
The terminal 2813 is connected to the 1394 Specificatio.
n according to the format of the asynchronous packet (see FIG. 11)
Data transfer for 2 (Write.Request)
The packet 3201 is transmitted (step S12 in FIG. 10).
2). At this time, the asynchronous packet 32 transferred from the 1394 terminal 2813 to the network connection device C is transmitted.
01, the physical ID (B2 [X]) of the 1394 terminal 2822 recognized by the topology X is written in the transmission destination ID (Destination ID) field, and the transmission source ID (Source ID) field is recognized by the topology X. Physical ID of 1394 terminal 2822
(A3 [X]) has been written.

Next, the network connection device C that has received the packet 3201 from the 1394 terminal 2813 stores the destination address and the source address of the packet 3201 because the destination terminal of the packet 3201 is not a terminal in the 1394 network X. With reference to the topology X in question, the packet 3201 is rewritten to a physical ID in the 1394 network Y to which the packet 3201 is transferred.

More specifically, the physical ID of the destination terminal of the packet 3201 is rewritten from B2 [X] to B2 [Y].
The physical ID of the source terminal of the packet 3201 is A3 [X]
To A3 [Y]. In this way, the network connection device C that has performed the rewriting process of the destination address and the source address of the packet to be transferred, converts the packet 3202 whose destination address and the source address are rewritten into 13
After arbitration processing in the network 94 (step S123 in FIG. 32), the destination terminal 139
It is transferred to the four terminals 2822 (B2 [Y]) (step S124 in FIG. 32).

In this case, the transfer of the asynchronous packet from the network connection device C to the 1394 terminal 2822 is performed in the same manner as the transfer of the asynchronous packet on the network X.

Also, as described above, in the 1394 network, if any processing requested from the transmission source terminal can be executed at the destination terminal, then the processing is performed from the destination terminal to the transmission source terminal. Ack. The Complete packet is to be sent back. This Ack. The transfer of the complete packet is also performed by the above request packet (request packet).
Can be executed in the same way as the transfer of

First, the destination 1394 terminal 2822
From Ack. In order to transmit the complete packet 3203, arbitration processing for acquiring the right to use the bus is executed (step S12 in FIG. 32).
5). If the 1394 terminal 2822 acquires the right to use the bus, the Ack. Compl
An et packet 3203 is transmitted (step S126 in FIG. 32), and the packet 3203 is transferred to the network connection device C.

Next, since the destination terminal of the packet 3203 is not a terminal in the 1394 network Y, the network connection device C receiving the packet 3203 transmits the destination address and the source address of the packet 3203 and the stored topology information. Referring to (topology Y), a rewriting process of the transfer destination of the packet 3203 to the physical ID in the 1394 network X is executed. Specifically, the physical ID of the destination terminal of the packet 3203 is set to A3
[Y] is rewritten to A3 [X], and the physical ID of the source terminal of the packet 3203 is rewritten from B2 [Y] to B2 [X].

As described above, the network connection device C, which has performed the rewriting process of the destination address and the source address of the packet to be transferred, converts the packet 3204 whose the destination address and the source address are rewritten into the arbitration process in the 1394 network X. (Step S in FIG. 32)
After 127), the destination terminal 1394 terminal 2813
(A3 [X]) (step S12 in FIG. 32).
8).

[0301] In this case, the network
The transfer of the asynchronous packet to the 394 terminal 2813 is executed in the same manner as described above.

Here, 1394 Specificat
In the Ack.ion, after transmitting a request packet (Request packet) for transferring the asynchronous packet, the Ack. The time until the complete packet returns must be kept within a certain time. However, Ack. If it is determined that sending the Complete packet takes time, A
ck. Complete packet is Ack. Pendi
ng packet or Ack. Send back a busy packet,
A notification that processing has been delayed is provided.

Therefore, as in the present embodiment, Write. Request packet or Ack. When transferring a complete packet, the network connection device C
k. Pending packet or Ack. A method of sending back a busy packet may be considered. This method has been described in detail in the second embodiment and the third embodiment, and therefore will not be described here.

Although only the asynchronous packet transfer method has been described above, it is obvious that the present embodiment can also transfer an isochronous packet as in the third embodiment.

6.2 Internal Configuration of Network Connection Apparatus FIG. 33 shows the network connection apparatus C shown in this embodiment.
1 shows an example of the internal configuration of the device.

To the network connection device C, together with a 1394 bus control processing unit 3306 and a 1394 protocol processing unit 3307 for performing data transfer with the 1394 terminal in the 1394 network X, data transfer with the 1394 terminal in the 1394 network Y is performed. 139 to do
A four-bus control processing unit 3302 and a 1394 protocol processing unit 3303 exist.

The 1394 protocol processing units 3307 and 33
A function 03 executes a so-called physical layer process, a link layer process, and a transaction layer process in the 1394 Specification.

The functions for connecting the 1394 networks include a topology storage unit 3301, an address conversion processing unit 3304, and a 1394 bridging processing unit 3
305 exists.

First, when starting up the network,
The topology information (topology X0, Y0) recognized by each of the networks X, Y is stored in the 1394 bus control unit 330.
2 and 3306 are transferred to the topology storage unit 3301. In each 1394 network, a new topology recognition process is executed based on the topology information stored in the topology storage unit 3301. The topology information (topology X, Y) of each 1394 network recognized as a result is also transferred from the 1394 bus control processing units 3302 and 3306 to the topology storage unit 3301. As a result, the topology storage unit 1201
This means that all the topology information (topologies X0, Y0, X, Y) of the 1394 networks X, Y have been obtained.

Next, the processing at the time of transferring an asynchronous packet from the 1394 network X will be described. First, an asynchronous packet sent from the 1394 network X is received by the 1394 protocol processing unit 3307. Here, in the network connection device C, 1
13 belonging to a network other than the 394 network X
If the 94 terminal is the destination terminal, the 1394 packet is transferred to the 1304 bridging processing unit 3305.

In the 1394 bridging processing unit 3305, the physical I / O of the destination terminal or source terminal of the 1394 packet is performed.
D is rewritten to a physical ID in the 1394 network Y to which the destination terminal belongs based on the topology information (topology X) stored in the topology storage unit 3301. The 1394 packet in which the physical IDs of the destination terminal and the source terminal are rewritten is transferred to the 1394 protocol processing unit 3.
The data is transmitted to the 1394 network Y via the network 303.

Conversely, the asynchronous packet sent from the 1394 network Y is received by the 1394 protocol processing unit 3303, and the destination terminal of the packet belongs to a network other than the 1394 network Y.
If the terminal is a 394 terminal, the 1394 packet is transferred to the 1394 bridging processing unit 3305.

In the 1394 bridging processing unit 3305, the physical I / O of the destination terminal or source terminal of the 1394 packet is performed.
D is rewritten to a physical ID in the 1394 network X to which the destination terminal belongs based on the topology information (topology Y) stored in the topology storage unit 3301. The 1394 packet in which the physical IDs of the destination terminal and the source terminal are rewritten is transferred to the 1394 protocol processing unit 3.
307 to the 1394 network X.

[0314] By the above processing, the address conversion processing in the network connection device C of the present embodiment can be executed.

[0315]

As described above, by using the network connection device according to the present invention, communication over a plurality of 1394 networks can be executed even if different networks exist between the 1394 networks. In addition, even if the terminal operates only with the 1394 protocol, non-139
Communication via four networks can be performed. Furthermore, by emulating non-1394 terminals (various servers) as if they belong to the 1394 network, even terminals that operate only with the 1394 protocol can communicate with non-1394 terminals outside the 1394 network. Can be done.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a configuration example of a home network using a network connection device of the present invention.

FIG. 2 is a diagram showing a detailed configuration example of a home network using the network connection device of the present invention.

FIG. 3 is a diagram showing an example of a procedure for notifying network topology information by a network connection device.

FIG. 4 is a conceptual diagram showing an example of 1394 network topology information stored by a network connection device.

FIG. 5 shows 13 stored for each network connection device.
The figure which showed an example of the detailed content of 94 network topology information.

FIG. 6 is a diagram showing an example of detailed contents of 1394 network topology information stored by a network connection device.

FIG. 7 is a diagram showing another example of a procedure for notifying the network topology information by the network connection device.

FIG. 8 is a diagram showing another example of the detailed contents of the 1394 network topology information stored by the network connection device.

FIG. 9 is a conceptual diagram in the case where 1394 networks are connected via Ethernet using a network connection device to transfer asynchronous packets (hereinafter, a second embodiment).

FIG. 10 is a diagram showing an example of an asynchronous packet transfer procedure when a 1394 network is connected via Ethernet using a network connection device.

FIG. 11 is a diagram showing an example of the format of an asynchronous packet transferred on a 1394 network.

FIG. 12 is a diagram showing an example of an internal block configuration of a network connection device according to a second embodiment of the present invention.

FIG. 13 is a conceptual diagram of a case where an 1394 network is connected via an ATM network by using a network connection device to transfer an isochronous packet (hereinafter, a third embodiment).

FIG. 14 is a diagram showing an example of an isochronous channel setting procedure when a 1394 network is connected via an ATM network using a network connection device.

FIG. 15 is a diagram showing an example of a connection table stored by the network connection device.

FIG. 16 is a diagram showing an example of a transfer procedure of an isochronous packet when a 1394 network is connected via an ATM network using a network connection device.

FIG. 17 is a diagram showing another example of the transfer procedure of the isochronous packet when the 1394 networks are connected via the ATM network using the network connection device.

FIG. 18 is a diagram showing an example of the format of an isochronous packet transferred on a 1394 network.

FIG. 19 is a diagram schematically illustrating an example of the internal configuration of a network connection device according to a third embodiment;

FIG. 20 is a diagram illustrating an example of an overall configuration when a 1394 network is connected via a public network using a network connection device (hereinafter, a fourth embodiment).

FIG. 21 is a diagram showing an example of a data transfer procedure when a 1394 network is connected via a public network using a network connection device.

FIG. 22 is a diagram showing another example of a data transfer procedure when a 1394 network is connected via a public network using a network connection device.

FIG. 23 is a conceptual diagram of a 1394 network topology stored in a network connection device when a 1394 network is connected via a public network using the network connection device.

FIG. 24 is a diagram illustrating an example of an overall configuration when an image server connected to a 1394 network and a public network is connected using a network connection device (hereinafter, a fifth embodiment).

FIG. 25 is a diagram showing an example of a procedure for setting an isochronous channel between a 1394 network and an image server connected to a public network using a network connection device.

26 shows a connection / connection according to the procedure shown in FIG. 25;
The figure which showed an example of the conceptual diagram of the topology information which the network connection apparatus A recognizes, when a channel is set.

FIG. 27 is a diagram showing an example of a procedure for receiving image data from an image server connected to a 1394 network and a public network using a network connection device.

FIG. 28 shows a case where two 13
FIG. 16 is a diagram showing an example of the overall configuration of a network when 94 networks are connected (hereinafter, a sixth embodiment).

FIG. 29 is a conceptual diagram of topology information stored by the network connection device.

FIG. 30 is a view showing an example of detailed contents of 1394 network topology information stored by the network connection device.

FIG. 31 is a view showing an example of detailed contents of 1394 network topology information stored by the network connection device.

FIG. 32 is a diagram showing an example of an asynchronous packet transfer procedure when a 1394 network is connected using a network connection device.

FIG. 33 is a diagram schematically illustrating an example of the internal configuration of a network connection device according to a sixth embodiment;

[Explanation of symbols]

110 network connection device A, 120 network connection device B, 130 network connection device C, 20
1 ... 1394 network X, 202 ... 1394 network Y, 203 ... 1394 network Z, 111-
113 ... 1394 terminals, 121-123 ... 1394 terminals, 131-133 ... 1394 terminals.

Claims (20)

[Claims] 1. A network connection device for connecting a first network and a second network, comprising: a first automatic configuration recognizing means for recognizing a topology of the first network and generating first topology information; Second automatic configuration recognition means for recognizing the topology of the second network and creating second topology information; topology information storage means for storing the first topology information and the second topology information; A topology information creating unit that creates new topology information that shares the first and second topology information stored in the topology information storage unit, based on the first and second topology information. 2. A network connection device for connecting a first network and a second network, comprising: a first automatic configuration recognizing means for recognizing a topology of the first network and creating first topology information; Second automatic configuration recognition means for recognizing the topology of the second network and creating second topology information; topology information storage means for storing the first topology information and the second topology information; Based on the first and second topology information stored in the topology information storage means, a topology information creating means for creating new topology information sharing them, and a new topology created by the topology information creating means. Recognizing the topology of the first network based on the information; Third to create a broadcast
An automatic configuration recognizing means for recognizing a topology of the second network based on new topology information created by the topology information creating means to create fourth topology information.
A network connection device, comprising: automatic configuration recognition means. 3. A network connection device for connecting a first network and a second network, wherein: a first automatic configuration recognizing means for recognizing a topology of the first network and creating first topology information; A second automatic configuration recognizing means for recognizing a topology of the second network and generating second topology information; and a new automatic configuration recognizing means for sharing these based on the first topology information and the second topology information. First topology information creation means for creating topology information; and third topology information created by recognizing the topology of the first network based on new topology information created by the first topology information creation means. Third
An automatic configuration recognizing means for recognizing a topology of the second network based on the new topology information created by the first topology information creating means to create fourth topology information;
Automatic topology recognition means, topology information storage means for storing the third topology information and the fourth topology information together with the first and second topology information, and the first and second topology information stored in the topology information storage means. And a second topology information creating means for creating new topology information based on the third and fourth topology information. 4. The system according to claim 1, wherein said first and second networks are I
The network connection device according to any one of claims 1 to 3, wherein EEE1394-1995 is used. 5. The terminal addresses assigned to terminals in the first and second networks included in the third topology information, and the first and second networks included in the fourth topology information An address conversion table for storing the correspondence between terminal addresses assigned to the terminals in the network; and referring to the address conversion table, the destination terminal address or the source terminal address of the packet received from the first network. First address translation means for rewriting at least one, and second address translation means for rewriting at least one of a destination terminal address and a source terminal address of a packet received from the second network with reference to the address translation table. 4. The network according to claim 3, comprising: Network connection device. 6. A network connection device for connecting a first network to a third network via a second network, wherein an automatic configuration for recognizing a topology of the first network and creating first topology information. Recognizing means, topology information exchanging means for exchanging the first topology information and topology information of the third network via the second network, and receiving by the first topology information and the topology information exchanging means. A topology information storage means for storing the topology information of the third network, and a new information sharing means for sharing these based on the first topology information and the topology information of the third network stored in the topology information storage means. Means for creating topology information, Network connection device being characterized in that provided. 7. A network connection device for connecting a first network to a third network via a second network, wherein the first network device recognizes the topology of the first network and creates first topology information. Automatic topology recognition means, topology information exchange means for exchanging the first topology information and topology information of the third network via the second network, exchange of the first topology information and the topology information Topology information storage means for storing the topology information of the third network received by the means, based on the first topology information and the topology information of the third network stored in the topology information storage means, Topology information creation procedure to create new topology information to be shared And second automatic configuration recognizing means for recognizing the topology of the first network based on the topology information newly created by the topology information creating means and creating second topology information. Characteristic network connection device. 8. A network connection device for connecting a first network to a third network via a second network, wherein the first network device recognizes a topology of the first network and creates first topology information. Automatic configuration recognizing means, first topology information exchanging means for exchanging the first topology information and the topology information of the third network via the second network, and the first topology information and the first topology information Based on the topology information of the third network received by the first topology information exchanging means, first topology information creating means for creating new topology information sharing them, and the first topology information creating means Recognizing the topology of the first network based on the newly created topology information The second to create a second topology information
Automatic topology recognition means; second topology information exchange means for exchanging the second topology information and the topology information of the third network via the second network; and the second topology information and the second topology information Topology information storage means for storing the topology information of the third network received by the second topology information exchange means; and the second topology information stored in the topology information storage means and the topology of the third network. And a second topology information creating means for creating new topography information sharing the information based on the information. 9. The method according to claim 1, wherein the first network is an IEEE 13
9. The method according to claim 6, wherein the first and second elements are 94-1995.
9. The network connection device according to any one of items 8 to 8. 10. The first network and the third network use the same data link layer scheme,
9. The data link layer system different from the data link layer system used in the first network and the third network is used for the second network. The network connection device according to one of the above. 11. The method according to claim 1, wherein the first network is an IEEE1.
9. The method according to claim 6, wherein using 394-1995, the topology information creation unit creates topology information by recognizing all terminals belonging to the second and third networks as child terminals in the IEEE 1394 protocol. The network connection device according to any one of the above. 12. The first network may be an IEEE 1
394-1995, wherein the topology information creating means determines that a terminal belonging to the first network is an IEEE1
The network connection device according to any one of claims 6 to 8, wherein topology information is created by recognizing the terminal as a root terminal in the 394 protocol. 13. A terminal address assigned to a terminal in the first network included in the first topology information and a terminal in the third network included in the topology information of the third network. An address translation table storing a correspondence between the assigned terminal address and the terminal addresses assigned to the terminals in the first and third networks included in the second topology information; A first address translation unit that rewrites at least one of a destination terminal address and a source terminal address of a packet received from the first network with reference to the table; and Destination terminal address and source of packets received from network 2 A second address translation unit that rewrites at least one of the last addresses; and a second encapsulation process that refers to the address translation table and encapsulates a packet received from the first network into a packet to be transmitted to the second network. 1 packet conversion means, and second packet conversion means for extracting a packet to be sent to the first network from a packet received from the second network with reference to the address conversion table. 9. The network connection device according to claim 8, wherein: 14. A terminal address assigned to a terminal in the first and third networks included in the second topology information, and the first and the second addresses included in the topology information of the third network. An address exchange table for storing the correspondence between terminal addresses assigned to terminals in the third network, and a destination terminal address and a source of a packet received from the first network with reference to the address conversion table. First address translation means for rewriting at least one of the terminal addresses; and with reference to the address translation table, at least one of a destination terminal address and a source terminal address of a packet received from the second network. Second address translation means for rewriting, the address A first packet translation unit for encapsulating a packet received from the first network into a packet to be transmitted to the second network with reference to the translation table; and referring to the address translation table, the second packet translation unit. 9. The network connection device according to claim 8, further comprising: a second packet converter for extracting a packet to be transmitted to the first network from a packet received from the network. 15. At least one of first resource acquisition means for acquiring communication resources in the first network and second resource acquisition means for acquiring communication resources in the second network. The network connection device according to any one of claims 1 to 3, wherein the network connection device is provided. 16. First resource acquisition means for acquiring communication resources in the first network based on request information described in a packet sent from a terminal in the second network, and And at least one of the second resource acquisition means for acquiring communication resources in the second network based on request information described in a packet sent from a terminal in the first network. The network connection device according to any one of claims 1 to 3, wherein the network connection device is provided. 17. A resource acquisition means for acquiring communication resources in the second network based on request information described in a packet sent from a terminal in the first network, When a packet sent from a terminal in the first network is a packet according to the IEC1883 protocol and is a request for data transmission or reception to a terminal in a network other than the first network,
The network connection according to any one of claims 1 to 3, wherein the resource acquisition unit is activated based on request information described in a packet according to the IEC1883 protocol. apparatus. 18. A first resource obtaining means for obtaining a communication resource in the first network, and the first resource obtaining means obtained by the first resource obtaining means.
Data transmission / reception request transmitting means for transmitting a request to a terminal in the first network in accordance with the IEC1883 protocol so as to transmit or receive data using a communication resource in the network. Claims 1-3 and 6-7
The network connection device according to any one of the above. 19. A first resource acquisition unit for acquiring a first communication resource in the first network, and a second resource acquisition unit for acquiring a second communication resource in the second network. A correspondence relationship between the first communication resource and the second communication resource using the first communication resource, and the second network using the first communication resource and the first communication resource First connection correspondence storage means for storing at least one of the correspondence relations of the terminal addresses in the first and second communication resources, and the second communication resources and the first communication resources using the second communication resources. And a correspondence between the second communication resource and a terminal address in the first network that uses the second communication resource. And a second connection correspondence storing means for storing at least one correspondence relation.
The network connection device according to any one of the above. 20. A first resource acquisition unit for acquiring a first communication resource in the first network, and a second resource acquisition unit for acquiring a second communication resource in the second network. A correspondence relationship between the first communication resource and the second communication resource using the first communication resource, and the second network using the first communication resource and the first communication resource First connection correspondence storage means for storing at least one of the correspondence relations of the terminal addresses in the first communication resource, and the second communication resource and the first communication resource using the second communication resource. And a correspondence between the second communication resource and a terminal address in the first network that uses the second communication resource. A second connection correspondence storage means for storing at least one correspondence relation; and a first connection correspondence storage means based on a source terminal address or connection number described in a packet received from the first network. A first packet transfer unit that searches for a first communication resource from a terminal and transfers the received packet to a terminal address or a connection in the second network corresponding to the searched first communication resource; A second communication resource is searched from the second connection correspondence storage means based on a source terminal address or a connection number described in a packet received from the second network, and the searched second communication is searched for. A terminal address or connection in the first network corresponding to a resource; Claims 1-3 and 6-7 for a second packet transferring means for transferring the received packet, characterized by comprising the
The network connection device according to any one of the above.