JP2001024687A - Communication controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain communication through an IP network between IEEEl394 terminals on which an IP layer is not mounded. SOLUTION: A server side router 10 and a client side router 11 are used so that a server side VCR12 as an IEEE1394 terminal and a client side VCR13 as an IEEE1394 terminal are connected through an ATM network 20 as an IP network. That is, the routers 10 and 11 are respectively provided with a conversion table for making an IP address correspond to an isochronous channel as prescribed by the IEEE1394 and a converting part for converting a packet format between an IP packet and an isochronous packet by referring to the conversion table.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an Internet Protocol (IP) capable of data transmission based on the Internet protocol.
otocol) A communication control device for relaying data transmission between a network and an IEEE 1394 serial bus based on the IEEE 1349 standard. For example, multimedia data such as video data is transmitted over a wide area network (WAN: Wi-Fi).
The present invention relates to a communication control device used in a video distribution system or the like for distributing using a de Area Network.

[0002]

2. Description of the Related Art FIG. 10 shows a wide area network (WAN).
1 shows an example of a video distribution system using an ATM (Asynchronous Transfer Mode) network. In this video distribution system, an ATM connected to the ATM network 20
The terminal 21 is a video server that stores and outputs video data and the like. An IEEE 1394 terminal 22 connected by an IEEE 1394 serial bus is a video client for requesting video data and displaying video images. The ATM network 20 is connected to the ATM / IEEE 139.
It is connected via a 4 IP router (hereinafter simply referred to as “router”) 23.

FIG. 10 shows an ATM terminal 21 and an ATM / I.
The IP addresses assigned to the IEEE 1394 router 23 and the IEEE 1394 terminal 22 are shown. A
TM terminal 21 and ATM / IEEE1394 IP router 2
And the IP address of the ATM network 3 is "19".
2.0.1.2 "and" 192.0.1.1 ", which belong to the same segment.
The IP address on the IEEE 1394 serial bus side of the IEEE 1394 IP router 23 and the IEEE 1394 terminal 22
The IP addresses of the respective IP addresses are "192.0.2.1"
And "192.0.2.2.2", which also belong to the same segment.

In this video distribution system, ATM
The exchange of packets between the terminal 21 and the IEEE 1394 terminal 22 is always performed via the ATM / IEEE 1394 IP router 23. ATM / IEEE1394I
The P router 23 temporarily terminates the communication on the ATM network side and the IEEE 1394 serial bus side, raises each packet to the IP layer, and performs IP routing in the IP layer, thereby performing the IP network and the IEEE 1394.
Packets are exchanged on the serial bus 24 side.

FIG. 11 shows an ATM terminal 21 and an ATM / IE.
EE1394IP router 23 and IEEE139
4 shows a protocol stack in the four terminals 22.

The protocol stack of the ATM terminal 21 is as follows:
Physical layer (hereinafter referred to as “PHY layer”), A
ATM layer handling TM cells, variable length (1 to 6553
ATM adaptation layer 5 (hereinafter referred to as "AAL5") handling data packets of 5 octets, IPover ATM layer handling IP packets, and IP (Interne
t Protocol) layer, TCP (Transmission Control Protocol)
l) It has a layer and an application layer of a video server. The ATM terminal 21 performs the following processing. 1. 1. Monitoring of connection requests issued by video clients to video servers Reading of video data from a storage device such as a hard disk, for example, a consumer digital VCR (Video Cassete
2. Read out DV (Digital Video) data defined by the Recorder) method (hereinafter referred to as “DV method”). 3. Conversion of DV data into TCP packets 4. Conversion from TCP packet to IP packet Send IP packet to video client

[0007] The protocol stack of the IEEE 1394 terminal 22 includes an IEEE 1394 PHY layer,
IEEE 1394 LINK layer, IPover that handles IP packets, IEEE 1394 layer, IP layer, TCP layer,
It has a video client application layer. The IEEE 1394 terminal 22 performs the following processing. 1. 1. Issuing a connection request to the video server 2. Receiving IP packet from video server 3. Conversion from IP packet to TCP packet 4. Conversion of TCP packet to DV data 5. Decoding of DV data into video signal Display of video images on a display device such as a CRT

[0008] ATM / IEEE1394 IP router 23
The ATM network side of the protocol stack of the PHY layer, the ATM layer, the AAL5 layer, and the IPoverA
It has a TM layer and an IP layer, and the IEEE 1394 serial bus side is an IEEE 1394 PHY
Layer, IEEE1394LINK layer, IPoverIEEE
It has an E1394 layer and an IP layer. ATM / I
The IP layer of the IEEE 1394 IP router 23 receives the received I
IP routing is performed based on the destination IP address information included in the P packet, and either the IPover ATM layer or the IPover IEEE 1394 layer is selected, and the received IP packet is output to the selected layer.

FIG. 12 shows a configuration of an IP packet output from the ATM terminal 21 as a video server. This IP packet has an IP header H_i indicating a destination IP address and the like.
Consists of p and data payload. IP header H_ip
The destination IP address is the video client I
"192. Allocated to EEE1394 terminal 22"
0.2.2 ", and the source IP address in the IP header is" 192.0.1.2 "which is its own address.
The data payload is DV data.

The IP packet shown in FIG.
0 through the ATM / IEEE 1394 IP router 23. In the IP layer, the ATM / IEEE1394 IP router 23 uses an IP header H shown in FIG.
_ip, the destination IP address “192.0.2.
2 ”and the predefined routing information as shown in FIG. 13, the IP packet of FIG.
It decides to route to the 394 serial bus side. As a result, the IP packet in FIG.
The signal is output to the IEEE 1394 layer and received by the IEEE 1394 terminal 22 via the IEEE 1394 serial bus 24. Thus, the IP packet transmitted by the ATM terminal 21 connected to the ATM network 20 is received by the IEEE 1394 terminal 22 connected to the IEEE 1394 serial bus 24.

As described above, the ATM terminal 21 functioning as a video server and the IEEE 1394 terminal 22 functioning as a video client perform communication using IP packets. Communication control between the ATM network 20 and the IEEE 1394 serial bus is controlled by the ATM / IEEE 1394 IP.
The router 23 is realized by performing IP routing, and the ATM / IEEE1394 IP router 23 functions as a communication control device.

As described above, in the IEEE 1394 terminal 21 and the ATM / IEEE 1394 IP router 23,
The protocol on the IEEE 1394 serial bus side is I
The implementation of the Over IEEE 1394 layer and the IP layer is required.

[0013]

SUMMARY OF THE INVENTION However, the IEEE
In a DV digital VCR currently available on the market as an E1394 terminal, the protocol stack has an IP
It does not have an over IEEE 1394 layer and an IP layer, and does not find such a direction. For this reason, DV
In order for the digital VCR to be compatible with the above-mentioned video distribution system, the IPover mounted on the VCR is required.
It is necessary to newly develop the IEEE 1394 layer and the IP layer. Moreover, compared to computers equipped with a high-speed CPU, such as personal computers (PCs) and workstations (WS), which are typical devices having an IP layer today, AV (Audio Vis
CPU) (Central P
The processing unit is relatively slow, and even if a new IP layer is developed for such a device, it is difficult to achieve the same performance as a PC or WS.

The video data distributed by the video server needs to be stored in advance in a so-called computer peripheral device such as a hard disk. However, video data is usually produced and produced by AV equipment such as digital VCRs.
Editing has been done. For this reason, video data produced and edited by an AV device such as a digital VCR must be finally transferred to a hard disk, which requires time for transfer.

The present invention has been made to solve such a problem, and has been developed to solve the above-mentioned problems.
It is an object of the present invention to provide a communication control device that enables a 394 terminal to communicate with an IP network.

[0016]

Means for Solving the Problems and Effects of the Invention A first aspect of the present invention relates to an interface for connecting to an IP network capable of data transmission based on the Internet protocol and an IEEE 11394 standard defined by the IEEE 1394 standard.
A communication control device having a 394 interface and relaying data transmission between the IP network and an IEEE 1394 serial bus based on the IEEE 1394 standard, wherein an isochronous channel defined by the IEEE 1394 standard is defined on the IP network. By referring to a first conversion table corresponding to an IP address to be converted and the first conversion table, the IEEE
A first converter for converting an isochronous packet received via the E1394 serial bus into an IP packet.

According to the first aspect, IEEE 139
An isochronous packet received by the communication control device via the 4 serial bus is converted into an IP packet by the communication control device. For this reason, an IEEE standard such as a DV digital VCR without an IP layer is used.
Even an E1394 terminal can transmit data using a WAN or LAN as an IP network by connecting to an IP network via the communication control device of the present invention. Also, when a video server is configured by AV equipment as an IEEE 1394 terminal,
The video data produced and edited by the AV device is
Since the data can be transmitted via the IP network (WAN or the like) via the communication control device of the present invention without being transferred to the hard disk, the video server can efficiently distribute the video data.

[0018] In a second aspect based on the first aspect, the IP network is a network capable of transmitting data based on a TCP / IP protocol, and the first conversion table is defined by the IEEE 1394 standard. Associating the isochronous channel with a combination of an IP address and a TCP port number defined on the IP network;
An isochronous packet received via a 1394 serial bus is converted into a TCP packet.

According to the second aspect of the present invention, one IEEE
Multiple IEEE13 connected to 1394 serial bus
By allocating a TCP port to the 94 terminals, those IEEE 1394 terminals can be identified by a combination of an IP address and a TCP port number, so that the number of IP addresses to be used can be reduced. Also,
By assigning an IP address to the server and assigning a TCP port number to each of the applications (services) provided by the server,
Server configuration (for example, what kind of video server is A
Service provided by the server can be used without being aware of whether or not the server is composed of V devices.

In a third aspect based on the first aspect, the first conversion means includes a buffer memory for storing the isochronous packet received via the IEEE 1394 serial bus, and stores the isochronous packet in the buffer memory. The read isochronous packet is read and converted into an IP packet.

According to the third aspect, the isochronous packet transmitted in synchronization with the predetermined cycle start packet is temporarily stored in the buffer memory when received by the communication control device. Transmission delays and jitters of ATM networks and the like are absorbed.

The fourth invention has an interface for connecting to an IP network capable of data transmission based on the Internet protocol and an IEEE 1394 interface defined by the IEEE 1394 standard, and the IP network and an IEEE 1394 standard based on the IEEE 1394 standard.
A communication control device for relaying data transmission to and from an IEEE 1394 serial bus, comprising: a second conversion table for associating an IP address defined on the IP network with an isochronous channel defined by the IEEE 1394 standard; By referring to the second conversion table, the IP address received via the IP network
And a second converter for converting the packet into an isochronous packet defined by the IEEE 1394 standard.

According to the fourth aspect, the IP packet received by the communication control device via the IP network is converted into an isochronous packet by the communication control device. For this reason, even an IEEE 1394 terminal such as a DV digital VCR in which the IP layer is not mounted is connected to the IP network via the communication control device of the present invention, so that it passes through the WAN or LAN as the IP network. Can receive the data sent.

In a fifth aspect based on the fourth aspect, the IP network is a network capable of data transmission based on a TCP / IP protocol, and the second conversion table is provided on the IP network. The combination of the defined IP address and TCP port number is
Corresponding to an isochronous channel defined by the IEEE 1394 standard, the second conversion means converts a TCP packet received via the IP network into an IEEE
It is characterized in that it is converted into an isochronous packet specified by the E1394 standard.

In a sixth aspect based on the fourth aspect, the second conversion means converts the IP packet into the isochronous packet and adds time information to a predetermined position in the isochronous packet, or And updating the time information at the predetermined position.

In a seventh aspect based on the sixth aspect, the second conversion means includes a buffer memory for storing the isochronous packet obtained by converting the IP packet, and an isochronous packet defined by the IEEE 1394 standard. At the timing based on the transfer, according to the number of isochronous packets stored in the buffer memory,
The isochronous packet is read from the buffer memory, counter information indicating the continuity of the isochronous packet transmitted to the IEEE 1394 serial bus is generated, and the counter information for the read isochronous packet is used as the time information. And counter generation means for adding or updating the isochronous packet.

According to the seventh aspect, appropriate counter information (time information) is set for the isochronous packet to be transmitted while considering the number of isochronous packets stored in the buffer memory. Properly convert isochronous packets converted from packets to IE
It can be transmitted to the EE1394 serial bus.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a communication control device according to an embodiment of the present invention will be described with reference to the drawings. <1. Video Distribution System Using Communication Control Device of Embodiment> FIG. 1 is a block diagram showing an example of a video distribution system using a router which is a communication control device according to an embodiment of the present invention. This video distribution system includes a first DV system digital VCR 12 and a first A
TM / IEEE1394 router 10, second DV system digital VCR 13, and second ATM / IEEE13
94 router 11. In this video distribution system, a first ATM / IEEE1394 router 1
0 and the first DV system digital VCR 12 are IEEE
They are mutually connected by a 1394 serial bus to form one subsystem, and this subsystem functions as a video server. The second ATM / IEEE 1394 router 11 and the second DV system digital VCR 13 are also IEEE
The EE1394 serial bus connects each other to form a subsystem, and this subsystem functions as a video client. And the first ATM
IEEE 1394 router 10 and second ATM / IEEE
The 1394 router 11 is connected to the ATM network 20 together. Note that the first ATM / IEEE1394 router 1
0 and the second ATM / IEEE 1394 router 11 belong to the same segment, and respectively belong to “192.0.1.
1 "and" 192.0.1.2 ".

FIG. 2 shows a protocol stack on the video server side and the video client side. A first DV system digital VCR on the server side (hereinafter referred to as “server side VC
R) 12 protocol stacks 212 are arranged in order from the lowest, the IEEE 1394 PHY layer and the IEEE 139 layer.
It has a 4 LINK layer and an application layer for generating video data. This application layer performs the following processing. 1. 1. Generation of DV data from tape recorded in DV format Conversion of DV data into isochronous packets. 3. Transmission of isochronous packet to isochronous channel number "10"

The protocol stack 213 of the second DV system digital VCR (hereinafter, referred to as “client VCR”) 13 on the video client side includes an IEEE 1394 PHY layer and an IEEE 1394 LI
It has an NK layer and an application layer for reproducing video data. This application layer performs the following processing. 1. 1. Reception of isochronous packet from isochronous channel number “20” 2. Conversion from isochronous packet to DV data 3. Decoding DV data to video signal Display of video images on a display device such as a CRT

First ATM / IEEE on video server side
1394 router (hereinafter referred to as “server-side router”) 10
The ATM network side of the protocol stack 210 of the PHY layer, the ATM layer, the AAL5 layer, and the IPov
erATM layer, an IP layer, and an IP / isochronous routing layer. The IEEE 1394 serial bus side includes an IEEE 1394 PHY layer, an IEEE
It has an E1394 LINK layer and an IP / isochronous routing layer. The IP / isochronous routing layer is one layer common to the ATM side and the IEEE 1394 side.

Second ATM I on Video Client Side
EEE1394 router (hereinafter "client-side router")
ATM among 11 protocol stacks 211
On the network side, the PHY layer, the ATM layer, and the AAL5
Layer, an IPover ATM layer, an IP layer, and an IP / isochronous routing layer. The IEEE 1394 serial bus side is, in order from the lowest, the IEEE 1394 PH.
It has a Y layer, an IEEE 1394 LINK layer, and an IP / isochronous routing layer. Also in the client-side router 11, the IP / isochronous routing layer is one layer common to the ATM side and the IEEE 1394 side.

FIG. 3 shows that the DV system digital VCR has the IE
Receive from IEEE1394 serial bus or IEEE13
4 shows the configuration of an isochronous packet transmitted to the 94 serial bus. This configuration is based on the IEC61883-1 standard. This isochronous packet
It is composed of a 64-bit isochronous header H_iso indicating an isochronous channel number and the like, a 64-bit CIP header H_cip indicating a DBC counter and the like indicating the continuity of isochronous packets, and DV video data Ddv as a data payload. .

<2. Configuration and Operation of Embodiment>
The server-side router 10 and the client-side router 11 according to the embodiment of the present invention will be described in detail.

Both the server-side router 10 and the client-side router 11 have a hardware configuration as shown in FIG. That is, these routers
0, an IEEE 1394 controller 60, an ATM controller 70, a CPU 52, and a memory 54 are connected. The IEEE 1394 controller 60 implements an IEEE 1394 interface, and implements an IEEE 1394 PHY layer.
It has a HY chip 61 and a LINK chip 62 for realizing an IEEE 1394 LINK layer. The ATM controller 70 implements an interface for connecting to the ATM network 20. Of the layers of the server-side router 10 and the client-side router 11, the layer that is not realized by the IEEE 1394 controller 60 and the ATM controller 70 is realized by the CPU 52 executing a predetermined program stored in the memory 54.

First, the first ATM which is a server-side router
-The IEEE 1394 router 10 will be described. The server-side router 10 receives an isochronous packet as transmission data transmitted from the server-side VCR 12 to the client-side VCR 13 over the IEEE 1394 serial bus. The isochronous packet received by the server-side router 10 is passed to the IP / isochronous routing layer via the IEEE 1394 PHY layer and the IEEE 1394 LINK layer.

FIG. 5 shows an example of the IP address in the server side router 10.
/ IEEE139 among isochronous routing layers
4 A part that implements a relay function of data transmission from a serial bus to an ATM network as an IP network (hereinafter referred to as “first
FIG. 3 is a block diagram illustrating a configuration of a relay unit). IP
The first relay unit in the / isochronous routing layer includes an isochronous packet receiving unit 80, a buffer memory 81, a first converting unit 83, and a first table 8
2 is provided.

When the isochronous packet is IEEE 139
When the data is passed from the 4LINK layer to the IP / isochronous routing layer having the above configuration, the isochronous receiving unit 80 receives the isochronous packet.

In the IEEE 1394 serial bus,
As shown in FIG. 6, the isochronous packet is transmitted in synchronization with an 8 kHz cycle start packet Pst output from the cycle master. Therefore, ATM network 2
The isochronous packet received by the isochronous packet receiving unit 80 is temporarily stored in the buffer memory 81 in order to absorb the transmission delay and jitter on the 0 side.

The first conversion unit 83 includes a buffer memory 81
The isochronous packet stored in the isochronous packet is extracted from the isochronous packet described in the isochronous header H_iso of the isochronous packet.
Referring to the channel and the first conversion table 82, the isochronous packet is converted into a packet in the IP packet format (IP packet). Here, the isochronous packet has a configuration as shown in FIG.
Conversion table 82 associates isochronous channel numbers with IP addresses. Now, the isochronous packet number “10” is described in the isochronous header H_iso of the isochronous packet extracted from the buffer memory 81, and the isochronous channel number is determined by the first conversion table 82 as shown in FIG. “10” and the IP address “192.0.1.
Assuming that “2” is associated with the first conversion unit 83, the first conversion unit 83 first refers to the first conversion table 82 to determine the isochronous channel number “10” written in the isochronous header H_iso. Is described in the first conversion table. Next, the isochronous header H_iso is removed, and the transmission destination IP address is set to the I
The first ATM / IEEE1 which is the P-address "192. 0.1.2" and the source IP address is the server-side router
394 router 10 itself's IP address "192.0.
By adding an IP header H_ip of 1.1 ", the isochronous packet extracted from the buffer memory 81 is converted into an IP packet. This IP packet is passed to the IPover ATM layer via the IP layer.

Thereafter, the IP packet is
The data is transmitted from the server-side router 10 to the ATM network 20 via the rATM layer, the AAL5 layer, the ATM layer, and the PHY layer.

In this manner, the server-side VCR 12 (the first DV system digital VCR 12) is
The isochronous packet output using the isochronous channel number "10" to the four serial buses has a destination IP address of "192. 0.1.2" and a source IP address of "192. 0.1.1". "Is the IP
The packet is converted into a packet and transmitted to the ATM network 20.

Next, the second ATM / IEEE 1394 router 11, which is a client-side router, will be described. When the IP packet, which is transmission data addressed to the client-side VCR 13, is sent to the ATM network 20, the IP packet is first sent to the client-side router 11 by the ATM network 20. When this IP packet is received by the client-side router 11, the IP packet is transmitted to the PHY layer, the ATM layer, and the AAL in the client-side router 11.
5 layers, IPover ATM layer, and IP
/ Is passed to the isochronous routing layer.

FIG. 8 shows a portion of the IP / isochronous routing layer of the client-side router 11 that implements a function of relaying data transmission from the ATM network 20 as an IP network to the IEEE 1394 serial bus (hereinafter referred to as a "second relay unit"). FIG. 2 is a block diagram showing the configuration of FIG. The second relay unit in the IP / isochronous routing layer includes a second conversion table 100, a second conversion unit 101, a buffer memory 102, and a counter generation unit 103.

When an IP packet addressed to the client-side VCR 13 is passed from the IPover ATM layer to the IP / isochronous routing layer via the IP layer, first, the second converter 101 writes the IP header H_ip in the IP packet. Source IP address and second
With reference to the conversion table 100, the IP packet is converted into an isochronous packet. Where IP
The packet has a configuration as shown in FIG. 12, and the second conversion table 100 associates an IP address with an isochronous channel number. Now, in the IP header H_ip, “192.0.
1.1 ", and the second as shown in FIG. 7 (b).
Of the IP address “192.
0.1.1 "and isochronous channel number" 20 "
Are associated with each other, the second conversion unit 1
01, first, by referring to the second conversion table 100, the source IP address written in the IP header H_ip
It is confirmed that the address “192.0.1.1” is described in the second conversion table 100. Next, I
By removing the P header H_ip and adding an isochronous header describing the isochronous channel number “20” associated with the IP address “192.0.1.1”, the IP address received from the lower layer is removed.
Convert a packet to an isochronous packet.

In the IEEE 1394 serial bus,
As shown in FIG. 6, the isochronous packet is transmitted in synchronization with an 8 kHz cycle start packet Pst output from the cycle master. Therefore, ATM network 2
The isochronous packet output from the second converter 101 is temporarily stored in the buffer memory 102 in order to absorb transmission delay, jitter, and the like on the 0 side.

The counter generator 103 reads the isochronous packets from the buffer memory 102 in units of packets according to the output timing of the isochronous packets shown in FIG. At this time, the counter generation unit 103
Reads a packet so that the buffer memory 102 does not become empty. That is, when the number of remaining packets in the buffer memory 102 is 1, the read start address is held after reading one packet, and when the number of remaining packets in the buffer memory 102 is 2 or more, reading starts after reading one packet. Change the address to the next packet start position. As a result of such processing, the counter of the DBC section in the CIP header H_cip shown in FIG. 3 may be discontinuous. In consideration of this point, the counter generation unit 103 generates counter information indicating a counter value to be set in the DBC unit, and based on the counter information, newly generates the DBC unit of the packet extracted from the buffer memory 102. And outputs an isochronous packet having a continuous DBC counter value.

The isochronous packet output from the IP / isochronous routing layer is based on the IEEE
Via the 1394 LINK layer and the IEEE 1394 PHY layer, the client side router 11 sends the IEEE 1394
Transmitted to the serial bus.

As described above, the IP packet received by the client-side router 11 from the ATM network 20 and whose source IP address is “192.0.1.1”
Packet, ie I sent from video server
The P packet has the isochronous channel number “20”
Is converted to an isochronous packet of IEEE13
It is sent to the 94 serial bus. Client-side VCR
The second DV system digital VCR 13 receives an isochronous packet of the isochronous channel number “20”, decodes the DV data in the packet, obtains a video signal, and reproduces a video image. Here, the video signal obtained by the decoding is the first DV digital VCR 12 which is the server side VCR.
Is the video signal output.

In the above, the video distribution system has been described focusing on the configuration and operation of the server-side router 10 and the client-side router 11 when transmitting data from the server-side VCR 12 to the client-side VCR 13. However, even when data is transmitted from the client side VCR 13 to the server side VCR 12, the same operation is performed by the same configuration. In other words, the client-side router 11 transmits an I / O signal from the IEEE 1394 serial bus to the IP / isochronous routing layer.
As a configuration of a portion for realizing a function of relaying data transmission to the ATM network 20 as a P network, the configuration is the same as the configuration of the first relay unit of the IP / isochronous routing layer in the server-side router 10 (FIG. 5). The server-side router 10 includes a portion of the IP / isochronous routing layer that realizes a function of relaying data transmission from the ATM network 20 as an IP network to the IEEE 1394 serial bus. It has the same configuration as the configuration of the second relay unit in the routing layer (see FIG. 8). Therefore, the client side VC
When data is transmitted from the R13 to the server-side VCR 12, the transmitted data is received by the client-side router 11 via the IEEE1394 serial bus,
In the IP / isochronous routing layer of the client-side router 11, the same operation as the operation of the first relay unit in the IP / isochronous routing layer of the server-side router 10 is performed. Then, the transmission data is sent from the client-side router 11 to the ATM network 20 and the AT
The data is received by the server-side router 10 via the M network 20. In the IP / isochronous routing layer of the server-side router 10, the same operation as the operation of the second relay unit in the IP / isochronous routing layer of the client-side router 11 is performed.

<3. Effects of Embodiment> According to the above-described embodiment, in the IP / isochronous routing layer of the server-side router 10 and the client-side router 11, the association between the IP packet and the isochronous packet and the conversion of the packet format are performed. By doing so, even if the device does not have an IP layer, such as a DV digital VCR as an IEEE 1394 terminal, the AT
Video data distribution via a wide area network such as an M network can be performed. In addition, a DV digital VCR as an IEEE 1394 terminal can directly read video data from a VCR tape and distribute it without transferring the video data to a hard disk or the like. Also, by updating the counter information in the isochronous header in the router on the receiving side, video distribution between a network such as a wide area network where transmission time is not guaranteed and an IEEE 1394 device requiring continuous counter information is possible. Becomes

<4. Modification> In the above embodiment, the IP address and the isochronous channel correspond in the first and second conversion tables 82 and 100 which are referred to when converting the packet format between the IP packet and the isochronous packet. However, this association need not be fixed. For example, on the client side, the user specifies the VCR 12 on the server side by the IP address and
When establishing a connection with the CR 12, the server-side router 10 searches for a free isochronous channel and assigns one of the free isochronous channels to the IP address. The association with the channel may be dynamically performed.

In the above embodiment, when the packet format is converted between the IP packet and the isochronous packet, the IP address is associated with the isochronous channel. Instead, the isochronous channel and the TCP port are associated with each other. May be associated with each other. For example, as shown in FIG. 9A, the server router 110 that relays an ATM network as an IP network and an IEEE 1394 serial bus has an IP address “192.
0.1.1 "and a plurality of AVs connected to the server-side router 110 via an IEEE 1394 serial bus.
Set the device to its IP address “192.0.1.1” and TC
It is identified by the combination with the P port number,
An isochronous channel number is associated with a TCP port number assigned to each AV device. In this case, for example, as shown in FIG. 9B, the combination of the IP address “192.0.1.1” and the TCP port number “100” is the isochronous channel number “20” according to the second conversion table. Is associated with. Also, in this case,
ATM in server-side and client-side routers
The protocol stack on the network side has a TCP layer, and TCP / IP between the server side router and the client side router.
Data transmission is performed based on this protocol. further,
In this case, the first converter 83 converts the isochronous packet into a TCP packet instead of converting it into an IP packet, and the second converter 101 converts a TCP packet, not an IP packet, into an isochronous packet. Will be. By using a TCP port with such a configuration, the number of IP addresses to be used can be reduced. In the above description, a case is described in which a plurality of AV devices as IEEE 1394 terminals are connected to the server-side router, but the same applies to a case where a plurality of IEEE 1394 terminals (AV devices) are connected to the client-side router. That is, an IP address is assigned to the client-side server, and a plurality of IEEE 1394 terminals connected to the client-side server have T
A CP port may be assigned.

Also, the server-side router 110 is provided with the IEEE1
Instead of assigning a TCP port number to each AV device connected in 394, a TCP port number may be assigned to each application provided by the AV device. In this case, for example, as shown in FIG. 9C, when two applications (two services) can be provided to a client by one AV device, two TCP port numbers are assigned to the AV device. Will be assigned. Further, a search application for knowing what kind of AV equipment is connected to the server-side router 110 may be operated in the router, and one TCP port may be assigned to the search application. . According to such a configuration, the IEEE 1394 is provided from outside the subsystem constituting the server.
The application (service) provided by the server can be identified and used by the TCP port number without being conscious of the device configuration of the server connected by the serial bus. For this reason, the service provided by the server becomes easy to use.

The UDP (User Datagram) is used in place of TCP, which is the protocol used in the above modification.
Protocol), and a UDP port may be assigned to each AV device or each application (service) provided by the AV device instead of the TCP port. In this case, the protocol stack on the ATM network side in the routers on the server side and the client side has a UDP layer at the same position as the TCP layer, and data is transmitted between the server side router and the client side router based on the UDP / IP protocol. Is performed. Since UDP does not support packet retransmission processing in TCP and the like, such a configuration reduces processing for communication.

Further, in the above embodiment, the network connecting the server side and the client side via the routers 10 and 11 is an ATM network as a wide area network (WAN).
Any network that can transmit data by the Internet protocol, that is, an IP network may be used.
It is not limited to a TM network, nor is it limited to a wide area network. Therefore, a LAN (L) capable of transmitting data between the server side and the client side by the Internet protocol via the communication control device (router) according to the present invention.
ocal Area Network), for example, an Ethernet (Ethernet) connection. In that case, a similar effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a video distribution system using a router as a communication control device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a protocol stack in each device constituting the video distribution system.

FIG. 3 is a diagram showing a configuration of an isochronous packet.

FIG. 4 is a diagram showing a hardware configuration of a router which is a communication control device of the embodiment.

FIG. 5 is a block diagram showing a configuration of a portion (first relay unit) of the router of the embodiment that realizes a relay function from the IEEE 1394 serial bus to the ATM network in the IP / isochronous routing layer.

FIG. 6 is a conceptual diagram of isochronous packet transmission.

FIG. 7 is a conceptual diagram of a conversion table for associating an IP address with an isochronous channel.

FIG. 8 illustrates an example in which the IP / isochronous routing layer in the router according to the embodiment is switched from an ATM network to an IEEE 13;
FIG. 9 is a block diagram showing a configuration of a part (second relay unit) that realizes a relay function to a 94 serial bus.

FIG. 9 is a diagram showing TCP port number assignment in a modification of the embodiment.

FIG. 10 is a block diagram showing a configuration of a conventional video distribution system.

FIG. 11 is a diagram showing a protocol stack in each device of the conventional video distribution system.

FIG. 12 is a diagram showing a configuration of an IP packet.

FIG. 13 is a diagram showing IP routing information.

[Explanation of symbols]

10 first ATM / IEEE1394 router (server side router) 11 second ATM / IEEE1394 router (client side router) 12 first DV system digital VCR (server side VCR) 13 second DV system digital VCR (client-side VCR) 20 ATM network 80 Isochronous packet receiving unit 81 Buffer memory 82 First conversion table 83 First conversion unit 100 Second conversion table 101 Second conversion unit 102 ... Buffer memory 103 ... Counter generation unit

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Claims (7)

[Claims] 1. An interface for connecting to an IP network capable of data transmission based on the Internet protocol and an IEEE standard defined by the IEEE 1394 standard.
An IEEE 1394 interface based on the IEEE 1394 standard, having an IEEE 1394 interface;
A first conversion table for associating an isochronous channel defined by the IEEE 1394 standard with an IP address defined on the IP network; By referring to the first conversion table, the I
A first conversion unit for converting an isochronous packet received via an IEEE 1394 serial bus into an IP packet. 2. The method according to claim 1, wherein the IP network is TCP / IP.
The first conversion table converts an isochronous channel defined by the IEEE 1394 standard into a combination of an IP address and a TCP port number defined on the IP network. 2. The method according to claim 1, wherein the first converter converts the isochronous packet received via the IEEE 1394 serial bus into a TCP packet.
The communication control device according to item 1. 3. The first conversion means includes a buffer memory for storing isochronous packets received via the IEEE 1394 serial bus, and reads an isochronous packet stored in the buffer memory to read an IP packet. The communication control device according to claim 1, wherein the communication control device converts the communication control device into a communication device. 4. An interface for connecting to an IP network capable of data transmission based on an Internet protocol, and an IEEE standard defined by the IEEE 1394 standard.
An E1394 interface, the IP network and an IEEE 1394 based on the IEEE 1394 standard
A communication control device for relaying data transmission to and from a serial bus, comprising: an IP address defined on the IP network;
By referring to a second conversion table corresponding to an isochronous channel defined by the EEE1394 standard and the second conversion table,
IP packets received via the P network
A second conversion unit that converts the packet into an isochronous packet defined by the EEE1394 standard. 5. The method according to claim 1, wherein the IP network is TCP / IP.
The second conversion table converts a combination of an IP address and a TCP port number defined on the IP network to an isochronous channel defined by the IEEE 1394 standard. The communication control according to claim 4, wherein the second conversion unit converts a TCP packet received via the IP network into an isochronous packet defined by the IEEE 1394 standard. apparatus. 6. The second conversion means converts the IP packet into the isochronous packet and adds time information to a predetermined position in the isochronous packet, or updates time information at the predetermined position. The communication control device according to claim 4, wherein: 7. A buffer memory for storing the isochronous packet obtained by converting the IP packet, wherein the second conversion means stores the isochronous packet in the buffer memory at a timing based on isochronous transfer defined by IEEE 1394 standard. According to the number of stored isochronous packets, the isochronous packets are read from the buffer memory, and counter information indicating the continuity of the isochronous packets transmitted to the IEEE 1394 serial bus is generated and read. 7. A counter generating means for adding or updating the isochronous packet to the isochronous packet using the counter information for the isochronous packet as the time information.
The communication control device according to item 1.