JPH0888654A - Path information transmission method for router and data communication system - Google Patents

Abstract

PURPOSE: To set path information to the router without mistake by learning the path information of other routers without setting all required path information for relaying to the router. CONSTITUTION: In the transmission method of path information for the router connected to a network 1 having a terminal equipment 11 and to other router B via an ISDN channel network and communicating the path information possessed by the router B with the network, the router A connects a channel to the other router B based on an ISDN line network address in a 1st table with respect to a path information request from the terminal equipment 11 and fetches, learns and stores the path information possessed by the other router B and sends the path information to the network 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a route information transmission method and a data communication system of a connection device such as a router device (hereinafter, referred to as “router”) that communicates route information between networks such as AN.

[0002]

2. Description of the Related Art Conventionally, this type of router is connected to a wide area network (hereinafter referred to as "wide area network") such as a public network or an ISDN network which is charged in proportion to the connection time or the amount of data. And when actually performing data communication between LANs,
The line is connected to the router of the communication partner, and when there is no data to be communicated, call control is performed to disconnect the line.

The call control function of the router has the following two types of functions. That is, in the first call control function, when the router receives data to be relayed (hereinafter referred to as “relay data”) from the terminal device connected to the LAN, the router connects the line with the communication partner router, and When no relay data was generated for a certain period of time, the router cut the line. In this call control function, the router has route information necessary for relaying in advance (hereinafter referred to as "route information").
Therefore, the route information is statically set or the route information is dynamically learned.

In the second call control function, the router originates / disconnects a call according to a call control command from a terminal device that transmits data.

[0005]

However, when the route information is statically set, it is necessary to set the above route information for all the connectable routers when the device is installed or the system is changed, and the setting operation is performed. However, there is a problem that the setting becomes complicated and the setting may be mistaken. In addition, when learning route information dynamically, it is necessary to artificially connect to all connectable routers when installing a device or changing the system, which makes the connection operation complicated. There was a point. Further, the second call control function has a problem in that the router needs a communication protocol for instructing calling / disconnection.

Further, although a fictitious network created for call control is assigned a network number that is not used, the administrator must set it in order to prevent the network number from becoming inconsistent. There is a problem that the operation is complicated and takes time. Further, there is a similar problem when changing the network number once assigned.

The present invention has been made in view of the above-mentioned problems, and it is possible to learn the route information of another connecting device without setting all the route information necessary for relaying in the connecting device. The purpose is to provide a method. Another object of the present invention is to provide a data communication system capable of automatically and easily allocating a fictitious network.

[0008]

In order to achieve the above object, according to the present invention, at least one other connection device (router) connected to a network having at least one terminal device and connected to another network. ) Via a wide area network, and in a route information transmission method of a connecting device for communicating route information between networks held by each of the routers, connection information for connecting to the other router via the wide area network. When a request for information (for example, information such as zone, service, name, etc.) about the network held by the other predetermined router is acquired from the terminal device, based on the connection information, the predetermined router and the wide area network. Via a connection process and a holding process for capturing and holding the route information transmitted from the predetermined router. Information transmission method is provided.

The route information transmitting method according to a second aspect includes a transmitting step of transmitting the route information taken in from a predetermined router to a network to which the router taking in the route information is connected. According to the route information transmission method of claim 3,
Call control information such as a call control zone is defined in each connection device, and upon receipt of the call control information, the line network is connected to communicate the route information.

According to the present invention, in the data communication system in which the connection devices respectively connected to the respective networks are connected via the line network, the connection devices are provided in the system when the call control information is created. There is provided a data communication system in which a network number which does not exist in the network is searched from the route information which the user has and is assigned to a predetermined network.

In the data communication system according to a fifth aspect, the connection device can change the network number that does not exist in the system when the same network number is separately assigned to a plurality of networks. Assign to network. In the data communication system according to claim 6, when the information peculiar to the network changes, the connection device changes to a network number that does not exist in the system and transmits the changed information to another network. .

[0012]

[Function] In response to the route information request from the terminal device, the line is connected to the corresponding router, and the route information corresponding to the above request is fetched and held from the requesting router, so that it can be used as a relay when the device is installed Without setting all the necessary route information, the connection information is used to connect the call to the other router to learn the route information without error, and the line is connected according to the above route information and relayed from the terminal device. Data can be sent to the destination network.

According to the route information transmitting method of claim 2,
Since the route information fetched from the predetermined router is transmitted to the network to which the terminal device is connected, for example, when another router is connected to the network, the other router also learns the route information. You can Further, in the route information transmitting method according to claim 3, when connecting to another network, a packet including a call control zone is generated, and the predetermined router connects the corresponding router to the line upon receiving the packet. Therefore, all route information necessary for relay can be learned and supplied to the network.

In the data communication system according to the fourth and seventh aspects, a temporary network number that does not exist in the system is retrieved from the route information and automatically assigned to the network. In the data communication system according to claim 5, if the same network number is assigned by duplication, a temporary network number that does not exist in the system is automatically assigned to one of the networks assigned by duplication. Allocate.

In the data communication system according to the sixth aspect, when the information peculiar to the network changes, the assigned network number is automatically changed and the changed information is transmitted to another network.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A route information transmission method for a connection device and a data communication system according to the present invention will be described with reference to the drawings of FIGS. FIG. 1 is a block diagram showing the configuration of a data communication system using the route information transmission method of the present invention.
In this embodiment, a plurality of routers A to C are connected via the ISDN network 10.

In the figure, a network 1 is composed of routers A and D, a terminal device 11, and a transmission line 12 to which the routers A, D and the terminal device 11 are connected. The network 2 includes a router D and a terminal device 13.
And a transmission line 14 to which the router D and the terminal device 13 are connected. The network 3 includes a router B, a terminal device 15, and a transmission line 16 to which the router B and the terminal device 15 are connected. The network 4 is composed of routers C and E and a transmission line 17 to which the routers C and E are connected. The network 5 is composed of a router E and a transmission line 18 to which the router E is connected.

The networks 1 and 2, the network 3, and the networks 4 and 5 construct LANs. Each terminal device 11, 13, 15 performs packet data communication by a predetermined communication protocol, for example, AppleTalk transaction protocol (hereinafter referred to as “ATP”), and connects to a network having no route information. In case of ATP as shown in FIG.
Get Zone List, which is a type of packet
t) packet to the router A, which is in the same LAN as the device itself.
It is sent to D and B to request the route information. When each terminal device receives a get zone list reply of FIG. 6 described later from a router in the same LAN as its own device, each terminal device includes an NBP (name, name Binding Protocol) packet to the router.

The packet of the get zone list shown in FIG. 2 includes a data link header indicating a physical protocol used (Ethernet in the embodiment), a DDP header indicating a packet forwarding process used in the router,
It is composed of an ATP header. The ATP header is of the ATP type (in the embodiment, the request “0100
TReq indicating "0000"), a bitmap indicating the number of responses to be received (fixed value "00000001" in the embodiment), and a TID indicating the ATP type identifier.
And a function indicating the type of packet using ATP (get zone list in the embodiment), and “0000
0000 "and a start index for storing the first index of the requested zone.

In the NBP packet shown in FIG. 3, the data link header, the DDP header, the function indicating the NBP type (request “1” in the embodiment), and the number of tuples in the NBP packet (implementation) In the example, it is composed of a tapple counter indicating “1”), an NBPID indicating an NBP type identifier, and an NBP tuple. The NBP tuple includes a network number indicating a network address of a transmission source terminal device, a node ID indicating a node identifier of the transmission source terminal device, a socket number indicating a socket number of the transmission source terminal device, and a tuple present in a packet. , An object field length indicating the number of characters of the object of the terminal device to be searched (for example, if the terminal device is a printer, the number of characters is "4"), and an object name of the terminal device to be searched. An object, a type that indicates the type of terminal device to be searched (for example, print, which is the service name of the terminal device), and a zone that indicates the number of characters in the zone to be searched (for example, if the zone is each region name, the number of characters in that region name) It is composed of a field length and a zone indicating a zone name to be searched.

Router A, as shown in FIG.
Information on a target index indicating a router (router B, C in the embodiment) of a connection partner for connecting a line via the line network 10 and address information of the ISDN line network set corresponding to the target index (example) Has a first table in which "100", "200", ..., For example, telephone number information) are stored. Further, the router A has information of a zone list as shown in FIG. 5, which is necessary for relaying data from the transmission source terminal device, such as a preset area or area for constructing the LAN. Information (each router that is a target index is shown in the embodiment) and a temporary network number of a network existing in the zone (in the embodiment,
And a second table in which the networks 1, 2, 3, 4, and 5 (provisional network numbers) are stored. The information of the target index shown in FIG. 4 is the same as the information of the zone list shown in FIG. Also, routers B and C
Also has a first table and a second table, respectively.

The routers A to C transmit and receive route information and relay data based on the information in the first and second tables. The routers A to C have the same LA as their own devices.
When the packet of the above-mentioned get zone list is received from the terminal device in N, Get Zone List Reply (Get Zone List Replay) which is a kind of ATP packet as shown in FIG.
ply) packet is transmitted to the terminal device. When the routers A to C receive the NBP packet from the terminal device, the routers A to C search for the corresponding target index (router) from the zone in the NBP packet, and the ISD
The line is connected to the router of the transmission partner based on the address of the N line network. Then, the router receives the route information from the destination router and learns its contents,
Send to a network within the same LAN.

The packet of the get zone list reply shown in FIG. 6 includes the data link header and the DDP.
Header and ATP type (response “1 in the embodiment
00100000 ”), a sequential number (“ 00000000 ”in the embodiment), the TID, a LastFlag indicating whether the packet is the last packet of the get zone list reply, a field area of“ 00000000 ”, and The number of zones indicating the number of zones in the packet, the length of the zone name indicating the length of the zone name of each index in the packet consisting of the above number of zones, and the zone name indicating the zone name of each of these indexes. It is composed of the name and.

The router D is a router for relaying data of various packets between the networks 1 and 2, and the router E
Is a router for relaying data of various packets between the networks 4 and 5, each having the table shown in FIG. Further, when the router D receives the route information from the router A, the router D learns the content of the route information, and the router E determines the router C.
When the route information is input from, the contents are learned.

Next, an operation of transmitting route information in the data communication system shown in FIG. 1 will be described. In addition,
Here, it is assumed that the terminal device 11 requests the route information and transmits the route information between the routers A and B. First, the terminal device 11 transmits a get zone list packet (see FIG. 2) to the router A via the transmission line 12 in order to request the AppleTalk zone list.

When the router A receives the get zone list packet, it responds to the request for the zone list.
The target index (router B, router C, ...) Of the first table shown in FIG. 4 as the call control zone is included in the packet of the get zone list reply (see FIG. 6) and transmitted to the terminal device 11. Upon receiving the get zone list reply packet, the terminal device 11 recognizes the target index for call control as one of the zones. When the terminal device 11 performs data communication with the terminal device 15 of the network 3, the call control zone in the NBP packet is set as the router B and the NBP is used.
Send the packet to Router A.

Next, when the router A receives the NBP packet, the router A sends the first NBP packet according to the zone in the NBP packet.
Then, the address of the ISDN line network corresponding to the router B is searched from the table of (1) to connect the line to the router B. Then, after the ISDN line connection, the router A makes a request for route information to the router B. On the other hand, the router B composes the route information (network address information, zone information) held in its own device into a packet and sends it to the router A. When the information is received, the content is learned and transmitted to the network 1 in the same LAN. The route information includes a set network number, gateway address, zone information, and the like. This route information is taken in by the router D that relays data between networks, and the router D learns its contents. , Got new network address information and zone information.

Therefore, in this embodiment, the address information of the ISDN line network for call control is set in the router connected to the wide area network for each partner router connected via the wide area network, and the address information of the ISDN line network for call control is set in the LAN. The terminal device transmits a request for route information held by the partner router to the call control router, and transmits the route information between the call control router and the partner router. There is no need to set all the necessary route information for the ISDN
By using the address information of the line network, the call can be connected and the route information can be learned without error. As a result, the call control router connects the line according to the learned route information,
The data to be relayed from the terminal device can be transmitted to the destination network.

Further, in this embodiment, the router sends the route information fetched from the partner router to the network. Therefore, when another router is connected to the network, the route information sent is transmitted. It can be received and the contents of the route information can be learned. Next, a system in which a router automatically assigns a temporary network number for call control will be described.

FIG. 7 is a block diagram showing another configuration of the data communication system according to the present invention. In the figure, a data communication system uses a LAN-to-LAN connecting device (hereinafter referred to as "remote router") A to C and F to carry out packet data communication by an ATP method at a remote LAN.
Are connected via the ISDN line network 10. The remote routers A to C and F have the index list shown in FIG. 8 and the call control table shown in FIG. In addition,
Since the index list of each remote router and the call control table have the same structure, the remote router A is used here.
The case will be described.

The index list has a structure similar to that of the first table (see FIG. 4), and information of target indexes indicating remote routers (for example, remote routers B, C, F, ...) To be connected, and the above-mentioned index list. Address information of the ISDN line network set corresponding to the target index (for example, "03-BBB", "03-CC").
"C", "03-FFF", ..., For example, telephone number information)
I remember and.

The call control table has the same configuration as the second table (see FIG. 5) and has a temporary network number (in the embodiment, the temporary network number x) of the network existing in the zone. Information on a zone list corresponding to the temporary network number (for example, each remote router as a target index) is stored. In the call control table of this embodiment, all the remote routers B, C, F, ... In the system are used as the information of the zone list corresponding to one temporary network number x. Not limited to this, for example, it is possible to divide remote routers into groups for each region and set a temporary network number for each group, or set a temporary network number for each remote router.

In addition to the above, the remote router is
It also has a routing table as shown in FIG. Here again, the case of the remote router A will be described. The routing table has network numbers existing in the system (in the embodiment, networks 1 and 3).
And the address of the relay router (in the embodiment, “0” for the network 1 and the address of the remote router B for the network 3) for relaying, the LAN side or I
Interface that indicates SDN side (LAN for network 1 and ISDN for network 3)
And the number of hops indicating the number of relay routers (“0” for the network 1 and “1” for the network 3 in the embodiment).

Next, according to the flow chart of FIG.
A tentative network number allocation operation for call control by the remote router A will be described. First, the remote router A acquires a random value (x) when generating a temporary network number for call control after activation (step 101). Note that this acquisition is performed using, for example, a random number table. Then, it is judged whether or not this x is already registered in the routing table of FIG. 10 (step 102).

Here, when the above x is included in the range of the network number of the route information registered in the routing table, the process returns to step 101, a random value is again obtained, and the above operation is repeated. When the above x is not included in the range of the network number of the route information registered in the routing table, the above x is assigned as the network number in the call control table as shown in FIG. 10
3), as shown in FIG. 10, it is also registered in the routing table (step 104). In the routing table, “0” is registered in the address, interface, and hop count of the relay router corresponding to the network number x so that the registered network number is a tentative network number.

Therefore, in this embodiment, a network number is randomly acquired and a network number that does not exist in the system is assigned to the call control table as a temporary network number. In a network in which any number can be assigned, a network number that does not exist in the system in the entire network is always automatically assigned, and the need for the network administrator to set it can be omitted.

In the present embodiment, all remote routers B, C, F, ... In the system are assigned to the call control table as zone list information corresponding to one temporary network number x. Therefore, the network number to be assigned is minimized, and thus the route information registered in the routing table can be reduced. Next, FIG.
A temporary network number allocation operation when the remote router A receives new route information will be described with reference to the flowchart of FIG.

First, as shown in FIG. 13, the remote router A receives new route information through the connection of the new network x via the local router D, the line connection of the ISDN 10, etc. (step 201). Since the local router D is a router that does not have the above-mentioned automatic network number assignment function, the name is different to distinguish it from the remote router.

Next, the remote router A determines whether the network number in the new route information n and the network number in the preset call control table overlap (step 202). If the network number in the route information n does not overlap with the network number in the call control table, the new route information is registered in its own routing table (step 203). When the network number x in the route information n and the network number x in the call control table overlap, information on the temporary network registered in the routing table (information on the temporary network number x ) Is deleted (step 204) and the newly received route information (in this case,
The route information including the information of the network number x of the new network) is registered in the routing table (step 205).

Thereafter, the remote router A proceeds to the temporary network generation routine for call control shown in FIG. 11 and executes the temporary network number assigning operation (step 206). The network number x in is a new temporary network number, for example, in FIG.
As shown in FIG. 4, the network number y is changed and assigned.

Therefore, in the present embodiment, a new temporary network number can be assigned and registered in the call control table as well as in the routing table. Therefore, the network number once assigned to the call control table can be registered. Even if you receive the route information of your network,
The router can newly register it as route information without discarding the received information and can always allocate a network number that does not actually exist in the entire system to the call control table.

Next, a case where the information peculiar to the network is changed will be described. In the call control table, in addition to the network number, call control information such as a zone list indicating an ISDN connection partner is allocated. However, these pieces of information are used when route information is transmitted to another network. It is transmitted in the same way, and the first set information remains unless the route information disappears once it is transmitted.
Therefore, if the route information does not change even if the ISDN line connection partner list is changed, the changed information will not be transmitted to another network.

Therefore, in this embodiment, as shown in FIG. 15, when the index list is changed (for example, the list of router B is deleted), remote router A
Retrieves the address of the router B from the address of the relay router in the routing table shown in FIG. 10 and deletes the corresponding route information (route information of the network 3 in FIG. 10). Next, the remote router A searches for a network number that does not exist in the changed routing table and automatically assigns a new network number, for example, the network number z as shown in FIG. 16, to change the zone list. Generate a call control table. Then, as the route information is changed, the remote router A transfers the changed route information to another network.

When transmitting the route information, it is preferable that the route information for the fictitious network is set in advance so as not to be transmitted. This is to reduce the amount of route information registered in the routing table of the transmission partner. Further, in the present embodiment, the case where the list of routers is deleted has been described, but when the list of routers is added, the call control table is automatically generated and new route information is transmitted in the same manner as above. it can.

Therefore, in this embodiment, when the list of routers is changed, a call control table is automatically generated and the changed route information is transmitted to another network.
In other networks, old route information and call control information can be deleted, and new route information and call control information can be automatically registered.

[0046]

As described above, according to the present invention, it is connected to a network having at least one terminal device and is connected to at least one other connecting device connected to another network via a wide area network. In the route information transmission method of a connection device for communicating the route information between networks held by each connection device, the connection information for connecting to the other connection device via the wide area network is held, and the terminal When a request for information about a network held by the other predetermined router is fetched from the device, a connection step of connecting to the predetermined router via the wide area network based on the connection information, and route information transmitted from the predetermined router. Since it includes a holding process of capturing and holding the other device, other connecting devices can be used without setting all the route information necessary for relaying in the connecting device. You can learn the route information.

In the route information transmitting method according to the second aspect, since the route information fetched from the predetermined router is transmitted to the network to which the own device is connected, another router connected to the network also learns the route information. You can
In the route information transmitting method according to claim 3, call control information such as a call control zone is defined in each connection device, and the line network is connected upon reception of the call control information to obtain the route information. Since communication is performed, all route information necessary for relay can be learned and supplied to the network.

In the data communication system according to claims 4 and 7, in a data communication system for performing data communication by connecting connecting devices respectively connected to respective networks via a line network, the connecting device is for call control. When creating information, a network number that does not exist in the system is searched from the route information and assigned to a predetermined network, so that a fictitious network can be assigned automatically and easily.

According to a fifth aspect of the data communication system, in the data communication system in which the connecting devices respectively connected to the respective networks are connected via a line network, the connecting devices have the same network number separately for a plurality of networks. When assigned, a network number that does not exist in the system is searched because a network number that does not exist in the system is searched and assigned to a network in which the network number can be changed and call control information is created. Numbers are always automatically assigned, eliminating the need for network administrators to set them.

In the data communication system according to claim 6, in the data communication system in which connecting devices respectively connected to the respective networks are connected via a network, the connecting device is connected to a network whose network number can be changed. When the unique information is changed, a network number that does not exist in the system is searched, the network number of the network is changed to the searched network number to create call control information, and the changed information is changed. Since the information is transmitted to another network, even if the information peculiar to the network is changed, the fictitious network can be automatically allocated and the changed information can be automatically transmitted to the other network.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a data communication system using a route information transmission method of the present invention.

2 is a configuration diagram showing a configuration of a packet of a get zone list communicated by the system of FIG.

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

4 is a configuration diagram showing a configuration of a first table of the router shown in FIG.

FIG. 5 is a configuration diagram showing a configuration of a second table of the same router.

6 is a diagram showing a configuration of a get zone list reply packet communicated by the system of FIG.

FIG. 7 is a block diagram showing another configuration of the data communication system according to the present invention.

FIG. 8 is a configuration diagram showing another configuration of the first table (index list).

FIG. 9 is a configuration diagram showing another configuration of a second table (call control table).

10 is a configuration diagram showing a configuration of a routing table of the router shown in FIG.

FIG. 11 is a flowchart for explaining a temporary network number allocation operation for call control by a remote router.

FIG. 12 is a flowchart for explaining a temporary network number allocation operation when the remote router receives new route information.

FIG. 13 is a block diagram showing still another configuration of the data communication system according to the present invention.

FIG. 14 is a configuration diagram showing a configuration of a call control table after changing a network number.

FIG. 15 is a configuration diagram showing a configuration of an index list after list modification.

FIG. 16 is a configuration diagram showing another configuration of the call control table after changing the network number.

[Explanation of symbols]

 1 to 5 network 10 ISDN line network 11, 13, 15 terminal device 12, 14, 16 to 18 transmission line A to F router

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04L 12/56 9466-5K H04L 11/20 102 Z

Claims (8)

[Claims] 1. A network which is connected to a network having at least one terminal device and is connected to at least one other connection device connected to another network via a line network and which is held by each connection device. In a route information transmission method of a connection device for communicating route information between devices, holding connection information for connecting with the other connection device via the line network, and held by the other predetermined connection device from the terminal device. A request for information regarding a network to be connected, a connection step of connecting to the predetermined connection device via the line network based on the connection information, and a holding step of acquiring and holding route information transmitted from the predetermined connection device. A route information transmission method for a connection device, comprising: 2. A network which is connected to a network having at least one terminal device and is connected to at least one other connection device connected to another network via a line network, and which is held by each connection device. In a route information transmission method of a connection device for communicating route information between devices, holding connection information for connecting with the other connection device via the line network, and held by the other predetermined connection device from the terminal device. A request for information regarding a network to be connected, a connection step of connecting to the predetermined connection device via the line network based on the connection information, and a holding step of acquiring and holding route information transmitted from the predetermined connection device. And a step of transmitting the route information to the connected network, the route information transmission of the connecting device. How to reach. 3. A network which is connected to a network having at least one terminal device and is connected to at least one other connecting device connected to another network via a line network and which is held by each connecting device. A route information transmission method of a connection device for communicating route information between devices, wherein call control information is defined in each of the connection devices, and the line network is connected upon receipt of the call control information, A method for transmitting route information of a connecting device, characterized in that: 4. A data communication system for performing data communication by connecting connecting devices respectively connected to respective networks via a line network, wherein the connecting device creates the call control information by the system. A data communication system characterized in that a network number not existing in the network is searched and assigned to a predetermined network. 5. A data communication system in which connecting devices respectively connected to respective networks are connected via a line network, wherein the connecting device, when the same network number is separately assigned to a plurality of networks, A data communication system, wherein a network number that does not exist in the system is searched and assigned to a network of which the network number can be changed to create call control information. 6. A data communication system in which connecting devices respectively connected to respective networks are connected via a line network, wherein the connecting device is capable of changing a network number when information peculiar to the network is changed. Searching for a network number that does not exist in the system, changing the network number of the network to the searched network number to create call control information, and transmitting the changed information to another network. A data communication system characterized by. 7. The connection device includes a network number of a network existing in the system, and has route information for relaying data communication. When allocating the network number, the route information is used. 7. The data communication system according to claim 4, wherein a network number that does not exist in the network is searched and assigned to a predetermined network. 8. The data communication system according to claim 4, wherein the connection device combines a plurality of networks and assigns the same network number.