JP3152287B2 - Shortcut communication system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a data transfer method, and more particularly, to a data transfer method in a connection-oriented network.

[0002]

2. Description of the Related Art Conventionally, as a shortcut communication system in a connection oriented network,
For example, in February 1997, Multiprotocol Over ATM Version 1.0 Straw Ballot (ATM Forum / STR-MPOA-
MPOA-01.00), pp. 14-55 (Multi-
Protocol Over ATM Version
1.0 DrawBallot (ATM Foru
m / STR-MPOA-MPOA-01.00), Fe
brury 1997, P14-P55) is known. In this shortcut communication system, communication between subnets is performed without passing through a router, thereby avoiding a decrease in communication quality due to software processing in the router.

FIG. 7 is a network configuration diagram showing an example of a conventional shortcut communication system. Referring to FIG. 7, shortcut server 11 is connected to shortcut client 5 via subnet 1 and shortcut server 12 is connected to shortcut server 11 via subnet 2 and
Is connected to the shortcut server 13 via the.
The shortcut server 13 is connected to the shortcut client 6 via the subnet 4. The shortcut servers 11, 12, and 13 process an address resolution request for a shortcut from a shortcut client.

[0004] The shortcut clients 5 and 6 send out address resolution requests and return address resolution responses, and have a function of generating a shortcut connection between the shortcut clients after completing the address resolution processing.

FIG. 8 is a system configuration diagram of a shortcut client in the shortcut communication system of FIG. Referring to FIG. 8, shortcut interface 51 exchanges a shortcut connection with a shortcut packet. The transmission packet cache 53 holds a table in which the correspondence between the shortcut packet to be transmitted and the shortcut connection is described. The shortcut packet transmitting unit 52 has a function of receiving a packet from the packet processing unit 56, determining a shortcut connection to be transmitted by referring to the transmission packet cache 53, and transmitting the shortcut connection to the shortcut interface 51.

The received packet cache 55 holds information such as a data link layer header added to the received shortcut packet. The shortcut packet receiving unit 54 receives the packet from the shortcut interface 51 and receives the received packet cache 55
, And performs a necessary process, and transmits a packet to the packet processing unit 56. The control message interface 58 exchanges control messages for shortcut communication with the network. The client shortcut control message processing unit 57 has a function of exchanging a control message with the control message interface 58, processes the control message according to the contents, and requires the contents of the transmission packet cache 53 and the reception packet cache 55. Make changes accordingly.

FIG. 9 is a system configuration diagram of a shortcut server in the shortcut communication system of FIG. Referring to FIG. 9, control message interface 102 exchanges control messages for shortcut communication with the network. The server shortcut control message processing unit 57 has a function of exchanging control messages with the control message interface 100.
Process the control message according to its content. The routing processing unit 101 has a function of determining a destination of a packet.

Next, the operation will be described with reference to FIGS. When performing a shortcut operation, in the shortcut client 5, the client shortcut control message processing unit 57 sends an address solution request for a shortcut to the control message interface 58. The address resolution request is subnet 1
And arrives at the shortcut server 11. In the shortcut server 11, the server shortcut control message processing unit 100 that receives the address resolution request through the control message interface 102
After the routing processing unit 101 determines the transfer destination of the address resolution request, the request is transferred to the next server, the shortcut server 12, through the control message interface 102.

[0009] The shortcut server 12 receives the above address resolution request, performs the same processing as the shortcut server 11, and then transfers the address resolution request to the shortcut server 13. Shortcut server 1
3 is a routing processing unit 101 and the transfer destination is a subnet 4
Is determined to be the shortcut client 6, and the content held in the received packet cache is added to the address resolution request and transferred to the shortcut client 6.

In the shortcut client 6,
The address resolution request is processed by the client shortcut control message processing unit 57, and generates an address resolution response that replies the shortcut address of the shortcut client 6 and sends it back to the shortcut server 13. Also, the client shortcut control message processing unit 57 writes information such as a header to be added to the received packet instructed to be held by the shortcut server in the received packet cache 55.

The shortcut server 13 returns the address resolution response to the shortcut server 12 which is the reply destination determined by the routing processing unit 101. Similarly, the shortcut server 12 sends the address resolution response to the shortcut server 11, and the shortcut server 11 sends the shortcut client 11 to the shortcut client. 5 is returned to the address resolution response. The client shortcut control message processing unit 57 in the shortcut client 5 writes the resolved shortcut client address in the transmission packet cache, and generates the shortcut connection 7.

When the above operation is completed and the shortcut connection 7 is generated, all communication from the shortcut client 5 to the shortcut client 6 is performed through the shortcut connection 7.

[0013]

By the way, in the above-mentioned shortcut communication system, the short-cut client requires memory resources and connection resources as many as the number of shortcut clients on the network. However, there is a problem that a large amount of memory resources and connection resources of the shortcut client are required.

SUMMARY OF THE INVENTION An object of the present invention is to provide a shortcut communication that can efficiently use network resources such as a communication band and a cache memory resource necessary for communication when performing a shortcut communication between a large number of nodes on a large-scale network. It is to provide a system.

[0015]

SUMMARY OF THE INVENTION A shortcut communication system in a connection-oriented network according to the present invention relays shortcut communication and integrates shortcut connections to the same destination. More specifically, this shortcut communication system includes:
Means for detecting shortcut communication exceeding a predetermined group of subnets (domains) and determining to relay the shortcut communication; means for receiving a shortcut packet for relay; and means for transmitting a shortcut packet Further comprising: means for holding correspondence information indicating to which shortcut connection a shortcut packet received from a certain shortcut connection is transferred; and means for transferring the shortcut packet with reference to the shortcut connection correspondence information. A shortcut relay node is provided.

[0016] A plurality of shortcut connections to the same destination that cross domains are relayed by a shortcut relay node to be combined into one connection. For this reason, a large amount of network resources for shortcut connections, cache memory resources that require an entry for each transmission source and destination are not affected by an increase in the size of the network.
Efficient use of network resources becomes possible.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

Referring to FIG. 1, in the illustrated example, an ATM network is used as a connection-oriented network, and an MPOA (M
A multi-Protocol Over ATM) system is used.

The subnet 1 and the subnet 2 belong to a domain 25 in which shortcut communication can be freely performed. Subnet 3 and subnet 4 belong to domain 26.
The shortcut relay node 22 located at the boundary between the domain 25 and the domain 26 is connected to the subnet 2 and the subnet 3, and the shortcut relay node 22
Can communicate with the shortcut server 11 via the subnet 2 and can communicate with the shortcut server 13 via the subnet 3.

The shortcut server 11 is the subnet 1
And the shortcut server 13 is connected to the shortcut client 6 via the subnet 4.

The shortcut server 11 and the shortcut server 13 have a function of transferring an address resolution request and an address resolution response from the shortcut client in the direction of the destination. It has a function of transmitting a resolution request and returning an address resolution response when receiving the address resolution request, and a function of generating a shortcut connection to a destination whose address is described in the resolution response and performing shortcut communication.

The shortcut relay node 22 detects a shortcut communication that crosses a domain and generates a shortcut connection between the transmission source and the relay node and between a destination shortcut client and the relay node. And transfers a shortcut packet received from a shortcut connection in one domain to a shortcut connection in another domain.

Next, referring to FIG. 2, FIG. 2 is a diagram showing a configuration example of the shortcut relay node shown in FIG. The shortcut interface 201 and the shortcut interface 202 are interfaces for shortcut communication from each domain. The transmission packet cache 204 is a cache of a table which stores a shortcut packet to be transmitted to the network to which shortcut connection. The received packet cache 206 is a table cache that holds information indicating what header information should be added to a packet received from a certain shortcut connection.

Relay shortcut packet transmitting section 203
Refers to the transmission packet cache, directs the packet from the packet processing unit 207 to an appropriate shortcut connection, and
Has the function of transmitting to The relay shortcut packet receiving unit 205 is connected to the shortcut interface 20.
The packet processing unit 207 has a function of acquiring appropriate header information by referring to the received packet cache based on the shortcut connection of the packet received from the packet 2 and transferring the packet with the header to the packet processing unit 207.

The correspondence table 212 is a table for holding information on which transmission packet cache entry the shortcut packet arriving from the shortcut connection corresponds to. The relay connection correspondence control unit 211 stores the packet processed by the relay shortcut packet receiving unit 205 in the correspondence table 212.
To notify which entry of the transmission packet cache corresponds to this packet.

Interface 210 for control message
Is an interface for transmitting and receiving an address resolution request and an address resolution response. The server shortcut control message processing unit 208
Processes control messages such as address resolution responses.
The relay processing unit 209 performs a relay process upon receiving an address resolution request for a shortcut that crosses a domain,
Return your address to the sender of the address resolution request,
It has a function of transmitting a new address resolution request to the destination of the address resolution request in order to set another shortcut connection. The routing processing unit 213 determines which interface needs to transmit a control message or the like such as the address resolution request and the address resolution response described above to which address.

Next, the operation of the shortcut communication system shown in FIG. 1 will be described with reference to the drawings.

Referring to FIGS. 1 and 2, when an address resolution request from shortcut client 5 to shortcut client 6 arrives at shortcut relay node 22 located at the boundary of domain 25 by shortcut server 11, shortcut relay node 2
In 2, the server shortcut control message processing unit 208 refers to the routing processing unit 213 to determine the next transfer destination of the address resolution request. When the relay processing unit 209 determines that the transfer destination exceeds the domain, the relay processing unit 209 instructs the server shortcut control message processing unit 208 to issue an address resolution response describing the address of the shortcut relay node. The server control message processing unit 208 instructed to issue an address resolution response from the relay processing unit 209 writes necessary information in the received packet cache, and then the address resolution response is transmitted to the control message interface 21.
0 is returned to the shortcut client 5.

After completing this processing, the relay processing unit 209 instructs the server control message processing unit to transmit a new address resolution request to the destination of the address resolution request. The server control message processing unit 208 receiving this instruction generates an entry in the transmission packet cache, and transmits an address resolution request to the shortcut client 6 using the control message interface 210. The search label of the entry of the received packet cache 206 and the search label of the entry of the transmitted packet cache 204 generated in the above processing are associated by the relay connection correspondence control unit 211, and the correspondence between the search labels is stored in the correspondence table 212. Written.

The address resolution request issued from the shortcut relay node 22 is transmitted to the shortcut client 6 via the shortcut server 13, and the shortcut client 6 returns an address resolution response describing the address of its own node. Upon receiving this, the shortcut relay node 22 creates a shortcut connection 24 with the shortcut client 24. After receiving the address resolution response from the shortcut relay node 22, the shortcut client 5 creates a shortcut connection 23 with the shortcut relay node 22. After the shortcut connection is generated, the packet from the shortcut client 5 to the shortcut client 6 is delivered to the shortcut relay node 22 via the shortcut connection 23 and received by the shortcut interface 202. The shortcut packet processing unit 205 refers to the received packet cache 206, passes the search label of the corresponding entry to the relay connection correspondence control unit 211, and based on the search label associated in the correspondence table 211, the entry of the transmission packet cache. Search for. The search result is transferred to the relay shortcut packet transmitting unit 203, and the shortcut packet received by the relay shortcut packet receiving unit 205 is transmitted to the shortcut connection 24 which is an appropriate shortcut connection.

FIG. 3 is a diagram showing an example of integration of shortcut connections from a plurality of shortcut clients in the system shown in FIG. Referring to FIG. 3, in FIG. 3, a shortcut client 7 is newly added to subnet 2 in the network of FIG.

In a situation where the shortcut communication from the shortcut client 5 to the shortcut client 6 has been set, when an address resolution request to the shortcut client 6 is made from the shortcut client 7, the address resolution request that has reached the shortcut relay node 22 is The relay processing unit 209 returns an address resolution response describing the address of the shortcut relay node 22 to the shortcut client 7 based on the determination. Thereby, the shortcut connection 27
Is generated. The relay processing unit 209 instructs the server shortcut control message processing unit 208 to issue an address resolution request to the shortcut client 6, which is the destination of the address resolution request from the shortcut client 7, but the transmission packet cache 204 has already generated the shortcut connection. The address resolution request is not transmitted because there is an entry of the shortcut client 7, and the search label of the entry of the received packet cache 206 generated as a result of the address resolution request from the shortcut client 7 and the search label of the already generated shortcut connection entry The association is made by the relay connection correspondence control unit 211, and the result is written in the correspondence table 212.

According to this processing, packets from the shortcut client 5 and the shortcut client 7 to the shortcut client 6 are transmitted to the domain 2
5, the packet is transmitted to the shortcut relay node 22 using two shortcut connections, and these packets are collected by the shortcut relay node and delivered to the shortcut client 6 by one shortcut connection.

The relay connection correspondence control unit 211 makes the search label of each cache entry a list structure and holds it in the correspondence table 212 in order to associate the received packet cache entry and the transmitted packet cache with each other. One to one, one to N (N is an integer of 2 or more), N to 1, N
This can be performed on the pair N.

As described above, in the shortcut communication system shown in FIG. 1, since the shortcuts in the domain can be combined into one by the shortcut relay node, the shortcut connection resources necessary for the shortcut communication to the same destination, and the shortcut client It is possible to reduce the amount of used memory resources of the received packet cache compared to the conventional shortcut communication system. Therefore, the present invention can be applied to a large-scale network.

Referring to FIG. 4, another example of the shortcut communication system according to the present invention will be described. here,
FIG. 4 is a network configuration diagram, and FIG. 5 is a system configuration diagram of the shortcut relay client in FIG. FIG. 6 is a system configuration diagram of the shortcut relay server in FIG.

In FIG. 4, the shortcut relay server 32 performs the routing process and the relay process among the processes of the shortcut relay node described with reference to FIG. 1, and the shortcut relay client 33 generates the shortcut connection and responds to the address resolution. , Sending a new address resolution request and associating the shortcut connection.

Shortcut relay server 32 that has received an address resolution request from shortcut client 5
Then, the relay processing unit 401 determines that the address resolution request exceeds the domain according to the transmission destination determined by the routing processing unit 402. Thereafter, the relay processing unit 401 instructs the server shortcut control message processing unit 400 to return an address resolution response to the shortcut relay client 33, and at the same time instructs the shortcut relay client 33 to transmit an address resolution request to the shortcut client 6. I do.

The instruction to return an address resolution response from the shortcut relay server 32 is received by the control message interface 310 in the relay client 33, and the client shortcut control message processing unit 308 generates an entry in the received packet cache 306. After the necessary information is written, an address resolution response is returned to the shortcut relay server 32 via the control message interface.

An instruction to issue an address resolution request to the shortcut client 6 is also received by the control message interface 310. After the client shortcut message processing unit 308 generates an entry in the transmission packet cache 304, the new address resolution request is issued. Is transmitted to the shortcut client 6. The search label of the entry in the received packet cache 306 generated in the above process and the search label of the entry in the transmitted packet cache 304 are associated by the relay connection correspondence control unit 311, and this correspondence is written in the correspondence table 312. The address resolution response returned from the shortcut relay client 33 to the shortcut relay server 32 is received by the shortcut client 5 and a shortcut connection 34 is generated.

The address resolution request transmitted from the shortcut relay client 33 to the shortcut client 6 is processed by the shortcut client 6 and an address resolution response is returned. Thereby, the shortcut connection 35 is generated.

The relay connection correspondence control unit 311 makes the search label of each cache entry a list structure and holds it in the correspondence table 312 in order to associate the entry of the cache for the received packet with the cache for the transmitted packet, and causes the correspondence table 312 to hold the search label. Entries can be associated with one-to-one, one-to-one, N-to-one, and N-to-N.

When the shortcut relay server 33 detects from the routing processing unit 402 that the network configuration in the domain 26 has been changed, it issues an address resolution request to quickly regenerate the shortcut connection to the target node. It is also possible to issue an instruction to the shortcut relay client.

As described above, in the shortcut communication system shown in FIG. 4, in addition to the points described with reference to FIG. 1, since the node that relays the shortcut has no routing processing unit, the device can be downsized. A plurality of relay nodes can be installed between domains.

[0045]

As described above, according to the present invention, it is possible to reduce the network resources required for the shortcut communication of the same destination, so that when the number of shortcut clients increases in a large-scale network, This also has the effect that network resources can be used effectively.

[Brief description of the drawings]

FIG. 1 is a network configuration diagram illustrating an example of a shortcut communication system according to the present invention.

FIG. 2 is a configuration diagram of a shortcut relay node shown in FIG. 1;

FIG. 3 is a diagram for explaining an example when integrating shortcut connections from a plurality of shortcut clients in FIG. 1;

FIG. 4 is a network configuration diagram for explaining another example of the shortcut communication system according to the present invention.

FIG. 5 is a configuration diagram of a shortcut relay client shown in FIG. 4;

FIG. 6 is a configuration diagram of a shortcut relay server shown in FIG. 4;

FIG. 7 is a diagram showing a network configuration in a conventional shortcut communication system.

FIG. 8 is a configuration diagram of a shortcut client in a conventional shortcut communication system.

FIG. 9 is a configuration diagram of a shortcut server in a conventional shortcut communication system.

[Explanation of symbols]

 1-4 Subnet 5,6 Shortcut Client 11,13 Shortcut Server 22 Shortcut Relay Node 23,24 Shortcut Connection 25,26 Domain

Claims (12)

(57) [Claims] 1. In a shortcut communication system in which address resolution processing is performed in a connection-oriented network to perform inter-subnet communication without passing through a router, relaying with the transmission source node of the shortcut communication in order to relay the shortcut communication A first means for setting a shortcut connection with the node as a first shortcut connection, a second means for setting a shortcut connection between the relay node and the destination node as a second shortcut connection, 3. A shortcut communication system, comprising: third means for controlling a correspondence relationship between a first shortcut connection and the second shortcut connection. 2. The shortcut communication system according to claim 1, wherein said relay node is provided with said third means, and said third means is provided with said first shortcut connection and said second shortcut connection. A shortcut communication system, wherein the correspondence is controlled when the ratio is 1: 1, 1: N, N: 1, or N: N (N is an integer of 2 or more). 3. The shortcut communication system according to claim 2, wherein the relay node holds a search label list of an entry of a transfer destination cache corresponding to an entry of a reception cache used when receiving a shortcut packet. Shortcut communication system comprising means for referring to the search label list and searching for a shortcut connection of a transfer destination corresponding to the received shortcut packet. 4. A shortcut communication system in which address resolution processing is performed in a connection-oriented network to perform inter-subnet communication without passing through a router. A first means for setting a shortcut connection with a node as a first shortcut connection, a second means for setting a shortcut connection between the own node and a destination node as a second shortcut connection, A shortcut relay client including third means for controlling a correspondence between the first shortcut connection and the second shortcut connection; A shortcut communication system comprising: a shortcut relay server that controls a shortcut relay process. 5. The shortcut communication system according to claim 4, wherein said third means is configured such that said first shortcut connection and said second shortcut connection are one-to-one, one-to-N, N-to-one, or N to N (N
A shortcut integer communication system, wherein the correspondence is controlled when the number is an integer of 2 or more). 6. The shortcut communication system according to claim 5, wherein the shortcut relay client holds a search label list of an entry in a transfer destination cache corresponding to an entry in a reception cache used when receiving a shortcut packet. And a means for referring to the search label list to search for a destination shortcut connection corresponding to the received shortcut packet. 7. The shortcut communication system according to claim 4, wherein the shortcut relay client holds a search label of an entry in a transfer destination cache corresponding to an entry in a reception cache used when a shortcut packet is received. Means for searching for a shortcut connection of a transfer destination corresponding to the received shortcut packet with reference to the search label. 8. In a shortcut communication system in which address resolution processing is performed in a connection-oriented network to perform inter-subnet communication without passing through a router, a shortcut communication client that performs shortcut communication when the network configuration changes. A shortcut communication system, comprising: a shortcut communication server having means for instructing the server to re-resolve the address. 9. The shortcut communication system according to claim 4, further comprising the shortcut communication server according to claim 8. 10. The shortcut communication system according to claim 5, comprising the shortcut communication server according to claim 8. 11. A shortcut communication system according to claim 6, further comprising the shortcut communication server according to claim 8. 12. The shortcut communication system according to claim 7, further comprising the shortcut communication server according to claim 8.