Composite communication network

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Industrial application field]

The present invention relates to self-routing of messages transferred within a communication network. Especially related to the transfer of management messages for managing the communication network. The present invention is used for a composite communication network having a hierarchical structure and including sub-networks such as a ring type, a star type, or a bus type in the hierarchical structure.

【0002】

[Conventional technology]

In conventional communication networks, network layer level routing protocols such as RIP (routine information protocol) and IS-IS are used to route management messages. In these protocols, the routing table information of each node is updated by exchanging the routing table information periodically or when a change request occurs, and routing based on the routing table is executed.

【0003】

[Problems to be Solved by the Invention]

In the case of RIP, such conventional management message routing has a problem that it cannot be applied to a large-scale network because the forwarding range of routing information is limited to 16 nodes. On the other hand, in IS-IS, the application is not restricted by the network size, but in order to manage the routing of the entire network on each node, the size of the routing information exchanged between the nodes and the routing table held by the nodes has increased. There is a problem that routing takes a lot of time. In addition, neither protocol is a method that specifically considers the physical characteristics of the ring-type network.

【0004】

An object of the present invention is to improve the above-mentioned drawbacks of the routing method, and to provide a connection method capable of being applied to a large-scale network and enabling high-speed routing.

【0005】

[Means for solving problems]

The present invention is a composite communication network having a hierarchical structure and including a sub-network in at least a part thereof, and a composite communication network in which a message set in a packet and displaying a transfer destination node is transferred within the communication network. In the GW (gateway) node having three or more connection routes in the communication network, a first routing table for nodes belonging to a layer other than the layer to which the node belongs, and this first routing table and The GW node in the communication network and nodes other than the GW node are provided with a first transfer control means for transferring the packet according to the inter-story transfer protocol with reference to the transfer destination node displayed in the packet. A second transfer that transfers the packet according to the intra-layer transfer protocol by referring to the second routing table for the node in the layer to which the node belongs, the second routing table, and the transfer destination node displayed in the packet. It is characterized by being provided with a control means.

【0006】

The sub-network is a ring type, a star type, a bus type, or a combined type thereof, and the first transfer control means and / or the second transfer control means have the transfer displayed in the packet. A means for identifying that the destination node is addressed to the own node, and when the means for identifying the destination node is identified as being addressed to the own node, a means for capturing the message of the packet and prohibiting the transfer of the packet. The first transfer control means and / or the second transfer control means includes means for identifying that the packet is for a health check, and the identifying means provides a health check packet. When identified, there is a means to capture the message of the packet and execute a health check of the own node, and a means to send failure information to multiple nodes when an abnormality is detected in the result of this health check. Including, the first forwarding control means and / or the second forwarding control means, when the message contains information for a routing change, the first routing table and / or the second. It can include means to automatically update its routing table according to that information.

【0007】

[Action]

In the present invention, among the nodes in the complex communication network, a node having three or more connection paths is defined as a GW (gateway) node in particular, and a message is transferred to the GW node across layers. Information and control means can be arranged, and in nodes other than the GW node, the information and control means can be configured in a limited manner so as to simply control message transfer in the layer to which the own node belongs. Therefore, message forwarding within the subnetwork can be speeded up and the scale of the forwarding table can be reduced. As a result, the device for controlling message forwarding between layers needs to be considered only for the GW node, and the hardware and software to be installed in the GW node are significantly reduced. Therefore, a node device of the same scale is required. Can be applied to large-scale networks.

【0008】

Further, if a means for automatically updating the routing table of each node is provided according to the management message, the communication throughput can be significantly improved.

【0009】

[Example]

Next, an embodiment of the present invention will be described with reference to the drawings.

【0010】

(First Example) FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention, and FIG. 2 is a diagram showing an example of an application network related to the first embodiment of the present invention.

【0011】

In the first embodiment of the present invention, a hierarchical structure is adopted, a sub-network is included in at least a part thereof, and a message set in a packet and displaying a forwarding node is transferred within the communication network. Further, as shown in FIG. 1, an internal application unit 103 and a network layer packet routing protocol unit 101 are arranged on a GW (gateway) node having three or more connection routes in the communication network, and the internal application unit 103. Is provided with a routing information table 113 including a first routing table for nodes belonging to a layer other than the layer to which the node belongs, and is displayed in the first routing table and packets in the network layer packet routing protocol unit 101. A network layer packet routing application unit 104 including a first transfer control means that refers to the transfer destination node and transfers the packet according to the inter-story transfer protocol is provided.

【0012】

In addition, the internal application unit 103 and the network layer packet routing protocol unit are also arranged in the GW node in the communication network and the nodes other than the GW node, and the internal application unit 103 is the node related to the node in the layer to which the node belongs. A routing information table 113 including a second routing table is provided, and the network layer packet routing application unit 104 refers to the second routing table and the forwarding node displayed in the packet to forward the packet according to the intra-layer forwarding protocol. A second transfer control means to perform is provided.

【0013】

As the sub-network, a ring type, a star type, a bus type, or a combined type thereof is used.

【0014】

Further, the first transfer control means and / or the second transfer control means includes means for identifying that the transfer destination node displayed in the packet is addressed to the own node, and the own node is provided by the identifying means. It includes means of capturing the message of the packet and prohibiting the forwarding of the packet when it is identified as being addressed.

【0015】

Next, the operation of the first embodiment of the present invention configured in this way will be described with reference to the drawings.

【0016】

The management packet (network packet 1) input from Ethernet 106 passes through the interface circuit 105 and is connected to the network layer packet routing application unit 104 in the network layer packet routing protocol unit 101. When network packet 1 is received by the network layer packet routing application unit 104, if the target GW node of the packet is its own node, a packet is sent to the message processing unit 112 in the internal application unit 103 via the interface circuit 107 and the internal bus. To transfer.

【0017】

If the target GW node is not its own node, the packet is set as network packet 2, the next destination GW node is extracted using the internal network layer routing table, and the data link layer corresponding to the direction of that GW node. Transfer to the packet routing application unit 109. The data link layer packet routing application unit 109 that has received the packet sends it to the management information communication medium 111 in the connection line.

【0018】

The management packet input from the management information communication medium 111 to the data link layer packet routing protocol unit 102 is determined by the data link layer packet routing application unit 109 whether or not the packet is destined for its own node. If the packet is destined for the local node and the packet is network packet 2, it is transferred to the network layer packet routing application unit 104 via the interface circuits 110 and 107. When the network layer packet routing application unit 104 receives a packet, it executes network layer level routing in the same manner as the above-described processing for network packet 1. If the packet is addressed to the local node and the packet is a ring packet, it is transferred to the message processing unit 112. On the other hand, if it is not addressed to its own node, it is transferred to the other data link layer packet routing application unit 109 via the interface circuit 110 and the internal bus and transmitted.

【0019】

When the message processing unit 112 receives the network packet 1 from the network layer packet routing application unit 104, it determines whether or not it is addressed to its own node, processes the message if it is addressed to its own node, and if it is not addressed to its own node. It is converted into a ring packet and transferred to the target node of the packet to the data link layer packet routing application unit 109 in the direction shown in the routing information table 113. At this time, the ring network identifier (NE #) of the target node is set in the packet. When a ring packet is received from the data link layer packet routing application unit 109, the message is processed internally.

【0020】

The routing information table 113 shown in FIG. 1 is not limited to the internal application section 103, and may be distributed to the network layer packet routing protocol section 101 and the data link layer packet routing protocol section 102.

【0021】

As shown in FIG. 2, the network in the first embodiment of the present invention is a composite network in which a bus-type subnetwork 202, a star-type subnetwork 203, and a tree-type subnetwork 204 are connected to the ring subnetwork 201. The GW node 205 of the ring subnetwork 201 in this network example is configured as shown in FIG. 1 as described above. At least the data link layer packet routing protocol section 102 and the internal application section 103 shown in FIG. 1 are mounted on the other nodes 206.

【0022】

Here, the outline of the routing method of the first embodiment of the present invention will be described with reference to FIG. FIG. 3 (a) is an example of Interlocked Rings in which the ring subnetwork 301 and the ring subnetwork 302 are connected. Nodes 303 to 307 and 312 having management information communication media with three or more roads are designated as GW nodes and are indicated by black circles. Figure (b) is a diagram showing a hierarchical routing image. GW nodes 303-307 and 312 perform routing between GW nodes with network layer level protocol 312. The GW node and the other nodes 308, 309, 310, 313, on the other hand, perform routing within the ring subnetworks with data link layer level routing protocol 314. The routing 311 from the upper OpS to the node 310 shown in FIG. 3 (a) is the routing operation shown in FIG. 3 (b) of the hierarchical routing method.

【0023】

Next, the three types of packets described with reference to FIG. 1 will be described, and the routing algorithms of the network layer packet routing application unit 104, the message processing unit 112, and the data link layer packet routing application unit 109 shown in FIG. 1 will be described. To do. FIG. 4A is a diagram showing the format configuration of network packet 1. This network packet 1 is a packet transferred between GW nodes using a management information communication medium outside the ring subnetwork. Assuming that the communication medium is Ethernet, it is composed of an Ethernet header 401, a network layer protocol header 402, and a DATA unit 403.

【0024】

FIG. 4B is a diagram showing the format configuration of network packet 2. Network packet 2 is routed at the network layer like network packet 1, but the scope of routing is limited to the ring subnetwork. It is composed of the protocol header 404 of the data link layer, the protocol header 402 of the network layer, and the DATA section 409. In particular, the protocol header 402 of the network layer contains the NW address (hereinafter NW #) of the target GW node in the routing of the network layer. Set.

【0025】

Further, the DATA unit 409 has a routing header 406 in the ring, and a destination NE address (hereinafter referred to as NE #) in the routing in the ring is set therein. NW # is an address that identifies GW nodes in the network, and NE address is an address that identifies each ring node in the ring subnetwork. Figure 8 shows an example of a ring subnet with its NE #, where the GW node has NW # and NE #.

【0026】

FIG. 4 (c) is a diagram showing the format of a ring packet routed at the data link layer in the ring subnetwork. The DATA unit 410 has an in-ring routing header like the network packet 2.

【0027】

FIG. 5 is a flowchart showing a packet processing flow of the network layer packet routing application unit in the first embodiment of the present invention. When the network layer packet routing application unit 104 receives network packet 1 or network packet 2, it maps the NW # of the target node of the packet and the NW # of its own node (S501), and if they match, it determines that it is addressed to its own node. Performs a process of transferring a packet to the message processing unit 112 (S505). If the NW # does not match, the internal routing table (network table) is searched (S502), and the information of the next destination GW node is extracted (S503). Next, in order to send the packet to the GW node, the packet is forwarded to the corresponding data link layer packet routing protocol unit 102 (S504).

【0028】

FIG. 6 is a flowchart showing the flow of packet processing of the message processing unit in the first embodiment of the present invention. When the message processing unit 112 receives the packet, it determines whether or not the local node is the target node of the packet (S601), and processes the message if it is addressed to the local node (S605). If it is not addressed to the local node, the NE # of the target node is obtained (S602), the transmission direction toward the target node is obtained (S603), and the interface circuit (INF) 110 of the corresponding data link layer packet routing protocol unit 102 is used. Forward the ring packet (S604).

【0029】

FIG. 7 is a flowchart showing the flow of packet processing of the data link layer packet routing application unit in the first embodiment of the present invention. When the data link layer packet routing application unit 109 receives the packet, it determines whether the packet is a packet transferred from the internal bus or a packet received from the management information communication medium in the continuous line (S701), and is forwarded from the internal bus. If the packet is sent, it is sent to the connection line (S702). Otherwise, the NE # to which the packet is sent is matched with the NE # of the local node (S703). If they do not match at this time, it is determined that the data is not addressed to the local node, and the data is simply transferred to the local data link layer packet routing protocol (S706). By this processing, the relay processing can be speeded up because the processing is not raised to the upper layer in the simple relay in the ring. If NE # matches, if the packet is network packet 2, it is forwarded to the network layer protocol (S707), and if the packet is a ring packet, it is forwarded to the message processing unit 112. (S705).

【0030】

9 (a) and 9 (b) are diagrams illustrating the operation of management message routing in the ring subnetwork in the first embodiment of the present invention. As shown in Fig. (B), the source node 901 is routed to the destination node 902 at the data link layer.

【0031】

10 (a) and 10 (b) are diagrams for explaining the operation when the management packet in the first embodiment of the present invention is routed from outside the ring subnetwork to the target node in the ring. From the source to GW node 1005 of the ring subnetwork, the management message is included in network packet 1 (1001) and transferred, converted to network packet 2 (1002) at GW node 1005, and up to GW node 1006 at the data link layer. Be routed. GW node 1006 terminates routing at the network layer and translates packets into ring packets 1003. Data link level routing is performed up to the destination node 1004.

【0032】

(Second Example) In the second embodiment of the present invention, the first transfer control means and / or the second transfer control means in the first embodiment includes means for identifying that the packet is for a health check. When a health check packet is identified by this identification means, the means for fetching the message of the packet and executing the health check of the own node, and the failure information when an abnormality is detected in the result of this health check. The first transfer control means and / or the second transfer control means include information (failure information) for routing change in the message. When, the first routing table and / or the second routing table is automatically updated according to the information, and other than that, it is configured in the same manner as in the first embodiment.

【0033】

In the second embodiment, it is assumed that the routing protocol has two levels, the L2 (level 2) routing protocol is implemented in the network layer, and the L1 (level 1) routing protocol is implemented in the data link layer. .. Therefore, in the following, the L2 routing protocol will be referred to as a network layer packet routing protocol, and the L1 routing protocol will be referred to as a data link layer packet routing protocol.

【0034】

The management packet (L2 packet) input from Ethernet 106 passes through the interface circuit 105 and is connected to the network layer packet routing application section 104 in the network layer packet routing protocol section 101. When the network layer packet routing application unit 104 receives an L2 packet, the purpose of the packet If the GW node is its own node, the packet is sent to the message processing unit 112 in the internal application unit 103 via the interface circuit 107 and the internal bus. Forward. If the target GW node is not its own node, it is transferred to the data link layer packet routing application unit 109 corresponding to the direction of the next GW node. The data link layer packet routing application unit 109 that received the packet sends it to the connection line (management information communication medium) 111.

【0035】

The management packet input from the line (management information communication medium) 111 to the data link layer packet routing protocol unit 102 is determined by the data link layer packet routing application unit 109 whether or not the packet is an L2 packet. If the packet is an L2 packet, if the local node is not a GW node, the process of transferring the packet to the other data link layer packet routing application unit 109 via the interface circuit 110 and the internal bus is executed, and the local node executes the process. If it is a GW node, it is transferred to the network layer packet routing application unit 104 via the interface circuits 110 and 107. When the network layer packet routing application unit 104 receives a packet, it executes network layer level routing in the same manner as the above-described processing for the L2 packet. If the packet is destined for the local node and the packet is an L1 packet, it is transferred to the message processing unit 112. On the other hand, if it is not addressed to its own node, it is transferred to the other data link layer packet routing application unit 109 via the interface circuit 110 and the internal bus and transmitted.

【0036】

When the message processing unit 112 receives an L2 packet from the network layer packet routing application unit 104, it determines whether or not it is addressed to its own node, processes the message if it is addressed to its own node, and processes it if it is not addressed to its own node. Is converted into an L1 packet and forwarded to the target node of the packet to the data link layer packet routing application unit 109 in the direction shown in the routing information table 113. At this time, the ring network identifier (NE #) of the target node is set in the packet. When a ring packet is received from the data link layer packet routing application unit 109, the message is processed internally.

【0037】

The routing information table 113 shown in FIG. 1 is not limited to the internal application section 103, and may be distributed to the network layer packet routing protocol section 101 and the data link layer packet routing protocol section 102 as in the first embodiment. is there.

【0038】

As shown in FIG. 2, the network in the second embodiment is also a composite network in which the bus-type subnetwork 202, the star-type subnetwork 203, and the tree-type subnetwork 204 are connected to the ring subnetwork 201. The GW node 205 of the ring subnetwork 201 in this network example is configured as shown in FIG. 1 as described above. At least the data link layer packet routing protocol section 102 and the internal application section 103 shown in FIG. 1 are mounted on the other nodes 206.

【0039】

Here, the outline of the routing method of the second embodiment of the present invention will be described with reference to FIG. FIG. 3 (a) is an example of Interlocked Rings in which the ring subnetwork 301 and the ring subnetwork 302 are connected. Nodes 303 to 307 and 312 having management information communication media with three or more roads are designated as GW nodes and are indicated by black circles. Figure (b) is a diagram showing a hierarchical routing image. GW nodes 303-307 and 312 perform routing between GW nodes with network layer level protocol 312. The other GW node and the other nodes 308, 309, 310 and 313 use the data link layer level routing protocol 313 to perform routing within the ring subnetworks. The routing 311 from the upper OpS to the node 310 shown in FIG. 3 (a) is the routing operation shown in FIG. 3 (b) of the hierarchical routing method.

【0040】

Next, the L1 and L2 packets described with reference to FIG. 1 will be described , and the routing algorithms of the network layer packet routing application unit 104, the message processing unit 112, and the data link layer packet routing application unit 109 shown in FIG. 1 will be described. explain. L2 packets are packets that are routed between GW nodes. Assuming that the communication medium is Ethernet, it is composed of an Ethernet header, a network layer protocol header, and a DATA part.

【0041】

Figure 4 (c) shows the format of L1 packets routed at the data link layer within the ring subnetwork. The L1 packet is composed of the protocol header 404 of the data link layer and the DATA part 410. The DATA section 410 has a routing header 406 in the ring. The destination NE address (hereinafter NE #) 407 and the source NE address (hereinafter NE #) 408 in the in-ring routing are set there. The NE address is an address that identifies each ring node in the ring subnet. In the case of a GW node, in addition to NE #, it has NW # as an identifier uniquely defined in the network. FIG. 8 is a diagram showing an example of a ring subnet with NE #.

【0042】

FIG. 5 is a flowchart showing the flow of packet processing of the network layer packet routing application unit in the second embodiment of the present invention. When an L2 packet is received, the operation is to map the NW # of the target node of the packet and the NW # of the local node (S501), and if they match, it is judged to be addressed to the local node and the packet is transferred to the message processing 112. (S505). If the NW # does not match, the internal routing table (network table) is searched (S502), and the information of the next destination GW node is extracted (S503). It then forwards the packet towards the corresponding data link layer packet routing protocol to send the packet towards the GW node (S504).

【0043】

FIG. 6 is a flowchart showing the flow of packet processing of the message processing unit in the second embodiment of the present invention. When the message processing unit 112 receives the packet, it determines whether or not the local node is the target node of the packet (S601), and if it is addressed to the local node, processes the message (S605). If it is not addressed to the local node, the NE # of the target node is obtained (S602), the transmission direction toward the target node is obtained (S603), and the interface circuit (INF) 110 of the corresponding data link layer packet routing protocol unit 102 is used. Forward the ring packet (S604).

【0044】

FIG. 11 is a flowchart showing the flow of packet processing of the data link layer packet routing application unit in the second embodiment of the present invention. When the data link layer routing application unit 109 receives the packet, it determines whether the packet is a packet transferred from the internal bus or a packet received from the management information communication medium in the connection line (S1101), and is transferred from the internal bus. If it is a packet, it is sent to the connection line (S1102). If not, it identifies whether the packet is an L1 packet or an L2 packet (S1103), if it is an L2 packet, determines whether the local node is a GW node (S1104), and if it determines that the local node is a GW node. Transfers to the network layer protocol INF (S1106), and if it is not a GW node, transfers to the other data link layer protocol INF (S1107). If it is determined to be an L1 packet, the packet destination NE # and the NW # of the local node are matched (S1105), and if they do not match, it is determined that the packet is not addressed to the local node and simply the other data link layer. Performs the process of transferring to the packet routing protocol (S1108). By this processing, the relay processing can be speeded up because the processing is not raised to the upper layer in the simple relay in the ring. If NE # matches, the packet is transferred to the message processing unit 112 (S1109).

【0045】

9 (a) and 9 (b) are diagrams illustrating the operation of management message routing in the ring subnetwork in the embodiment of the present invention. As shown in Fig. (B), the source node 901 is routed to the destination node 902 at the data link layer.

【0046】

10 (a) and 10 (b) are diagrams for explaining the operation when the management packet in the second embodiment of the present invention is routed from outside the ring subnetwork to the target node in the ring. The management message is included in the L2 packet (1001) and transferred from the source to the GW node 1003 of the ring subnetwork, the network layer routing is terminated at the GW node 1003, and the L2 packet is converted into the L1 packet (1002). Route to the destination node 1004 at the data link layer. In FIGS. 9 and 10, the start point nodes 1001 and 1003 of the in-ring routing refer to the routing table to determine the transmission direction.

【0047】

FIG. 12 is a diagram showing an example of a routing table in the second embodiment of the present invention. This routing table is an example of the routing table configured on node 1 of network 1204. In the table, NE # 1201, the status 1202 of the management information communication medium, and the packet transmission direction 1203 are set in the order of the nodes connected to the ring (CW direction). The status of the management information communication medium 1202 is set to the status of the management information communication medium between the local node and the next node. In this example, since a failure has occurred between node 5 and node 3, 1 (during failure) is set in the information field on the right side of node 5. In the transmission direction 1203, the transmission direction of the packet for forwarding the packet toward the target node is set. For example, to transfer a packet from node 1 to node 5, the CW direction is the shortest path, so 00 is set in the sending direction. The CW direction is the shortest for forwarding packets to node 3, but 01 (CCW direction) is set because the status of the management information communication medium between nodes 3 to 5 is failing.

【0048】

FIG. 13 is a diagram showing a method of autonomously and decentrally updating the routing table in the second embodiment of the present invention. Each node in the ring periodically exchanges health check packets 1301 between neighboring nodes to check that the management information communication medium is normal. When an abnormality in the management information communication medium such as no response is detected, the abnormality notification message 1302 is broadcast along the ring to the other management information communication medium. For the error notification message, at least NE # 1303 of the node that detected the failure and NE # information 1304 of the other node of the failure communication medium are set. Each node that receives the error notification message forwards the message to the next node, takes it inside, and updates the routing table.

【0049】

[Effect of the invention]

As described above, according to the present invention, it is possible to speed up the processing by performing the data link layer level routing at the relay node in the ring, and the number of hosts to be managed also in the network layer level routing. Since the number of routes is significantly reduced, the routing table can be reduced, which has the effect of speeding up the routing. Furthermore, the routing table update function can achieve high reliability at the data link layer level.

[Simple explanation of drawings]

[Figure 1]

The block diagram which shows the structure of 1st Example and 2nd Example of this invention.

[Figure 2]

The figure which shows an example of the application network which concerns on 1st Example and 2nd Example of this invention.

[Fig. 3]

(a) and (b) are diagrams illustrating the basic operations of the first embodiment and the second embodiment of the present invention.

[Fig. 4]

(a) and (b) are diagrams showing the configuration of the packet format in the first embodiment of the present invention, and (c) is a diagram showing the configuration of the packet format in the first embodiment and the second embodiment of the present invention.

[Fig. 5]

The flowchart which shows the flow of the packet processing of the network layer packet routing application part in 1st Example and 2nd Example of this invention.

[Fig. 6]

The flowchart which shows the flow of the packet processing of the message processing part in 1st Example and 2nd Example of this invention.

[Fig. 7]

The flowchart which shows the flow of the packet processing of the data link layer packet routing application part in 1st Embodiment of this invention.

[Fig. 8]

The figure which shows the example of the NE address defined in the node in a ring which concerns on 1st Example and 2nd Example of this invention.

[Fig. 9]

(a) and (b) are diagrams illustrating the operation of management message routing in the ring subnetwork in the first embodiment and the second embodiment of the present invention.

[Fig. 10]

(a) and (b) are diagrams for explaining the operation when routing from outside the ring subnetwork to the target node in the ring in the first embodiment and the second embodiment of the present invention.

[Fig. 11]

The flowchart which shows the flow of the packet processing of the data link layer packet routing application part in the 2nd Embodiment of this invention.

[Fig. 12]

The figure which shows an example of the routing table in the 2nd Example of this invention.

[Fig. 13]

The figure which shows the method of updating the routing table in the second embodiment of the present invention in an autonomous and decentralized manner.

[Explanation of symbols]

101 Network Layer Packet Routing Protocol Department 102 Data Link Layer Packet Routing Protocol 103 Internal application section 104 Network Layer Packet Routing Application Department 105, 107, 110 Interface Circuits (INF) 106 Ethernet (management information communication medium) 108 Database for internal parameters (PARA) 109 Data Link Layer Packet Routing Application 111 lines (management information communication medium) 112 Message processing unit 113 Routing information table