JP2017224891A - Router device, routing control method and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow for common transfer, routing control of an inputted packet, regardless of difference in the corresponding communication protocol.SOLUTION: A router device includes an input interface for specifying path indication information of a packet inputted from an input port, and adding to the packet, a switch performing path changeover of a packet inputted from the input interface, based on the path indication information, an output interface for outputting a packet outputted from the switch from the corresponding output port, and a controller performing control related to specification of the path indication information. A router device is configured so that an input port to which a packet corresponding to UNI is inputted is connected with the switch, via a path for adding the path indication information of the input interface, and an input port to which a packet corresponding to NNI is inputted is connected not going through the path for adding the path indication information.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a router device, a route control method, and a computer program.

  FIG. 16 shows an example of the router device 200 corresponding to the packet transfer network. The router apparatus 200 shown in FIG. 1 corresponds to an optical cross-connect capable of wavelength-multiplexing and transmitting signal lights having different wavelengths over an optical fiber, for example, and enabling wavelength selection and path switching.

  The router device 200 in FIG. 1 includes an input interface unit 210 (210-1 to 210-N), a switch unit 220, an output interface unit 230 (230-1 to 230-N), and a controller 240.

  The input interface units 210-1 to 210-N input IP packets from the input ports # 1 to #N, respectively. The input interface unit 210 includes a route search unit 211 and a label assignment unit 212.

  For the input IP packet, the route search unit 211 searches the forwarding table, for example, by a longest match engine (LME) and selects the next hop. As shown in FIG. 17, the label assigning unit 212 adds an internal label indicating an output port number corresponding to the selected next hop to the IP packet.

  The switch unit 220 performs path switching (switching) so that the IP packet input from the input interface unit 210 is input to the output interface unit 230 connected to the output port of the output port number indicated by the label.

  The output interface unit 230 includes a label removal unit 231 and a priority control unit 232. The output interface unit 230 removes the label from the IP packet input from the switch unit 220 by the label removal unit 231, performs priority control as necessary by the priority control unit 232, and outputs the IP packet from the corresponding output port. .

A bottleneck in a communication network including a router device is a longest match search. Specifically, a Patricia tree search can be applied when performing the longest match search by software processing. In this case, a maximum of log ₂ N stages is required for the IP address length N for IPv4. If the IP address is in the IPv6 format, the number of search stages is further increased. The longest match search can be realized by hardware. In this case, for example, T-CAM (Ternary-Content Addressable Memory) is used for the routing table. However, since the capacity is small, an IP backbone or a large capacity address cannot be handled.

  Further, in backbone networks corresponding to communication carriers and the like, there are various forms of data transfer services including not only the Internet protocol (IP) but also Ethernet (registered trademark).

  However, many telecommunications carriers are in the situation where individual service networks are constructed for each data transfer service to be provided. For this reason, a lot of division losses have occurred with respect to network equipment construction costs and maintenance costs.

As a specific example, IP and Ethernet have very different protocols even when paying attention to the route selection control function.
For example, in an IP network, a transfer route of an IP packet (IP datagram) is specified by a route control protocol such as OSPF (see, for example, Non-Patent Document 1) or BGP (see, for example, Non-Patent Document 2).

  In addition, in principle, Ethernet is premised on a bus type or tree type network and topology, and does not provide a highly flexible route selection mechanism such as an IP network. In recent years, therefore, an SPB (Shortest Path Bridging) protocol (for example, Non-Patent Document 3) has been proposed.

Open Shortest Path First (OSPF) version2, IETF RFC2328 A Border Gateway Protocol 4 (BGP-4), IETF RFC4271 Shortest Path Bridging (SPB), IEEE 802.1aq-2012

  However, SPB is a technique that enables operation in a network topology with a higher degree of freedom other than a bus type or a tree type as in an IP network even in Ethernet. However, in SPB, for example, there remains a problem in ensuring reliability necessary for solving the loop problem that is a problem peculiar to the Ethernet communication protocol.

  In view of the above circumstances, an object of the present invention is to provide a technique that enables common transfer and path control to be performed regardless of differences in communication protocols to which input packets correspond.

  One aspect of the present invention specifies route instruction information indicating a route until a packet input to an input port reaches a destination, and adds the route instruction information to the input packet; A switch unit that performs path switching so that a packet input from the input interface unit is output from the output port indicated by the path instruction information, and is connected between the output port and the switch unit, and the switch unit An output interface unit that outputs a packet output from a corresponding output port, and a controller that performs control related to specification of the route instruction information, and a packet corresponding to a user network interface is input to the switch unit The designated input port is the route instruction information of the input interface unit. Is connected via the addition of paths, a router device input ports the packet is input corresponding to the network network interface is connected not via a path for adding the routing information.

  One aspect of the present invention is the router device described above, further including a storage unit that stores route instruction information added to the packet in a storage unit, wherein the input interface unit has the destination of the input packet as the route instruction. If it is the same as the packet to which the information is added, the route instruction information stored in the storage unit is added to the inputted packet without specifying the route instruction information.

  One aspect of the present invention is the above router device, wherein the input interface unit is provided for each input port, and when a packet corresponding to the user network interface is input, the input packet is When a packet corresponding to the network interface is input through a path to which route instruction information is added, the input packet is output without being routed through a path to which the route instruction information is added.

  One aspect of the present invention is the above-described router device, and the controller is connected to a router device including the input interface unit, the switch unit, and the output interface unit via a network.

  One aspect of the present invention is the router device described above, wherein the input interface unit that receives a packet corresponding to a user network interface adds transfer destination information indicating a transfer destination router device to the input packet. When the router device corresponding to the destination of the packet corresponding to the user network interface receives the packet to which the forwarding destination information is added, the forwarding is performed from the output port corresponding to the added forwarding destination information. The router relay information based on the one or more transfer destination information is output to the router device to which the first transfer destination information is added, and the input interface unit of the router device to which the first transfer destination information is added includes the transfer destination information. Route instruction information based on the router relay information is attached to the packet with the same destination as the packet to which Doing, so that in accordance with the added routing information is transferred.

  One aspect of the present invention is the above-described router device, which includes a plurality of the input interface units, the switch unit to which packets output from the plurality of input interface units are input, and the output interface unit And a net.

  One aspect of the present invention is a path control method in a router device including an input interface unit, a switch unit, an output interface unit, and a controller, wherein the input interface unit receives a packet input to an input port as a destination. An input interface step for specifying route instruction information indicating a route to reach the destination and adding the route instruction information to the inputted packet, and an input port to which a packet corresponding to a user network interface is inputted is the input interface. The switch unit connected via a path to which the route instruction information is added, and an input port to which a packet corresponding to a network interface is input is connected without going through the path to which the route instruction information is added For the input packet according to the routing information. A switching step for switching a route so that the output is output from the output port shown, and the output interface unit connected between the output port and the switch unit A path control method for executing an output interface step for outputting from an output port.

  One embodiment of the present invention is a computer program for causing a computer to function as the router device.

  According to the present invention, it is possible to perform common transfer and path control regardless of a difference in communication protocol to which an input packet corresponds.

It is a figure which shows the structural example of the router apparatus in 1st Embodiment. It is a figure which shows the example of the IP packet to which route instruction information was added in 1st Embodiment. It is a figure which shows the example of a mode of the connection between the some router apparatuses in 1st Embodiment. It is a figure which shows the structural example of the input interface part in 2nd Embodiment. It is a figure which shows the example of the path | route information which the cache part in 2nd Embodiment memorize | stores. It is a figure which shows the example of the IP packet to which route instruction information was added in 2nd Embodiment. It is a figure which shows the structural example of the router apparatus in 3rd Embodiment. It is a figure which shows the structural example of the input interface part in 3rd Embodiment. It is a figure which shows an example of the network structure containing the router apparatus in 3rd Embodiment. It is a figure which shows the structural example of the router apparatus in 4th Embodiment. It is a figure which shows the example of a connection aspect between the networks by the some router apparatus 100 in 4th Embodiment. It is a sequence diagram which shows the example of a process sequence which the router apparatus connected between networks in 5th Embodiment performs. It is a sequence diagram which shows the example of a process sequence which the router apparatus connected between networks in 5th Embodiment performs. It is a figure which shows the example of the IP packet in 5th Embodiment. It is a figure which shows the structural example of the network communication network in 6th Embodiment. It is a figure which shows the structural example of a router apparatus. It is a figure which shows the example of the IP packet to which the internal label was added by the router apparatus.

<First Embodiment>
FIG. 1 shows a configuration example of the router device 100 in the present embodiment. The router device 100 of this embodiment inputs a packet transferred from an external network (or subnet), and transfers the input packet to a transfer destination node indicated by the destination IP address. The router device 100 according to the present embodiment corresponds to an optical cross-connect capable of wavelength-multiplexing and transmitting signal lights having different wavelengths on an optical fiber, and capable of selecting wavelengths and switching routes.

  The router device 100 in FIG. 1 includes input interface units 110-1 to 110-(N−1), a switch unit 120, output interface units 130-1 to 130 -N, and a controller 140.

  In the following description, when the input interface units 110-1 to 110- (N-1) are not particularly distinguished, they are described as the input interface unit 110, and the output interface units 130-1 to 130-N are particularly distinguished. If not, it is described as an output interface unit 130.

  In the router apparatus 100 according to the present embodiment, each of the N input ports # 1 to #N for inputting a packet is a UNI (User Network Interface) as an interface corresponding to a transfer source of the input packet. And NNI (Network Network Interface) are assigned in advance.

  Specifically, in the example of the figure, UNIs are assigned to odd-numbered input ports such as input port # 1, input port # 3, input port # 5. NNI is assigned to even-numbered input ports such as port # 2, input port # 4, input port # 6... Input port #N.

  Note that the above-described aspects of UNI and NNI allocation to the input ports # 1 to #N are merely examples. For example, UNI (or NNI) may be assigned to input ports # 1 to # k-1, and NNI (or UNI) may be assigned to input ports #k to #N. Also, the number of input ports assigned to UNI and NNI need not be the same.

  An input interface unit 110 is provided for each input port corresponding to the UNI. The input interface unit 110 includes a route search unit 111 and a label assignment unit 112.

An IP packet transmitted from the user terminal is input to the input port corresponding to the UNI.
The route search unit 111 searches the forwarding table held by itself using the destination IP address stored in the input IP packet.

  The forwarding table in the present embodiment reflects the route information specified by the controller 140 through source routing. That is, in the forwarding table, for example, corresponding to each destination IP address, information on the router device that passes through the route to the router device of the network including the destination IP address is shown.

  The route search unit 111 searches the forwarding table corresponding to the route search unit 111 to identify route instruction information indicating the route to the destination IP address for the input IP packet. The route instruction information here is information indicating the router device (relay router) through which the IP packet passes until the destination IP address is reached.

  The label assignment unit 112 stores the route instruction information specified by the route search unit 111 in the input IP packet. Specifically, as shown as an IP packet in FIG. 2, a plurality of output port numbers (output port numbers) corresponding to the next router device to the router device of the network including the destination IP address are respectively added as labels. The That is, the route instruction information is stored in the IP packet in the label stack format. Such label addition can be performed at high speed because it is a simple routing process to the output port.

In the example of the figure, the route instruction information includes labels indicating the output port numbers of # 4, # 2, and # 5 from the outside to the inside of the label stack. Such routing information is output from the output port # 4 of the first-stage router device when the IP packet is transferred to the next-stage (second-stage) router device. When transferring the IP packet to the router device, the IP packet is output from the output port # 2 of the second-stage router device, and the IP to the third- to fourth-stage router device (router device of the network including the destination IP address) This indicates that the packet is transferred from the output port # 5 of the third-stage router device.
The label assigning unit 112 outputs the IP packet storing the route instruction information to the switch unit 120.

  On the other hand, an IP packet to which a label as route instruction information has been added is input to an input port corresponding to NNI. In this case, there is no need to newly add route instruction information by the router device 100. Therefore, an input port corresponding to NNI is connected to the switch unit 120 without going through the input interface unit 110.

The switch unit 120 outputs the IP packet input from each of the input ports from the output port indicated by the route instruction information added to the input IP packet among the output ports # 1 to #N. Performs route switching and outputs.
As described above, the IP packets output through the route switching of the switch unit 120 are all in a format to which route instruction information is added.

  The output interface units 130-1 to 130-N are provided corresponding to the output ports # 1 to #N. Each of the output interface units 130 receives the IP packet output from the switch unit 120 and outputs the IP packet from a corresponding output port. The output interface unit 130 shown in the figure includes a label removal unit 131 and a priority control unit 132.

The label removal unit 131 removes the label indicating the output port corresponding to the own router device from the route instruction information as the label stack stored in the IP packet input to the output interface unit 130.
The priority control unit 132 outputs the IP packet after performing the priority control when the priority control is necessary for the input IP packet.

  The controller 140 executes control related to the specification of the route instruction information in the router device 100. The controller 140 obtains route information by a routing protocol and constructs a routing table. The forwarding table held by the input interface unit 110 is created based on the routing table.

  The router device 100 in the present embodiment is provided for each network (including subnets). The router device 100 corresponding to each network is connected as shown in FIG. 3, for example.

  In the figure, an example in which three router apparatuses 100-1, 100-2, and 100-3 are connected is shown. In the figure, a router device 100-1 is a first-stage (first-stage) router apparatus 100 serving as a gateway router. The router device 100-2 is the router device 100-2 in the second stage. The router device 100-3 is the router device 100-3 at the third stage.

  As described above, all the IP packets output from each of the output ports of the router device 100 have a format in which route instruction information is added. Therefore, the second-stage router apparatus 100-2 inputs the IP packet transferred from the first-stage router apparatus 100-1 through an input port corresponding to NNI.

Similarly, the third-stage router apparatus 100-3 inputs an IP packet transferred from the second-stage router apparatus 100-2 through an input port corresponding to NNI.
That is, when the IP packet via UNI input to the first-stage router apparatus 100-1 is transferred in the order of the second-stage router apparatus 100-2 and the third-stage router apparatus 100-3, The routing instruction information is added to the packet only by the input interface unit 110 in the first-stage router device 100-1.

  Here, when it is specified that the route of the UNI-compatible IP packet input by the router device 100-1 is a route that passes through the router devices 100-2 and 100-3 in order, the transfer is performed as follows. Control is performed.

  In the first-stage router apparatus 100-1, the IP packet to which the route instruction information is added by the input interface unit 110 is switched to the output port of the number indicated by the added route instruction information by the switch unit 120. . The output port of the switching destination is an output port connected to the NNI-compatible input port in the second-stage router device 100-2. The IP packet output from the switch unit 120 is input to the output interface unit 130 connected to the corresponding output port.

  The output interface unit 130 of the router device 100-1 removes the label indicating the output port number corresponding to the router device 100-1 from the label stack as the route instruction information for the input IP packet, and if necessary, Output priority from the corresponding output port. As a result, the IP packet to which the route instruction information is added by the first-stage router apparatus 100-1 is input to the NNI-compatible input port of the second-stage router apparatus 100-2.

  In the second-stage router device 100-2, the IP packet input to the NNI-compatible input port is input to the switch unit 120 without going through the input interface unit 110. Note that the input interface unit 110 in the second-stage router apparatus 100-2 is connected to a UNI-compatible input port, and thus inputs an IP packet transferred from a user network not shown in the figure.

  In the second-stage router apparatus 100-2, the switch unit 120 outputs the input IP packet from the output port connected to the NNI-compatible input port of the router apparatus 100-3 indicated by the route instruction information. Switch the route to The IP packet output from the switch unit 120 is output from the corresponding output port after the corresponding label is removed and priority control is performed if necessary in the output interface unit 130. As a result, the IP packet input to the second-stage router device 100-2 is input to the NNI-compatible input port in the third-stage router device 100-3.

  Also in the third-stage router device 100-3, the IP packet input to the NNI-compatible input port is input to the switch unit 120 without going through the input interface unit 110. Note that the input interface unit 110 in the third-stage router device 100-2 is also connected to a UNI-compatible input port, and thus inputs an IP packet transferred from a user network not shown in the figure.

  In the third-stage router apparatus 100-3, the switch unit 120 performs path switching so that the input IP packet is output from an output port corresponding to the router apparatus indicated by the path instruction information. The IP packet output from the switch unit 120 is output from the corresponding output port after the corresponding label is removed and priority control is performed if necessary in the output interface unit 130.

  As understood from the above description, the router device 100 according to the present embodiment adds the route instruction information in the label stack format to the input UNI-compatible IP packet, thereby enabling the IP address in the NNI-compatible format. Convert to packet. The IP packet in the NNI compatible format is transferred according to the added route instruction information. That is, forwarding by label switching is performed. That is, the IP packet is transferred to the router device at the next stage after the switching is performed with reference to the label as the route instruction information in the switch unit 120 and the corresponding label is removed.

  On the other hand, since the IP packet input from the NNI-compatible input port is in the NNI format with the route instruction information already added, the switch unit 120 and the output interface unit 130 perform the forwarding by label switching as it is, It is transferred to the router device 100 at the next stage.

  In other words, the router apparatus 100 according to the present embodiment has a format in which route instruction information is added corresponding to the NNI when the IP packet input to the input port is input to the switch unit 120 regardless of the type. ing. Therefore, in the switch unit 120 and subsequent units, it is only necessary to carry out forwarding by label switching in common without depending on the format of the input IP packet. Further, as can be understood from the description with reference to FIG. 3, the UNI-compliant IP packet to which the route instruction information is added by the first-stage router device is input and labeled as an NNI-compliant packet in the subsequent-stage router device. Forwarding by switching can be performed. In this way, when the packet is input as an NNI compatible packet, the input interface unit 110 becomes unnecessary. Therefore, forwarding can be performed with a simple configuration.

  As described above, depending on the router device 100 according to the present embodiment, common transfer and path control can be performed regardless of a difference in communication protocol to which an input packet corresponds.

Second Embodiment
Next, the second embodiment will be described. FIG. 4 shows a configuration example of the input interface unit 110A in the present embodiment. In the figure, the same parts as those in FIG.

  In addition to the route search unit 111 and the label assignment unit 112, the input interface unit 110 </ b> A in the same figure further includes a cache unit 113 (an example of a storage unit), a cache processing unit 114, and a multiplexer 115.

  The cache unit 113 stores the route information specified by the route search unit 111. Specifically, as shown in FIG. 5, the cache unit 113 stores path information as cache data in association with the destination IP address. In the figure, an example is shown in which route information indicated by “7, 5, 4” is stored in correspondence with the destination IP address indicated by ad_1. “7, 5, 4” in the route information indicates an output port number for each router device according to the route order in which the IP packet is transferred. In other words, the routing information in the figure sequentially transfers IP packets from the output port # 7 of the first router device, the output port # 5 of the second router device, and the output port # 4 of the third router device. Indicates what should be done.

The cache processing unit 114 reads route information (target route information) associated with the destination IP address stored in the input IP packet from the cache unit 113.
When the read is successful (cache hit) because the target route information is stored in the cache unit 113, the cache processing unit 114 adds the read target route information to the input IP packet to the multiplexer 115. Output.

  Here, the fact that the target route information is stored in the cache unit 113 means that an IP packet having the same destination IP address as the IP packet input this time has already been input in the past. In this case, the route instruction information to be added to the IP packet input this time may be any information that indicates the same route as the target route information that has been successfully read. Therefore, when the target route information is successfully read, the cache processing unit 114 stores the route instruction information based on the read target route information in the IP packet. Thereby, the route search information is added to the IP packet at high speed without performing route search by the route search unit 111.

  FIG. 6 shows an IP packet to which route instruction information is added by the cache processing unit 114 as described above. In the figure, in response to the fact that the destination IP address of the IP packet is ad_1, an example in which the route information associated with the destination IP address of ad_1 in the cache data of FIG. 5 is added as the route instruction information. It is shown.

  On the other hand, when the reading of the target route information fails, the target route information is not stored in the cache unit 113. Therefore, the cache processing unit 114 in this case outputs the input IP packet to the route search unit 111. As a result, the route search unit 111 performs route search on the input IP packet to identify the route information, and the label attaching unit 112 converts the route instruction information as a label stack indicating the specified route information into the IP packet. Add to the corresponding output port. In this case, the route search unit 111 stores the specified route information in the cache unit 113 in association with the destination IP address.

  As described above, the multiplexer 115 receives the IP packet to which the route instruction information is added by the label attaching unit 112 or the IP packet to which the route instruction information is added by the cache processing unit 114. The multiplexer 115 outputs the input IP packet to the switch unit 120.

For example, when transferring user data such as image data, streaming data, and backup data, IP packets (IP fragment packets) of the same destination IP address including the divided user data are consecutive. In the configuration of the input interface unit 110A in the present embodiment, the following operation is obtained in such a case.
That is, in the input interface unit 110A, the cache processing unit 114 fails to read the target route information from the cache unit 113 when the first IP fragment packet is input. Therefore, in this case, the route search unit 111 performs route search, and the label assigning unit 112 performs label assignment. Further, the route search unit 111 stores the route information specified by the route search in the cache unit 113.
When the second and subsequent IP fragment packets are input, the cache processing unit 114 succeeds in reading the target route information from the cache unit 113. Therefore, in this case, the input interface unit 110A adds route instruction information based on the target route information read from the cache unit 113 to the IP packet.
Here, when the time required for the route search unit 111 to search the forwarding table and specify the path information is compared with the time required for the cache processing unit 114 to read the cache unit 113, the latter Is shorter. With the configuration of the present embodiment, route instruction information can be added to an IP fragment packet and transferred at high speed.

<Third Embodiment>
Subsequently, the third embodiment will be described. FIG. 7 shows a configuration example of the router device 100 in the present embodiment. In this figure, the same parts as those in FIG.

  The router apparatus 100 in the figure includes input interface units 110B-1 to 110B-N corresponding to the input ports # 1 to #N, respectively. In the description of the present embodiment, the input interface units 110B-1 to 110B-N are described as the input interface unit 110B unless otherwise distinguished.

FIG. 8 shows a configuration example of the input interface unit 110B. In the figure, the same parts as those in FIG.
The input interface unit 110B shown in the figure further includes a demultiplexer 116 and a multiplexer 117 in addition to the route search unit 111 and the label assignment unit 112.

The demultiplexer 116 receives an IP packet, and multiplexes the input IP packet without passing through the path (first path) by the route search unit 111 and the label assignment unit 112 and the route search unit 111 and the label addition unit 112. The data is output to one of the paths connected to 117 (second path). When a signal in which a plurality of IP packets are multiplexed is input, the demultiplexer 116 separates the multiplexing of the IP packets, and either the route search unit 111 or the multiplexer 117 is separated for each separated IP packet. Output for.
The multiplexer 117 multiplexes the IP packet that passes through the first path and the IP packet that passes through the second path, and outputs the multiplexed packet to the switch unit 120.

  If the input IP packet is UNI-compliant, the demultiplexer 116 outputs the input IP packet to the first path. As a result, the IP packet corresponding to the UNI is added with the route instruction information through the first path, and is output from the multiplexer 117 to the switch unit 120.

  On the other hand, when the input IP packet is NNI compatible, the demultiplexer 116 outputs to the second path. The route instruction information is already added to the NNI-compatible IP packet. Therefore, in this case, route instruction information is prevented from being added by passing the IP packet through the second path.

  Note that whether the IP packet input to the demultiplexer 116 corresponds to NNI or UNI can be identified based on the presence / absence of route instruction information. Whether the IP packet corresponds to NNI or UNI can be identified by the demultiplexer 116 or the controller 140.

  In such a configuration, an input interface unit 110B having the same configuration is provided for each input port, and processing can be performed in accordance with whether the input IP packet is UNI-compliant or NNI-compliant. . Thereby, for example, path control can be performed more flexibly than when either NNI or UNI is fixedly assigned to each input port.

  In the configuration of the present embodiment, for example, the route instruction information may be added to the UNI-compatible IP packet by the first-stage router device 100 as described in the first embodiment. The router devices 100 in the second and subsequent stages are handled as NNI compatible IP packets and perform forwarding.

  In addition, in the case of the router device 100 according to the configuration of the present embodiment, for example, when an NNI-compatible IP packet and a UNI-compatible IP packet are input to one input interface unit 110B in a multiplexed state, the following As such, each packet can be processed.

  FIG. 9 shows an example of a network configuration including the router device 100 in the present embodiment. The figure shows a mode in which IP packets output from each of the routers R1 and R2 are multiplexed (eg, time division multiplexed) by the L2 switch SW and then input to the router device 100 of the present embodiment. It is.

  In such a case, a signal (multiplexed signal) obtained by multiplexing the IP packet input from the L2 switch SW to the router device 100 is input to one input interface unit 110B. In this case, the input interface unit 110B separates the input multiplexed signal, and outputs the UNI compatible IP packet to the first path among the separated IP packets, and the NNI compatible packet to the second path. Output to. As a result, the NNI compatible IP packet via the second path and the IP packet converted to NNI compatible via the first path are output from the input interface unit 110B to the switch unit 120. That is, the router device 100 according to the present embodiment can perform routing for each of the multiplexed IP packets by using one input interface unit 110B.

<Fourth embodiment>
Subsequently, a fourth embodiment will be described. FIG. 10 shows a configuration example of the router device 100 in the present embodiment. In the figure, the same parts as those in FIG.

  The router apparatus 100 shown in the figure does not include a controller. In the present embodiment, a controller that performs path control is provided outside the router apparatus 100 as a center controller 140A. The center controller 140A is connected to the input interface unit 110A in the router device 100 via the network NW.

  FIG. 11 shows an example of a connection mode between networks by a plurality of router devices 100 in the present embodiment. In the figure, components similar to those in FIG.

  As shown in the figure, the center controller 140A is connected to the input interface unit 110 in each of the plurality of router devices 100 via the network NW. That is, the center controller 140A in the present embodiment is provided in common for the plurality of router devices 100.

  The center controller 140A recognizes route information corresponding to a plurality of connected router devices 100, and holds a routing table corresponding to each router device 100, for example.

  In the router device 100 according to this embodiment, the route search unit 111 of the input interface unit 110 notifies the center controller 140A of the destination IP address of the input UNI-compatible IP packet. The center controller 140A searches the corresponding routing table for route information corresponding to the notified destination IP address, and transmits the searched route information to the input interface unit 110. In the input interface unit 110, the label assigning unit 112 The received route information is added to the IP packet as route instruction information and output to the switch unit 120.

  With such a configuration of the present embodiment, path control can be performed over a plurality of router devices 100 in an integrated manner. This makes it possible to perform efficient route control, for example, by specifying a more optimal route as compared to the case where route control is performed independently for each router device, for example.

  For example, in this embodiment, each of the router devices 100 may hold a forwarding table created based on the routing table constructed by the center controller 140A. In addition, the input interface unit 110 in each of the router devices 100 may specify route information with reference to the forwarding table.

<Fifth Embodiment>
Subsequently, a fifth embodiment will be described. The sequence diagrams of FIGS. 12 and 13 show an example of a processing procedure executed by the router device 100 of the present embodiment for path control.

  12 and 13 show the transfer of IP packets via the four router devices 100-IN, 100-RL1, 100-RL2, and 100-DES connected between networks as the router device 100 of this embodiment. An example in which is performed is shown. The router apparatus 100-IN is an input-side router apparatus to which a UNI-compliant IP packet is input. The router device 100-RL1 is a router device that relays the IP packet transferred from the router device 100-IN. The router device 100-RL2 is a router device that further relays the IP packet transferred from the router device 100-RL1. The router device DES is a router device on the destination side corresponding to the network including the destination IP address.

In this case, among the output ports of the router device 100-IN, the number of the output port connected to the router device 100-RL1 is [#i]. Among the output ports of the router device 100-RL1, the number of the output port connected to the router device 100-RL2 is [#j]. Among the output ports of the router device 100-RL2, the number of the output port connected to the router device 100-DES is [#K].
In the description of the present embodiment, a case where the configuration of the router device 100 is the same as that in FIG. 1 will be described as an example.

  First, with reference to FIG. 12, an example of an IP forwarding processing procedure performed in response to an input of an IP packet whose router relay information is not cached to the router apparatus 100-IN will be described. The packet whose router relay information is not cached is an IP packet in which router relay information associated with the same destination IP address is not stored in the cache provided in the corresponding input interface unit 110. More specifically, for example, it is an IP fragment packet first input to the router apparatus 100-IN.

In the router apparatus 100-IN, an IP packet whose router relay information is not cached is input as a UNI-compliant IP packet (step S101).
FIG. 14 shows the IP packet pck1 input in step S101. In the IP packet pck1, transfer destination information is not yet stored. Ad_1 stored in the IP packet pck1 indicates a destination IP address.

  In response to the input of the IP packet pck1 for which the router relay information is not cached, the route search unit 111 in the input interface unit 110 of the router device 100-IN performs a route search. By the route search, the router device 100-RL1 is specified as the next-stage router device to which the IP packet pck1 is to be transferred. In this case, the label assigning unit 112 uses a label indicating the number #i of the output port connected to the router device 100-RL1 specified by the route search unit 111 as the transfer destination information indicating the output destination router device. It is added to pck1 (step S102).

  FIG. 14 shows an IP packet pck2 obtained by adding transfer destination information indicating the output port number #i to the IP packet pck1 in step S102.

  The IP packet pck2 output from the input interface unit 110 is output by the switch unit 120 to the output interface unit 130 corresponding to the output port of number #i. The output interface unit 130 corresponding to the output port of the number #i outputs the input IP packet pck2 from the output port of the number #i without particularly performing label removal (step S103). That is, the router device 100-IN stores the transfer destination information indicating the next-stage router device 100-RL1 by the input interface unit 110 for the input UNI-compatible IP packet. As a result, the IP packet is transferred from the output port corresponding to the added transfer destination information. That is, the packet is transferred by IP forwarding.

  The router apparatus 100-RL1 inputs the UNI-compatible IP packet pck2 transferred by IP forwarding as described above (step S104). Here, the router device 100-RL2 can determine whether or not the input IP packet is UNI-compatible by, for example, whether or not a label is added.

In the input interface unit 110 of the router device 100-RL2, the route search unit 111 specifies the next-stage router device to which the IP packet is to be transferred in response to the input of the UNI-compatible IP packet pck2. The label assigning unit 112 adds transfer destination information indicating the number of the output port corresponding to the identified router device to the IP packet pck2.
In this case, the next-stage router device to which the IP packet is to be transferred is specified as the router device 100-RL2. In the router device 100-RL1, the number of the output port connected to the router device 100-RL2 is #j. Therefore, the label assigning unit 112 of the router apparatus 100-RL1 further adds transfer destination information indicating the output port number #j to the IP packet pck2 (step S105).

  FIG. 14 shows an IP packet pck3 obtained by further adding transfer destination information indicating the output port number #j to the IP packet pck2 in step S105.

The IP packet pck3 output from the input interface unit 110 is output by the switch unit 120 to the output interface unit 130 corresponding to the output port number #j.
The output interface unit 130 outputs the input IP packet pck3 (step S106). In this way, the IP packet pck3 is also transferred by IP forwarding.

The router apparatus 100-RL2 inputs the UNI-compatible IP packet pck3 transferred as described above (step S107).
In the input interface unit 110 of the router device 100-RL2, the route search unit 111 specifies the next-stage router device to which the IP packet is to be transferred in response to the input of the UNI-compliant IP packet pck3. The label assigning unit 112 adds transfer destination information indicating the number of the output port corresponding to the specified router device to the IP packet pck3.

  In this case, the next-stage router device to which the IP packet is to be transferred is specified as the router device 100-DES corresponding to the destination. In the router device 100-RL2, the number of the output port connected to the router device 100-DES is #K. Therefore, the label assigning unit 112 of the router device 100-RL1 further adds transfer destination information indicating the output port number #j to the IP packet pck3 (step S108).

  FIG. 14 shows an IP packet pck4 obtained by further adding transfer destination information indicating the output port number #j to the IP packet pck3 in step S108.

The IP packet pck4 output from the input interface unit 110 is output by the switch unit 120 to the output interface unit 130 corresponding to the output port of number #K.
The output interface unit 130 outputs the input IP packet pck4 (step S109). In this way, the IP packet pck4 is also transferred by IP forwarding.

The router apparatus 100-DES inputs the IP packet pck4 transferred as described above (step S110).
In the router apparatus 100-DES corresponding to the destination, the input IP packet pck4 is input from the input interface unit 110 to the switch unit 120. The switch unit 120 outputs the IP packet pck4 to the output interface unit 130 corresponding to the output port connected to the destination IP address in the network corresponding to the router device 100-DES. The output interface unit 130 having received the IP packet pck4 transfers the input IP packet pck4 to the destination IP address (step S111).

  Further, as illustrated in FIG. 14, the router device 100-DES extracts the destination IP address in the input IP packet pck4 and the transfer destination information added so far as router relay information INF_RL. As shown in FIG. 14, the router apparatus 100-DES stores the router relay information INF_RL and transmits an IP packet pck5 destined for the router apparatus 100-IN (step S112). That is, the router device 100-DES notifies the router relay information to the router device 100 to which the first transfer destination information is added. Note that the input interface unit 110 may be configured to extract the router relay information and generate the IP packet pck5 including the extracted router relay information INF_RL. In this case, the input interface unit 110 performs route search for the generated IP packet pck5 using the router device 100-IN as the destination IP address to identify the route information, and sends the IP address to the next-stage router device indicated by the identified route information. A label may be added so that the packet pck5 is transferred.

  The router device 100-IN that has received the IP packet pck5 extracts the router relay information INF_RL from the input IP packet pck5, and stores the extracted router relay information INF_RL in the cache. The router relay information INF_RL can be viewed as a structure in which an output port number (transfer destination information) for each router device arranged in the order of passage up to the destination IP address is associated with the destination IP address.

Next, with reference to FIG. 13, description will be given of transfer by label switching that is executed in response to an input of an IP packet whose router relay information is already cached.
The IP packet whose router relay information is already cached is an IP packet in which router relay information including the same destination IP address is cached among IP packets input to the router device 100-IN.

In the router apparatus 100-IN, an IP packet whose router relay information is already cached is input as an IP packet corresponding to UNI (step S121).
In this case, in the router device 100-IN, the route search unit 111 in the input interface unit 110 that has input the IP packet may not perform the route search. Then, the label assigning unit 112 in the input interface unit 110 sends the transfer destination information in the router relay information INF_RL including the same destination IP address as the input IP packet to the route instruction in the label stack format for the input IP packet. Information is added (step S122).
FIG. 14 shows an IP packet pck6 to which transfer destination information in the router relay information INF_RL is added as route instruction information.

  The IP packet pck6 to which the route instruction information is added is input to the switch unit 120. The switch unit 120 outputs the input IP packet pck6 to the output interface unit 130 corresponding to the output port number #i indicated by the reference target label in the route instruction information. In this case, the output port number #i indicated by the label to be referenced is the number of the output port connected to the router device 100-RL1.

  The output interface unit 130 removes the reference target label from the route instruction information for the input IP packet pck6, and outputs it from the corresponding output port (step S123). That is, in this case, the IP packet pck6 is transferred by label switching. The IP packet pck6 output in step S123 is input to the router device 100-RL1 at the next stage as indicated by the route instruction information.

  The IP packet pck6 output from the router apparatus 100-IN has a format corresponding to NNI by adding the route instruction information. Therefore, in the router device 100-RL1, the IP packet pck6 input from the router device 100-IN is input to the switch unit 120 without passing through the input interface unit 110. The switch unit 120 outputs the input IP packet to the output interface unit 130 corresponding to the output port number #j indicated by the reference target label in the route instruction information. In this case, the output port number #j indicated by the reference target label is the number of the output port connected to the router device 100-RL2. The output interface unit 130 having received the IP packet pck6 removes the label to be referred to this time from the route instruction information, and outputs it from the corresponding output port (step S124). That is, in this case as well, IP packet transfer by label switching is performed.

  Also in the router device 100-RL2, the NNI-format IP packet pck6 input from the router device 100-RL1 is input to the switch unit 120 without passing through the input interface unit 110. The switch unit 120 outputs the input IP packet pck6 to the output interface unit 130 corresponding to the output port number #K indicated by the label to be referenced in the route instruction information. The output port number #K indicated by the reference target label is the number of the output port connected to the router device 100-DES.

The output interface unit 130 having received the IP packet pck6 removes the label of the output port number corresponding to the IP packet pck6 and outputs it from the corresponding output port by label switching (step S125).
The router apparatus 100-DES transfers the IP packet pck6 output in step S125 to the destination IP address (step S126).

  According to such a configuration, when a large number of IP packets having the same destination IP address are transmitted, the cached router relay information is used as the route instruction information for the second and subsequent IP packets without performing route search. It is possible to add and transfer by label switching. As a result, the time required to transfer the packet in the router device through which the IP packet passes is shortened, and the transfer delay of the IP packet can be suppressed.

<Sixth Embodiment>
Subsequently, a sixth embodiment will be described. FIG. 15 shows a configuration example of a network communication network supported by the present embodiment. In this figure, the same parts as those in FIG. 1 and FIG.

  In the network communication network shown in the figure, input interface units 110-1 to 110-N are provided for every N input ports # 1 to #N. Each of the input interface units 110-1 to 110-N is connected to the center controller 140A via the network NW.

  The input interface unit 110 specifies route information corresponding to the destination of the input UNI-compatible IP packet by route search, adds the specified route information to the IP packet in the form of a label stack, and switches the switch network SWN. Output to.

  Note that NNI-compatible IP packets may also be input to the switch network SWN. The NNI-compatible IP packet may be input to the switch network SWN via an input port not including the input interface unit 110, for example. Alternatively, in the present embodiment, as in the input interface unit 110B of FIG. 8, the first path to which route information is added and the second path to which route information is not added may be switched.

  The switch network SWN is input with either an IP packet in the NNI format by adding route information to a UNI-compatible IP packet or an NNI-compatible IP packet to which route information has been added.

  The switch network SWN includes, for example, the functions of the switch unit 120 in FIG. 1 and the output interface unit 130 provided corresponding to each output port. That is, in this embodiment, the switch network SWN functions as one router device.

  In such a configuration, the route search is performed by the input interface units 110-1 to 110-N before the IP packet is input to the switch network SWN. That is, an IP packet to which route information in the label stack format has been added is input to the switch network SWN.

  The longest match search performed as a route search is an electrically complicated process. In this embodiment, the route search process is performed before the IP packet is transferred to the switch network SWN. For this purpose, the switch network SWN according to the present embodiment performs a process of switching the route by referring to the route information stored in the IP packet for the packet input by the function of the switch unit 120, and the output interface unit 130. The process of removing the label of the route information may be performed by the function. Since these processes are simple processes, the processing load on the switch network SWN can be reduced. Thereby, the mounting configuration of the relay router corresponding to the switch network SWN can be simplified.

  You may make it implement | achieve at least one part of the router apparatus in embodiment mentioned above with a computer. In that case, a computer program for realizing this function may be recorded on a computer-readable recording medium, and the computer program recorded on the recording medium may be read by the computer system and executed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a computer program that is dynamically stored for a short time, such as a communication line when a computer program is transmitted via a network such as the Internet or a communication line such as a telephone line. What is held, and what holds a computer program for a certain period of time, such as a volatile memory inside a computer system serving as a server or client in that case, may also be included. The computer program may be for realizing a part of the functions described above, and may be a combination of a computer program already recorded in the computer system with the functions described above. It may be realized using a programmable logic device such as an FPGA (Field Programmable Gate Array).

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

DESCRIPTION OF SYMBOLS 100 ... Router apparatus, 110 ... Input interface part, 111 ... Route search part, 112 ... Label assignment part, 113 ... Cache part, 114 ... Cache processing part, 115 ... Multiplexer, 116 ... Demultiplexer, 117 ... Multiplexer, 120 ... Switch , 130 ... Output interface unit, 131 ... Label removal unit, 132 ... Priority control unit, 140 ... Controller, 140A ... Center controller

Claims (8)

An input interface unit that identifies route instruction information indicating a route until the packet input to the input port reaches the destination, and adds the route instruction information to the input packet;
For a packet input from the input interface unit, a switch unit that performs path switching so that the packet is output from the output port indicated by the path instruction information;
An output interface unit connected between the output port and the switch unit, and outputting a packet output from the switch unit from a corresponding output port;
A controller that performs control related to the specification of the route instruction information,
An input port to which a packet corresponding to a user network interface is input is connected to the switch unit via a path to which the route instruction information of the input interface unit is added, and a packet corresponding to the network interface is input. A router device to which a designated input port is connected without going through a path to which the route instruction information is added. A storage unit that stores the route instruction information added to the packet in the storage unit;
The input interface unit is
If the destination of the input packet is the same as the packet to which the route instruction information is added, the route instruction information stored in the storage unit is not input without specifying the route instruction information. The router device according to claim 1, wherein the router device is added to a packet. The input interface unit is
When a packet corresponding to the user network interface is input for each input port, the input packet is routed through a path to which the route instruction information is added, and a packet corresponding to the network interface is The router device according to claim 1, wherein when the packet is input, the input packet is output without being routed through a path to which the route instruction information is added. The controller is
The router apparatus as described in any one of Claim 1 to 3 connected via a network with respect to the router apparatus provided with the said input interface part, the said switch part, and the said output interface part. The input interface unit that has input a packet corresponding to the user network interface adds transfer destination information indicating a transfer destination router device to the input packet, thereby outputting an output port corresponding to the added transfer destination information Transfer from
When the router device corresponding to the destination of the packet corresponding to the user network interface receives the packet to which the transfer destination information is added, the router relay information by the one or more transfer destination information added is transferred to the first transfer destination. Output to the router device with the information added,
The input interface unit of the router device to which the first transfer destination information is added is added by adding route instruction information based on the router relay information for a packet having the same destination as the packet to which the transfer destination information is added. The router device according to any one of claims 1 to 4, wherein the transfer is performed according to the route instruction information. A plurality of the input interface units;
The router apparatus according to claim 1, further comprising: a switch network including the switch unit to which packets output from the plurality of input interface units are input and the output interface unit. A route control method in a router device comprising an input interface unit, a switch unit, an output interface unit, and a controller,
An input interface step in which the input interface unit identifies route instruction information indicating a route until a packet input to an input port reaches a destination, and adds the route instruction information to the input packet;
An input port to which a packet corresponding to the user network interface is input is connected via a path to which the route instruction information of the input interface unit is added, and an input port to which the packet corresponding to the network interface is input is the path. A switching step for switching the path so that the switch unit connected without going through the path to which the instruction information is added is output from the output port indicated by the path instruction information for the input packet;
An output interface step for causing the output interface unit connected between the output port and the switch unit to output a packet output from the switch unit from a corresponding output port; and
Path control method to execute.   The computer program for functioning a computer as a router apparatus as described in any one of Claims 1-6.

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