JP4520934B2 - Complex network and gateway router - Google Patents

Description

  The present invention relates to a traffic forwarding technique in a network, and more particularly to a communication method between gateway routers.

  In order to cope with the rapid increase in IP (Internet Protocol) traffic, a large amount of traffic is diverted from the IP network to the optical network, the cost required for transferring IP packets is reduced, and as a result, the network becomes larger and more economical. Is desired. A technology that realizes this is GMPLS (Generalized Multi-Protocol Label Switching) that can control and integrate the router and OXC (optical cross-connect) and flexibly establish and release the optical path from the router (non-patented) Reference 1).

GMPLS is a protocol group that realizes optical path control, and standardization of these protocols is in progress in the Internet Engineering Task Force (IETF). However, the GMPLS regulations are intended for how to control the optical path, and it is not included in the target how to communicate traffic at the IP layer after the optical path is established.
Eric Mannie (Editor), “Generalized Multi-Protocol Label Switching (GMPLS) Architecture”, RFC 3945 [online], Oct 2004, IETF, [searched September 20, 2005], Internet <URL: http: // www. ietf.org/rfc/rfc3945.txt>

In general, in an IP network, route information is exchanged between a plurality of routers by a routing protocol, and a routing table for determining a transfer destination of an IP packet based on the route information is generated. An optical path established by GMPLS looks like a normal link when viewed from the router. Therefore, if a routing protocol is operated on the link, routing of the IP network becomes possible independently of control of GMPLS.
However, when an optical path is frequently established and released by GMPLS, the above method frequently updates the topology of the IP network, and the network may not be stable. Furthermore, there is also a problem that route information is frequently exchanged and a load is applied to the router. The present invention has been made to solve such problems, and an object of the present invention is to provide a composite network capable of stabilizing the network and suppressing a load on a router constituting the IP network, and the composite network. It is an object to provide a gateway router constituting a network.

In order to solve the above problem, an invention according to claim 1 is an IP network including a plurality of gateway routers connected to a plurality of external networks and a plurality of routers that relay forwarded traffic. A composite network including a plurality of optical cross-connects respectively connected to a plurality of gateway routers and providing an optical path between the plurality of gateway routers, A routing table that includes a destination address indicating the destination of the network and a next-hop information indicating the address of the router to which traffic is transferred next, and an optical path establishment control means for establishing an optical path between a plurality of optical cross-connects If, when the optical path establishment control means establishes a light path, the light path Receiving an address applied, the entries with the address applied to the optical path which has received the information of the next hop, and a cooperative control means for recording in the routing table, the traffic between a plurality of external network The present invention proposes a composite network for transferring via optical paths established between optical cross-connects connected to a plurality of gateway routers connected to external networks.

  Further, in the invention according to claim 2, the gateway router uses the IBGP (Internal Border Gateway Protocol) to advertise the route information of traffic transferred between a plurality of external networks via the IP network. The gateway router that further includes a route search means for receiving the route information, and proposes a composite network in which the next hop to which the traffic is transferred is set to the address of the optical path by the cooperation control means.

  According to a third aspect of the present invention, the optical path establishment control means establishes an optical path using a GMPLS (Generalized Multi-Protocol Label Switching) protocol, and the cooperation control means receives an external network after establishing the optical path. In order to divert the forwarded traffic to the established optical path, the address given to the optical path is notified as the extension information of GMPLS signaling, and this address is used as the next hop of BGP (Border Gateway Protocol) to the gateway router. Provide a composite network that records in the routing table.

  In the invention according to claim 4, when the cooperation control unit records the entry in which the next hop information is specified as the address assigned to the optical path in the routing table, the priority of the entry is high. The information shown is also recorded, and the gateway router provides a composite network that selects the traffic forwarding route according to the priority recorded in the routing table.

The invention according to claim 5 is a gateway router that is connected to an external network and an optical cross-connect and constitutes an IP network including a plurality of routers, wherein a destination address indicating a traffic destination and the traffic are A routing table containing information on the next hop indicating the address of the router to be transferred, an optical path establishment control means for controlling establishment and release of an optical path between optical cross-connects, and an optical path establishment control means. Coupling control means for receiving an address assigned to the optical path when establishing the optical path and recording an entry assigned to the optical path that received the next hop information in the routing table, Routing in which the link control means rewrites the traffic transferred to a given external network Based on Buru, it provides a gateway router forwarding toward the optical path where the light path establishment control unit is established.

  According to a sixth aspect of the present invention, there is provided route search means for advertising and receiving route information of traffic transferred between a plurality of external networks via an IP network using IBGP (Internal Border Gateway Protocol). In addition, the cooperation control means provides a gateway router that sets the next hop to which traffic is forwarded to the address of the optical path when the route information is received.

  Further, in the invention according to claim 7, the optical path establishment control means establishes an optical path using a GMPLS (Generalized Multi-Protocol Label Switching) protocol, and the cooperation control means sends an external network after establishing the optical path. In order to divert the transmitted traffic to the established optical path, the address given to the optical path is notified as extended information of GMPLS signaling, and this address is sent to the routing table as the next hop of BGP (Border Gateway Protocol). A gateway router for recording is proposed.

  In the invention according to claim 8, when the cooperation control unit records the entry in which the next hop information is specified as the optical path address in the routing table, the information indicating that the priority of the entry is high. A gateway router that records and selects a traffic forwarding route according to the priority recorded in the routing table is provided.

  The invention according to claim 9 is a program for causing a computer to operate as a gateway router.

  According to the first aspect of the present invention, traffic that communicates between external networks can be transferred using an optical path without operating IP routing on an optical path established between gateway routers. Become. This prevents the topology of the IP network from changing due to the establishment or release of the optical path, prevents an increase in the load on the router that constitutes the IP network, and frequently controls the optical path while maintaining the stability of the IP network. Will be able to.

  According to the second aspect of the present invention, it is possible to transfer traffic to the optical path in conjunction with IBGP that is normally used as a routing protocol when transferring traffic between external networks via an IP network. As a result, the traffic transferred between the external networks can be transferred via the optical path without any change in the routing design of the current IP network.

  For example, assuming another ISP (Internet Service Provider) as an external network, when an IP network is used to provide a transit service from a downstream ISP to an upstream ISP or a transit service for a peering ISP, Traffic that simply passes through the IP network (transit traffic) can be transferred via the optical path, and no load is applied to the router of the IP network. Further, assuming a corporate network that is a user of an IP network as an external network, if there is a lot of traffic between sites of the corporate network, the traffic can be transferred through an optical path.

  In this way, since IBGP is used for exchanging route information between external networks with a large amount of traffic in general, the traffic is bypassed to the optical path without taking care of the setting of the already operating IBGP. The effect that can be achieved is particularly great in that it is less affected by setting changes during installation.

  According to the invention of claim 3, by notifying the IP address assigned to the optical path as the extended information of GMPLS signaling, the routing table can be automatically updated when the optical path is established. . As a result, the network operator can automatically bypass the IP traffic only by instructing the router to establish the optical path, thereby reducing the labor of the operator. Furthermore, since the optical path can be frequently established and released according to the increase / decrease in traffic over time, network resources can be used efficiently as a result.

  According to the fourth aspect of the present invention, even when entries having the same destination address and different next hops are recorded in the routing table, traffic is transferred with priority on the optical path. For example, an entry in which a next hop for a route passing through an IP network is set may be recorded in the routing table even with the same destination address. Since traffic is transferred with priority, network resources can be used efficiently as described above.

  According to the fifth aspect of the present invention, as in the first aspect of the present invention, traffic that communicates between external networks without using IP routing on the optical path established between the gateway routers can be transferred to the optical path. A network that can be used and transferred can be realized.

  According to the invention of claim 6, as in the invention of claim 2, the traffic that communicates between the gateway routers exchanging route information with IBGP can be transferred to the gateway router without modifying the setting of IBGP. A network that can transfer to an optical path established between them can be realized.

  According to the invention of claim 7, as in the invention of claim 3, it is possible to realize a network capable of transferring traffic via the optical path simultaneously with the establishment of the optical path.

  According to the eighth aspect of the invention, as in the fourth aspect of the invention, traffic is transferred with priority given to the optical path.

  According to the ninth aspect of the present invention, the gateway router according to the present invention can be implemented using a computer.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Preferred embodiments of the invention will be described with reference to the accompanying drawings.
In this embodiment, it is assumed that GMPLS is used to establish an optical path (see Non-Patent Document 1), and GMPLS signaling is extended to notify an IP address assigned to the optical path. To do. In the following description, a router is used as a term indicating a device including a gateway router.

(Composite network configuration)
For example, FIG. 1 is a diagram illustrating a configuration of a composite network according to the present embodiment. First, an outline of a composite network will be described with reference to FIG. The composite network of this embodiment is composed of three layers: an IP network 1, an optical network 2, and a GMPLS control plane 3. Hereinafter, each layer will be described in detail.

  First, the IP network 1 is composed of two gateway routers 7 (R1, R2) and two routers 6 (R3, R4), of which the gateway routers 7 (R1, R2) are respectively connected to the external network A ( 4) and a function of connecting to the external network B (5). Further, in the IP network 1, the routers (R1 to R4) operate OSPF (Open Shortest Path First) as a routing protocol to generate a routing table in the IP network 1, and the gateway routers 7 (R1, R2). ) Is operated to exchange route information between the external network A (4) and the external network B (5).

  The external network A (4) and the external network B (5) are networks of an organization different from the IP network 1 (for example, other ISPs, corporate users who are customers of the IP network 1, etc.) In the network, there are networks called subnets (#A, #B), which are connected to gateway routers 7 (R1, R2) of IP network 1 via gateway routers 7 (R11, R21), respectively.

Next, an optical network 2 composed of a plurality of optical cross-connects (OXC) 8 exists in a lower layer of the IP network 1, and gateway routers 7 (Rl, R2) of the IP network 1 are connected to the optical network 2. It has connectivity.
In the lower layer of the optical network 2, there is a GMPLS control plane 3 for performing control such as establishment and release of the optical path of the optical network 2 using the GMPLS protocol, and a gateway router 7 (with optical path establishment capability) ( Rl, R2) and OXC 8 hold a control plane instance 9 that operates the GMPLS protocol. The GMPLS control plane 3 is configured as a logically separate network from the optical network 2 and the IP network 1, but can be physically configured using a part of the IP network 1.

(Gateway router configuration)
Next, FIG. 2 is a configuration diagram illustrating the internal configuration of the gateway router 7 in the present embodiment. The configuration of the gateway router 7 will be described with reference to FIG. 2 (see FIG. 1 as appropriate). Here, only functional units relating to control functions such as the routing protocol and GMPLS protocol related to the present invention are extracted and drawn, but actually a packet transfer processing function and the like are also mounted.

  First, the GMPLS protocol control unit 101 corresponds to the control plane instance 9 of the gateway router 7 (R1, R2) shown in FIG. 1, operates the GMPLS protocol, and controls the establishment and release of an optical path. carry out. The GMPLS protocol control unit 101 transmits an optical path establishment / release signaling message to the OXC 8 and other routers (R1 to R4) via the GMPLS control plane 3. The GMPLS protocol control unit 101 corresponds to the optical path establishment control means in the claims.

  Next, the GMPLS-BGP cooperation control unit 102 cooperates with the GMPLS protocol control unit 101 and the BGP protocol control unit 103 to receive from the establishment destination (destination) of the optical path when a new optical path is established. The routing table 106 is rewritten in order to transfer a packet destined for the BGP route to the optical path. The detailed operation procedure of the GMPLS-BGP cooperation control unit 102 will be described later. The GMPLS-BGP cooperation control unit 102 corresponds to the cooperation control means in the claims.

  Next, the BGP protocol control unit 103 establishes a peer of IBGP (Interior BGP) with another gateway router 7 (R1 or R2), receives the route information, and displays the result as a BGP table 107 and a routing table. 106, and the route information is advertised to the external network A (4) and the external network B (5). Conversely, route information is obtained from the external network A (4) and the external network B (5) through the peer of EBGP (Exterior BGP) established between the external network A (4) and the external network B (5). It also serves to receive and advertise it to other gateway routers 7 (R1 or R2). The BGP protocol control unit 103 corresponds to route search means in the claims.

  Next, the OSPF protocol control unit 104 establishes an OSPF neighbor with the adjacent router 6 (R3 or R4) in the IP network 1, and exchanges route information in the IP network 1. The result is recorded in the OSPF table 108 and also recorded in the routing table 106.

  Next, the optical path DB 105 is a database that stores information on optical paths established by the GMPLS protocol control unit 101 using the GMPLS protocol. Here, FIG. 3 is a table showing an example of information stored in the optical path DB 105. As shown in FIG. 3, the optical path DB 105 includes a destination router ID 201 indicating an ID of a router (R1 to R4) serving as an optical path destination, and other information 202 regarding the optical path attribute (bandwidth, path type, route). Etc .: omitted in FIG. 3) In addition to the optical path address 203 indicating the interface address (address recognized on the IP network) of the optical path on the own side as information newly required in the present embodiment, And the destination optical path address 204 indicating the interface address of the other party's optical path.

The routing table 106 is equivalent to a general router routing table. Here, FIG. 4 is a table showing an example of information stored in the routing table 106. As shown in FIG. 4, the routing table 106 includes a destination address 301 indicating the destination of the packet, a next hop 302 indicating the address of the router (R1 to R4) to which the packet destined for the destination address 301 is transferred next, When there are a plurality of next hops for the same destination address and an output interface 303 indicating the number of an interface that outputs a packet to reach the router (R1 to R4) designated by the next hop, A cost 304 indicating the priority between them is included and stored.
In the routing table 106 shown in FIG. 4, when “R11” or “R3” is described in the next hop 302 item, it indicates the interface address of the router (R11, R3) shown in FIG. And Originally, it should be described in the IP address format, but here, for the sake of simplicity, the router numbers (R1 to R4, R11, R21) shown in FIG. 1 are used.

Next, the BGP table 107 is equivalent to a BGP database held by a general gateway router. Here, FIG. 5 is a table showing an example of information stored in the BGP table 107. It should be noted that the BGP table 107 shown in FIG. 5 is written by extracting only the portions necessary for explaining the present embodiment.
As shown in FIG. 5, in the BGP table 107, the destination address 401 indicating the destination of the packet and the router ID of the other router (R1 or R2) that advertised the route information of the destination address 401 by BGP are described. , The item “BGP Next Hop” indicated by reference numeral 402 is stored. The BGP table 107 shown in FIG. 5 shows the BGP table 107 of the gateway router 7 (Rl). For example, in the first row, the gateway table 7 (R1) itself is connected to the external network A (4 In the second line, the gateway router 7 (R2) displays the route information of the subnet #B in the external network B (5) as the gateway router 7 (Rl). ). Thereby, it is understood that the gateway router 7 (Rl) has only to transmit the packet addressed to the subnet #B in the direction of the gateway router 7 (R2).

  Next, the OSPF table 108 is a table generated by the OSPF protocol control unit 104 and holds information regarding the topology in the IP network 1. Here, FIG. 6 is a table showing an example of information stored in the OSPF table 108. As shown in FIG. 6, the OSPF table 108 stores a pair of a destination address 501 indicating the destination of the packet and a next hop 502 indicating the address of the router (R1 to R4) to which the packet is sent next. . The OSPF table 108 shown in FIG. 6 shows a part of the OSPF table 108 of the gateway router 7 (Rl). For example, in order to transfer a packet to the gateway router 7 (R2), first, the router 6 ( R3) indicates that the packet should be transferred. Also, as shown in the third line, “Direct” is described for the router 6 (R3) having a line with which it can directly communicate, without passing through other routers (R2, R4). It indicates that the packet can be transferred directly.

  The gateway router 7 according to the present embodiment includes a router device composed of dedicated hardware, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a hard disk drive, and a network interface. It is embodied by a computer having a card or the like. For example, when the gateway router 7 is implemented using a computer, the GMPLS protocol control unit 101, the GMPLS-BGP cooperation control unit 102, the BGP protocol control unit 103, and the OSPF protocol control unit 104 shown in FIG. This is realized by developing a dedicated program stored in the drive in the RAM and executing it by the CPU. The optical path DB 105, the routing table 106, the BGP table 107, and the OSPF table 108 of the gateway router 7 are realized by providing a hard disk drive corresponding to each computer or allocating each area of one hard disk drive.

(Packet transfer procedure)
Next, a packet transfer procedure in the composite network having the above-described configuration will be described. FIG. 7 is a sequence diagram for explaining a packet transfer procedure in the composite network shown in FIG. The packet transfer procedure shown in FIG. 7 includes a procedure for advertising route information by BGP (first step), a procedure for transferring a packet before establishing an optical path (second step), and optical transmission using GMPLS signaling. It consists of four stages: a procedure for establishing a path and redirecting a packet transfer path to the optical path (third stage), and a procedure for transferring a packet after establishing the optical path (fourth stage). In the following description, it is assumed that the information of each table shown in FIGS. 3 to 6 is stored in the gateway router 7 (R1). Also, refer to FIGS. 1 to 6 as appropriate.

First, in the first stage, the gateway router 7 (R2) receives route information from the gateway router 7 (R21) of the external network B (5) to the subnet #B by EBGP (step S11), and performs BGP protocol control. The unit 103 advertises the route information to the gateway router 7 (R1) using IBGP (step S12).
At this time, the router ID of the gateway router 7 (R2) (denoted as “R2” in FIG. 7) is specified as “Next Hop” in the IBGP message.
Upon receiving the IBGP route information, the gateway router 7 (R1) records it in the BGP table 107 (second line of the BGP table 107 shown in FIG. 5), and refers to the OSPF table 108 (see FIG. 6). The next hop at the time of packet transfer is determined. In the BGP table 107, the gateway router 7 (R2) is described as “Next Hop” of the subnet #B. Therefore, referring to the OSPF table 108, in order to reach the gateway router 7 (R2), as the next hop, First, it is understood that the packet should be transferred to the router 6 (R3). Therefore, it is recorded in the routing table 106 that the next hop is the router 6 (R3) for the destination address “#B” (second line of the routing table 106 shown in FIG. 4). This procedure is a standard operation in a network that operates BGP and OSPF.

Next, as a second stage, a procedure for transferring a packet via the IP network 1 when the gateway router 7 (Rl) receives a packet addressed to the subnet #B will be described. When the gateway router 7 (Rl) receives the packet addressed to the subnet #B, the gateway router 7 (Rl) refers to the routing table 106 (see FIG. 4) stored therein and detects that the next hop is the router 6 (R3).
Note that since the optical path is not established at the time of the second stage, it is assumed that the entry in the third row of the routing table 106 shown in FIG. 4 has not been described yet. Next, the packet is transferred to the router 6 (R3) (step S21). The same processing is performed in the other routers 6 (R3, R4) and the gateway router 7 (R2) that have received this packet, and finally reaches the destination subnet #B from the gateway router 7 (R21). In this way, in the second stage, packets are transferred via the adjacent routers (R1 to R4, R21) one by one.

  Next, as a third stage, a procedure for establishing an optical path between the gateway routers 7 (Rl, R2) will be described. The instruction to set the optical path itself is given by the operator to the gateway router 7 (R1), or the gateway router 7 (R1) monitors the increase or decrease of the traffic. However, the present invention is not limited to this.

  First, when the gateway router 7 (Rl) receives an instruction to establish an optical path, the GMPLS protocol control unit 101 transmits GMPLS signaling (step S31) to establish an optical path to the gateway router 7 (R2). Notify you. At this time, in addition to the standard-compliant information element, an address (own optical path address) to be given to the own interface after the optical path is established is determined. As the determination method, a method in which the operator inputs to the gateway router 7 (R1), a method in which the gateway router 7 (R1) accumulates addresses that can be used in advance, and a method for appropriately selecting them from there are considered. Here, ‘/ 30’ is assigned as the interface address. For example, “100.1.1.1/30” is assigned in the flowchart shown in FIG.

Next, the gateway router 7 (R2) that has received the signaling message secures an optical path resource by a procedure according to the standard, and then the own optical path address' 100.1. Designated by the gateway router 7 (Rl). An address (destination optical address) used as an interface address by the gateway router 7 (R2) is selected from the same subnet as 1.1 / 30 ′.
In the flowchart shown in FIG. 7, since the gateway router 7 (Rl) uses “100.1.1.1/30”, as an address that can be used from “100.1.1.0/30” that is the same subnet, Select 100.1.1.2/30 '. By specifying “/ 30”, an address that can be used by the gateway router 7 (R2) is arbitrarily determined. Therefore, the selection logic can be simplified, but it is not necessarily “/ 30”. Then, an address selected by the gateway router 7 (R2), for example, '100.1.1.2/30' is assigned to the interface as a destination optical path address (when viewed from the gateway router 7 (Rl)), and a reply of GMPLS signaling It is described in the message and transmitted to the gateway router 7 (Rl) (step S32).

  When the gateway router 7 (Rl) receives the GMPLS signaling response message from the gateway router 7 (R2), the GMPLS protocol control unit 101 establishes the optical path and sets the own optical path address in its own interface. At the same time, the information on the established optical path, the own optical path address, and the destination optical path address are recorded in the optical path DB 105 (step S33, the first line of the optical path DB 105 shown in FIG. 3).

Thereafter, the gateway router 7 (Rl) searches the BGP table 107 (see FIG. 5) by the GMPLS-BGP cooperation control unit 102, and the traffic from the gateway router 7 (R2) to the external network B (5) The routing table 106 (see FIG. 4) is rewritten so as to transfer to the optical path established earlier (step S34).
Specifically, first, “BGP Next Hop” in the BGP table 107 is searched for the same destination router ID (gateway router 7 (R2) in FIG. 3) of the optical path established earlier. In the BGP table 107 shown in FIG. 5, the destination address “#B” in the second row corresponds to this. Next, a new entry is added to the routing table 106 as the destination optical path address “100.1.1.2” of the optical path established earlier as the next hop for the searched destination address. At this time, the cost value of this entry is minimized (third line of the routing table 106 shown in FIG. 4). In addition, it is judged that a priority is so high that this cost value is small.

Finally, as a fourth stage, a procedure for transferring a packet addressed to the subnet #B after establishing the optical path will be described.
As in the second stage, when the gateway router 7 (Rl) receives a packet addressed to the subnet #B, the routing table 106 is searched using the destination address '#B' as a key. In the routing table 106 shown in FIG. 4, there are two entries corresponding to the destination address “#B”. Of these, the entry with the lower cost (the third line where the next hop is “100.1.1.2”) has priority. Is done. Therefore, the next transfer destination of the packet addressed to the subnet #B is “100.1.1.2”, and since the address is assigned to the optical path established earlier, the packet is transferred to the optical path. The

  At this time, if the entry in the third row of the routing table 106 shown in FIG. 4 is not described, a hop-by-Hoff route passing through the router 6 (R3) is selected as in the second stage. . In this embodiment, by notifying the destination optical path address when the optical path is established by GMPLS, the route via the optical path is added to the routing table 106 using the information. As a result, the optical path can be automatically used for transfer after the optical path is established.

The same effect can be obtained by operating the routing protocol on the optical path. However, when the optical path is frequently established and released, the network topology seems to change each time, and the network stability is improved. There is a problem of lacking. In the present embodiment, this problem is solved by automatically using the optical path for transfer without operating the routing protocol on the optical path.
Further, when the optical path is released, the interface address assigned to the optical path becomes invalid, and the GMPLS-BGP cooperation control unit 102 deletes the entry from the routing table 106 (see FIG. 4).

  As described above, according to the composite network according to the present embodiment described above, after the optical path is established by GMPLS, the packet transferred between the external networks via the own IP network without operating the routing protocol on the optical path. It is possible to automatically transfer to that optical path. As a result, packets that are forwarded to the external network can be forwarded via the optical path while maintaining the stability of the network topology, and the external network can be forwarded without affecting the forwarding of traffic in and out of the local IP network. It becomes possible to provide the transfer service between.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various embodiments based on the present invention can be performed by those skilled in the art of the present invention. Is possible. Therefore, the present invention is defined by the technical idea described in the claims.

It is drawing which shows the structure of the composite network which concerns on embodiment of this invention. It is a block diagram of a gateway router. It is drawing explaining the information stored in optical path DB. It is drawing explaining the information stored in the routing table. It is drawing explaining the information stored in the BGP table. It is drawing explaining the information stored in the OSPF table. It is a sequence diagram explaining the transfer procedure of a packet.

Explanation of symbols

1 IP network 2 Optical network 3 GMPLS control plane 4 External network A
5 External network B
6 routers 7 gateway routers 8 OXC (optical cross-connect)
9 Control plane instance 101 GMPLS protocol control unit 102 GMPLS-BGP cooperation control unit 103 BGP protocol control unit 106 Routing table

Claims (9)

An IP network including a plurality of gateway routers connected to a plurality of external networks, and a plurality of routers that relay traffic to be transferred, and a plurality of optical cross-connects respectively connected to the plurality of gateway routers An optical network that provides an optical path between the plurality of gateway routers,
The gateway router is
A routing table that contains a destination address indicating the destination of the traffic and next hop information indicating the address of the router to which the traffic is forwarded next;
An optical path establishment control means for establishing an optical path between the plurality of optical cross-connects;
When the optical path establishment control means establishes an optical path, an address assigned to the optical path is received , and an entry having the next hop information as an address assigned to the received optical path is set as the routing. A linkage control means for recording in a table,
Forwarding traffic transferred between the plurality of external networks via the optical path established between the optical cross-connects connected to the plurality of gateway routers connected to the external network, respectively. ,
A complex network characterized by The gateway router further includes route search means for advertising and receiving the route information of the traffic transferred between the plurality of external networks via the IP network using an IBGP (Internal Border Gateway Protocol). ,
The gateway router that has received the route information sets the next hop to which the traffic is transferred to the address of the optical path by the cooperation control unit,
The composite network according to claim 1. The optical path establishment control means establishes the optical path using GMPLS (Generalized Multi-Protocol Label Switching) protocol,
The cooperation control means notifies an address given to the optical path as extended information of GMPLS signaling in order to divert traffic transferred from the external network to the established optical path after the establishment of the optical path. , Recording this address in the routing table of the gateway router as the next hop of BGP (Border Gateway Protocol),
The composite network according to claim 1, wherein: The cooperation control unit records information indicating that the priority of the entry is high when the entry in which the next hop information is specified as an address assigned to the optical path is recorded in the routing table. And
The gateway router selects a forwarding route of the traffic according to the priority recorded in the routing table;
The composite network according to any one of claims 1 to 3, wherein: A gateway router that is connected to an external network and an optical cross-connect and constitutes an IP network including a plurality of routers,
A destination table indicating a destination of traffic, and a routing table storing information including next hop information indicating an address of the router to which the traffic is forwarded next;
Optical path establishment control means for controlling establishment and release of an optical path between the optical cross-connects;
When the optical path establishment control means establishes an optical path, an address assigned to the optical path is received , and an entry having the next hop information as an address assigned to the received optical path is set as the routing. A linkage control means for recording in a table,
Forwarding the traffic forwarded to a predetermined external network toward the optical path established by the optical path establishment control means based on the routing table rewritten by the cooperation control means;
A gateway router characterized by Route search means for advertising and receiving the route information of the traffic transferred between the plurality of external networks via the IP network using IBGP (Internal Border Gateway Protocol);
When the link control means receives the route information, the next hop to which the traffic is transferred is set to the address of the optical path;
The gateway router according to claim 5. The optical path establishment control means establishes the optical path using GMPLS (Generalized Multi-Protocol Label Switching) protocol,
The cooperation control means notifies an address given to the optical path as extended information of GMPLS signaling in order to divert traffic transmitted from the external network to the established optical path after the establishment of the optical path. Rewriting the routing table with this address as the next hop of BGP (Border Gateway Protocol),
The gateway router according to claim 5 or claim 6, wherein: The cooperation control unit records information indicating that the priority of the entry is high when the entry having the next hop information as an address assigned to the optical path is recorded in the routing table. And
The gateway router selects a forwarding route of the traffic according to the priority recorded in the routing table;
The gateway router according to any one of claims 5 to 7, wherein:   The program for operating a computer as a gateway router of any one of Claim 5 thru | or 8.

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