JP4145834B2 - GMPLS + IP / MPLS node, GMPLS network and inter-network connection method - Google Patents

Description

The present invention relates to a connection scheme between networks using different types of switching schemes. In particular, GMPLS (Generalized Multi Protocol Label Switching) network and IP / MPLS (Internet
(Protocol / Multi Protocol Label Switching) network.

FIG. 6 shows a network composed of conventional IP / MPLS nodes. In the network in IP / MPLS, the switching capability of the interface of the node is all PSC (Packet Switching Capable). The MPLS architecture is defined to support data transfer based on labels (see, for example, Non-Patent Document 1). In RFC3031, LSR (Label
Switching Router) is a node that has a data transfer plane that can identify the boundary of an IP packet or a cell (an IP packet with a label attached), and performs data transfer processing according to the contents of the IP packet header or cell header I mean. In GMPLS, the LSR is not only a node that performs data transfer processing according to the contents of the IP packet header or cell header. The LSR in GMPLS includes devices that perform transfer processing based on information on time slots, wavelengths, and physical ports of files.

On the other hand, the interface of LSR in GMPLS has PSC (Packet Switch Capable), TDM (Time-Division Multiplex Capable), LSC (Lambda) for each switching capability.
Switch Capable) and FSC (Fiber Switch Capable). FIG. 7 shows the concept of labels in GMPLS.

(Description of PSC)
The interface of the PSC can identify the boundary of the IP packet or cell, and performs data transfer processing according to the contents of the IP packet header or cell header. In FIG. 7A, in the packet layer, a uniquely defined label is defined for each link, and the label is added to the IP packet to form an LSP (Label Switch Path). The link in FIG. 7A is a link defined between LSRs for transferring IP packets. When an IP packet is transferred over SDH / SONET, it is an SDH / SONET path, and when it is transferred over Ethernet (registered trademark), it is an Ethernet path.

(Description of TDM)
The TDM interface performs data transfer processing based on time slots that are repeated periodically. In FIG. 7B, in the TDM layer, the label is a time slot. An example of the TDM interface is a DXC (data cross-connect) interface, which connects a time slot assigned to the input side and a time slot assigned to the output side, and thus a TDM path, that is, SDH / SONET. Form a path. The link may be a wavelength path or simply a fiber.

(Explanation of LSC)
The LSC interface performs data transmission processing based on the wavelength in the fiber through which data is transmitted. In FIG. 7C, in the Lambda layer, the label is a wavelength. An example of an LSC interface is an OXC (optical cross-connect) interface, which connects a wavelength assigned to the input side and a wavelength assigned to the output side to form a Lambda path. An OXC interface having an LSC performs switching in units of wavelengths.

(Description of FSC)
The FSC interface performs data transfer processing according to the actual physical port position of the fiber through which data is transmitted. In FIG. 7D, in the fiber layer, the label is a fiber. An example of an FSC interface is an OXC interface, which connects an input side fiber and an output side fiber to form a fiber path. An OXC interface having an FSC performs switching on a fiber basis. A link means a physical collection of fibers, such as a conduit.

The interfaces of the above switching capabilities can be used in layers. In order from the upper layer, FSC, LSC, TDM, and PSC. Also in GMPLS, a path for each of the above switching capabilities is called an LSP. FIG. 8 shows the hierarchical structure of the LSP. PSC-LSP belongs to TDM-LSP, and the link of PSC-LSP is TDM-LSP. TDM-LSP belongs to LSC-LSP, and the link of TDM-LSP is LSC-LSP. The LSC-LSP becomes an FSC-LSP, and the link of the LSC-LSP becomes an FSC-LSP. Considering the case where the TDM layer is omitted, the PSC-LSP belongs to the LSC-LSP, and the link of the PSC-LSP is the LSC-LSP. The relationship between LSC-LSP and FSC-LSP is the same as in FIG. The lower the layer, the larger the LSP bandwidth.
E. Rosen, A. Viswanathan, and R. Callon, "Multiprotocol Label Switching Architecture," RFC 3031. J.Moy, "OSPF Version 2," RFC 2328. R. Coltun, "The OSPF Opaque LSAOption," RFC 2370. K. Kompella and Y. Rekhter, "OSPF Extension in Support of Generalized MPLS," IETFdaft, draft-ietf-ccamp-ospf-gmpls-extensions-12.txt, Oct. 2003. P. Ashwood-Smith et al, “GeneralizedMPLS Signaling-RSVP-TE Extensions”, IETF RFC3473, Jan. 2003. D. Awduche et al., “RSVP-TE: Extensions to RSVP for LSP Tunnels,” RFC 3209, December 2001. A. Banerjee et al, “Generalized Multiprotocol Label Switching: An Overview of Routing and Management Enhancements,” IEEE Commun. Mag., Pp. 144-150, Jan. 2001. D.katz et al., “Traffic Engineering Extensions to OSPF Version2,” IETF RFC3630, Sep. 2003.

  In general, a GMPLS network is composed of two networks. The first is a network for transferring a control packet of a protocol for controlling a network represented by a routing protocol or a signaling protocol. This network is called Control Plane (C-plane).

  The second is a network in which a label path is set by the control protocol. This network is called Data Plane (D-plane), and the user's data packet is transferred in the label path of this D-plane.

  In the GMPLS network, the topology of the network is advertised by a routing protocol. For example, in the case of the Open Shortest Path First (OSPF) protocol, the C-plane network topology is advertised by Router-LSA, and the network topology configured by the D-plane label path is advertised by Opaque-LSA.

  As shown in the background art, when advertising a label path to an IP / MPLS network, Router-LSA (a special Router-LSA for advertising a label path to an IP / MPLS network; here, a label path Router -Calling LSA) will cause some problems.

  For example, the label path Router-LSA created for advertisement to the IP / MPLS network is also advertised inside GMPLS. In general, the GMPLS node manages C-plane and D-plane separately, but if the label path Router-LSA is advertised here, is it the original Router-LSA representing C-plane? The label path Router-LSA cannot be distinguished. That is, a network in which C-plane and label path are mixed is recognized. If a network in which such C-plane and label path are mixed is recognized, it is difficult to select a correct route.

  The present invention is based on such a background, and when the GMPLS network and the IP / MPLS network are connected, the routing protocol operates normally, and based on this, the traffic engineering is performed. Accordingly, it is an object of the present invention to provide a GMPLS + IP / MPLS node and a GMPLS network that can distribute traffic and can effectively use network resources.

  When the GMPLS network and the IP / MPLS network, which are two networks of different management methods, coexist, the label path set in the GMPLS network is advertised as a normal link in the IP / MPLS network, thereby making the IP / MPLS network From the above, it appears that a normal link exists in the GMPLS network, and the GMPLS node can also be regarded as an IP / MPLS node. As a result, the IP / MPLS node can select a route in the GMPLS network according to its own policy. Such a technique is called traffic engineering.

  The point of this technique is that, when the IP / MPLS network is notified of the label path in the GMPLS network that is normally advertised by Opaque-LSA, it is advertised by Router-LSA.

  That is, the first aspect of the present invention is a GMPLS + IP / MPLS node. The feature of the present invention is that the content of the advertised Opaque-LSA is analyzed, and the GMPLS extension is included in the LSA. And means for recognizing that the node that created the Opaque-LSA is a GMPLS node when the GMPLS extension is included in the LSA based on the identification result of the identification means. And means for creating a list of GMPLS nodes based on the recognition result of the means for recognizing, and whether or not the node that created the Router-LSA with reference to the list when the Router-LSA is advertised is a GMPLS node And the Router-LSA based on the confirmation result of the means for confirming When it is confirmed that the created node is a GMPLS node, the Router-LSA is advertised as it is to the GMPLS network, and the GMPLS C-plane among the information of the Router-LSA is displayed on the IP / MPLS network. And a means for deleting the portion shown and advertising.

  As a result, the GMPLS C-plane is not advertised in the IP / MPLS network, and therefore a situation in which a network in which the C-plane and the label path are mixed is recognized in the IP / MPLS network. Therefore, correct route selection can be performed.

  The advertising means, when it is later found that the Router-LSA created by the GMPLS node was mistakenly advertised as it is to the IP / MPLS network, the part indicating the GMPLS C-plane is included in the information held by the Router-LSA. Means for deleting and re-advertisement can be provided.

  At this time, the means for re-advertisement includes means for giving a flag indicating that the Router-LSA is a re-advertisement to the Router-LSA to be re-advertised, and whether or not the flag is present when the Router-LSA is received. When the flag is given, it is possible to provide means for overwriting the previously received Router-LSA with the Router-LSA.

  As a result, even when a Router-LSA from a GMPLS node that is not yet recorded in the GMPLS node list is mistakenly advertised as it is to the IP / MPLS network, this can be corrected.

  A second aspect of the present invention is a GMPLS network characterized in that the GMPLS + IP / MPLS node of the present invention is arranged as an edge node of the GMPLS network.

  According to a third aspect of the present invention, by installing the information processing apparatus, the information of the advertised Opaque-LSA is analyzed in the information processing apparatus, and whether or not the GMPLS extension is included in the LSA. And a function for recognizing that the node that created the Opaque-LSA is a GMPLS node when the GMPLS extension is included in the LSA based on the identification result of the identifying function, and the recognition A function for creating a list of GMPLS nodes based on the recognition result of the function to be performed, and when Router-LSA is advertised, it is checked whether the node that created the Router-LSA is a GMPLS node by referring to the list The node that created the Router-LSA based on the function and the confirmation result of the function to be confirmed When it is confirmed that the node is an MPLS node, the Router-LSA is advertised as it is to the GMPLS network, and the part indicating the GMPLS C-plane is deleted from the information held by the Router-LSA in the IP / MPLS network. And a function corresponding to the GMPLS + IP / MPLS node having the function of advertising.

  When the router-LSA created by the GMPLS node is advertised as it is to the IP / MPLS network as the function to be advertised later, the part indicating the GMPLS C-plane is included in the information held by the router-LSA. The function to delete and re-advertise can be realized.

  As the function of re-advertisement, a function of assigning a flag indicating that the Router-LSA is a re-advertisement to the Router-LSA to be re-advertised is realized, and the presence or absence of this flag is identified when the Router-LSA is received. When the flag is added, the function of overwriting the previously received Router-LSA with the Router-LSA can be realized.

  A fourth aspect of the present invention is a recording medium readable by the information processing apparatus on which the program of the present invention is recorded. By recording the program of the present invention on the recording medium of the present invention, the information processing apparatus can install the program of the present invention using this recording medium. Alternatively, the program of the present invention can be directly installed in the information processing apparatus via a network from a server holding the program of the present invention.

  As a result, when a GMPLS network and an IP / MPLS network are connected using a general-purpose information processing device, the routing protocol operates normally, and traffic engineering is performed based on this to distribute traffic. And a GMPLS + IP / MPLS node and a GMPLS network that can effectively use network resources can be realized.

  The fifth aspect of the present invention is to analyze the content of the advertised Opaque-LSA, identify whether or not the GMPLS extension is included in the LSA, and based on the identification result of this identifying step. When the LMP includes a GMPLS extension, the step of recognizing that the node that created the Opaque-LSA is a GMPLS node, and the step of creating a list of GMPLS nodes based on the recognition result of the recognizing step And when the Router-LSA is advertised, referring to the list, confirming whether or not the node that created the Router-LSA is a GMPLS node, and confirming the Router-LSA based on the confirmation result of the confirming step. Confirmed that the node that created the LSA is a GMPLS node In this case, the router-LSA is advertised as it is to the GMPLS network, and the IP / MPLS network is advertised by deleting the part indicating the GMPLS C-plane from the information of the router-LSA. Is an inter-network connection method executed by an edge node of a GMPLS network connected to an IP / MPLS network.

  As the advertisement step, when it is later found that the Router-LSA created by the GMPLS node is mistakenly advertised as it is to the IP / MPLS network, the portion indicating the GMPLS C-plane is included in the information of the Router-LSA. The step of deleting and re-advertise can be performed.

  The re-advertisement step includes a step of giving a flag indicating that the Router-LSA is a re-advertisement to the Router-LSA to be re-advertised, and a step of identifying the presence or absence of the flag when the Router-LSA is received. When the flag is added, the step of overwriting the previously received Router-LSA with the Router-LSA can be executed.

  According to the present invention, when a GMPLS network and an IP / MPLS network are connected, the routing protocol operates normally. Based on this, traffic engineering can be performed to distribute the traffic, and network resources can be effectively used. It becomes possible to utilize.

  A GMPLS + IP / MPLS node and a GMPLS network according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of the GMPLS + IP / MPLS node of this embodiment. However, in FIG. 1, functional blocks related to the standard operation of OSPF are omitted.

  As shown in FIG. 1, the GMPLS + IP / MPLS node according to the present embodiment analyzes the contents of the advertised Opaque-LSA and identifies whether or not the GMPLS extension is included in the LSA. A GMPLS node that recognizes that the node that created the Opaque-LSA is a GMPLS node when the GMPLS extension is included in the LSA based on the identification result of the analysis unit 1 and the Opaque-LSA content analysis unit 1 The recognizing unit 2, the list creating unit 3 that creates the GMPLS node list 4 based on the recognition result of the GMPSL node recognizing unit 2, and when the Router-LSA is advertised, the GMPLS node list 4 is referred to and the Router- Check if the node that created the LSA is a GMPLS node When it is confirmed that the node that created the Router-LSA is a GMPLS node based on the confirmation result of the MPLS node confirmation unit 5 and the GMPLS node confirmation unit 5, the Router-LSA is directly advertised to the GMPLS network. The IP / MPLS network includes an advertising unit 6 that deletes a part indicating GMPLS C-plane from the information of the Router-LSA and advertises the information.

  When the advertising unit 6 later discovers that the Router-LSA created by the GMPLS node was mistakenly advertised as it is to the IP / MPLS network, the advertising unit 6 deletes the portion indicating the GMPLS C-plane from the information held by the Router-LSA. And means for re-advertisement.

  Further, the means for re-advertisement of the advertising unit 6 includes means for giving a flag (Eflag) indicating that the Router-LSA is a re-advertisement to the Router-LSA to be re-advertised, and when the Router-LSA is received Is provided with a router-LSA correction unit 7 for overwriting the previously received router-LSA with the router-LSA when the flag is given.

  FIG. 2 is a diagram illustrating the GMPLS network and the IP / MPLS network according to the present embodiment. In this embodiment, as shown in FIG. 2, the GMPLS + IP / MPLS node of this embodiment is arranged as an edge node of the GMPLS network.

  This embodiment can be implemented as a program that, when installed in a general-purpose information processing apparatus, causes the information processing apparatus to realize functions corresponding to the GMPLS + IP / MPLS node of the present embodiment. This program is recorded on a recording medium and installed in the information processing apparatus, or installed in the information processing apparatus via a communication line, so that the information processing apparatus has an Opaque-LSA content analysis unit 1 and a GMPLS node recognition unit. 2, functions corresponding to the list creation unit 3, the GMPLS node list 4, the GMPLS node confirmation unit 5, and the advertisement unit 6 can be realized.

  Next, the operation of the GMPLS + IP / MPLS node of this embodiment will be described with reference to FIGS. FIG. 3 is a flowchart showing the label path advertisement procedure. FIG. 4 is a flowchart showing an operation procedure of the GMPLS + IP / MPLS node as the GMPLS edge node. FIG. 5 is a flowchart showing an operation procedure of a GMPLS + IP / MPLS node as a GMPLS non-edge node.

  In the flowcharts of FIG. 3 to FIG. 5, the description about the standard operation of OSPF is omitted. When the GMPLS network and the IP / MPLS network are linked, the GMPLS C-plane link is not shown to the IP / MPLS network, and the GMPLS is not shown. In order to show a part of the label path (Packet LSP) of the D-plane to the IP / MPLS network, an operation necessary for the GMPLS node is described.

  As shown in FIG. 3, when there is a label path to be advertised in the IP / MPLS network (Decision 1-1), the label path advertisement procedure advertises the C-plane and the label path with the Router-LSA and the label path with the Opaque-LSA. Advertise (Process1-1).

  That is, a label path to be advertised to the IP / MPLS network is regarded as a link, and a Router-LSA is issued assuming that there is a label path link in addition to a C-plane link. At the same time, the Opaque-LSA If flag that advertises the label is set (If flag = 1) and advertised.

Further, necessary information of the Opaque-LSA is copied and a new Router-LSA is issued. As an information change item in the Router-LSA performed at this time, LS
Change type from 10 to 1. Change Link ID sub-TLV to Link State ID. Local / Remote interface IP addr to Router-LSA
Change to link. Increase Router-LSA # links.

  When there is no label path to be advertised in the IP / MPLS network (Decision 1-1), the C-plane is advertised by Router-LSA and the label path is advertised by Opaque-LSA (Precess 1-2). This is a general process.

  The role of the Iflag will be described in more detail. The label path represented by the Opaque-LSA on which the Iflag stands indicates that it is also advertised in the Router-LSA in order to advertise to the IP / MPLS network.

  The link in Router-LSA pointed to by Opaque-LSA with Iflag = 1 is not incorporated into the GMPLS C-plane topology. That is, the GMPLS C-plane is configured by a Router-LSA whose advertisement transmission source router is GMPLS and is not indicated by the Opaque-LSA with Iflag = 1. The link of Router-LSA pointed to by the Opaque-LSA is identified by Advertising Router, Link ID sub-TLV, Local / Remote interface IP address.

  At this time, if there is an existing Router-LSA having the same advertisement transmission source router, it is merged and added to the link.

  Next, an operation procedure of the GMPLS + IP / MPLS node as the GMPLS edge node will be described with reference to FIG. When the LSA is received, whether the LSA is a GMPLS Opaque-LSA or an MPLS Opaque-LSA is determined based on whether or not it has a GMPLS extended sub-TLV (Decision 2-1).

  As a result, when it is determined that the received LSA is GMPLS Opaque-LSA, the node matches the GMPLS node list held by the node (Decision 2-2), and when it is not in the list, the address of the advertisement sending router (Advertising Router) In the GMPLS node list (Process2-1). Further, it is determined whether or not there is a Router-LSA of the same advertisement transmission source router (Decision2-3). If there is, an advertisement obtained by deleting the C-plane information from the Router-LSA is sent to the IP / MPLS network (label path). Information is left), and the Opaque-LSA advertising this label path is set to Eflag = 1 and re-advertised (Process2-2).

  The process (Process2-2) comes when the Router-LSA is received before the Opaque-LSA issued by the GMPLS node. At this time, Router-LSA representing C-plane cannot be blocked from flowing into the IP / MPLS network. For this reason, it is necessary to delete C-plane information that has flowed out to the IP / MPLS network. Since the IP / MPLS node that has received the Router-LSA from which the C-plane information has been deleted overwrites the Router-LSA that includes the C-plane information with a new one, the C-plane information is deleted.

  The reason why the destination of this Router-LSA is limited only to the IP / MPLS network is that when the GMPLS node receives this Router-LSA, the C-plane topology is deleted. When this Router-LSA is transmitted to the IP / MPLS network, it returns to the GMPLS network. In order for the returned Router-LSA not to erase the C-plane topology, it is necessary to distinguish this Router-LSA from the normal Router-LSA.

  The Opaque-LSA that can identify the link of the Router-LSA blocked at the edge node is advertised with Eflag = 1. This indicates that the Opaue-LSA advertisement transmission source router re-advertises the Router-LSA for deleting the Router-LSA erroneously advertised to the IP / MPLS network.

  As a result, even when a C-plane deletion Router-LSA returned from the IP / MPLS network is received, it can be filtered by the GMPLS edge node. When the deletion request is generated from the GMPLS side when the C-plane link is actually disconnected, since the Eflag is 0, the deletion request can be handled as usual.

When the received LSA is GMPLS Opaque-LSA (Decision 2-1), all IF (Inter
Advertise to Face) (Process2-3). Here, IF is an interface of a node and means an advertisement receiving port.

  When the received LSA is Router-LSA (Decision 2-1), it is determined whether or not the advertisement transmission source router is in the GMPLS node list (Decision 2-4). The router determines whether there is an Opaque-LSA with Eflag = 1 (Decision 2-5). If there is an Opaque-LSA with Eflag = 1 in the same advertisement transmission source router, it is deleted (Process2-4). If there is no Opaque-LSA with Eflag = 1 in the same advertisement transmission source router, advertisement is made to all IFs (Process 2-5).

  Also, it is determined whether or not the advertisement transmission source router is included in the GMPLS node list (Decision2-4). If it is included, based on the list, an advertisement other than the IP / MPLS network is advertised as it is. The network is advertised with the C-plane information deleted from the Router-LSA (the label path information remains). Further, the Opaque-LSA advertising this label path is set to Eflag = 1 and re-advertised (Process2-6).

  Next, the operation procedure of the GMPLS non-edge node will be described with reference to FIG. When the GMPSL non-edge node receives the LSA, it advertises to all IFs as it is (Process3-1).

  According to the present invention, when a GMPLS network and an IP / MPLS network are connected, the routing protocol operates normally. Based on this, traffic engineering can be performed to distribute the traffic, and network resources can be effectively used. Therefore, both the user who uses the network and the business operator who manages the network can improve the convenience and contribute to the reduction of the communication cost and the cost of the communication equipment.

The block block diagram of the GMPLS + IP / MPLS node of a present Example. The block diagram of the GMPL network of a present Example. The flowchart which shows the label path | pass advertisement procedure of a present Example. The flowchart which shows the operation | movement procedure of the GMPLS edge node of a present Example. The flowchart which shows operation | movement of the GMPLS non-edge node of a present Example. The figure which shows the network comprised by an IP / MPLS node. The figure which shows the concept of a label. The figure for demonstrating the hierarchization of LSP.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Opaque-LSA content analysis part 2 GMPLS node recognition part 3 List creation part 4 GMPLS node list 5 GMPLS node confirmation part 6 Advertising part 7 Router-LSA correction part

Claims (11)

Means for analyzing the content of the advertised Opaque-LSA and identifying whether or not the GMPLS extension is included in the LSA;
Means for recognizing that the node that created the Opaque-LSA is a GMPLS node when a GMPLS extension is included in the LSA based on the identification result of the identifying means;
Means for creating a list of GMPLS nodes based on the recognition result of the recognition means;
Means for confirming whether the node that created the Router-LSA is a GMPLS node by referring to the list when the Router-LSA is advertised;
When it is confirmed that the node that created the Router-LSA is a GMPLS node based on the confirmation result of the confirmation means, the Router-LSA is advertised as it is to the GMPLS network, and the IP / MPLS network A GMPLS + IP / MPLS node comprising means for deleting and advertising a part indicating GMPLS C-plane in the information of Router-LSA.   The advertising means, when it is later found that the Router-LSA created by the GMPLS node was mistakenly advertised as it is to the IP / MPLS network, the part indicating the GMPLS C-plane is included in the information held by the Router-LSA. 2. The GMPLS + IP / MPLS node according to claim 1, further comprising means for deleting and re-advertisement. The means for re-advertisement comprises means for giving a flag indicating that the Router-LSA is a re-advertisement to the Router-LSA to be re-advertised,
The GMPLS + IP / MPLS according to claim 2, further comprising means for recognizing the presence or absence of the flag when receiving the Router-LSA and overwriting the previously received Router-LSA with the Router-LSA when the flag is given. node.   A GMPLS network, wherein the GMPLS + IP / MPLS node according to claim 1 is arranged as an edge node of the GMPLS network. By installing on an information processing device,
A function of analyzing the content of the advertised Opaque-LSA and identifying whether or not the GMPLS extension is included in the LSA;
A function for recognizing that the node that created the Opaque-LSA is a GMPLS node when a GMPLS extension is included in the LSA based on the identification result of the identifying function;
A function of creating a list of GMPLS nodes based on the recognition result of the recognition function;
A function of confirming whether the node that created the Router-LSA is a GMPLS node by referring to the list when the Router-LSA is advertised;
When it is confirmed that the node that created the Router-LSA is a GMPLS node based on the confirmation result of the function to be confirmed, the Router-LSA is advertised as it is to the GMPLS network, and the IP / MPLS network A program that realizes a function corresponding to a GMPLS + IP / MPLS node having a function of deleting and advertising a part indicating GMPLS C-plane in information held by Router-LSA.   When the router-LSA created by the GMPLS node is advertised as it is to the IP / MPLS network as the function to be advertised later, the part indicating the GMPLS C-plane is included in the information held by the router-LSA. 6. The program according to claim 5, which realizes a function of deleting and re-advertisement. As the function of re-advertisement, realize a function of giving a flag indicating that the Router-LSA is a re-advertisement to the Router-LSA to be re-advertised,
The program according to claim 6, wherein the presence / absence of the flag is identified when the Router-LSA is received, and when the flag is given, the function of overwriting the previously received Router-LSA with the Router-LSA is realized.   A recording medium readable by the information processing apparatus on which the program according to claim 5 is recorded. Analyzing the content of the advertised Opaque-LSA and identifying whether the GMPLS extension is included in the LSA;
Recognizing that the node that created the Opaque-LSA is a GMPLS node when a GMPLS extension is included in the LSA based on the identification result of the identifying step;
Creating a list of GMPLS nodes based on the recognition result of the step of recognizing;
Confirming whether the node that created the Router-LSA is a GMPLS node by referring to the list when the Router-LSA is advertised;
When it is confirmed that the node that created the Router-LSA is a GMPLS node based on the confirmation result of this confirmation step, the Router-LSA is advertised as it is to the GMPLS network, and the IP / MPLS network An inter-network connection method in which the step of deleting and advertising the part indicating GMPLS C-plane in the information of Router-LSA is executed by an edge node of the GMPLS network connected to the IP / MPLS network.   As the advertisement step, when it is later found that the Router-LSA created by the GMPLS node is mistakenly advertised as it is to the IP / MPLS network, the portion indicating the GMPLS C-plane is included in the information of the Router-LSA. The inter-network connection method according to claim 9, wherein the deleting and re-advertisement step is executed. The re-advertisement step includes a step of giving a flag indicating that the Router-LSA is a re-advertisement to the Router-LSA to be re-advertised;
The step of identifying the presence or absence of this flag when the Router-LSA is received and the step of overwriting the previously received Router-LSA with the Router-LSA when the flag is given are executed. Network connection method.

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