JP2008219172A - Control network, communication method, and node device - Google Patents

Abstract

The present invention relates to a technique capable of reducing a load on a node device when a failure occurs in a network.
An interface 10-1 of a caller node device 100 and an interface 10-2 of a callee node device 200 constitute a path 21. Further, the interface 11-1 and the interface 11-2 constitute a path 22. Then, path operation management is performed using the multiple logical interface 20-1 bundled with the interfaces 10-1 and 11-1 and the multiple logical interface 20-2 bundled with the interfaces 10-2 and 11-2. When a failure occurs in the path 10, the multiple logical interface is maintained as it is and switched to the path 11, so that it is not necessary to exchange control information, and the load on the node device can be reduced.
[Selection] Figure 1

Description

  The present invention relates to a control network, a node device, and a communication method related to failure recovery when a failure occurs in a network having a plurality of layers.

With the progress of broadband, in recent communication networks, the introduction of GMPLS (Generalized Multi-Protocol Label Switching) technology and the like has facilitated resource management and path control across multiple layers. For example, Non-Patent Document 1 discloses a highly reliable technology for a control network that uses a FastRoute of MPLS (Multi-Protocol Label Switching) or the like to quickly switch a route when a failure occurs and recover from the failure. .
Young Hwa Kim, “Requirements for the Resilience of Control Plane”, draft-kim-ccamp-cpr-reqts, CCAMP Working Group, Internet-Draft (Oct. 15,2005)

  However, in the failure recovery method disclosed in Non-Patent Document 1, when a failure occurs in a network, it is necessary to change the interface for exchanging topology information and update the changed topology information. For this reason, when updating the topology information, there is a concern that the topology information may be updated incorrectly or that the performance may be degraded due to the overload of the node device caused by the processing.

  In general, there are a large number of node devices between node devices located at endpoints that need to transmit and receive control information for path establishment such as topology information and path information. Because it has such a network configuration, all the node devices existing between the node devices located at the endpoints have means for exchanging topology information to be changed, or when holding topology information to be changed, Excessive functions will be deployed in the control network.

  Therefore, an object of the present invention has been made to solve such a conventional problem, and exists when there is a failure in a multi-layer network between node devices located at the end points of the control network. To provide a technique that makes it possible to reduce the load on a large number of node devices and also reduce the load on a node device located at an end point.

  The invention according to claim 1 is a control network for exchanging control information for establishing a path by using a network of a plurality of layers, and a caller node or an incoming call for exchanging control information for establishing the path When the first node device serving as a party node transmits the control information to the other first node device, the control is performed so that the second node device serving as a relay node that does not decode the control information is transmitted. A plurality of encapsulated interfaces that encapsulate and transmit information; a multiple logical interface comprising the plurality of encapsulated interfaces; identification information of the multiple logical interface; and the plurality of encapsulated interfaces included in the multiple logical interface. A storage unit that associates and stores identification information, and a capsule that exchanges the control information When switching the interface, the identification information stored in the storage unit is referred to, and the switching destination encapsulation interface is selected from the encapsulation interfaces included in the multiple logical interface corresponding to the encapsulation interface to be switched. And a switching means.

  The invention according to claim 4 is a communication method used in a control network for exchanging control information for establishing a path using a network of a plurality of layers, and exchanging control information for establishing the path When the first node device serving as the caller node or the callee node transmits the control information to the other first node device, the first node device is transmitted through the second node device serving as a relay node that does not decode the control information. A plurality of encapsulation interfaces that encapsulate and transmit the control information, a multiple logical interface composed of the plurality of encapsulation interfaces, identification information of the multiple logical interface, and the multiple logical interfaces included in the multiple logical interface. A storage unit for storing the identification information of the encapsulation interface in association with each other, and the control information Switching means for switching the encapsulation interface for exchanging the information, and when the switching means switches the encapsulation interface for exchanging the control information, the switching information is referred to by referring to the identification information stored in the storage unit. A switching-destination encapsulation interface is selected from the encapsulation interfaces included in the multiple logical interface corresponding to a certain encapsulation interface.

  The invention according to claim 5 is used in a control network for exchanging control information for establishing a path using a network of a plurality of layers, and a caller node or an incoming call for exchanging control information for establishing the path A node device serving as a user node, wherein when the node device transmits the control information to another node device, the second node device serving as a relay node that does not decode the control information is transmitted. A plurality of encapsulation interfaces for encapsulating and transmitting control information, a multiple logical interface comprising the plurality of encapsulation interfaces, identification information of the multiple logical interface, and the plurality of encapsulation interfaces included in the multiple logical interface The control information is exchanged with a storage unit that stores the identification information in association with each other. When switching the encapsulation interface to be switched, referring to the identification information stored in the storage unit, from the encapsulation interface included in the multiple logical interface corresponding to the encapsulation interface to be switched, the switching-destination encapsulation interface And switching means for selecting.

According to the first, fourth, or fifth aspect of the invention, since the first node device includes the encapsulation interface, the second node device exchanges control information between the first node devices. This node device does not need to be provided with a function like the first node device.
In addition, since the multiple logical interface is configured to bundle a plurality of encapsulated interfaces, even if a failure occurs in one encapsulated interface, the multiple logical interface is not changed. Therefore, the load can be reduced as compared with the load such as the exchange of control information and the path calculation process according to the conventional path change in the first node device.
Furthermore, even if a failure occurs in one encapsulated interface, the multiple logical interface is not changed, so that the link controlled by the multiple logical interface is not affected.

  According to a second aspect of the present invention, in the control network according to the first aspect, the first node device includes an alive monitoring unit that detects a failure in the multi-layer network, and the switching unit includes the storage unit. The encapsulated interface in which the failure is not detected is referred to from the encapsulated interface included in the multiple logical interface corresponding to the encapsulated interface in which the failure is detected by the alive monitoring means with reference to the identification information stored in the unit. And selecting as a switching destination encapsulation interface.

  According to the second aspect of the present invention, since the failure can be detected quickly by providing the life and death monitoring means for detecting the failure in the multi-layer network, the failure is detected from the encapsulation interface where the failure is detected. It is possible to quickly switch to a non-encapsulated interface and to perform stable network operation management.

    According to a third aspect of the present invention, in the control network according to the second aspect, the first node device includes continuity confirmation means for confirming conduction of the encapsulation interface, and the continuity confirmation means includes: By transmitting and receiving continuity confirmation information using the switching-destination encapsulation interface selected by the switching unit, the presence or absence of conduction of the encapsulated interface is detected, and the switching unit conducts continuity by the continuity confirmation unit. The encapsulation interface detected as being present is switched as the switching destination encapsulation interface.

  According to the third aspect of the present invention, before switching from an encapsulation interface in which a failure has been detected to an encapsulation interface in which a failure has not been detected, the continuity of the selected encapsulation interface in which a failure has not been detected is confirmed. Thus, it is possible to switch the path appropriately when a failure occurs.

  According to the present invention, when a failure occurs in a network of a plurality of layers, it is not necessary to provide an excessive function in a large number of node devices existing between node devices located at the end points of the control network, and the end points It is also possible to reduce the load on the node device located in the network.

  Next, the best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described in detail with reference to the drawings as appropriate.

(Embodiment)
A configuration of a highly reliable control network 1000 having a plurality of layers according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram showing an example of the configuration of a highly reliable control network 1000 according to an embodiment of the present invention.

As shown in FIG. 1, the high-reliability control network 1000 having a plurality of layers includes a caller node device 100, a callee node device 200, and a relay node device 300 (300-1, 300-2). The caller node device 100 and the callee node device 200 are node devices located at an endpoint that exchanges control information for establishing a path, and are physically connected via the relay node device 300.
The caller node device 100 and the callee node device 200 are the first node devices described in the claims. The relay node device 300 is the second node device described in the claims.

  Specifically, the caller node device 100, the callee node device 200, and the relay node device 300 are devices including an optical cross-connect, a router, a switch, and the like. A plurality of relay node devices 300 are included in the high-reliability control network 1000, and the number is not particularly limited. The relay node device 300 may or may not have the function of establishing those paths. However, in the configuration example illustrated in FIG. 1, it is assumed that the relay node device 300 is a node device that does not need to exchange control information.

  In addition, establishment of a path between the sender node device 100 and the receiver node device 200 in the high-reliability control network 1000 is performed according to RFC3473 (Generalized Multi-Protocol Label Switching (GMPLS), which is a standard specification of IETF (Internet Engineering Task Force). ) Signaling Resource ReserVation Protocol-Traffic Engineering (RSVP-TE) Extensions).

  Here, referring to FIG. 1, the configuration of the sender node device 100 and the receiver node device 200 will be described using FIG. 2. 2A is a block diagram illustrating a hardware configuration of the caller node apparatus 100 of FIG. 1, and FIG. 2B is a block diagram illustrating a hardware configuration of the callee node apparatus 200 of FIG.

As shown in FIG. 2A, the caller node device 100 includes a processing unit 410, an input / output unit 510, and a storage unit 610.
The processing unit 410 includes a CPU (Central Processing Unit) 411 that executes arithmetic processing, and a main memory 412 that is a storage unit that the CPU 411 uses for arithmetic processing. The main memory 412 is realized by a RAM (Random Access Memory) or the like.
The storage unit 610 stores various data used by the CPU 411 for arithmetic processing and data transmitted / received by the input / output unit 510. The storage unit 610 is realized by a hard disk device or the like.
The input / output unit 510 includes an input / output interface 511 and a network interface 512 that is a communication interface. The input / output interface 511 receives input from an input device such as a keyboard or a mouse connected to the caller node device 100, and outputs various data output from the processing unit 410 to an output device such as a liquid crystal monitor. .

  Similarly to FIG. 2A, the recipient node apparatus 200 includes a processing unit 420, an input / output unit 520, and a storage unit 620 as shown in FIG. 2B. Since the function of each part is the same as that of the caller node device, description thereof is omitted.

  Returning to FIG. 1 (see FIG. 2 as appropriate), the processing unit 410 of the caller node device 100 and the processing unit 420 of the callee node device are connected to the interface 10-1 of the caller node device 100 and the callee node device 200. Control information is transmitted and received through the interface 10-2. Similarly, control information is transmitted and received via the interface 11-1 of the caller node device 100 and the interface 11-2 of the callee node device 200.

These interfaces 10 and 11 are interfaces (hereinafter referred to as encapsulated interfaces) that encapsulate and transmit control information for path establishment such as topology information and path information. With this encapsulation, it is possible to construct a tunnel that passes through the relay node device 300 that does not need to exchange control information.
Encapsulation means IPinIP or GRE (Generic Routing Encapsulation).

  Returning to FIG. 1 (see FIG. 2 as appropriate), the processing unit 410 of the sender node device 100 configures a logical interface 20-1 in which the encapsulation interfaces 10-1 and 11-1 are bundled. In addition, the processing unit 420 of the called party node device 200 constitutes a logical interface 20-2 in which the encapsulation interfaces 10-2 and 11-2 are bundled. The logical interfaces 20-1 and 20-2 are hereinafter referred to as multiple logical interfaces.

  Here, the association between the multiple logical interface 20 and the encapsulation interfaces 10 and 11 will be described with reference to FIG. 3A is a diagram showing the association between the multiplexed logical interface 20-1 and the encapsulation interfaces 10-1 and 11-1, and FIG. 3B is a diagram showing the association between the multiplexed logical interface 20-2 and the encapsulation interfaces 10-2 and 11-. FIG.

  As shown in FIG. 3A, the multiple logical interfaces 20-1, 20-2 and the encapsulation interfaces 10-1, 11-1, 10-2, 11-2 have individual identification information that can be identified. Is attached. The identification information 801 of the multiple logical interface 20-1 is stored in the storage unit 610 in association with the identification information 802 and 803 of the encapsulation interfaces 10-1 and 11-1. In addition, the identification information 811 of the multiple logical interface 20-2 is stored in the storage unit 620 in association with the identification information 812 and 813 of the encapsulation interfaces 10-2 and 11-2.

  This identification number may be set by the operator, but each of the caller node device 100 and the callee node device 200 is assigned a unique identification number (such as an IP address) in the control network. Therefore, the identification number may be combined with the number uniquely generated by the caller node device 100 or the callee node device 200 in its own node device.

  A path between the caller node device 100 and the callee node device 200 is established by the multiple logical interface 20. As a result, the adjacent node of the caller node device 100 becomes the callee node device 200 logically.

  In the embodiment of the present invention, the relay node device 300 is not a node device located at the end point. Therefore, when the path between the caller node device 100 and the callee node device 200 is established, path information is generated. Not involved. That is, when control information for establishing a path is transmitted from the caller node device 100 to the callee node device 200, the relay node device 300 does not capture the control information.

  Here, the operation of the above-described multiple logical interface 20 will be described in more detail by taking IP (Internet Protocol) transfer of messages as an example.

The caller node device 100, the callee node device 200, and the relay node device 300 are each an IP node and have a function of performing IP transfer of a message. Then, the caller node device 100 exchanges control information with the callee node 200 via the multiple logical interface 20 for path management, network operation management, and the like.
For example, path monitoring can be performed using RSVP-TE (Resource reSerVation Protocol-Traffic Engineering). Also, network operation management such as link status can be performed using LMP (Link Management Protocol) or OSPF-TE (Open Shortest Path First-Traffic Engineering).

Therefore, the caller node device 100 and the callee node device 200 use a tunnel using the logical multiple logical interface 20 for exchanging control information. IP forwarding.
In the packet structure, an IP transfer address is assigned before the address of the multiple logical interface 20, and IP transfer is performed using the IP transfer address.
Then, the control information transmitted from the caller node device 100 is IP transferred by relay node transfer, arrives at the callee node device 200, and the IP address given before the address of the multiple logical interface 20 is removed, Processing is performed based on the multiple logical interface 20.

  Next, the configuration of the sender node device 100 will be described with reference to FIG. FIG. 4 is a diagram illustrating an example of a block configuration of the caller node device 100 according to the embodiment of the present invention. However, the relay node device 300 is omitted in FIG.

As shown in FIG. 4 (see FIG. 2 as appropriate), the processing unit 410 of the caller node device 100 includes a topology information storage unit 110, a topology information exchange unit 111, a path information storage unit 120, a path establishment unit 121, and a switching unit 130. The functional block includes a life / death monitoring unit 131, a logic interface configuration unit 140, a continuity confirmation unit 141, and the like.
The input / output unit 510 has a function of encapsulating control information and transmitting / receiving control information such as topology information and path information to / from the callee node device 200.
The storage unit 610 includes a topology / path information DB (database) 101 and a logical interface information DB 102 that store processing results of the processing unit 410 and the like. The topology / path information DB (database) 101 and the logical interface information DB 102 may be constructed as one database.
The topology path information DB 101 is a database that stores topology information exchanged between node devices when the highly reliable control network 1000 is constructed, established path information, and the like. Further, the logical interface information DB 102 stores logical interface information such as identification information of the encapsulated interfaces 10 and 11 of the caller node device 100 and the callee node device 200 and the multiple logical interface 20, as shown in FIG. It is a database.
Details of operations of the processing unit 410 and the input / output unit 510 will be described later.

  Next, the configuration of the receiver node device 200 will be described with reference to FIG. FIG. 5 is a diagram showing an example of a block configuration of the called party node device 200 according to the embodiment of the present invention.

As shown in FIG. 5, the processing unit 420 of the called party node device 200 includes a topology information storage unit 210, a topology information exchange unit 211, a path information storage unit 220, a path establishment unit 221, a switching unit 230, a life / death monitoring unit 231, It is configured to include functional blocks such as a logic interface configuration unit 240 and a continuity confirmation unit 241.
The input / output unit 520 has a function of transmitting / receiving control information such as topology information and path information to / from the sender node device 100.
The storage unit 620 includes a topology / path information DB (database) 201 and a logical interface information DB 202 that store processing results of the processing unit 420. However, the topology / path information DB (database) 201 and the logical interface information DB 202 may be constructed from a single database.
Note that the configuration of the receiver node device 200 is the same as that of the sender node device 100, and the description thereof is omitted.

  Next, the flow of processing when a multiple logical interface relating to the caller node device 100 and the callee node 200, exchange of topology information, path establishment, and failure occurs will be described with reference to FIG. FIG. 6 is a diagram illustrating an example of the operation of the functional blocks constituting the caller node device 100 and the callee node device 200 according to the embodiment of the present invention. The relay node device 300 is omitted because it is not directly involved in the processing flow.

In FIG. 6 (see FIGS. 4 and 5 as appropriate), the caller node device 100 includes the encapsulation interfaces 10-1 and 11-1, and the encapsulation interface 10 is triggered by the time when the control network is constructed. The logical interface configuration unit 140 configures the multiple logical interface 20-1 associated with -1,11-1 (step S4101). As shown in FIG. 3, the multiple logical interface 20-1 is associated with the encapsulation interfaces 10-1 and 11-1, stored in the storage unit 610, and referred to when a path is established.
The multiplexed logical interface 20-1 is operated after the continuity confirmation for confirming that the encapsulation interfaces 10-1 and 11-1 operate normally is performed by the continuity confirmation unit 141.

As in the case of the caller node device 100, the callee node device 200 includes the encapsulation interfaces 10-2 and 11-2, and the encapsulation interface 10-2 is triggered when the control network is constructed. , 11-2 is configured by the logical interface configuration unit 240 (step S4201). As shown in FIG. 3, the multiple logical interface 20-2 is associated with the encapsulation interfaces 10-2 and 11-2, stored in the storage unit 620, and referred to when a path is established.
The multiplexed logical interface 20-2 is operated after the continuity confirmation for confirming that the encapsulation interfaces 10-2 and 11-2 operate normally is performed by the continuity confirmation means 241.

  Then, after configuring the multiple logical interface 20, the topology information exchanging means 110 and 210 of the caller node device 100 and the callee node device 200 generate the topology information of the control network related to the own node device, and the multiple logical interface 20 Through the interface 20, the topology information is mutually converted to share the topology information related to the entire control network (step S4102, step S4202). Then, the topology information storage units 111 and 211 store the collected topology information relating to the entire control network in the respective topology path information DBs 101 and 201.

  The topology information stored in the topology path information DBs 101 and 201 by the topology information storage means 110 and 210 is read by the path establishment means 121 and 221 and an operation for obtaining an optimum path is performed. Based on the calculation result, the path establishment request 121 of the sender node device 100 transmits the path establishment request to the receiver node 200 via the multiple logical interface 20.

  At that time, the path establishing means 121 of the sender node device 100 transmits a path establishment request including identification information of the encapsulated interface used for control information exchange to the receiver node device 200 via the multiple logical interface 20. To do. Then, the callee node device 200 receives the transmitted path establishment request, confirms an available line resource, and establishes a path.

  As a result, a path is established between the caller node device 100 and the callee node device 200 (steps S4103 and S4203). The path information thus established is stored in the topology / path information DBs 101 and 201 by the path storage information means 120 and 220, respectively.

As described above, the multiple logical interface 20 is configured by bundling a plurality of encapsulation interfaces 10 and 11 together.
That is, control information for path establishment and operation management is transmitted and received using a multiple logical interface 20 in which a plurality of encapsulation interfaces 10 and 11 are bundled together. Since the tunnel is formed through the encapsulation interfaces 10 and 11 and control information is transmitted and received through the tunnel in this way, the caller node device 100 and the callee node device 200 are logical interfaces. This makes it possible to operate as an adjacent node.

  On the other hand, when a path is established, a change occurs in the free resources of the line. Along with this, the topology information exchanging means 110 and 210 convert the topology information again via the multiple logical interface 20 in order to exchange the topology information after the resource fluctuation has occurred (step S4104). Step S4204). The topology information storage units 111 and 211 store the topology information in the topology path information DBs 101 and 201, respectively.

  Next, when the encapsulation interface 10 is used in the multiple logical interface 20 in which the encapsulation interfaces 10 and 11 are bundled together and the encapsulation interface 11 is redundant, the capsule of the sender node device 100 is used. Processing when a failure occurs in the linking interface 10-1 will be described.

  For example, the occurrence of a failure in a multi-layer network is detected when the monitoring information is transmitted by the alive monitoring means 131 of the caller node device 100 and there is no response from the callee node device 200 (step S4105). ) In addition, the fault location is identified. That is, the failure detection is performed when monitoring information such as a control protocol packet is transmitted / received through a link associated with the multiple logical interface 20 using a control protocol such as RSVP, OSPF, or LMP, and a response cannot be received. This is done by a method of determining that a failure has occurred.

  When the alive monitoring unit 131 of the caller node device 100 detects a failure, the switching unit 130 transmits the switch request information to the callee node device 200 that is a logical adjacent node (step S4106). Then, the callee node device 200 that has received the switching request information makes a switching response by the switching unit 230 (step S4206).

Next, while holding the multiple logical interface 20 used at that time, the switching means 130, 230 switches the failed encapsulation interface 10 to the encapsulation interface associated with the identification information of the multiple logical interface 20. Is switched to another encapsulation interface 11 in which no failure has been detected, and the switching is completed (steps S4107 and S4207). When selecting another encapsulation interface bundled in the multiple logical interface 20, a table or the like as shown in FIG. 3 is referred to.
Note that network alive monitoring can also be performed using a physical interface without using the multiple logical interface 20.

  Further, when switching the failed encapsulation interface 10 to the encapsulation interface 11 in which no failure has been detected, the continuity confirmation means 141 of the caller node device 100 and the callee node device 200 are switched before switching. It is also possible to transmit / receive continuity confirmation information to / from the confirmation unit 241 to detect the presence / absence of continuity of the encapsulation interface 11 and to switch to the encapsulation interface 11 when continuity is detected.

  As described above, in the embodiment of the present invention, the caller node device 100 and the callee node device 200 include the encapsulation interfaces 10 and 11, so that a tunnel is formed between both node devices. Therefore, the relay node device 300 existing between the caller node device 100 and the callee node device 200 does not need to exchange control information, and functions like the caller node device 100 and the callee node device 200. Need not be deployed.

Further, since the caller node device 100 and the callee node device 200 are provided with a plurality of encapsulated interfaces 10 and 11 and exchange control information through the multiple logical interface 20 that bundles them together, there is a failure. When this occurs in the encapsulation interface 10, it is possible to switch from the failed encapsulation interface 10 to another encapsulation interface 11 without a failure without changing the multiple logical interface 20.
Therefore, the load on the caller node device 100 and the callee node device 200 is hardly affected.
That is, in the embodiment of the present invention, the load on the caller node device 100 and the callee node device 200 for transmitting and receiving control information due to a failure is hardly affected, and thus the caller node device 100 and the callee node device 200 are not affected. It becomes possible to reduce the load in the.

  Therefore, according to the embodiment of the present invention, since the node device located at the end point (the node device that should exchange control information) includes the encapsulation interface, the control information is transferred between the node devices located at the end point. It is only necessary to exchange them, and the load on the control network can be reduced.

  In addition, even if a failure occurs in a specific encapsulated interface in the multiple logical interface, the multiple logical interface is not changed as it is without a failure. Since there is no encapsulation interface, topology information is not updated due to a failure. This makes it possible to reduce the load on the node device located at the end point. In addition, it is possible to perform quick switching, and it is possible to quickly perform failure recovery.

  Furthermore, since the multiple logical interface is not changed even if a failure occurs, there is an effect that the link related to the multiple logical interface is not affected.

It is a figure which shows the example of a structure of the reliable control network which concerns on embodiment of this invention. (A) is a block diagram showing a hardware configuration of the caller node device of FIG. 1, and (b) is a block diagram showing a hardware configuration of the callee node device of FIG. (A) Diagram showing the association between the multiple logical interface 20-1 and the encapsulation interfaces 10-1, 11-1, and (b) Association between the multiple logical interface 20-2 and the encapsulation interfaces 10-2, 11-2. FIG. It is a figure which shows the example of the block configuration of the sender | caller node apparatus which concerns on embodiment of this invention. It is the figure which showed the example of the block configuration of the callee node apparatus 200 which concerns on embodiment of this invention. It is a figure which shows the example of operation | movement of the functional block which comprises the sender node apparatus 100 and the callee node apparatus 200 which concern on embodiment of this invention.

Explanation of symbols

10, 11 Encapsulated interface 20 Multiple logical interface 100 Sender node device 101, 201 Topology path information DB
102, 202 Logical interface information DB
110, 210 Topology information storage means 111, 211 Topology exchange means 120, 220 Path information storage means 121, 221 Path establishment means 130, 230 Switching means 131, 231 Life / death monitoring means 140, 240 Logical interface configuration means 141, 241 Continuity confirmation Means 200 Callee node device 300 Relay node device 1000 Highly reliable control network

Claims (5)

A control network for exchanging control information for establishing a path using a multi-layer network,
A first node device that becomes a caller node or a callee node that exchanges control information for establishing the path,
When transmitting the control information to the other first node device, a plurality of encapsulations that encapsulate and transmit the control information so as to pass through a second node device serving as a relay node that does not decode the control information Interface,
A multiple logical interface comprising the plurality of encapsulated interfaces;
A storage unit that stores the identification information of the multiple logical interface and the identification information of the plurality of encapsulated interfaces included in the multiple logical interface in association with each other;
When switching the encapsulation interface for exchanging the control information, referring to the identification information stored in the storage unit, switching from the encapsulation interface included in the multiple logical interface corresponding to the encapsulation interface to be switched is performed. Switching means for selecting the previous encapsulation interface;
Providing
A control network characterized by The first node device is:
Life and death monitoring means for detecting a failure in the network of the multiple layers,
The switching means is
An encapsulation in which the failure is not detected from an encapsulation interface included in a multiple logical interface corresponding to the encapsulation interface in which a failure is detected by the alive monitoring means with reference to the identification information stored in the storage unit Selecting an interface as the encapsulation interface of the switching destination;
The control network according to claim 1. The first node device is:
Comprising continuity confirmation means for confirming the continuity of the encapsulation interface;
The continuity confirmation means includes
Detecting the presence or absence of conduction of the encapsulated interface by sending and receiving continuity confirmation information using the encapsulation interface of the switching destination selected by the switching means,
The switching means is
Switching the encapsulation interface detected as being conductive by the continuity confirmation means as the switching-destination encapsulation interface;
The control network according to claim 2. A communication method used in a control network for exchanging control information for establishing a path using a multi-layer network,
A first node device that becomes a caller node or a callee node that exchanges control information for establishing the path,
When transmitting the control information to the other first node device, a plurality of encapsulations that encapsulate and transmit the control information so as to pass through a second node device serving as a relay node that does not decode the control information Interface,
A multiple logical interface comprising the plurality of encapsulated interfaces;
A storage unit that stores the identification information of the multiple logical interface and the identification information of the plurality of encapsulated interfaces included in the multiple logical interface in association with each other;
Switching means for switching an encapsulation interface for exchanging the control information;
With
When the switching means switches the encapsulation interface for exchanging the control information,
Referring to the identification information stored in the storage unit, selecting a switching destination encapsulation interface from the encapsulation interfaces included in the multiple logical interface corresponding to the encapsulation interface to be switched;
A communication method characterized by the above. A node device used as a control network for exchanging control information for establishing a path using a multi-layer network and serving as a caller node or a callee node for exchanging control information for establishing the path. ,
The node device is
A plurality of encapsulation interfaces that encapsulate and transmit the control information so as to be transmitted through a second node device that is a relay node that does not decode the control information when transmitting the control information to the other node devices;
A multiple logical interface comprising the plurality of encapsulated interfaces;
A storage unit that stores the identification information of the multiple logical interface and the identification information of the plurality of encapsulated interfaces included in the multiple logical interface in association with each other;
When switching the encapsulation interface for exchanging the control information, referring to the identification information stored in the storage unit, switching from the encapsulation interface included in the multiple logical interface corresponding to the encapsulation interface to be switched is performed. Switching means for selecting the previous encapsulation interface;
Providing
A node device characterized by the above.

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