WO2013033997A1

WO2013033997A1 - Method and system for implementing cross reversal of control plane

Info

Publication number: WO2013033997A1
Application number: PCT/CN2012/074998
Authority: WO
Inventors: 张帅
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-09-08
Filing date: 2012-05-02
Publication date: 2013-03-14
Also published as: CN102325045B; CN102325045A

Abstract

Disclosed are a method and system for implementing cross reversal of a control plane. The method comprises: a head node carrying out cross reversal and transmitting a path signaling containing a cross reversal identifier to a downstream node; a middle node and a tail node receiving the path signaling in sequence and carrying out cross reversal according to the cross reversal identifier in the path signaling; the tail node transmitting a resource reservation (Resv) signaling containing the cross reversal identifier to an upstream node after the cross reversal is successful; the middle node with successful cross reversal forwarding the Resv signaling from the tail node to the upstream node; and the head node receiving the Resv signaling forwarded by the middle node and finishing cross reversal according to the cross reversal identifier in the Resv signaling. Correspondingly, further disclosed is a system for implementing cross reversal of a control plane. The present invention can solve the reversal problem of reply or optimization under a resource sharing multiplexing scenario.

Description

Method and system for realizing control plane crossover switching

The present invention relates to the field of optical communications, and in particular, to a method and system for implementing control plane crossover switching. Background technique

The architectural model of ASON (Automatically Switched Optical Network) is defined in the ITU-T G.8080 automatic switched optical network architecture. It consists of three parts: the transport plane, the control plane and the management plane. Among them, the control plane is the most distinctive part of the ASON network. It is mainly for customer services, and implements call management and connection control functions such as automatic discovery, path calculation, resource assignment, signaling interaction, and cross-switching. Recommendations for the ASON standard, ITU-T G.7713.2, describe RSVP-TE (Resource Reservation Protocol-Traffic Engineering), as GMPLS (Generalized Multiprotocol Label Switching). Switching Protocol) The extension of RSVP in traffic engineering. The RSVP-TE protocol implements the process of establishing, tearing down, and refreshing end-to-end connections in the distributed call and management model of the ASON network.

Restoring rerouting and optimizing rerouting is one of the basic functions of the ASON network. They all replace the original connection by re-routing with idle resources in the network, which fully reflects the flexibility and intelligence of the ASON network. Taking the replyable service as an example, the network not only needs to reserve resources of the original working connection, but also needs to reserve resources for restoring the connection, thus resulting in relatively low utilization of network resources. As shown in Figure 1, the traditional reply switching mode can only implement the switching of the first node A and the tail node Z. The restored connection/optimized connection cannot use the resources of the original working connection, resulting in low resource utilization. In order to improve resource utilization, the scenario shown in Figure 2 can be used, that is, the working connection, the recovery connection/optimization connection (the connection between node A and node B) uses the same resources. Responsible for business For example, if a link is connected (such as the connection between Node B and Node C), you can choose to use the non-faulty resource (the resource between Node A and Node B) in the original working connection to create a recovery connection. This processing can effectively improve the utilization of network resources after rerouting. When the original working connection (connection between Node B and Node C) is removed, the service needs to switch the crossover from the recovery connection (the connection between Node B and Node D) to the original working connection (between Node B and Node C) In the connection, the first node subnet point (SNP) is taken as an example, and the cross-switching action in the sending and receiving direction is as shown in FIG. 3, taking node A in FIG. 1 as an example, and in the path (Path) direction, the crossover is restored. (the connection between node A and node D) is switched to the original working connection (the connection between node A and node B), in the direction of resource reservation (Resv), the crossover is restored from the connection (between node A and node D) The connection) is switched to the original working connection (the connection between node A and node B). If there is a scenario of resource sharing multiplexing as shown in FIG. 2 at the working connection and the recovery connection at this time, then it is necessary to perform a cross-switching operation on each node of the working connection. Taking Node B in Figure 2 as an example, in the Path direction, the crossover is switched from the restored connection (the connection between Node B and Node D) to the original working connection (the connection between Node B and Node C), in the direction of Resv. On, the crossover is switched from the recovery connection (the connection between the node B and the node D) to the original working connection (the connection between the node B and the node C). For the same reason, for the service optimization process, if the resource sharing and multiplexing scenario shown in Figure 2 occurs in the working connection and the optimized connection at this time, the cross switching operation of each node is also required.

Therefore, in the resource sharing and multiplexing scenario, how to solve the cross-switching problem of each node in the replyable service or the optimized service becomes a technical problem to be solved urgently. Summary of the invention

It is an object of the present invention to provide a method and system for implementing control plane crossover switching, which is used to solve the problem of replying or optimizing switching in a resource sharing multiplexing scenario.

According to an aspect of the present invention, a method for implementing control plane crossover switching according to an embodiment of the present invention includes: During the cross-switching operation in the automatic switched optical network ASON, the first node performs cross-switching, and sends a path Path signaling with a cross-switching identifier to the downstream node;

The intermediate node and the tail node sequentially receive the Path signaling, and perform cross-switching according to the cross-switching identifier therein;

After the cross-switching succeeds, the tail node sends a resource reservation Resv signaling containing the cross-switching identifier to the upstream node;

The intermediate node that successfully cross-switches forwards the Resv signaling from the tail node containing the cross-switching identifier to the upstream node;

The head node receives the Resv signaling forwarded via one or more intermediate nodes and performs cross-switching based on the cross-switching identifier therein.

Further, when the first node or the intermediate node performs cross-switching, the respective Path timeout timers are started.

Further, the method further includes:

When the tail node fails to perform the cross-switching, the tail node recovers to the state before the cross-switching, and sends a path error PathErr signaling with the cross-switching failure identifier to the upstream node, so that the intermediate node and the first node sequentially according to the PathErr signaling. Restore to the pre-crossover state.

Further, the method further includes:

The intermediate node cancels its Path timeout timer according to the received Resv signaling, and after determining that the cross-switching fails, returns to its pre-reversal state, and sends a resource reservation error with a cross-switching failure identifier to its downstream node. ResvErr signaling restores other intermediate nodes and tail nodes downstream to the pre-crossover state.

After receiving the ResvErr signaling and recovering to the pre-crossover state, the tail node sends a PathErr signaling containing the cross-switching failure identifier to its upstream.

Further, the method further includes:

The first node cancels its Path timeout timer according to the received Resv signaling, and determines the intersection After the switchover fails, the state is restored to the pre-crossover state, and the ResvErr signaling with the cross-switching failure identifier is sent to its downstream node to restore the downstream intermediate node and the tail node to the pre-crossover state.

Further, if the Path Timeout Timer of the intermediate node does not receive Resv signaling or PathErr signaling from the downstream within the timeout period, it sends PathErr signaling to its upstream node to make other intermediate nodes and the first node upstream. Restore to the pre-crossover state in turn.

Further, the method further includes: setting a cross-switching identifier in the Path signaling and the Resv signaling, and setting a cross-switching failure in the PathErr signaling and the ResvErr signaling respectively. Identifier.

According to another aspect of the present invention, a system for implementing control plane crossover switching according to an embodiment of the present invention includes: a first node, an intermediate node, and a tail node;

The first node is configured to perform cross-switching during the cross-switching operation in the automatic switched optical network ASON, and send Path signaling including the cross-switching identifier to the downstream node, and receive Resv signaling forwarded through one or more intermediate nodes , performing cross-switching according to the cross-switching identifier therein;

The intermediate node is configured to receive the Path signaling, perform cross-switching according to the cross-switching identifier therein, and forward the Resv signaling containing the cross-switching identifier from the tail node to the upstream node after the cross-switching succeeds;

The tail node is configured to receive the Path signaling, perform cross-switching according to the cross-switching identifier therein, and send Resv signaling with the cross-switching identifier to the upstream node after the cross-switching is successful.

The system also includes:

The setting module is configured to respectively set a cross-switching identifier in the Path signaling and the Resv signaling, and respectively set a cross-switching failure identifier in the PathErr signaling and the ResvErr signaling. Compared with the prior art, the beneficial effects of the embodiments of the present invention are as follows: the invention utilizes the extension of the RSVP-TE protocol signaling to implement the cross-switching operation of each node of the ASON control plane, and effectively solves the work in the resource sharing and multiplexing scenario. The problem of cross-switching for connecting, restoring, and optimizing connections not only improves the utilization of rerouting network resources, but also improves the flexibility of the control plane for cross-switching. DRAWINGS

1 is a schematic diagram of a scenario in which a recovery connection/optimization connection does not use a working connection resource provided by the prior art;

2 is a schematic diagram of a scenario of working connection and recovery connection/optimization connection resource sharing multiplexing provided by the prior art;

3 is a cross-sectional view of a SNP transmission and reception direction when a head node triggers a reply in the prior art; FIG. 4 is a flowchart of a method for implementing control plane cross-switching according to an embodiment of the present invention; FIG. 5 is an Admin_Status according to an embodiment of the present invention. Object data format map;

6 is a data format diagram of an Error_Spec object according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of signaling interaction in a scenario of a successful handover in a handover scenario according to the first embodiment of the present invention; FIG. 8 is a schematic diagram of signaling interaction in a scenario of signaling unreachable according to the second embodiment of the present invention; A schematic diagram of signaling interaction in a scenario where a first node cross-switching failure is provided in the embodiment;

FIG. 10 is a schematic diagram of signaling interaction in an intermediate node cross-switching failure scenario according to a fourth embodiment of the present invention; FIG.

FIG. 11 is a schematic diagram of signaling interaction in a scenario of a tail node cross-switching failure according to a fifth embodiment of the present invention; FIG.

FIG. 12 is a schematic diagram of a working connection and a recovery connection path and an intersection situation according to a sixth embodiment of the present invention. detailed description

The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

FIG. 4 is a flowchart of a method for implementing control plane cross-switching according to an embodiment of the present invention. As shown in FIG. 4, the method includes:

Step 401: During the cross-switching operation in the automatic switched optical network ASON, the first node performs cross-switching, and sends Path signaling with the cross-switching identifier to the downstream node.

Step 402: The intermediate node and the tail node sequentially receive the Path signaling, and perform cross-switching according to the cross-switching identifier therein.

Step 403: After the cross-switching succeeds, the tail node sends Resv signaling including the cross-switching identifier to the upstream node.

Step 404: The intermediate node that successfully cross-switches forwards the Resv signaling from the tail node containing the cross-switching identifier to the upstream node.

Step 405: The head node receives the Resv signaling forwarded by one or more intermediate nodes, and completes cross-switching according to the cross-switching identifier therein.

The purpose of the present invention is to implement cross-switching of each node on the ASON control plane. In order to achieve the above object, the embodiment of the present invention extends the Admin_Status object and the Error_Spec object in the RSVP-TE protocol, as shown in FIG. 5 and FIG. 6.

FIG. 5 is a diagram showing the data format of the Admin_Status object provided by the embodiment of the present invention, as shown in FIG. 5. In the signaling interaction process, in order to identify which signaling is signaling for cross-switching, the present invention adds an identifier bit to the Admin_Status object, and uses the cross-switching identifier of the identifier bit to determine the Path letter. Whether or not Resv signaling is used for cross-switching.

The Admin_Status object is defined in [RFC3473 (GMPLS Signaling RSVP-TE Extensions)], which can describe the management status information of the Label Switching Path (LSP) and is widely used in Path signaling, Resv signaling, Notify signaling, etc. The extended Admin_Status object data format is shown in Figure 5, where each identifier is defined as follows:

R bit: Defined in [RFC3471 (GMPLS Signaling Functional Description)], indicating whether the edge node needs to feed back the Admin_Status object to the head node;

S-bit (Switch): The identifier added by the present invention is used to indicate whether the LSP needs to be cross-switched. If the S position is "1", it indicates that the LSP needs to be cross-switched. The S bit introduced by the present invention needs to be used together with the R bit. In the Path signaling, if the S position is "1", the R bit also needs to be set to "Γ, so that the Resv signaling can continue to include the S bit information. .

H-bit: RSVP-TE signaling extension for management plane-to-control plane LSP handover in the GMPLS-enabled transport network (RFC5852 (RSVP-TE Signaling Extension for LSP Handover from the Management Plane to the Control Plane in a GMPLS - Enabled Transport Network) )] is defined to indicate whether it is a migration of a persistent link PC and a soft permanent link SPC service;

L bit: in [RFC4872 (RSVP-TE Extensions in Support of End-to-End

GMPLS Recovery, an RSVP-TE extension that supports end-to-end GMPLS recovery) is defined to indicate whether the LSP is locked.

I-bit: Defined in [RFC4783 (MPLS Segment Recovery)] to indicate whether the LSP masks the alarm.

C-bit: in [RFC4974 (GMPLS RSVP-TE Signaling Extensions in Support of

Calls, GMPLS RSVP-TE signaling extensions for calls) are defined to indicate whether the signaling is used to control and manage calls;

T bit: Defined in [RFC3471], indicating whether the signaling is "test, mode"; A bit: defined in [RFC3471], indicating whether it is in the management off state;

Bit D: Defined in [RFC3471] to indicate whether the LSP is removed.

FIG. 6 is a diagram showing the data format of the Error_Spec object provided by the present invention, as shown in FIG. When using Path signaling for cross-switching, there may be cases where the switchover fails, such as local crossover failure, signaling network failure, and node restart. Therefore, in order to enable the already set crossover to fall back to the previous state, the embodiment of the present invention uses PathErr and ResvErr signaling to implement the cross fallback, so the present invention adds a new Error Code to the Error_Spec object. Field, using the cross-switching failure identifier of this field, identifies the cross-switching failure.

The Error-Spec object is defined in [RFC2205 (RSVP- Version 1 Functional Specification)], which can describe in detail which node in the LSP has an error and what kind of error occurred. . Therefore, the Error_Spec object is widely used in signaling such as PathErr and ResvErr. The data format of Error_Spec in the IPv4 address format is shown in Figure 6.

When cross-switching fails, each identifier is defined as follows:

Error_Node_Addr field: Fill in the first node that failed to switch;

Flags field: When set to 1, it indicates that the node is still a fault point in ResvErr signaling; Error_Code field: is the "Cross Switch Procedure Fail" added by the present invention, and the identifier bit is 36. , continuation of the definition of the value of the Error_Code field in [RFC5852].

Error_Value field: The definition of the present invention is: When the value of this field is 1, it means "Switch Fail". When the value of this field is 2, it means "Path Timeout".

The implementation process of the control plane cross-switching in the signaling mode is divided into five scenarios, and the processing process in each scenario is shown in FIG. 7 to FIG.

FIG. 7 is a schematic diagram showing signaling interaction in a scenario of successful cross-switching according to the first embodiment of the present invention. As shown in FIG. 7, the specific steps include:

Step 701: The first node triggers a service reply or optimization process, first performs a local cross-switching operation, and then assigns the S bit of the Admin_Status object in the Path signaling to "1", and sends the Path signaling to the downstream node to start the path timeout timing. The path timeout timer is timed. It is 1 minute.

In the cross-switching operation, in the reply process, the crossover needs to be switched from the restored connection to the original working connection; in the optimization process, the crossover needs to be switched from the working connection to the optimized connection.

Step 702: After receiving the Path signaling, the intermediate node determines whether the S bit of the Admin_Status object in the Path signaling is "". If yes, the path signaling is only used for cross-switching; if not, the path is The signaling is not used for the signaling of the cross-switching. When the intermediate node finds that the S bit of the Admin_Status object is "1", it first performs the local cross-switching operation, then forwards the Path signaling to the downstream node, and starts its Path timeout timer.

Step 703: After receiving the Path signaling forwarded by one or more intermediate nodes, the tail node finds that the S bit of the Admin_Status object in the Path signaling is "1" and performs a local cross-switching operation. After waiting for the local crossover to succeed, the S bit of the Admin_Status object in the Resv signaling is assigned the value "1", and the Resv signaling is sent to the upstream node.

Step 704: After receiving the Resv signaling, the intermediate node cancels its Path timeout timer, finds that the S bit of the Admin_Status object is "1", waits for the local crossover to succeed, and continues to forward the Resv signaling to the upstream node.

Step 705: After receiving the Resv signaling forwarded by one or more intermediate nodes, the first node cancels its Path timeout timer, and finds that the S bit of the Admin_Status object is "1", and waits for the local crossover to succeed, and the first node continues. Other processes of replying or optimizing, this crossover process ends.

FIG. 8 is a schematic diagram showing the signaling interaction in the signaling unreachable scenario provided by the second embodiment of the present invention. As shown in FIG. 8, the specific steps include:

Step 801: The first node triggers a service reply or optimization process, performs a local cross-switching operation, and sets the S bit of the Admin_Status object in the Path signaling, sends the Path signaling to the downstream node, and starts its Path timeout timer.

Step 802: After receiving the Path signaling, the intermediate node LSR A performs a local cross-switching operation. And sending the Path signaling to the downstream node, and starting its Path timeout timer.

Step 803: The Path signaling sent by the intermediate node LSR A is not sent to the downstream node LSR B and/or Egress LER due to a signaling network failure or a node power failure.

Step 804: The intermediate node LSR A has not received the Resv signaling or PathErr signaling from the downstream for a long time, causing its Path timeout timer to expire.

Step 805: The intermediate node LSR A rolls back the state before the local crossover to the switching, and sends the PathErr signaling to the upstream node, where the Error_Node_Addr field of the Error_Spec object in the PathErr signaling is assigned the IP address of the downstream node, and the Error_Code field is assigned the value 36. (Cross Switch Procedure Fail ), Error—Value field is assigned 2 (Path Timeout).

Step 806: After receiving the PathErr signaling, the first node rolls back the local crossover to the state before the switching, and then stops the reply process or the optimization process, and records the reason for the crossover failure according to the values of the Error_Node_Addr and Error_Value fields. The switching process ends.

FIG. 9 is a schematic diagram of signaling interaction in a scenario of a first-node cross-switching failure scenario according to the third embodiment of the present invention. As shown in FIG. 9, the specific steps include:

Step 901: The first node triggers a service reply or optimization process, performs a local cross-switching operation, and simultaneously sets the S position of the Admin_Status object in the Path signaling, and sends the Path signaling to its downstream node.

Step 902: After receiving the Path signaling, the intermediate node performs a local cross-switching operation, and forwards the Path signaling to its downstream node.

Step 903: After receiving the Path signaling forwarded by one or more intermediate nodes, the tail node performs a local cross-switching operation, and after the local cross-switching is successful, assigns the S-bit of the Admin_Status object in the Resv signaling to " Γ and send Resv signaling to its upstream node.

Step 904: The intermediate node receives the Resv signaling, and after waiting for the local cross-switching to succeed, continues to forward the Resv signaling to its upstream node.

Step 905: After the first node receives the Resv signaling forwarded by one or more intermediate nodes, Waiting for the local crossover result, but the result of the first node waiting is the crossover failure. The first node rolls back the local crossover to the state before the switchover, and then sends a resource reservation error to its downstream node.

(ResvErr) signaling, where the Error_Node_Addr field in the Error_Spec object is assigned the local node IP address, the Error_Code field is assigned the value 36 (Cross Switch Procedure Fail), and the Error_Value field is assigned the value 1 (Switch Fail). Finally, the first node stops replying or optimizing the process, and records that the crossover failure is caused by the failure of the first node crossover, and the crossover process ends.

Step 906: After receiving the ResvErr signaling, the intermediate node rolls back the local crossover to the state before the switching, and forwards the ResvErr signaling to its downstream node.

Step 907: After receiving the ResvErr signaling forwarded by one or more intermediate nodes, the tail node rolls back the local crossover to the state before the switching.

FIG. 10 is a schematic diagram showing the signaling interaction in the scenario of the cross-switching failure of the intermediate node according to the fourth embodiment of the present invention. As shown in FIG. 10, the specific steps include:

Step 1001: The first node triggers a service reply or optimization process, performs a local cross-switching operation, and simultaneously sets the S position of the Admin_Status object in the Path signaling, and sends the Path signaling to the downstream node.

Step 1002: After receiving the Path signaling, the intermediate node performs a local cross-switching operation, and forwards the Path signaling to its downstream node.

Step 1003: After receiving the Path signaling forwarded by one or more intermediate nodes, the tail node performs a local cross-switching operation, and after waiting for the local cross-switching success, assigns the S-bit of the Admin_Status object in the Resv signaling. "1" and send Resv signaling to its upstream node.

Step 1004: After receiving the Resv signaling, the intermediate node waits for the local cross-switching result, but the intermediate node waits for the cross-switching failure. The intermediate node first rolls back the local crossover to the state before the switching, and then sends ResvErr signaling to the downstream node, where the Error_Node_Addr field in the Error_Spec object is assigned the local node IP address, and the Error_Code field is assigned 36 (Cross Switch Procedure Fail), the Error—Value field is assigned the value 1 (Switch Fail). Step 1005: After receiving the ResvErr signaling, the tail node rolls back the local crossover to the state before the switching. Then, the PathErr signaling is sent to the upstream node, where the content filled in the Error_Spec object is consistent with the ResvErr signaling.

Step 1006: The intermediate node receives the PathErr signaling, and forwards the PathErr signaling directly to the upstream node because the local crossover has been rolled back.

Step 1007: After receiving the PathErr signaling, the first node rolls back the local crossover to the state before the switching, and then stops the reply or optimization process, and records the reason for the crossover failure according to the values of the Error_Node_Addr and Error_Value fields. The crossover process ends.

FIG. 11 is a schematic diagram of signaling interaction in a scene of a tail node cross-switching failure according to the fifth embodiment of the present invention. As shown in FIG. 11, the specific steps include:

Step 1101: The first node triggers a service reply or optimization process, performs a local cross-switching operation, and simultaneously sets the S position of the Admin_Status, and sends a Path signaling to the downstream node to start a Path timeout timer.

Step 1102: After receiving the Path signaling, the intermediate node performs a local cross-switching operation, and sends the Path signaling to the downstream node to start a Path timeout timer.

Step 1103: After receiving the Path signaling forwarded by one or more intermediate nodes, the tail node performs a local cross-switching operation. Wait for the local crossover result, but the tail node waits for the crossover failure. The tail node first rolls back the local crossover to the state before the switching, and then sends the PathErr signaling to the upstream node, where the Error_Node_Addr field in the Error_Spec object is assigned the local node IP address and the Error_Code field is assigned 36 (Cross Switch Procedure)

Fail ), The Error—Value field is assigned the value 1 (Switch Fail).

Step 1104: The intermediate node receives the PathErr signaling, rolls back the local crossover to the state before the switching, and forwards the PathErr signaling to the upstream node.

Step 1105: The first node receives PathErr signaling forwarded by one or more intermediate nodes, Roll back the local crossover to the state before the switchover, then stop the reply or optimize the process, and

The values of the Error_Node_Addr and Error_Value fields record the cause of the crossover failure. The crossover process ends.

The embodiment of the present invention further provides a system for implementing control plane crossover switching, where the system includes: a first node, an intermediate node, and a tail node;

Optionally, the system further includes:

The setting module is configured to respectively set a cross-switching identifier in the Path signaling and the Resv signaling, and respectively set a cross-switching failure identifier in the PathErr signaling and the ResvErr signaling.

The optical layer with the first node being A and the tail node being Z can reply to the service as a specific embodiment. The restored working connection and the restored connection path and the crossover situation can be as shown in FIG. 12, wherein the working connection and the wavelength used for the recovery connection are used. the same. After the work connection alarm disappears, the service triggers the reply switch operation. The specific implementation steps are as follows:

Step 1201: The working connection and the recovery connection use the same resource in the first node A, so the first node A does not need to perform a cross-switching operation; Step 1202: The first node A sets the S position of the Admin_Status object in the Path signaling, and sends the Path signaling to the intermediate node B to start its Path timeout timer.

Step 1203: After receiving the Path signaling, the intermediate node B first determines, by using the S bit of the Admin_Status object, that the Path signaling is signaling used for the cross-switching operation;

Step 1204: The intermediate node B determines that the cross-switching command needs to be sent to the board, and the cross-connection of the downstream and downstream interfaces is switched to the working connection.

Step 1205: The intermediate node B continues to send the Path signaling to the intermediate node C, and starts its Path timeout timer.

Step 1206: After receiving the Path signaling, the intermediate node C determines, by using the S bit of the Admin_Status object, that the Path signaling is signaling used for the cross-switching operation;

Step 1207: The intermediate node C determines that the local cross-switching operation is not required, and therefore continues to send the Path signaling to the node Z, and starts its Path timeout timer.

Step 1208: After receiving the Path signaling, the tail node Z determines, by using the S bit of the Admin_Status object, that the Path signaling is signaling used for the cross-switching operation;

Step 1209: The tail node Z determines that the cross-switching command needs to be sent to the board, and the crossover between the upstream and the upstream is switched to the working connection.

Step 1210: After the tail node Z waits for the cross-setting to respond successfully, it sends Resv signaling to the central node C, where the S bit of the Admin_Status object in the Path signaling is carried;

Step 1211: The central node C receives the Resv signaling, and determines, by using the S bit of the Admin_Status object, that the Resv signaling is signaling used for the cross-switching operation;

Step 1212: The central node C first cancels the Path timeout timer, and then waits for the cross setting to be successful, and then continues to send the Resv signaling to the central node B.

Step 1213: The central node B receives the Resv signaling, and determines, by using the S bit of the Admin_Status object, that the Resv signaling is signaling used for the cross-switching operation;

Step 1214: The central node B first cancels its Path timeout timer, and then waits for the crossover After the response is successful, the Resv signaling is continued to be sent to the first node A;

Step 1215: After receiving the Resv signaling, the first node A determines, by using the S bit of the Admin_Status object, that the R _esv signaling is signaling for the cross-switching operation;

Step 1216: The first node A first cancels its Path timer, and then waits for the local cross setting. After the response is successful, the other reply process continues, and the refresh switching process ends.

In summary, the embodiment of the present invention implements the cross-switching operation of the service from the restored connection to the original working connection and the cross-switching operation of the working connection to the optimized connection by using the signaling manner, thereby effectively solving the service reply in the resource reuse scenario or The cross-switching problem in the optimization process improves the utilization of network resources and improves the flexibility of the control plane to implement cross-switching.

Although the invention has been described in detail above, the invention is not limited thereto, and various modifications may be made by those skilled in the art in accordance with the principles of the invention. Therefore, modifications made in accordance with the principles of the present invention should be construed as falling within the scope of the present invention.

Claims

A method for implementing control plane cross-switching, wherein the method comprises: during a cross-switching operation in an automatic switched optical network (ASON), the first node performs cross-switching, and sends a path with a cross-switching identifier to the downstream node. Signaling

2. The method according to claim 1, wherein the method further comprises: when the first node or the intermediate node performs cross-switching, starting respective path timeout timers.

3. The method according to claim 1, wherein the method further comprises:

4. The method according to claim 1, wherein the method further comprises:

The intermediate node cancels its Path timeout timer according to the received Resv signaling, and after determining the crossover failure, returns to the pre-crossover state, and sends a resource reservation error Res vErr with the crossover failure identifier to the downstream node. The signaling is such that other intermediate nodes and tail nodes downstream thereof are sequentially restored to the pre-crossover state.

5. The method according to claim 4, wherein the method further comprises:

After the tail node receives the ResvErr signaling and returns to the state before the cross-switching, it sends its upstream section The point sends PathErr signaling containing the cross-switching failure identifier.

6. The method according to claim 1, wherein the method further comprises:

The first node cancels its Path timeout timer according to the received Resv signaling, and after determining the crossover failure, returns to the pre-crossover state, and sends the ResvErr signaling with the crossover failure identifier to the downstream node, so that the first node The downstream intermediate node and the tail node are sequentially restored to the pre-crossover state.

The method according to any one of claims 1 to 6, wherein the method further comprises: if the Path Timeout Timer of the intermediate node does not receive Resv signaling or PathErr signaling from the downstream node within its timing time Then, the PathErr signaling is sent to the upstream node, so that the other intermediate nodes and the first node in the upstream are sequentially restored to the state before the cross-switching.

8. The method according to claim 7, wherein the method further comprises the step of setting before the cross-switching operation:

A cross-switching identifier is set in Path signaling and Resv signaling, and a cross-switching failure identifier is set in PathErr signaling and ResvErr signaling, respectively.

9. A system for implementing control plane cross-switching, wherein the system comprises: a first node, an intermediate node, and a tail node; wherein

The head node is configured to perform cross-switching during a cross-switching operation in the automatic switched optical network ASON, and send Path signaling with a cross-switching identifier to the downstream node, and receive the Resv forwarded through one or more intermediate nodes. Signaling, performing cross-switching according to the cross-switching identifier therein;

The intermediate node is configured to receive the Path signaling, perform cross-switching according to the cross-switching identifier therein, and forward the Resv signaling containing the cross-switching identifier from the tail node to the upstream after the cross-switching succeeds Node

The tail node is configured to receive the Path signaling, perform cross-switching according to the cross-switching identifier therein, and send the cross-switching to the upstream node after performing the cross-switching success. Resv signaling of the identifier.

10. The system of claim 9, wherein the system further comprises: