Method for constructing bidirectional lable swap path in optical network

Abstract

A method for building up bidirection label switched path, this method starts from initial node of bidirection label switched path (LSP), sends the bidirection LSP establishment request to descendant node node-by-node and obtains the tally set of the up and down stream of present node according to available resource information of present chain section and the up and down stream tally set provided by up stream node, until final node; if the establishment request of bidirection LSP is sent to final node and the received available up and down stream tally set are not all empty, the final node selects available up and down stream label from received available tally set, then start from next node of bidirection LSP, send bidirection LSP establishment response and the up and down stream label selected by down stream node to previous node node-by-node, until initial node; this method can complete the establishment of bidirection LSP within a signalling turn back..

Description

technical field [0001] The invention relates to a method for establishing a bidirectional label switching path (LSP) in an optical network. Background technique [0002] In the current optical network system, such as Synchronous Digital Hierarchy / Synchronous Optical Network (SDH / SONET) network, the application of General Label Switching Protocol (GMPLS) signaling supports the operation of establishing a bidirectional LSP with one signaling, and bidirectional LSP can be divided into It is the path in the same direction as the signaling direction and the path in the reverse direction, and the establishment process of the path in the same direction adopts "downstream on demand", that is, the label allocation method in which the downstream node allocates and provides labels only when the upstream node requests it; The reverse path uses "downstream active", that is, the downstream node actively provides labels to the upstream node. A bidirectional LSP is two LSPs with the same i...

AI Technical Summary

Problems solved by technology

[0006] From the above example, it can be seen that when the first node specifies the upstream label, it does not consider the limit of the acceptable label of the subsequent node, which causes the problem of repeated retries of the upstream label. In extreme cases, the number of retries is equal to the number of nodes involved in the bidirectional LSP minus one.

The existence of the retry label phenomenon seriously affects the establishment time of bidirectional LSP based on GMPLS signaling in SDH / SONET network, and delays the service recovery time when the fault is restored.

As a result, existing methods have a low success rate when label-switched paths are limited in label selection on links passing through

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