Patent ID: 6084882
Filing Date: 2000-07-04
Classification: H04L

Abstract:
A method for determining, in a packet communication network, at least one first identifier identifying at least one first packet directional path, which is to be logically defined in each of a plurality of links in a bypassing path, where said bypassing path bypasses a faulty signal path extending from a first node through a second node to a third node, said bypassing path extends from said first node through at least one midway node to said third node, and said at least one first packet directional path is to be determined corresponding to at least one second packet directional path which is logically defined in each of a plurality of links in the faulty signal path;the packet communication network contains a plurality of nodes, and each of the plurality of nodes contains unused identifier storing means for storing, in said each of the plurality of nodes, information on at least one unused identifier each being available for use in identifying a packet directional path in each link incoming to the said each of the plurality of nodes; andsaid third node contains original identifier storing means for storing, in said third node, at least one second identifier identifying said at least one second packet directional path in the link between the first node and the second node;said method comprising the steps of:(a) determining, in said third node, as said at least one first identifier identifying said at least one first packet directional path in the link between the third node and a first one of the at least one midway node located one node upstream of the third node on the bypassing path, at least one unused identifier among the at least one unused identifier stored in the third node by the unused identifier storing means, so that each of the at least one second identifier corresponds to one of the at least one first identifier determined in the link between the third node and the first one of the at least one midway node on the bypassing path;(b) transferring, from the third node to the first one of the at least one midway node, said at least one second identifier and the at least one first identifier determined in the link between the third node and the first one of the at least one midway node, so that the correspondence between each of the at least one first identifier and one of the at least one second identifier, is recognizable;(c) receiving, at each of the at least one midway node on the bypassing path, from one of the third node and a second one of the at least one midway node which is located one node downstream of said each midway node, said at least one second identifier and said at least one first identifier determined in the link between said each midway node and said one of the third node and the second one of the at least one midway node, and recognizing the correspondence between each of the at least one second identifier and one of the at least one first identifier determined in the link between said each midway node and said one of the third node and the second one of the at least one midway node;(d) determining, after step (c), in said each midway node, as said at least one first identifier identifying said at least one first packet directional path in a link between said each midway node and one of the first node and a third one of the at least one midway node which is located one node upstream of said each midway node on the bypassing path, at least one unused identifier among the at least one unused identifier stored in said each midway node by the unused identifier storing means, so that each of the at least one first identifier determined in the link between said each midway node and said one of the first node and the third one of the at least one midway node on the bypassing path;(e) transferring, from said each midway node to said one of the first node and the third one of the at least one midway node, said at least one second identifier and said at least one first identifier determined in the link between said each midway node and said one of the first node and the third one of the at least one midway node, so that the correspondence between each of the at least one second identifier and one of the at least one first identifier determined in the link between said each midway node and said one of the first node and the third one of the at least one midway node, is recognizable; and(f) receiving, at the first node, from a fourth one of the at least one midway node located one node downstream of the first node one the bypassing path, said at least one second identifier and the at least one first identifier determined in the link between the first node and said the fourth one of the at least one midway node, and recognizing the correspondence between each of the at least one second identifier and one of the at least one first identifier determined in the link between the first node and said the fourth one of the at least one midway node.