Patent ID: 7209434
Filing Date: 2007-04-24
Classification: H04L

Abstract:
1. A path modifying method for use in a label transfer network including a plurality of label switching nodes for transferring received data in accordance with label information of said received data, said method comprising: transmitting a path modifying request from an ingress label switching node positioned at an upstream side end of a partial section of a work path which is intended for path modification to an egress label switching node positioned at a downstream end of the partial section via a detour path between said ingress label switching node and said egress label switching node; executing a partial path modification from said work path (hereinafter referred as a “old path”) of the partial section to said detour path so as to use said detour path as a new data transfer path (hereinafter referred as a “new path”) between said ingress label switching node and said egress label switching node, by returning a label allocation request for allocating new label information for the partial section, which is between said ingress label switching node and said egress label switching node, of said new path from said egress label switching node to said ingress label switching node in response to reception of said path modifying request on said egress label switching node; allocating new label information (upstream side label information) for the partial section, which is between said ingress label switching node and said egress label switching node, of the upstream side in the detour path from said ingress node to said egress node forming the new path when receiving said path modifying request; associating each of said upstream side label information on said new path newly allocated and upstream side label information on said old path already allocated with downstream side label information already allocated with respect to said old path; and releasing only label information for the upstream side in said old path at the time of reception of a label release request on said old path for implementing partial path modification.