Patent ID: 7835312

Claim:
A method of updating label-switched paths for forwarding data in a data communications network in response to a change in a network comprising the steps, performed at an updating node of: receiving notification of a network change; commencing at the updating node a first period timer having a first period and a second period timer having a second period; constructing a post-change label-switched path to a destination node in the changed network; in response to receiving a packet for forwarding to the destination node, determining whether a next hop node toward the destination node in the post-change network is downstream a pre-change label-switched path toward the destination node in the pre-change topology, and, if so, forwarding the packet to the next hop node using the pre-change label-switched path in the pre-change topology as though the first period is terminated, otherwise, waiting until termination of the first period and forwarding the packet using the post-change label-switched path in the changed network only after termination of the first period; and at the updating node, after termination of the second period subsequent to termination of the first period, removing the pre-change label-switched paths; wherein the updating node comprises the one or more computing devices.