Technique for determining whether to reestablish fast rerouted primary tunnels based on backup tunnel path quality feedback

摘要

In one embodiment, a primary tunnel is established from a head-end node to a destination along a path including one or more protected network elements for which a fast reroute path is available to pass traffic around the one or more network elements in the event of their failure. A first path quality measures path quality prior to failure of the one or more protected network elements. A second path quality measures path quality subsequent to failure of the one or more protected network elements, while the fast reroute path is being used to pass traffic of the primary tunnel. A determination is made whether to reestablish the primary tunnel over a new path that does not include the one or more failed protected network elements, or to continue to utilize the path with the fast reroute path, in response to a difference between the first path quality and the second path quality.

主权项

1. A method comprising:
calculating, by a path computation element (PCE) that includes one or more processors, a path of a primary tunnel from a head-end node to a destination, the path including one or more protected network elements for which a fast reroute path is available, the fast reroute path beginning at a point of local repair (PLR) node along the path and extending to a remerge point along the path and arranged to, in the event of failure of the one or more network elements, pass traffic of the primary tunnel around the failed one or more network elements; ascertaining a first path quality of the primary tunnel that measures path quality prior to failure of the one or more protected network elements while the fast reroute path is not being used to pass traffic of the primary tunnel; ascertaining a second path quality of the primary tunnel that measures path quality subsequent to failure of the one or more protected network elements while the fast reroute path is being used to pass traffic of the primary tunnel; and determining whether to reestablish the primary tunnel over a new path that does not include the one or more failed protected network elements, or to continue to utilize the path with the fast reroute path, in response to a difference between the first path quality and the second path quality.