Protecting multi-segment pseudowires

A head end network device of a multi-segment pseudowire, wherein the multi-segment pseudowire extends from the head-end network device to a tail-end network device, and wherein the multi-segment pseudowire spans a plurality of packet switch network tunnels, the head end network device comprising:

• a processor;
• a communication interface;
• and
• a memory comprising instructions executable by the processor, wherein the processor is in communication with memory and the communication interface;
• the communication interface is configured to receive, from each respective pseudowire stitching point on a primary path of the multi-segment pseudowire, an indication of an ability to act as a stitching point for the multi-segment pseudowire and reachability information of each respective pseudowire stitching point on the primary path;
• the instructions are configured to determine, for each respective pseudowire stitching point on the primary path of the multi-segment pseudowire that signals an ability to act as a stitching point for the multi-segment pseudowire, a backup path that excludes the respective pseudowire stitching point, wherein the backup path for each respective pseudowire stitching point is a pre-computed backup path because the backup path is computed prior to a failure in any pseudowire stitching point on the primary path;
• and
• the instructions are further configured to select the pre-computed backup path that excludes a failed pseudowire stitching point in response to receipt of an indication of a failure of the failed pseudowire stitching point.

A non-transitory computer readable medium having stored thereon a computer program comprising instructions executable with a processor to:

• signal, at a first pseudowire stitching point, to at least one of a head-end network device or a tail-end network device an ability of the first pseudowire stitching point to act as a stitching point for a multi-segment pseudowire, wherein the multi-segment pseudowire extends from the head-end network device to the tail-end network device, wherein a primary path of the multi-segment pseudowire includes the first pseudowire stitching point and a second pseudowire stitching point, wherein the multi-segment pseudowire is configured to emulate attributes of a plurality of telecommunications services on a packet switched network, and wherein the signal of the ability comprises an advertisement of reachability information of the first pseudowire stitching point to the at least one of the head-end network device or the tail-end network device,
• wherein, for each respective pseudowire stitching point on a primary path of the multi-segment pseudowire that signals an ability to act as a stitching point for the multi-segment pseudowire, a backup path that excludes the respective pseudowire stitching point is computed prior to a failure of the respective pseudowire stitching point;
• detect a failure of the second pseudowire stitching point at the first pseudowire stitching point;
• and
• transmit data indicative of the failure of the second pseudowire stitching point to the head-end from the first pseudowire stitching point, wherein the pre-computed backup path that excludes the second pseudowire stitching point is selected by the head-end network device in response to receipt of the data, and the pre-computed backup path is selected by the tail-end network device in response to receipt by the tail-end network device, over the pre-computed backup path, of an indication of the failure of the second pseudowire stitching point.