US Patent 10063464 Protection switched source routing

A network element configured to operate in a source routing network, wherein the network element comprises a receiver, a transmitter, and a processor coupled to the receiver and the transmitter. The processor may be configured to cause the network element to receive from an upstream network element, a liveness protection probe comprising a header that comprises a list of one or more ordered connection identifiers that indicate a network path traversing the source routing network through which the liveness protection probe should be forwarded, transmit the liveness protection probe toward a downstream network element according to the connection identifiers, receive the liveness protection probe from the downstream network element, and transmit the liveness protection probe to the upstream network element according to a second list of one or more ordered connection identifiers contained within the header.