Patent attributes
Testing the liveliness of a data plane of a label switched path (LSP) using a two stage approach. The first stage may use a general echo request operation that may be implemented using hardware. Therefore, the first stage does not heavily burden the control plane of the LSR. If a suspect LSP passes the first stage of the diagnostic operation, nothing more needs to be done. If, however, the suspect LSP fails the first stage, the diagnostic operation proceeds to a second stage. The second stage of the diagnostic operation sends probing massages through the suspect LSP, but uses the control plane to deliver the acknowledging messages. If the suspect LSP fails the second stage of the diagnostic operation, the ingress LSR can infer that the LSP is down, and begin recovery actions. The probing messages may include padding so that MTU limits can be tested. In addition, the probing messages may be encapsulated in a protocol that allows flow control, thereby protecting an LSR that can receive such messages from DoS attacks.
