SDP ping performs in-band unidirectional or round-trip connectivity tests on SDPs. The SDP ping OAM packets are sent in-band, in the tunnel encapsulation, so it follows the same path as traffic within the service. The SDP ping response can be received out-of-band in the control plane, or in-band using the data plane for a round-trip test.
For a unidirectional test, SDP ping tests:
egress SDP ID encapsulation
ability to reach the far-end IP address of the SDP ID within the SDP encapsulation
path MTU to the far-end IP address over the SDP ID
forwarding class mapping between the near-end SDP ID encapsulation and the far-end tunnel termination
For a round-trip test, SDP ping uses a local egress SDP ID and an expected remote SDP ID. Because SDPs are unidirectional tunnels, the remote SDP ID must be specified and must exist as a configured SDP ID on the far-end router SDP round trip testing is an extension of SDP connectivity testing with the additional ability to test:
remote SDP ID encapsulation
potential service round trip time
round trip path MTU
round trip forwarding class mapping