The value of tnOamVccvPingCtlSdpIdVcId specifies the SDP binding of the FEC 128 pseudowire to be used when performing a vccv-ping operation. A non-zero value is mandatory when testing a FEC 128 pseudowire. The all-zeros value indicates an unused SDP binding. If tnOamVccvPingCtlSdpIdVcId is set to a non-default value, the following objects must be default: tnOamVccvPingCtlSpokeSdpId, tnOamVccvPingCtlSaiiGlobalId, tnOamVccvPingCtlSaiiPrefix, tnOamVccvPingCtlSaiiAcId, tnOamVccvPingCtlTaiiGlobalId, tnOamVccvPingCtlTaiiPrefix, and tnOamVccvPingCtlTaiiAcId. If the value of tnOamVccvPingCtlSdpIdVcId is non-zero and invalid, or the pseudowire is administratively down, or unavailable, the OAM Echo request message probe is not sent and an appropriate error value is written to tnOamPingHistoryStatus for that probe entry. Once the interval timer expires, the next probe attempt will be made if required.