OAM functions are supported only at Tunnel termination points (no intermediate checks).
Connectivity verification (CV) is based on the periodic transmission of CV packets from ingress to egress of a T-MPLS connection. The period is provisionable.
The egress of the T-MPLS connection extracts T-MPLS CV from the T-MPLS signal checking for the defects. The main defects concern:
The presence of continuity in T-MPLS trail
The connectivity to the specified source in T-MPLS trails
Forward defect indication (FDI) is used for alarm suppression at client layer.
Detected failures at link layer trigger FDI packets insertion in all the pass-through tunnels correspondent to the link where the failure is detected.
FDI packets are transmitted with the periodicity of 1s, until the fail condition is cleared.
Remote defect indication (RDI) is used for alarm suppression at client layer.
Detected failures at link layer trigger FDI packets insertion in all the pass-through tunnels correspondent to the link where the failure is detected.
FDI packets are transmitted with the periodicity of 1s, until the fail condition is cleared.
The following VLNC62 T-MPLS tunnel segment conditions/alarms are detected and reported:
LOC Loss of Connectivity: Lock of CV packets for a period greater than 3.5 the CV provisioned period.
MMG Unexpected MEG: A CV packet with MEL=0 and an invalid MEG value (that is with a MEG_ID different from the configured MG_ID at the received MEP) has been received.
SSF Server Signal Failure: cSSF = FDI or CI-SSF.
UNM Unexpected MEP: A CV packet with MEL=0 and a valid MEG_ID, but with an invalid MEP (that is with a MEP_ID different from the configured PeerMEP_ID at the receiving MEP) has been received.
UNP Unexpected Period: A CV packet with MEL=0, valid MEG_ID, valid MEP_ID, but with an invalid CV_PHB (that is with a received PHB value different from the configured PHB at the receiving MEP) has been received.
UNPHB Unexpected PHB: A CV packet with MEL=0, valid MEG_ID, valid MEP_ID, but with an invalid CV_Period (that is with a received Period value different from the configured Period at the receiving MEP) has been received.
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