When provisioning a spoke-SDP on an Epipe, what MUST match on both ends of the service?

When configuring an Epipe service between two Provider Edge (PE) routers using a spoke-SDP, the Virtual Circuit Identifier (VC-ID) is the critical parameter that MUST be identical on both PEs for that specific service. The VC-ID is used in the Targeted LDP (T-LDP) signaling process to identify and bind the correct pseudowire endpoints together across the MPLS network. A mismatch in the VC-ID will prevent the pseudowire from coming up, and the Epipe service will fail to establish.

A. The Service ID is a locally significant identifier on each router and does not need to match between the two PEs.
B. The Customer ID is a local identifier for administrative purposes and is not used in the signaling process between PEs.
C. The SAP ID (Service Access Point) identifies the local physical or logical port for the service and is inherently local to each PE.
E. The SDP ID (Service Distribution Path) is a local identifier for the transport tunnel; the SDP used on one PE does not need to match the other.

- Nokia 7750 SR and 7950 XRS MPLS Guide, Release 22.10.R1, Part Number: 3HE 18380 AAAD TQZZA, Section: "Pseudowire Signaling". This section details the use of the VC-ID in the FEC element of T-LDP messages to uniquely identify a pseudowire between two PEs.

- IETF RFC 4447, "Pseudowire Setup and Maintenance Using the Label Distribution Protocol (LDP)", Section 3. This RFC, which forms the basis for Nokia's implementation, specifies that the VC ID is part of the Forwarding Equivalence Class (FEC) Element used to identify the pseudowire.