Global optimization is supported on the PCE. Local optimization of a replication segment using PCEP is not supported. If the PCE calculates an optimized path for a candidate path, that path instance is different from the current path instance. For this reason, a candidate path contains two path instances. The PCE must download a new path instance with an LSP ID of 0 and the PLSP ID of the current candidate path. This behavior applies to replication segments only.
When the current path instance is modified from the PCE to the PCC, the PCC-assigned LSP ID and PLSP ID are sent from the PCE to the PCC. This behavior ensures that the LSP ID of the replication segment for the existing path instances does not change.