Each of the primary, secondary standby, and secondary non-standby paths of the same LSP must use a separate path LSP-ID (PLSP-ID). The PCE function of the NSP, the NRC-P, checks the LSP-IDENTIFIERS TLV in the LSP object and can identify which PLSP-IDs are associated with the same LSP or the same RSVP-TE session. The parameters are the IPv4 Tunnel Sender Address, the Tunnel ID, the Extended Tunnel ID, and the IPv4 Tunnel Endpoint Address. This approach allows the use of all the PCEP procedures for all three types of LSP paths.
The PCC indicates to the PCE the following states for the path in the LSP object: down, up (signaled but not carrying traffic), or active (signaled and carrying traffic).
The PCE tracks active paths and displays them in the NSP GUI. It also provides only the tunnel ID of an active PLSP-ID to a destination prefix when a request is made by a service or a steering application.
The PCE recomputes the paths of all PLSP-IDs that are affected by a network event. The user can select each path separately on the NSP GUI and trigger a manual resignal of one or more paths of the RSVP-TE LSP.
Enabling the srlg option on a secondary standby path results in no operation. The NRC-P supports link and SRLG disjointness using the PCE path profile. The user can apply the PCE path profile to the primary and secondary paths of the same LSP. See PCE Path Profile Support for more information.