The PCE path profile ID and path group ID are configured at the LSP level.
The NRC-P can enforce path disjointness and bidirectionality among a pair of forward and a pair of reverse LSP paths. Both pairs of LSP paths must use a unique path group ID along with the same Path Profile ID, which is configured on the NRC-P to enforce path disjointness or path bidirectionality constraints.
When the user wants to apply path disjointness and path bidirectionality constraints to LSP paths, it is important to follow the following guidelines. The user can configure the following sets of LSP paths.
Configure a set consisting of a pair of forward LSPs and a pair of reverse LSPs each with a single path, primary or secondary. The pair of forward LSPs can originate and terminate on different routers. The pair of reverse LSPs must mirror the forward pair. In this case, the path profile ID and the path group ID configured for each LSP must match. Because each LSP has a single path, the bidirectionality constraint applies automatically to the forward and reverse LSPs, which share the same originating node and the same terminating routers.
Configure a pair consisting of a forward LSP and a reverse LSP, each with a primary path and a single secondary path, or each with a couple of secondary paths. Because the two paths of each LSP inherit the same LSP level path profile ID and path group ID configuration, the NRC-P path computation algorithm cannot guarantee that the primary paths in both directions meet the bidirectionality constraint. That is, it is possible that the primary path for the forward LSP shares the same links as the secondary path of the reverse LSP and vice-versa.