Nokia 7705 - Behavior of Secondary LSP Paths; PCE Path Profile Support

PCEP
332
MPLS Guide
© 2022 Nokia.
Use subject to Terms available at: www.nokia.com
3HE 18686 AAAB TQZZA
4.5.4 Behavior of Secondary LSP Paths
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.
4.5.5 PCE Path Profile Support
The PCE path profile ID and path group ID are configured at the LSP level
(config>router>mpls>lsp>path-profile).
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.
When the user wants to apply path disjointness and path bidirectionality constraints
to RSVP-TE LSP paths, it is important to follow the following guidelines. The user can
configure the following sets of LSP paths:
Note: 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.