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PCEP
330
- If the PCE successfully finds a path, it replies with a PCRep message with
the ERO.
- If the PCE does not find a path, it replies with a PCRep message containing
the No-Path object.
4. If the local CSPF or the PCE returns a path, the PCC performs the following
actions.
- The PCC signals the LSP with the RSVP control plane and moves traffic to
the new MBB path. It then sends a PCRpt message with the delegation
D-bit set to return delegation and containing the RRO and LSP objects, with
the LSP-IDENTIFIERS TLV containing the LSP-ID of the new MBB path.
The message includes the metric, LSPA, and bandwidth objects where the
P-flag is clear, which indicates the operational values of these parameters.
Unless the user disabled the report-path-constraints option under the pcc
context, the PCC also includes a second set of metric, LSPA, or bandwidth
objects with the P-flag set to convey to the PCE the constraints of the path.
- The PCC sends a PathTear message to delete the state of the older path in
the network. The PCC then sends a PCRpt message to the PCE with the
older path LSP (PLSP-ID) and the remove R-bit set to also have the PCE
remove the state of that LSP from its database.
5. If the local CSPF or the PCE returns no path or the RSVP-TE signaling of the
returned path fails, the router makes no further requests. That is, there is no retry
for the MBB.
- The PCC sends a PCErr message to the PCE with the LSP Error code field
of the LSP-ERROR-CODE TLV set to a value of 8 (RSVP signaling error) if
the MBB failed due to a RSVP-TE signaling error.
- The PCC sends a PCRpt message with the delegation D-bit set to return
delegation and containing the RRO and LSP objects, with the
LSP-IDENTIFIERS TLV containing the LSP-ID of the currently active path.
The message includes the metric, LSPA, and bandwidth objects where the
P-flag is clear to indicate the operational values of these parameters.
Unless the user disabled the report-path-constraints option under the pcc
context, the PCC also includes a second set of metric, LSPA, and
bandwidth objects with the P-flag set to convey to the PCE the constraints
of the path.
6. The ingress LER takes no action in the case of a network event triggered MBB,
such as FRR global revertive or TE graceful shutdown.
- The ingress PE keeps the information as required and sets the state of MBB
to one of the FRR global revertive or TE graceful shutdown MBB values but
does not perform the MBB action.
Use subject to Terms available at: www.nokia.com
© 2022 Nokia.
MPLS Guide
3HE 18686 AAAB TQZZA
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