All MBB types are supported for PCC-controlled LSPs. The LSP MBB procedures for a
PCC-controlled LSP (path-computation-method pce and
pce-control disabled) are as follows.
Procedure
MPLS submits a path request, including the updated path constraints, to the local
CSPF.
If the local CSPF returns a path, the PCC signals the LSP with
RSVP control plane and moves traffic to the new MBB path.
If pce-report is enabled for this LSP, the PCC sends a
PCRpt message with the delegation bit clear to retain control and containing the
RRO and LSP object with the LSP identifiers TLV containing the LSP-ID of the new
MBB path. It includes the metric, LSPA, and BANDWIDTH objects where the P-flag
is clear, which indicates the operational values of these parameters. Unless the
user disables 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 the
constraints of the path to the PCE.
If the CSPF returns no path or the RSVP-TE signaling of the
returned path fails, MPLS puts the LSP into retry mode and sends a request to
the local CSPF every retry-timer seconds and up to the value
of retry-count.
When pce-report is enabled for the LSP and the FRR Global
Revertive MBB is triggered following a bypass LSP activation by a PLR in the
network, PCC issues an updated PCRpt message with the new RRO reflecting the PLR
and RRO hops. PCE releases the bandwidth on the links that are no longer used by
the LSP path.