Brocade Multi-Service IronWare Multiprotocol Label Switch (MPLS) Configuration Guide (Supporting R05.6.00) User Manual
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Multi-Service IronWare Multiprotocol Label Switch (MPLS) Configuration Guide
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MPLS Fast Reroute using facility backup over a bypass LSP
1
A new instance of the bypass LSP becomes active as soon as it is signaled. After the new instance
becomes active, the old instance is released.
To minimize the effect on user traffic, signaling of a new instance for the bypass LSP not does
occur when the current instance is carrying traffic. In this regard, adaptive bypass LSPs behave
differently from adaptive regular LSPs. When a reoptimization calculation finds a better route while
the bypass LSP is carrying traffic, the reoptimization is discarded, and another calculation is made
the next time the reoptimization timer expires. An attempt to change an LSP parameter when the
bypass LSP is carrying traffic is delayed until the bypass LSP is no longer carrying traffic. The
configuration is accepted and it takes effect when the LSP is re-routed or the new instance is
signaled.
For bandwidth-protected LSPs, it is possible that a new bypass LSP instance could have a lesser
bandwidth than the cumulative bandwidth of the LSPs it is protecting. For example, the user could
alter the bandwidth of the bypass LSP with the traffic-eng mean-rate command. In this case,
backups are released using a priority-based scheme until the bandwidth of the new bypass
instance is at least as big as the cumulative bandwidth of the LSPs it protects.
For instructions on how to configure an adaptive bypass LSP, refer to
.