Nokia 7705 SAR-W Series Manual page 76

MPLS and RSVP-TE
If the user disables dynamic bypass tunnels on a node while dynamic bypass tunnels
are activated and passing traffic, traffic loss will occur on the protected LSP.
Furthermore, if no manual bypass tunnel exists that satisfies the constraints of the
protected LSP, the LSP will remain without protection.
If the user configures a bypass tunnel on Node B
tunnels have been disabled, LSPs that had been previously signaled and that were
not associated with any manual bypass tunnel (for example, none existed) will be
associated with the manual bypass tunnel, if it is suitable. The node checks for the
availability of a suitable bypass tunnel for each of the outstanding LSPs every time
an RESV message is received for these LSPs.
If the user configures a bypass tunnel on Node B and dynamic bypass tunnels have
not been disabled, LSPs that had been previously signaled over dynamic bypass
tunnels will not automatically be switched to the manual bypass tunnel, even if the
manual bypass tunnel is a more optimized path. The user must perform a make-
before-break switchover at the head end of these LSPs. The make-before-break
process is enabled using the adaptive option.
If the manual bypass tunnel goes into the down state on Node B and dynamic bypass
tunnels have been disabled, Node B (PLR) will clear the "protection available" flag in
the RRO IPv4 sub-object in the next RESV refresh message for each affected LSP.
It will then try to associate each of these LSPs with one of the manual bypass tunnels
that are still up. If it finds one, it will make the association and set the "protection
available" flag in the next RESV refresh message for each of these LSPs. If it cannot
find one, it will keep checking for one every time an RESV message is received for
each of the remaining LSPs. When the manual bypass tunnel is back up, the LSPs
that did not find a match are associated back with this tunnel and the protection
available flag is set starting in the next RESV refresh message.
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6. If the PATH message for the primary LSP path indicated link protection is
desired, and no manual bypass was found after Step 1, and/or no dynamic
bypass LSP was found after performing Step 3, the primary LSP will have no
protection and the PLR node must clear the Local Protection Available flag in the
IPv4 address sub-object of the RRO, starting in the next RESV refresh message
it sends upstream. The PLR will not search for a node-protect bypass LSP in this
case.
7. If the PLR node successfully makes an association, it must set the Local
Protection Available flag in the IPv4 address sub-object of the RRO, starting in
the next RESV refresh message it sends upstream.
8. For all primary LSPs that requested FRR protection but are not currently
associated with a bypass tunnel, the PLR node—upon reception of an RESV
refresh message on the primary LSP path—repeats Steps 1 to 7.
Use subject to Terms available at: www.nokia.com
© 2022 Nokia.
(Figure 8) and dynamic bypass
3HE 18686 AAAB TQZZA
MPLS Guide