Figure 19: Normal Operation - Alcatel-Lucent 7450 Manual

The system supports single-phased coordination between the LSP endpoints, in which the
initiating LER performs the protection switchover to the alternate path and informs the far-end
LER of the switch.
Bidirectional protection switching is achieved by the PSC protocol coordinating between the two
end points to determine which of the two possible paths (i.e. the working or protect path),
transmits user traffic at any given time.
It is possible to configure non-revertive or revertive behavior. For non-revertive, the LSP will not
switch back to the working path when the PSC switchover requests end, while for revertive
configurations, the LSP always returns back to the working path when the switchover requests
end.
The following figures illustrate the behavior of linear protection in more detail.
7450 ESS MPLS Guide
A
Working
Protection
Selector
Bridge
Working
Protection
Selector
Normal Condition

Figure 19: Normal Operation

MPLS and RSVP
Z
Selector
Selector
Bridge
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