Configuring Mpls Protection Switching; Overview; Protection Switching Triggering Modes - HP MSR2000 Configuration Manual

Configuring MPLS protection switching

In this chapter, "MSR2000" refers to MSR2003. "MSR3000" collectively refers to MSR3012, MSR3024,
MSR3044, MSR3064. "MSR4000" collectively refers to MSR4060 and MSR4080.

Overview

MPLS Protection Switching (PS) provides an end-to-end linear protection mechanism for MPLS TE tunnels.
It associates an MPLS TE tunnel (working tunnel) with another MPLS TE tunnel (protection tunnel) to form
a protection group. When the working tunnel fails, traffic is immediately switched to the protection tunnel,
ensuring continuous traffic forwarding.

Protection switching triggering modes

A failure on the working tunnel triggers a protection switching. Protection switching can also be triggered
by a command or a signal fail indication.
Command switching (external switching)—A PS is triggered by an externally configured switching
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command, which can define the following switching actions (in the descending order of priority):
Clear—Clears all configured switching actions.
Lockout of protection—Always uses the working tunnel to forward traffic.
Forced switch—Forces traffic to be switched from the working tunnel to the protection tunnel.
Manual switch—Manually switches traffic from the working tunnel to the protection tunnel. If a
failure has occurred on the protection tunnel, traffic is not switched.
Signal fail switching—A PS is automatically triggered by a signal fail indication. The signaling can
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be BFD detection for MPLS TE tunnels or interface state (up/down) detection through link layer. For
more information about configuring MPLS BFD for MPLS TE tunnels, see "Configuring MPLS OAM."
The following shows the protection switching triggers in the descending order of priority:
Clear
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Lockout of protection
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Forced switch
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Signal fail on the protection tunnel—The signaling protocol detected a failure on the protection
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tunnel.
• Signal fail on the working tunnel—The signaling protocol detected a failure on the working tunnel.
Clear signal fail—The signaling protocol detected that the working or protection tunnel has
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recovered.
Manual switch
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If multiple triggers exist, the one with the highest priority determines the tunnel for traffic forwarding.
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