Path Switching Modes - HP HPE FlexNetwork MSR Router Series Configuration Manual

An external switching command is executed on the node.
•
1+1 protection switching—Typically, traffic travels along both the working and protection
tunnels, and the egress node receives traffic from the working tunnel. When either of the
following events occurs, the egress node determines from which tunnel it receives traffic
according to the protection state:
The ingress or egress node detects a failure on the working tunnel.
An external switching command is executed on the node.
NOTE:
• The tunnel ingress or egress node can detect tunnel failures through BFD for MPLS or other
detection mechanisms. For more information about BFD for MPLS, see
OAM."
• The protection state indicates the comprehensive status of a PS protection group. For more
information, see the display mpls forwarding protection command in MPLS Command
Reference.

Path switching modes

A bidirectional MPLS TE tunnel switches the traffic forwarding path in one of the following modes:
•
Unidirectional path switching—When an external switching command or a signal fail triggers
protection switching for traffic in one direction, PS switches the traffic forwarding tunnel only in
this direction. The traffic forwarding tunnel in the other direction does not change.
•
Bidirectional path switching—When an external switching command or a signal fail triggers
protection switching for traffic in one direction, PS switches the traffic forwarding tunnels in both
directions.
The ingress node and the egress node periodically send Protection State Coordination (PSC)
packets to each other to coordinate the protection state. When one tunnel end performs a PS,
the other end also performs a PS.
1:1 protection switching supports both unidirectional and bidirectional path switching. 1+1 protection
switching supports only bidirectional path switching.
Protocols and standards
•
RFC 6372, MPLS Transport Profile (MPLS-TP) Survivability Framework
•
RFC 6378, MPLS Transport Profile (MPLS-TP) Linear Protection
Compatibility information
Commands and descriptions for centralized devices apply to the following routers:
•
MSR1002-4/1003-8S.
•
MSR2003.
•
MSR2004-24/2004-48.
•
MSR3012/3024/3044/3064.
Commands and descriptions for distributed devices apply to MSR4060 and MSR4080 routers.
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"Configuring MPLS