Specifications

6-10
Cisco XR 12000 Series Router SIP and SPA Software Configuration Guide, Release 3.2
Release 3.2, OL-6396-01, Rev.A1 January 9, 2006
Chapter 6 Configuring POS SPAs on Cisco IOS XR Software
Configuration Tasks
Configuring Fast Reroute and SONET APS
When APS is configured on a router, it does not offer protection for tunnels; because of this limitation,
fast reroute (FRR) still remains the protection mechanism for Multiprotocol Label Switching (MPLS)
traffic-engineering.
When APS is configured in a SONET core network, an alarm might be generated toward a router
downstream. If this router is configured with FRR, you may want to configure a hold-off timer at the
SONET level in order to prevent FRR from being triggered while the core network is doing a restoration.
Perform this task to configure the delay.
Summary Steps
1. configure
2. controller sonet number
Step 21
end
or
commit
Example:
RP/0/0/CPU0:router(config-sonet)# end
or
RP/0/0/CPU0:router(config-sonet)# commit
Saves configuration changes.
• When you issue the end command, the system prompts
you to commit changes:
Uncommitted changes found. Commit them before
exiting (yes/no/cancel)? [cancel]:
– Entering yes saves configuration changes to the
running configuration file, exits the configuration
session, and returns the router to EXEC mode.
– Entering no exits the configuration session and
returns the router to EXEC mode without
committing the configuration changes.
– Entering cancel leaves the router in the current
configuration session without exiting or
committing the configuration changes.
• Use the commit command to save the configuration
changes to the running configuration file and remain
within the configuration session.
Step 22
show aps
Example:
RP/0/0/CPU0:router# show aps
(Optional) Displays operational status for all configured
SONET APS groups.
Step 23
show aps group [number]
Example:
RP/0/0/CPU0:router# show aps group 3
(Optional) Displays operational status for configured
SONET APS groups.
• The show aps group command is more useful than the
show aps command when there are multiple groups
defined.
Command or Action Purpose