Cisco 10000 - Manual (Page 322)

14-20
Cisco 10000 Series Router Software Configuration Guide
OL-2226-23
Chapter 14 Configuring Automatic Protection Switching
Multirouter Automatic Protection Switching
Figure 14-1 Multirouter APS Configuration
On the protect circuit, the K1 and K2 bytes from the line overhead (LOH) of the SONET frame indicate
the current status of the APS connection and convey any requests for action. This signalling channel is
used by the two ends of the connection to maintain synchronization.
The working and protect circuits themselves, within the router or routers in which they terminate, are
synchronized over an independent communication channel, not involving the working and protect
circuits. In
Figure 14-1 , this independent channel may be a different ATM connection or a
lower-bandwidth connection. In a router configured for multirouter APS, the configuration for the
protect interface includes the IP address of the router (normally its loopback address) that has the
working interface.
This chapter describes the MR-APS feature in the following topics:
• Feature History for MR-APS, page 14-20
• Restrictions for MR-APS, page 14-21
• Configuration Tasks for MR-APS, page 14-21
• Monitoring and Maintaining the MR-APS Configuration, page 14-27
Feature History for MR-APS
Router A
ATM 2/0/0
Working interface
SONET
network
equipment
add/drop multiplexer (ADM)
ATM 1/0/0
ATM 1/0/0
Router B
ATM 3/0/0
Protect interface
95570
Cisco IOS Release Description Required PRE
12.0(23)SX This feature was introduced on the Cisco 10000 series
router. PRE1
12.0(26)S This feature was integrated into Cisco IOS Release
12.0(26)S. PRE1
12.3(7)XI2 This feature was integrated into Cisco IOS Release
12.3(7)XI2. PRE2
12.2(28)SB This feature was integrated into Cisco IOS Release
12.2(28)SB. PRE2