Specifications

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Cisco AS5800 Operations, Administration, Maintenance, and Provisioning Guide
DOC-7810814=
Chapter 6 Provisioning
Router-Shelf Redundancy
Hitless Redundancy
Hitless redundancy is not supported. When a router-shelf failover occurs, all calls associated with that
router shelf are lost. Cisco AS5800 redundancy ensures that resources (particularly trunk lines) do not
remain unusable while the controlling router is down.
Network Management
Redundancy management via SNMP is not supported. However, an SNMP trap will be issued by the
backup router when the router failover event occurs. The trap “ccrSwitchStatusChange” defined in the
CISCO-C8500-REDUNDANCY-MIB as well as the SNMP variables “ccrCpuMode” and “ccrCpuStatus”
are used for issuing a failover.
Failover Performance
Enabling failover has no significant (greater than 1%) impact on system performance, both before and after
failover has occurred. With a redundant router, of the same model as the active router, acting purely as a
standby, the load capacity threshold is unchanged, thereby not affecting performance.
External Services
A single active router is conceptually simpler, and makes it easier to support failover when dealing with
external servers, such as signalling controllers for RPMS server, SS7.
Note RPMS server must be configured with the same information for both router shelves to
ensure full functionality before and after a switchover.
SS7 Setup
In an SS7 environment, call signalling comes via an external SC2200 rather than directly from the switch
over the trunk line (as for CAS and ISDN). After a switchover has occurred, both routers must be
connected to the SC2200. Use SS7’s redundant link manager (RLM) to provide redundant links between
a single router and the signalling controller. Configure RLM links from both the active and standby
routers so a change of routers will look like a change from one redundant link to another.
Configuring Redundancy
Router-shelf failover is a simple configuration command on the two router shelves in split-dial-shelf
configuration mode. The command is issued in “redundancy” configuration submode:
router(config)# redundancy
router(config-r)# failover group-number <group-code>
This command must be configured on both routers. The parameter group-code is used by the system
controller and must be the same for both routers forming the redundant pair. It identifies both routers as
the same set of dial-shelf resources.