Lucent Technologies 7820-0802-003 manual Configuring Shelf-Controller Redundancy APX

Configuring Shelf-Controller Redundancy	2
(APX 8000)

Overview of redundancy operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Configuring the APX 8000 for shelf-controller redundancy . . . . . . . . . . . . . . . . . . . . . 2-3

Obtaining status information about redundant shelf controllers . . . . . . . . . . . . . . . . . . 2-9

Overview of redundancy operations

The APX 8000 can operate with a single shelf controller or with two redundant shelf controllers. When the APX 8000 runs with two shelf controllers, one controller takes on the active role of primary controller while the other performs as the passive, secondary controller that automatically takes over control of the system if the primary controller fails. In an APX 8000 with a single shelf controller, no controller redundancy exists.

In an APX 8000 with two shelf controllers, the primary shelf controller performs all controller operations for the APX 8000:

•Managing the slot cards

•Maintaining a central repository of the unit’s configurations (including the current NVRAM configuration)

•Performing call control and processing operations

•Managing all centralized functions, such as SNMP access and communication with a RADIUS server.

In addition, all profiles are modified on the primary controller. When a configuration change is made on the primary controller, the entire configuration is copied to the secondary controller. The secondary controller must be loaded with the same boot and operational code as the primary controller.

Shelf-controller startup and primary election

When an APX 8000 with redundant controllers boots up, each shelf controller passes the power-on self tests (POST) during the boot code loading process. The controllers establish communication with each other over the packet bus, and exchange context information (Redundancy profile and Redundancy-Stats profile information) through the heartbeat protocol. Each controller has its own context (known as Context[1] or Context[2]), which is associated with the controller’s serial number. The controllers use the context information to track each other’s status.

APX 8000/MAX TNT/DSLTNT Physical Interface Configuration Guide 2-1