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V5.2 Maintenance and Administration

Overview

Normally, the CSP maintains the V5 interface after configuration. By default, it notifies the host upon failures. But you must still monitor the interface status, link status, and user port status to assure the healthy operation of the V5 arrangement.

When performing maintenance on your V5 system, you may require V5 interface, link, and user port management.

V5 Interface

The host can send a PPL Event Request for a V5 Interface state to be reported back to the host in a PPL Event Indication. This PPL Event Indication returns if there is an available communication to the far end. The PPL software also includes a PPL Event Request named C Channel Status Request that returns an indication of which C Channel is active.

Link Status

Link status can be queried with the PPL Event Request message. The status of all 16 links are returned in individual bytes. The status is a bit mask representation of:

State | Description
--- | ---
0 | Link non-operational
1 | Link operational
3 | Remotely blocked
5 | Locally blocked

Link blocking is the last resort blocking mechanism—it should be used only in case of internal failure or emergency.

The LE can reject non-deferred blocking and deferred blocking from the AN side, but it must accept forced blocking. Note that forced blocking can bring the interface out of service if the primary or secondary link is blocked. The LE can block a link, but only forcibly. This forced block automatically tears down any active call and puts each circuit on the link into a blocked state.

The AN side does not share this limitation. Deferred blocking can be requested from the AN side to the LE side, so that the LE side waits until all calls on the link are idle before it blocks the link. This is the preferred case for non-AN-initiated link blocking. Non-deferred blocking can be requested from the AN side to the LE side, so that the LE side releases all calls, then returns a link blocked indication to the AN side. Our implementation of V5 has been designed so that when a link is blocked, LAPV processing is disabled but Layer 1 is unaffected, and remains aligned. If the host wants to disable Layer 1, it can bring the spans out of service.

User Ports

A user port ID uniquely identifies a subscriber on the V5 interface. In some circumstances, it might be necessary to block or unblock a user port. Blocking and unblocking is accomplished by the host sending PPL Event Requests to the L3P Manager component. When the user port blocking procedures are received, the active call (if there is one) is cleared. Both the AN side and LE side support the blocking and unblocking of the user port. The AN side can also request deferred blocking on a user port, where the user port remains unblocked until the active call goes idle. Our current implementation sends an unblock request if there is a call active, and a block request if it is inactive.

Matrix Switchover

If a Matrix Series 3 card switchover occurs when V5.2 interfaces are in service, the time taken before the newly activated CSP Matrix Series 3 Card can process calls is longer than with non-V5.2 protocols running. The time taken will be dependant on the details of the V5.2 configuration.

See Programmable Protocol Language.
A condition that, when met, drives a state machine from one state to another. A condition that drives a Component out of its current state by invoking an associated primitive.
The condition of a component at a given instant. The current "context" of a PPL object, such as Idle, Seizing, Answered. In PPL files, a State is represented by a circle.