Notes On Switchcdred; Notes On Switchapsln; Configuring Aps 1+1 - Cisco BPX-BXM-155-8DX Installation And Configuration Manual

Chapter 26 Configuring SONET Automatic Protection System
In the APS 1+1 configuration, if the protection line is active and the last user request is
Note
"clear," a switchdred will cause the working line to be active if there is no line condition
on working line. When APS 1+1 comes up, it will come up on the working line if the
working line is clear. When a switchcdred is issued, the active card also comes up on the
working line if the working line is clear and there is no user request. In the case where the
working line is in alarm or there is a user request to switch to the protection line
(switchapsln), the card will first come up on the working line. Then the card will detect
the alarm or the user request and switch to the protection line.

Notes on switchcdred

Note In the APS 1+1 configuration, if the last user request was a W –> P switch, then dsplog
will log a W –> P switching event when a switchcdred is issued. On a switchcdred, the
newly active card comes up on working line first. Then it responds to a user request to
switch from working to protection by switching to the protection line and sending an
event notification to that effect. The event notification can be seen in the event log by
using the dsplog command.
It may be necessary to perform a switchcdred (switchyred) command after performing a
Note
service switch with the switchapsln command so that the backcard that the service switch
selects has its associated front card active.

Notes on switchapsln

With APS 1+1, when repetitive switchapsln commands are issued, up to two in a row can be executed
sequentially, when alternating between options 3 and 4 (forced switch), or 5 and 6 (manual switch), but
no more. Attempts to execute a third switchapsnln will not succeed, and the following error message
is displayed:
"Cannot request manual W->P when manual P->W switch in progress"
If users desire to perform repetitive switchapsln commands, they should issue a clear switch
between each W-P, P-W pair of commands, for example:
switchapsln 2.1

Configuring APS 1+1

This an example of configuring APS 1+1 redundancy:
Verify that appropriate front and back cards are installed along with APS two-card daughterboard.
Step 1
Step 2 Ensure that lines are connected, for example on port 1 of BXM card in slot 2 and port 1 of BXM card
in slot 3.
Step 3 Execute the following commands and verify chan half= no, and standard= GR-253 (default)
Release 9.3.0, Part Number 78-10674-01 Rev. D0, July 2001
1
APS 1+1 (Card and Line Redundancy)
Cisco BPX 8600 Series Installation and Configuration
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