Nortel Meridian 1 Option 11C Manual page 89

Service message function
Service messages are used to monitor the following:
• D-channel establishment
• D-channel sanity polling
• B-channel or ISL status change
• Channel status audit.
D-channel establishment
When the D-channel establishes, the B-channel status is supported by sending
service messages for each B-channel controlled by a D-channel. This allows
the far end to synchronize its channel states. These services messages are sent
when the D-channel is brought up automatically by the system or manually
by using LD 96.
D-channel sanity polling
If a D-channel has been idle for 30 seconds, a service message is sent to poll
the sanity of the link. The service message is sent regardless of whether the
near end is configured as master or slave.
B-channel status change
Whenever there is a status change for a B-channel or an ISL channel, the new
status is reported to the far end in a service message. Status change can occur
through service change or maintenance operations, such as the addition or
deletion of a channel in LD 14, or disabling of the associated loop, shelf, card
or unit in LD 30, LD 32, LD 36, LD 41 or LD 60.
Channel status audit
LD 30 is enhanced to allow channel status audit to be initiated. The channels
associated with each D-channel are examined and their status is reported to
the far end by service messages.
Service message commands
You activate the service messages in LD 96 on a per D-channel basis. The
commands are:
• ENL SERV N: turns on the support of service and service acknowledge
messages for DCH link N. The command should only be executed when
the specified D-channel is in the disabled state.
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