Aastra Telecom C53I User Guide

Operational Features

41-001160-00, Rev 01  Release 2.0

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Operational IP Phone Features

You can enable the BLF feature on Asterisk to enable monitoring for specific 
extensions.  BLF on Asterisk is possible through the “hint” extension parameter.

Add the following in the Asterisk extensions.conf file for each target extension 
being monitored.

For example: 

exten -> 9995551212,hint,SIP/9995551212

Add the following in the Asterisk sip.conf file for each subscriber if it is not 
defined already.

For example:

[9995551212]
Subscribecontext=sip

You can enable the BLF feature on BroadSoft BroadWorks Rel 13 or higher 
through the BroadWorks Web Portal.  Each user must have the Busy Lamp Field 
service enabled for their user.  The user must add each desired extension to the 
“Monitored Users List” on the Busy Lamp Field service page and also enter in a 
list name for the monitored users BLF list on the same page.

Changes to the “Monitored Users List” are dynamic and the Aastra IP phones are 
automatically updated without requiring a restart.

For sample BLF configurations, see