This is an attempt to create a 'silent alarm' giving the calling party the ability to alert a central dispatch center in the event of an incident. The dispatcher needs the ability to be notified of where the call is originating and then be able to hear anything picked up by the caller's endpoint microphone.
Successful completion of the job will yield the following dial plan script behavior:
-When the calling party dials an extension (likely using a BLF speed dial), a speakerphone call will be initiated
-The called party will be a preprogrammed outbound number terminating over a SIP trunk to a POTS line
-Upon initiation of the call, the called party's endpoint should immediately be muted
-When answered by the called party, immediately play a brief prerecorded message to the called party
-Proceeding the message, open an indefinite-length call
This is, in essence, a 'reverse-intercom' scenario. The calling party should hear *nothing* and should receive no audible feedback whatsoever that the call has been placed. The only feedback to the calling party will be the illumination of the BLF on their phone. This behavior is a function of the telephone endpoint and is not a requirement of this job.
The called party will receive the call, be presented with a brief message, and then will hear everything being picked up by the calling party's endpoint microphone.