We have a CME , lets consider we are making internal calls:
when user A is speaking on the line and user B calls user A, is there a way for user B to get that user A is busy or on another call without limiting user A to a busy-trigger-per-button, i want user A to receive the call and user B to know that user A is on another call without being transfered to the call busy number.
this is the current config of the dn:
ephone-dn 4 dual-line
call-forward busy 41199
call-forward noan 41199 timeout 15
yup ephone 4 is User A, the thing is, it wont go to 41199 when only 1 line is used as the dual line can have multiple lines before giving you a busy tone, in this case user A while speaking will see that user B is calling him and user B will be waiting for user A to answer him, what i want is to have User B notified that user A is on another call.
I think Islam's line of thinking is valid. While you may not be able to natively alter the ringback tone heard by the calling party. I think that using a Monitor/Watch solution is a good idea. You don't even need to call the remote party. Just look at the phone for a visual confirmation of status.
You can use the blf-speed-dial approach or you can simply add a Monitor or Watch line appearance on the calling party.
Of course, if you are trying to make this universally applicable to all call origination points (including the PSTN) then monitor/watch won't help.
I'd ask myself if thinking of the problem in a different way is still addressing the core requirement.
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