How to add dial tone on outgoing call in Sip.js?

Question

JavaScript

Hello. I use the sip.js library (sipjs.com) to make calls from the site. I made a dialing of the number when clicking on it in this way:

$('.callNumber').on('click', function() {
session = userAgent.invite('sip:' + $(this).text() + '@mylink', options);
});

But when dialing a number in this way, there are no beeps, complete silence until the person picks up the phone. How can I implement beeps when dialing a number, as well as quick beeps if the number is busy?

Also interested in the question what methods are there to end the call or put it on hold? Thanks a lot for your help.

Answer 1

Party B should notify that the phone is ringing and it's time to play the CPV by sending a sip packet 180 or 183.
Maybe there are no these packets?

Answer 2

In order to receive CPV in WebRTC, you need to enable PRACK response support on the server (option 100rel). The requirement for this option must also be specified when creating a session in the sip.js client.