Ringback sound

[Lanista12]

Hello, Siniypin.
I have the same problem as in issue #39.
I used pjsip4net in my c# project and it works just fine. Quality is good, no interference or noise(other libraries had some problems with that), but there is one major problem: if someone calls me, the one does not hear any ringback sounds.
In issue #39 you gave an example how to solve this problem using conference bridge and WavPlayer.
https://gist.github.com/siniypin/47326a9fd78af95a3ff7
I tried to do that and I worked well, the caller heard every sound it played, but it worked only after I answered the call, and I need it to be played before I pick up the phone.
If I execute this code on CallManager_Ring event _ua.CallManager.Calls.First().ConferenceSlotId return -1(I assume it is because I din't aswer the call yet, so connection is not established and ther is no media stream and sound port binded to it).
If I execute the code anythere after _call.Answer() it return 1 and it works properly.

P.S: Sorry for bad grammar. English is not my native language.

[Robert]

Hi, if I get you right, you want to stream a sound to a speaker device on a calling side before the call has been answered. For that you just have to create a sound player that will stream your audiofile to the speaker device and interconnect them via a ConferenceBridge. I'll stress that once again, you have to interconnect player and a speaker device, a call has nothing to do with the ringtone playback. A CallManager provides necessary callbacks for you to properly start and stop the playback at the right moments.

[Robert]

@Lanista12 did it help? Did you figure this stuff out?

[Lanista12]

@siniypin, no. Still trying figure that out.

[Robert]

So what's the problem? Did you understand the suggestion?

[Lanista12]

Yeah, I understood, but I realised that my approach was wrong from the begining. I found out that you don't need to send ringback tone at all.
I used Wireshark to analyse traffic and I found that when you have incoming call, you have these packets if you use another sip-library(ozeki in my case):
--> Request :INVITE sip:qwerty@1.2.3.4:32001;transport=TCP;rinstance=9887998e21ce5942 SIP/2.0
<-- Status: SIP/2.0 100 Trying
<-- Status: SIP/2.0 180 Ringing
And caller hear pingback sounds.
But then I used pjsip4net, it had not got last packet with status code 180:
--> Request :INVITE sip:qwerty@1.2.3.4:32001;transport=TCP;rinstance=9887998e21ce5942 SIP/2.0
<-- Status: SIP/2.0 100 Trying

it seems like this is the issue.

[Robert]

Check out this comment: #62 (comment)

[Lanista12]

It didn't help.
I did as it said in #62:
var cfg = Configure.Pjsip4Net().With(x => x.Config.Require100Rel = true);
But I have the same problem.

[Robert]

Can you post your code here?

[Lanista12]

This is how I initialize UserAgent:

                var cfg = Configure.Pjsip4Net().With(x => x.Config.Require100Rel = true);
                _ua = cfg.Build().Start();//build and start
                _ua.ImManager.IncomingMessage += IncomingMessage;
                _ua.CallManager.CallRedirected += CallRedirected;
                _ua.CallManager.IncomingDtmfDigit += IncomingDtmfDigit;
                _ua.ImManager.NatDetected += OnNatDetected;
                _ua.CallManager.IncomingCall += CallManager_IncomingCall;
                _ua.CallManager.Ring += CallManager_Ring;
                _ua.CallManager.CallStateChanged += CallManager_CallStateChanged;

[Robert]

I assume a CallManager_Ring callback is never executed, correct?

[Robert]

Can you post a CallManager_Ring implementation here as well?

[Lanista12]

Here is my implementation of CallManager_Ring

        private void CallManager_Ring(object sender, RingEventArgs e)
        {
            // start ringtones
            if (e.RingOn)
            {
                if (e.IsRingback)
                {
                    MediaHandlers.StartRingback();
                }
                else
                {
                    MediaHandlers.StartRingtone();
                }
            }
            else
            {
                MediaHandlers.DetachAudio();

                RechangeCurrentSpeaker();
            }
        }

StartRingBack and StartRingTone is methods to play ringtones localy.

[Robert]

So it is never executed, am I right?

[Robert]

OK, I think I understand your problem a bit better now. Whenever you call a pjsip4net based app, the callee (basically any SIP-client) doesn't hear any ringback, because the app just never replies with 180.
That is a missing feature in pjsip4net. I'd need some time to add it and publish a new version of pjsip4net. Alternatively, you can fork the project, fix it and send me a pull request. Then I could quickly include it and publish to the nuget.

[Lanista12]

Ok. Roughly speaking, how long will it take for you to add this changes?

[Robert]

I won't promise you anything. You have to understand that I voluntarily maintain this library and support you guys in my spare time.

[Lanista12]

Ok. Not trying to compel you or something like that. Just trying to understand if you find it an easy task, so you can fix it super fast, or should I try to do that. Nothing else.

[Robert]

@Lanista12 please do a favor, fix it and send me a pull request back. I'm currently overloaded. My idea was to track if the ring event has been handled by the app code and call a downstream API with proper params (http://www.pjsip.org/docs/latest-1/pjsip/docs/html/group__PJSUA__LIB__CALL.htm#ga6dd4a80bd96c319398e218bbffda5153) to tell pjsip to send 180 back .

[Lanista12]

Ok. I'll do my best.