Outbound call problem with audio

[DigitalDaz]

I have had a couple of issues with outbound calling....

On the occasional call we are having a problem with no audio. I have tracked the issue and discovered the following.

A normal INVITE goes out from freeswitch to the trunk the call is answered at the remote end and we receive a 200OK with a=inactive in the SDP, this gets relayed by freeswitch to the handset and so we now have a call in progress without audio.

Immediately after this, we receive a re-INVITE from the trunk with a=sendrecv in the SDP which should then restore the audio. The problem is, this reinvite is never forwarded to the handset so it is still stuck without audio.

Has anyone ever come across behaviour and if so, how did you resolve it?

TIA
Daz

 

[DigitalDaz]

@hfoster I believe you had a similar problem?

 

[wouam31]

Hi!
What if you stop sending "a=inactive" in the internal profile?

<param name="inbound-late-negotiation" value="true"/>

Just a thought...

 

[DigitalDaz]

Hi!
What if you stop sending "a=inactive" in the internal profile?



Just a thought...

That was an idea but I think that breaks other things, I found something that fixed it though I had to manually patch freeswitch: https://github.com/signalwire/freeswitch/pull/3215

 

[hfoster]

Yeh, Broadworks PBXs seem to immediately start with sdp=inactive and then immediately switch to sendrecv. FreeSWITCH doesn't like it, so the SDP never starts flowing. We did it in a rather janky manner and replaced the SDP inactive message with just sendrecv on our SBCs. I just really couldn't be bothered to paw through the FreeSWITCH code, submit a pull request, wait for it to hit master, etc.

That pull request looks exactly what our problem was.