Solved Silent calls from new Sip trunk

[robk]

We have a Gamma Sip trunk provided by a 3rd party this is currently it is working correctly on a new number.

We have applied to port our main no and DDI ranges over from our ISDN lines (yes the old system is that old).

We have been given details of Gamma's test platform, and been asked to test the new number ranges, but everything we test gives silent calls. (calls to and from normal PSTN nos work correctly).

The 3rd party seem to refer to an issue with 3cx, but we have no idea what may be causing this.

Has anyone seen anything like this before?

 

[nub]

Did your system pass the firewall check?

 

[robk]

Yes, the firewall check is ok. The 3cx instance is hosted on AWS.

What we don't understand is incoming and outgoing calls on the sip pilot no all work. Its when we introduce the Gamma porting test system that we hit the problem.

 

[leejor]

Look at the 3CX Activity Log, and compare a working call to a silent one...any differences? Since they are all coming over the same trunk group, my first guess would be that it is something beyond your provider, seeing as this has not been working previously. It could be something such as a Codec mismatch, between the originating provider and your current provider

 

[robk]

We are not changing provider, just porting numbers. So currently calls to the number assigned to the sip trunk work.

If we use the gamma test platform to confirm the details of the numbers being ported are correct. We get no audio.

Wireshark only shows audio rtp traffic leaving us, nothing comes back from gamma.

 

[leejor]

Wireshark only shows audio rtp traffic leaving us, nothing comes back from gamma.

Well...it certainly sounds like (no pun intended), a problem at the far end. I would suggest contacting gamma and describing the issue, along with presenting the Wireshark results.

 

[JohnS_3CX]

Are you running on 5060? (Gamma requirement)

Have you tried running a capture from the PBX (during outgoing calls) and checking the Contact address that your are sending in the SDP? If it looks correct (ie. the public IP of the PBX since its AWS) then you need Gamma to troubleshoot their end too.

 

[robk]

Apparently after several calls to our 3rd party support, Gamma have told them there's a potental problem with the test platform, with silent/one way audio.

So actually everything was working!

 

[leejor]

Potential Problem? It seems that has been confirmed.