SOLVED Help Weird audio issue

Hi Guys

I am have an issue where if i call a tenants DID from my domain i get no audio
if they use they're IP phone and call they're DID no audio
if i call any other customer on the PBX i get no audio
if they use they're IP phone and call they're DID no audio

If i call them from a landline or cellphone it works fine
if they call within themselves extension to extension it works fine also
if they call anybody in the world that is not on the pbx it works fine

if they use they're IP phone and call they're DID no audio

any idea's would be great this was previously working fine only noticed this when a customer called for support and the could not reach our business. Only changes done on PBX were updates
fusion version 4.5.9 freeswitch version 1.8.2

@Adrian Fretwell If rtp or sdp is issue and my provider doesnt proxy media where would i adjust this?

Both the source and the destination numbers pertain to the same static trunk on our side (Enterprise trunk) with failover.

When you initiate the call, the media will come from the PBX towards what your PBX for the destination number is adverting in the SDP.

No media will transit the Iristel network (we do not proxy media for static trunks).

Yes from the outside works fine but if i use iristel trunk from my domain and call a client that uses iristel trunk no audio

Adrian Fretwell said:

So everything is fine when Iristel IS proxying the media. Checking what IP addresses and ports are being written into the SDP bodies will be your only hope of diagnosing this. See if you can get packet traces of both calls that work and calls that fail and compare them.

Click to expand...

OK i will try your suggestion
Just a weird issue since i havent made any changes besides update fusion
I will let you know
thanks @Adrian Fretwell

@Adrian Fretwell thank you for your help you were absolutely right firewall was the issue!!