[Linphone-developers] Problem with audio channels starting sometimes

[Stuart Roe]

Devs,

Can anyone point me in the direction I should be looking.

I have a problem such that if I place a call from A to B, then the audio 
is connected successfully, both parties can be heard.

If the call is reversed (B calls A), then one half of the audio doesn't 
set up. The channel from A to B is operational, but the B to A isn't 
heard. Sometimes, both channels fail, with linphone dropping the call 
shortly afterwards.

Environment details:

Both A and B are running Windows Linphone

Both A and B are behind NATing firewall/routers.

SIP communications is via TCP and the various messages can be seen 
passing though the SIP server.

STUN is being used.

If I've missed any appropriate details, please let me know.

Stuart