[OpenSIPS-Users] One way audio - media port changed (opensips / mediaproxy)

[Iñaki Baz Castillo]

El Miércoles, 3 de Febrero de 2010, Magnus Burman escribió:
> None of my users are behind NAT, they're all on public IPs (I control their
> connection).

It could occur that the gateway just allows RTP from certains IP's.


> Sorry if it's a stupid question, but what do you mean with "the SDP is not
> modified by mediaproxy"?

Do you know how MediaProxy works by replacing the media IP in the SDP of 
INVITE and responses? Take a look to the first (initial) INVITE. The INVITE 
arrives to OpenSIPS with a media address XX.XX.XX.XX in the SDP, but when it 
leaves the proxy to go to the gateway the media is different because opensips 
has modified it to make it going through the MediaProxy server.

But this doesn't occur for the re-INVITE as you can see in your trace.

 
> On line 276 in the re-invite (Opensips --> UA) the port used is different:
> m=audio 40518 RTP/AVP 18 8 0 101'
> The original invite (line 73) reads: m=audio 58928 RTP/AVP 18 8 0 101'

Not just the port but also the SDP. And this occurs because the explained 
above: opensips is not replacing the ip:port in the SDP for the re-INVITE and 
its response. You should check why not.

However I don't know mediaproxy module functions very well so I don't know 
what "engage_mediaproxy" should do. I just can tell you what is happening in 
the trace.


-- 
Iñaki Baz Castillo <ibc at aliax.net>