[Serusers] HELP: mediaproxy re-INVITE NAT detection

[Andreas Granig]

Hello,

Andreas Sikkema wrote:
> What I've seen is, is that this is a bug/feature in the mediaproxy
> itself where a new INVITE will be ignored on an existing call. I've
> fixed this on our development proxy a long time ago and can't remember
> how much I had to fix.

We had this problems especially for handling codec switches, for example 
from G.729/G.711 to T.38 and back, and also for conditional call 
forwards, where the second INVITE had another destination IP for RTP.

I posted a fix some time ago, see 
http://lists.iptel.org/pipermail/serdev/2004-October/002991.html
Sorry, never got concrete feedback from ag-projects about this.

But note that we've faced some other problems, especially for T.38: 
Mediaproxy waits for RTP packets from both parties before starting to 
relay the traffic, but in T.38 the receiver only answers when it gets 
some T.38 traffic, so we had to force the forwarding of RTP packets in 
rtphandler.py:handle_read() to the visible IP of the other party before 
that one could sign in.

Hope this helps,
Andy