[Asterisk-Dev] How IAX workd behind the firewall

[Adam Hart]

Craig Southeren wrote:
<snip>
>>
>>That's H.323 I believe, SIP just uses one RTP port as stated in SDP payloads
> 
> 
> Nope - fully compliant RTP requires both the control and data ports.
> 
> Of course, an implementation may chose to be non-compliant and not
> implement RTCP, but then another endpoint is free to stop the call if it
> it does not respond. Cisco gateways are notorious for doing this.
> 
>    Craig
> 
Ok, I'll accept that - Although what RFCs say and what most SIP clients 
do is two different things.

-Adam