[Devel] ignore rtp proxy if two clients are behind NAT and if they have the same external ip

[Piotr Szymanek]

> to debug, try to print (via xlog) the i:13 avp and $src_ip.

Ok work but
I trying 
xlog("[$avp(i:13)], [$src_ip]");

this format is ok ?
becouse I always get 
[<null>], [<null>c_ip] 

Thanks 
Piter