On 2014-12-16 21:27, John Andersen wrote:
On 12/16/2014 12:12 PM, Carlos E. R. wrote:
NOT every SIP provider, only some of the heavy ones. Many only provide signaling and addressing.
Still, if you and your caller are behind nat or a firewall, (or NAT) TURN will be used, and I've NEVER run into a single sip provider that did not also host or recommend a turn server. Most of the time its totally automaticly provided.
Nope. We tested it in a lab without internet connection (wire removed). A switch that emulates an internet network (ie, internet addresses), but isolated, two routers, two separate local networks, some standalone voip hardware phones. No turn server anywhere, no connection to internet. And it worked. We just had to use normal network tools like iptraf, ntop, ethereal, to find where the traffic was going to/from and thus decide what to change. Anyway, if there is an intermediary involved, you see its IP addresses in the packets. It is quite simple to spot. -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)