or do they leave the LAN if they don't really need to?
If both parties in a call are in the same LAN, does the SIP/Skype call voice packets travel in and out through the internet?
If so, how do I to avoid it? I want to save bandwidth and improve call quality.
I know that with SIP the control packets must reach the controller, which is remote more often than not, but the actual voice packets can travel in a P2P connection, without leaving the LAN. What I am not sure is how to make it work, and if the same thing can happen to Skype.