And there are some thousands of web pages on it. In short it's a method for VOIP implementation. For most that's all you need to know.
Bob
I'm not really sure if this is the right forum for this topic but here it goes.. Currently I'm on a training for a certain company that delivers SIP Trunk. I really don't understand the concept. Can you please explain it to me or at least give me a link of a site where I can study it further? I tried doing some research but no luck so far.. Hope you guys can help me.. Thanks..

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic