VoIPowering Your Office: The Wild iPBX Roundup, Part 2

[moderator1]

"... SIP has become the popular VoIP protocol: Virtually all VoIP networks, endpoints and gateways support SIP. IAX is a native Asterisk protocol that is not nearly as well supported as SIP. H.323 is the grandmommy of VoIP protocols, and is used mainly by big commercial carriers. It is well-supported in most VoIP gear. SIP is similar to H.323 in the way it works, but is less complex and not nearly as heavyweight."... more from http://www.voipplanet.com/backgrounders/article.php/3702621