Vamsi, This document might be useful: http://tools.ietf.org/html/rfc5853 It is focused on SIP, but it explains the idea. In SIP terms, an SBC is a B2BUA. In H.323, this would be considered a gateway. It’s just a special kind of gateway with only IP interfaces on each side, versus one with PSTN interfaces. An SBC might handle media, signaling, or both. Generally, SBCs provide protocol interworking between H.323 and SIP, or even between the multitude of SIP flavors ;-) Paul From: itu-sg16-bounces@lists.packetizer.com [mailto:itu-sg16-bounces@lists.packetizer.com] On Behalf Of navakiva@gmail.com Sent: Monday, June 27, 2011 12:30 PM To: itu-sg16@lists.packetizer.com Subject: [itu-sg16] Need References in understading Session Border Controllers Hi Experts, Dont know whether i can ask this here. Just giving a try. Request you to give some references in understanding Session Border Controllers. Regards Vamsi Kishore