Sip Trunking

Last days i was reading about sip trunking, Very sad to say a lot of people hype on this but not body points to a standard.

ex:
http://global.mci.com/ca/resources/whitepapers/pdf/SIP_WhitePaper.pdf

http://www.tmcnet.com/channels/sip-trunking/

there are a lot people even claim "global sip trunking leader". Just wondering, if there is any standard existing then how they are going to have people interoperate.

Finally i understood the problem in another way. Sip was intended to use on a different paradigm and people try to fit it in the IP PBX TRUNK paradigm.

ex: Provider runs one proxy server and gives 10 users for the PBX, and its doesn't allow the PBX users to directly access the provides sip server.

I am still not sure which is the standard they follow :
http://www.sipforum.org/sipconnect

Sad to say no sip trunking providers say this is the standard they follow :-(
© yankandpaste®

Tailpiece: lets may hay while sun shines, who cares on a standard, we need only buzzwords.