A quick post on SIP trunking

SIP trunks are not the circuits themselves. a SIP trunk is the voice channels being delivered over an IP circuit rather than something else like ISDN.

The physical media the SIP trunk is delivered on can vary and is normally specified by the SP, it could be Ethernet, ADSL, a leased line of some kind, or perhaps delivered into an MPLS cloud and then onwards from there.

SIP trunks need to be terminated by a SBC for example Cisco CUBE.

That'll do for now. I'll add later if I find out more.

Here's a link to my previous post:
http://twhittle1.blogspot.co.uk/2013/04/cisco-cube-and-sip-trunks.html?view=mosaic