[asterisk-biz] UK SIP trunking

[Julian Lyndon-Smith]

We are looking into the possibilities of hooking our asterisk system 
into a SIP trunk for inbound and outbound calls in the UK.

One of the requirements would be to set our caller id to any number used 
by us (including 0845 / 0800)

We run up to 50 simultaneous external calls, and are currently using 1.4 
of asterisk.

Does anyone know of such a provider in the UK ? Has anyone had any 
dealings with Spitfire 
(http://www.spitfire.co.uk/SIP_Trunking_tel.shtml?headerbar=1)

Thanks!

Julian