ITSP in UK with SIP trunking for inbound 800 service←SIP→MX250 IP PBX queues calls←SIP→Agents in USA
With this approach, inbound 800 calls get queued -- in UK or USA, depending on the location of MX250 IP PBX -- and then delivered to agents as they become available.
In general terms, you'll want to find out from your IP PBX equipment manufacturer whether or not they maintain interoperability with an ITSP in the country where you wish to have the 800 number service. If the manufacturer does have some ITSPs for you to choose from, they can likely put you in touch with the ITSP to get an account set up. Using this type of service can typically save a company a lot of money.
This was first published in April 2006