Business ISP Spitfire has launched a SIP Trunking service. Spitfire’s SIP Trunking has been designed as an ISDN30 and ISDN2 replacement offering business quality secure telephony at typically a third less than the monthly rental cost of an equivalent ISDN service.

The Session Initiation Protocol (SIP) is a signalling protocol used for establishing sessions in an IP network. A session could be a simple two-way telephone call or it could be a multi-media conference session.

One of the first ISPs and fixed line operators to launch a SIP service, Spitfire offers a complete end to end SIP service via their own IP and TDM infrastructure. Spitfire can provide a direct connection between the customers’ premises and Spitfire’s core network over an ADSL, SDSL or WES circuit.

As an Interconnected Fixed Line Operator and one of only 29 CPS Operators in the UK, Spitfire also has number ranges on all UK dialling codes, together with non-geographic number ranges, allowing them to provide one of the only fully integrated SIP services available today, delivering a genuine ISDN30e replacement.

The service has been used by Spitfire staff at their own offices for the past year and has been in field trials for six months.