SIP, or Session Initiation Protocol, is fast turning into the standard term used by the Telecoms Industry to refer to the replacement of traditional Analogue PSTN /ISDN connections with IP based solutions. But, SIP is not a standard solution like Analogue /ISDN PSTN have been for the last two decades in the United Kingdom. SIP has not yet become a standard and as a result integrating SIP devices to a SIP Network is not the desired and familiar "Plug and Play".