Crunch time is coming for VoIP services as demands grow for access to emergency service numbers, a VoIP hardware supplier has warned.

"VoIP is currently the only call service not required to allow 999 calls," said Steve Davis, sales and marketing VP for VegaStream. "Specifically, the problems are to do with finding your geographic location, and with what happens if your broadband connection goes down."

The geographic issue is that callers can connect to an IP PBX from anywhere, so unless the 999 operator can trace them via their IP address - which requires a specialist service, and is uncertain even then - the only location data received will be that of the PBX.

Speaking at the IP'07 exhibition in London, Davis added that research by Ofcom last year discovered that 78 percent of UK households with a VoIP service that did not provide 999 access incorrectly thought that it did provide 999 access or didn't know if it did.

He said that companies using VoIP need to ensure not only that they keep a PSTN line for emergencies, but that their PBX automatically diverts 999 calls to that line.

"Ofcom has recommended that all VoIP services need to be able to make 999 calls, and this could be mandated as early as January 2008," he noted.

VegaStream's answer is new firmware for its VoIP gateways that intercepts emergency calls and re-routes them onto the PSTN. "It means there is no need to reprogram your PBX, and it could avoid the huge challenges that an Ofcom ruling could present," Davis claimed.