Telephone service over the internet may not always connect to emergency 911 service, police warn.

About 200,000 Canadians have signed up for voice over internet protocol (VoIP) service with the country's largest provider, Vonage.

911 operators can easily see a caller's number and address if the call is made on a conventional phone.
911 operators can easily see a caller's number and address if the call is made on a conventional phone.

The technology allows people to save money on long distance calls.

Cellphones and VoIP may not provide the best results for 911 calls, said Cindy Brown, who works at the communications centre for Winnipeg police.

If callers cannot give their location or they hang up, it can take 30 minutes to an hour to track down the number from the service provider, Brown said.

"Then we have to try and locate the subscriber's address, try and locate them at home, and hopefully there's someone there that can tell us where the person is that made the call."

Users can contact their service provider to find out if their address will be displayed during 911 calls. If not, she suggests they may want to keep a traditional telephone line available for emergency calls.

Although tracing works fine if people are using Vonage from home, the service can be used anywhere there is an internet connection.

"Because it's mobile, if you dial 911, we may not know where you are," said Bill Rainey, president of Vonage Canada. "That's where the new technology can create a few short-term obstacles."

Police are also concerned about the implications of the technology for national security.

Officers want the ability to monitor VoIP calls just as they can obtain a search warrant to wiretap conventional phones.

It's not as easy to monitor VoIP conversations because of the way the voice is delivered, said Norm Wong, a lawyer with the federal Justice Department.

The voice is delivered over packets in internet protocol, said Wong. "It's not one voice channel that can be easily tapped."

Wong said his department is working on new laws to force VoIP companies to make it easier to monitor calls.

Rainey said he's willing to, although it's not clear who will pay for the technological fixes for the problems and when they will be in place.