Locating VoIP callers in emergencies

Published 15 June 2009

Callers who use VoIP to call 999 (the U.K. equivalent of the U.S. 911) run the risk of making it difficult, if not impossible, for the police, paramedics, and fire crews to attend emergencies promptly; a system is being developed to locate Internet phones

U.K. Phone companies are developing a system to allow 999 — the equivalent of the U.S. 911 — operators to pinpoint the location of Internet callers, as concerns that the increasing use of VoIP could mean police, paramedics, and fire crews are unable to attend emergencies promptly. The hope is that the technology could be in place in some ISPs next year, according to the chairman of the industry group leading the work. The majority of calls to 999 are currently made via traditional landlines and mobile phones. BT has seen a ten-fold increase in the volume of VoIP calls to its emergency contact centers in the last eighteen months, however.

Chris Williams writes that the ability to locate emergency calls is vital as callers may be under duress, too ill to speak, or may simply not know where they are. Traditional landlines can be found by what amounts to a reverse directory lookup, but using the line identity number and mobile phone coordinates approximated by triangulation, solving VoIP location is a more complex problem.

Typically, VoIP users are allocated a number by their provider and are able to log in and make calls on any broadband connection. They could be at several sites in one day. That means a solution would require cooperation between VoIP providers and ISPs.

The group tasked with developing the system has been working under the auspices of the NICC — a U.K. network industry interoperabilty body — for about three years and is chaired by John Medland, BT’s policy manager for 999 services. He said: “It has been difficult. We’ve tried to share as much with the industry as possible to get cooperation.”

He said the work was partly motivated by documented international cases in which a caller’s use of VoIP caused serious problems for the emergency services. Last year, a toddler died in Canada after paramedics were dispatched to the address the family had given when they signed with their VoIP provider. They had since moved without updating their details, and no system existed for the emergency operator to locate their call in real time.

Despite the problems of getting competing companies and sectors to work together, Medland’s group aims to publish its suggested solution next month, based on work by the Internet Engineering Task Force, an international standards body.

Williams writes that, at first glance, the solution is simple. When a VoIP user makes a 999 call, their provider knows the IP address they are calling from.

So to trace the call, the VoIP firm could forward the IP address to a central 999 authority, which would look up which ISP serves that range. The central authority would then contact that ISP for a line identity number, which would allow a reverse directory lookup to retrieve the address of the caller, as with a traditional call. All this would happen automatically in a matter of milliseconds.

The major stumbling block is that many ISPs front end systems are not connected to their back end database, so they cannot quickly match an IP address to a line identity. Under the forthcoming NICC proposals, ISPs would be asked to install a “Location Information Server” in their network to bridge the gap and serve the 999 authorities’ data requests.

Equipment and maintenance costs mean some ISPs are likely to be resistant to the proposals, however. OFCOM, which regulates 999 services, has indicated to ISPs that even if they are not the VoIP provider, they are bound by law to make location data available to emergency services. The watchdog was taking an “active interest” in the NICC work, Medland said.

At a recent meeting of U.K. networking experts, Nominet researcher Ray Bellis, who also sits on the NICC working group, suggested some ISPs might want to sell on VoIP location data to marketeers to recoup their costs. Medland said the group is completely focused on emergency applications. “I’d really like to see the it [deployed] this time next year,” he said.