If you need to call 911 from the office, try to make sure your office is in Florida, not Colorado. That's because Florida is one of five states that require enterprise PBXs to provide emergency services with the exact location of callers, whereas Colorado is one of three with laws on the books saying they don't need to provide any location data at all. In most other states, emergency services may be able to determine only the postal address of the building containing the PBX, not the actual phone from which a 911 call was made.

That will change in 2006, when the FCC is likely to introduce regulations mandating that PBXs provide detailed location information compatible with Enhanced 911 (E-911), the technology that automatically tells 911 dispatchers where callers are. In December last year, it issued a notice of proposed rule making that gave states one year to introduce their own legislation. Some have (see "State Enterprise E-911 Laws" below, left), but the majority haven't, so the FCC is set to act and introduce national rules.

Impact Assessment: Location Tracking Click to Enlarge in another window

That's good news for people who need to call the cops from a sprawling corporate campus, but a potential headache for the IT managers who need to implement the capability. Some may see it as an opportunity to replace aging TDM telephony with a shiny new converged network, but VoIP has its own E-911 challenges. While most PBXs can be programmed to provide some location data, VoIP providers don't always know what to do with it. And forget about mobility outside the enterprise network: Although vendors like to demonstrate technology that can track users to within a few feet, real VoIP services are lucky if they can guess the right time zone.

State Enterprise E-911 Laws Click to Enlarge in another window

ROUTING AROUND THE RULES

Superficially, VoIP's failure to provide emergency services echoes that of cell phones a decade earlier. The 911 system is largely separate from the PSTN, but both are based on the same circuit-switched architecture and were designed to work together. Dedicated 911 trunk lines link telephone exchanges to the country's thousands of local Public Safety Answering Points (PSAPs), call centers staffed by emergency dispatchers.

Each PSAP serves a relatively small area, so it's relatively simple for them to implement E-911 for PSTN lines. Nearly every PSAP now contains a database of Automatic Location Information (ALI), which maps all the phone numbers within its coverage area to a specific place--at the least a street address, and sometimes a precise location within a building. The ALI data usually pops up in front of the dispatcher's screen as soon as a 911 call is connected so that people in emergencies don't need to give directions.

The FCC's attempts to push cell phone operators into providing accurate E-911 data have taken longer than safety advocates had wanted, but they've been successful for the most part. After four years of delays and extensions, regulations that require carriers to provide the PSAP with an accurate grid reference for 95 percent of 911 callers are finally coming into effect at the end of this month. To meet them, the carriers have invested heavily in location-tracking technology. Many reuse the same technology for commercial location services: The most successful is Sprint Nextel, which can track large fleets of delivery and service trucks using GPS phones.

Wireless E-911 Requirements Click to Enlarge in another window

The same isn't happening with VoIP. Although the FCC spent much of this year setting strict regulations about the availability of E-911 through VoIP, the VoIP service providers have discovered a simple loophole. Instead of actually providing E-911, they can get their customers to sign a waiver accepting that 911 services may not be available. That may be enough for home users who see Internet telephony as a way to avoid long distance calls, but not for enterprises that want VoIP to reproduce all the PSTN's functionality.

The rules affecting VoIP service providers that do try to offer E-911 can lead to absurd situations. Most VoIP providers can only offer E-911 services within the coverage area of some PSAPs, and the FCC requires them to cut off all non-emergency connectivity to customers who move outside that area. "They want us to suspend all capability except the one that we can't deliver," says Caitlin Clark-Zigmond, director of product management at New Global Telecom, a wholesale VoIP provider.

Even worse, current FCC rules require that users update the ALI database manually--either by talking to a person in a call center or entering an address into a Web form (see "E-911 In a VoIP Network"). They're supposed to go through this process every time they move between buildings to avoid wasting time when calling 911.

The threat of being cut off when outside the E-911 service area gives people a powerful incentive to lie. "It depends what's important to you," says Clark-Zigmond. "We think it would be better to have the correct location of the caller, even if it isn't automatically delivered to the correct PSAP."