Last month, the Federal Communications Commission adopted new 911 rules for VoIP service providers that require these companies to have access to the 911 system, so their customers can make emergency calls that are routed directly to the local PSAP. But the critical capability that remains elusive at this point is the ability to pinpoint nomadic and mobile VoIP users.

Virtual, soft-client-only VoIP services, such as those from Skype, cannot provide E911 location precisely because the services work from anywhere—whether from a public Internet terminal at Starbucks or in the home. If a VoIP customer uses the service from a remote destination, the carrier will continue to route 911 calls to the location where the VoIP client was originally registered, even if the site is several thousand miles away from the place where the emergency is happening.

While no one has the answer to locating nomadic and mobile callers at this point, 911 solution providers 911 Enable believes its work with enterprises to deploy 911 capability within their organizations might lead to an answer, said Lev Deich, CTO with 911 Enable. The company’s clients include Boeing—the largest VoIP enterprise deployment to date, with 100,000 IP phones—and John Deer, to name a few.

State regulations in at least 15 states require that enterprises with multi-line telephone systems (MLTS) or private branch exchanges (PBXs) ensure that when a user calls 911 on their systems, ANI (Automatic Number Identification) and ALI (Automatic Location Identification) is provided to the PSAP.

911 Enable’s Emergency Gateway for the enterprise is designed to automatically track and assign locations to IP phones as they move and re-register on the corporate network. This helps to protect employees who make rotational use of workspace, log into IP phones and share line appearances.

One key piece of the solution is subnet tracking. Each building location can be assigned one or more subnets and can be tracked during a 911 call by mapping the endpoint’s IP address to the corresponding IP subnet and assigned location. The result is the ability to pinpoint a caller at a specific cubicle. The solution also covers workers that telecommute.

“We need to know where the person is a in certain amount of square feet, and that also applies to large distributed campuses and teleworkers,” Deich said.

As such, 911 Enable believes solutions in the enterprise will spill over into the open public network. “We’re hoping the enterprise market does come up and believe that some principles can be applied in the public side,” Deich said.