PITTSBURGH—While public-safety answering points, voice-over-IP service providers and third-party facilitators labor to deploy 911 emergency call services to VoIP subscribers, a plethora of issues currently exist that threaten to have a negative impact on the effectiveness of such deployments, according to panelists speaking this week at the National Emergency Number Association Conference.

Several of the issues involve multiple street address guides, or MSAGs, which define address elements such as the exact spelling of streets and address number ranges. John Cummings, vice president of E-911 for VoIP provider Vonage, reminded PSAP representatives in the audience that it is critical for VoIP service providers to receive up-to-date MSAG data as soon as possible.

“What we’re looking to do, as we get deployments completed, is get your MSAG data, so we’re getting calls routed to the right place,” he said. “We’re also working very hard to make sure all of our customer information is validated against the MSAG.”

Provisioning 911 service to VoIP subscribers has been complicated by typing errors made by subscribers when they register the current location of their VoIP handsets, which typically occurs when the subscriber travels, or when the data they provide is inconsistent with standard MSAG style. According to Cummings, Vonage requests voice positioning centers (VPCs) to validate the data typed into its Web interface.

“If they’re unable to validate it, we’ll go back and tell the customer that they haven’t provided us with a valid address at some level,” Cummings said. “We work with each of the [VPC] vendors to provide a third-party intercept. When a call comes in from someone without a valid address, we’re going to verbally challenge them to give them that address so we can deliver that call.”

Timothy Lorello, senior vice president for Telecommunication Systems, one of the VPC vendors to which Cummings referred, said there are several methods to validate whether the information typed by the subscriber is valid.

“If there is an MSAG-validation stack in the front end, it will catch errors before they go into the MSAG, so you should not have invalid MSAG records,” he said. “Such issues should not be the normal situation. If you’re running into errors as the normal situation, then something is broken in the process that needs to be fixed—and it is fixable. It is something that’s fixable immediately and not something that’s going to take weeks, months or years.”

But Lorello acknowledged there is no current method to inform PSAPs when a record is in error, or whether it has been corrected by the system’s safety-net processes.
“In real time, there’s not way to do that, unless someone makes it part of a standard,” Lorello said.

According to NENA Operations Issues Director Rick Jones, the FCC’s VoIP 911 order did not address MSAG validation. He said NENA filed comments last year regarding the need for such validation, but the commission has yet to take any action.

A bigger problem is that many VoIP subscribers fail to update the location of their handsets when they take them with them on business or vacation trips, said Lorello, whose company this week announced the addition of an MSAG-based routing application to its existing VPC solution.

“We’re very concerned about this. … Encourage your PR arms to let people know, especially in the summer months, that if they’re taking their phones with them, to re-register them,” he said.

Another problem concerns gaps and overlaps in the geographic information system information provided by PSAPs, according to Carey Spence, director of state government affairs for 911 systems provider Intrado.

“Your GIS experts and our GIS experts need to sit down and work that out,” Spence said. “It’s something that we’re finding is a key issue.”