E9-1-1 Calling: The Way Forward for VoIP

When you dial 911, you expecte that emergency response personnel will be able to find you and send help without delay. “This is true for traditional telephony in our homes,” the paper says. “But what if you’re calling from inside an enterprise PBX (News - Alert) telephone network, where many extensions, some with their own numbers and some without, all share common trunk lines?”

What if, as the paper asks, “you are a teleworker calling from your laptop VoIP client and you are not in your office? Will your emergency call go to the correct Public Safety Answering Point? Can emergency teams find you? Will someone on-site be notified automatically?”

The paper explains

As the paper explains: “With today’s E911 system, the PBX can automatically send the PSAP operator information about the location of the caller via caller ID, called an Emergency Location Identification Number, or ELIN. The Local Exchange Carrier (LEC) routes the 911 call with the ELIN to a specialized E911 Tandem Office or Selective Router. At this point, the ELIN is matched against a special Master Street Address Guide database that returns the physical location associated with the caller’s telephone number as well as the appropriate

“Provide comprehensive emergency service functionality, meet legislative 911 requirements while achieving reliability and availability targets, support mobility, with dynamic location determination and call treatment, as well as support IP client access devices, such as IP phones and IP softphones and provide the right balance of granularity versus complexity to implement corporate policy on E911 services, administration and security.”