The VoIP E911 Myth Just Won't Die

It also has this statement that contributes to the ongoing myth that E911 doesn't work in IP Telephony:

"VoIP doesn’t allow for easy 911 calling because the voice server has no idea where the phone is, just its IP address."

If you know the IP address and that IP address is on your network, that may give you a pretty good clue as to where the phone is located! Also, IP phones have MAC addresses which, in a properly configured IP Telephony system and network can give you extremely accurate 911-caller location information.

Bottom line is that all the major enterprise-class IP Telephony manufacturers provide the functionality to accurately locate 911 callers, and its done routinely in enterprise class deployments. It is possible that someone in a Toronto office, could bring their IP Phone to Tokyo and make a 911 call from the new location; this would obviously cause a problem.

There are 3 ways to address the problem:

1. Prevent the activation of an IP Telephone from an IP address that is not within your approved defined network boundary. This can be done with policy or it can be technically enforced.
2. If an IP Phone registers with an IP address that is outside of your defined boundary, force the user to enter their location information.
3. Use some common sense!

The context of the article was enterprise-class IP Telephony and that's an important distinction from consumer based VoIP services. But even with these, E911 can work just fine for non-nomadic users. My street address is registered with my Vonage service. If I call 911 from my Vonage phone, my location address will be relayed accurately. A greater concern for me in this case, is that the quality of my broadband connection may be too poor for an intelligible conversation with 911 services personnel. But that's the subject of another post.

Here's some pointers on how some of the IP Telephony manufacturers address E911.

Avaya's Approach (PDF)

Cisco's Solution

Nortel Works With Qovia

I'll keep doing what I can to dispel the silly notion that enterprises deploying IP Telephony are putting the effectiveness of emergency services at risk.

Rick McCharles
www.ric.ca