If you're designing or implementing VoIP in your organization, you need to be aware of changing expectations and possible legal requirements regarding emergency services and 911.
As everyone knows, there are two big problems with VoIP and 911. First, 911 calls, unlike other numbers, are routed based on the source, instead of the destination. Second, given the mobility associated with VoIP, there's no easy way to tell 911 operators the physical location of the phone (which may be important, for instance, in the event the caller can't speak and needs medical attention).
And as everyone knows, for the first 4 or 5 years of VoIP adoption, we've pretty much dodged the issue while waiting on a good technical solution. VoIP services, such as Packet8 and Vonage have made it clear that users shouldn't dial 911 from the VoIP phone, but should use a regular telephone instead. And most corporate IT departments have gone to some lengths to explain to users what to do in the event of an outage.
But, on May 19th of this year, the FCC issued rules that -- while there is still some debate on the details -- make it clear that VoIP will be expected to solve these problems soon. As a result, some VoIP services are routing 911 to the right Public Safety Answering Point (PSAP) and even delivering the permanent location of the phone to the 911 operators. This means if you're traveling, your 911 call will go to the local PSAP and not your home PSAP, but the local PSAP will get your home address.
While corporate installations may not be specifically subject to these FCC requirements, you should still pay attention to them as they might still affect your company's liability, if for instance, your company is sued because a location wasn't sent to 911 correctly.
Unfortunately, there's not a standard that we can implement to solve this location problem today, but there are things you can do to limit your liability. The most drastic is to implement controls that prevent your users from moving their phones.
The easiest solution to help limit liability is probably a lot of repeated communication with your users. As an example, you might use XML to send messages to the display area on the phones like "Do not dial 911 from this phone while traveling".
Tom Lancaster, CCIE# 8829 CNX# 1105, is a consultant with 15 years experience in the networking industry, and co-author of several books on networking, most recently, CCSPTM: Secure PIX and Secure VPN Study Guide published by Sybex.