The FCC has issued an order requiring VoIP systems that interact with the old-fashioned phone network to provide 911service. Carriers have 120 days to comply.
It won’t be easy for VoIP carriers to provide the 911 service that people have come to expect from the traditional phone system. The biggest challenge in providing 911 on VoIP is knowing where the caller is located.
In the traditional phone system, it’s easy to know the caller’s location. The phone company strings wires from its facility to customers’ homes and offices. Every call starts on a phone company wire, and the phone company knows where each of those wires originates; so they know the caller’s location. The phone company routes 911 calls to the appropriate local emergency call center, and they provide the call center with the caller’s location. One big advantage of this system is that it works even if the caller doesn’t know his location precisely (or can’t communicate it clearly).
Things are different in the VoIP world. Suppose I’m running a VoIP application on my laptop. I can make and receive VoIP calls whenever my laptop is connected to the Internet, whether I’m at home, or in my office, or in a hotel room in Zurich. My VoIP endpoint and my VoIP phone number can be used anywhere. No longer can the carrier map my phone number to a single, fixed location. My number goes wherever my laptop goes.
How can a VoIP carrier know where my laptop is at any given moment? I’m not sure. The carrier could try to see which IP address (i.e., which address on the Internet) my packets are coming from, and then figure out the physical location of that IP address. That will work well if I connect to the Net in the simplest possible way; but more sophisticated connection methods will foil this method. For example, my VoIP network packets will probably appear to come from the Princeton computer science department, regardless of whether I’m at my office, at home, or in a hotel somewhere. How will my VoIP carrier know where I am?
Another approach is to have my laptop try to figure out where it is, by looking at its current IP address (and other available information). This won’t work too well, either. Often all my laptop can deduce from its IP address is that there is a fancy firewall between it and the real Internet. That’s true for me at home, and in most hotels. I suppose you could put a GPS receiver in future laptops, but that won’t help me today.
We could try to invent some kind of Internet-location-tracking protocol, which would be quite complicated, and would raise significant privacy issues. It’s not clear how to let 911 call centers track me, without also making me trackable by many others who have no business knowing where I am.
Tim Lee at Technology Liberation Front suggests creating a protocol that lets Internet-connected devices learn their geographic location. (It might be an extension of DHCP.) This is probably feasible technically, but it take a long time to be adopted. And it surely won’t be deployed widely within 120 days.
All in all, this looks like a big headache for VoIP providers, especially for ones who use existing standard software and hardware. Maybe VoIP providers will take a best-effort approach and then announce their compliance; but that will probably fail as stories about VoIP 911 failures continue to show up in the media.
Of course, VoIP carriers can avoid these rules by avoiding interaction with the old-fashioned phone network. VoIP systems that don’t provide a way to make and receive calls with old-fashioned phone users, won’t be required to provide 911 service. So the real effect of the FCC’s order may be to cut off interaction between the old and new phone systems, which won’t really help anyone.