O'Reilly logo

VoIP Hacks by Theodore Wallingford

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Hack #6. Got 911?

For a multitude of technical and political reasons, Internet TSPs have been slow to make reliable Emergency 911 dispatch dialing available for their customers. Here's how to know if you've got it.

If you recently signed up for VoIP telephone service, the likelihood of you having 911 service is low, but some TSPs do offer it. The fastest way to find out if your TSP offers it is to contact them and ask. Vonage, for instance, supports 911 call routing to most public safety jurisdictions, but you've got to activate this "feature" first. Here's a snippet from Vonage's end-user agreement:

You acknowledge and understand that 911 dialing does not function unless you have successfully activated the 911dialing (sic) feature by following the instructions from the "Dial 911" link on your dashboard, and until such later date, that such activation has been confirmed to you through a confirming email. You acknowledge and understand that you cannot dial 911 from this line unless and until you have received a confirming email.
2.5 Failure to Designate the Correct Physical Address When Activating 911 Dialing
Failure to provide the current and correct physical address and location of your Vonage equipment by following the instructions from the "Dial 911" link on your dashboard will result in any 911 communication you may make being routed to the incorrect local emergency service provider.

This is a heavy-handed contract item, but what it means is that you have to use Vonage's prescribed, email-based activation routine to use its 911 call routing. Of course, I'm not a lawyer, and I can't provide an attorney's interpretation of this agreement, so contact Vonage if you're unsure about it. Other providers might handle 911 call routing similarly, so make sure you ask before you sign up if 911 is a highly important feature.

The best way to deal with this intimidating contract is to know firsthand whether your TSP has you set up for 911 calling, or be ready for an emergency in case it doesn't. That's what you're about to do.

The Problems with VoIP Emergency Dialing

With a traditional phone line, the power for the line and phone comes from a central power source at the phone company's exchange switch. This means that even during isolated power outages, you can still make and receive calls—including 911 calls. With VoIP, your electric company and in-house electrical circuits provide the power. If a circuit blows or the electrical supply fails, you won't be able to make any calls.

This would also be the case if your Internet connectivity failed or experienced a VoIP-prohibitive traffic jam. You wouldn't be able to make calls, or you might not be able to hear or be heard. Neither would be acceptable in an emergency calling situation, yet broadband VoIP TSPs can't prescribe a solution to this problem. This is because the TSP doesn't control the traffic between your VoIP device, your ISP, and the rest of the Net that provides the data transport between your VoIP device and the TSP. Unfortunately, there aren't many solutions to these issues.

Hack a Compromise Solution

In the event of an emergency, you're going to want to know you can pick up the phone and reach help quickly. You can do a few things to ensure this.

Keep a Plain Old Telephone Service (POTS) line for 911 calls.

By keeping a traditional phone line hooked up, you ensure that you can reach 911 using "the old phone," and you provide a line that your VoIP ATA might be able to use for 911 dialing. Many VoIP ATAs and VoIP-integrated broadband routers, such as the Zoom X5V and V3 routers, allow you to connect a standard POTS line that 911 calls can be routed to in case of an emergency. Check with your VoIP TSP to see if it supports this kind of connection.

Program your VoIP device with speed dial to mimic 911.

If you absolutely can't keep a POTS line around (or you prefer not to bear the expense of one merely for 911 dialing), you might be able to get your VoIP equipment to somewhat mimic the real thing:

  • Program speed-dial buttons or key combinations on your IP phone or softphone that will auto-dial the local fire department or dispatch center via its regular, non-911 number. You should be able to obtain the local 10-digit phone number for the emergency dispatcher by contacting the administrative office of your local fire department. Ask them to give you the phone number of the line where 911 calls are answered. If you get lucky, the person you ask will know what VoIP is and will understand why you're asking, but don't count on it.

  • If that's a dead end, you can program speed-dial buttons or key combinations (maybe even 9-1-1 itself) into your IP phone or softphone as a shortcut for calling a trusted neighbor or family member. This isn't exactly emergency dispatching, but it's better than nothing.

Use a cell phone for 911.

Like a POTS line, a cell phone can often be used effectively to reach the 911 dispatcher, but check with your cell phone carrier to make sure 911 service is available and reliable in your service area. Just because wireless 911 service has been mandated by the Federal Communications Commission doesn't mean it works everywhere, so check with your carrier to be sure.

Use a good old-fashioned permanent marker.

If all else fails, using a felt-tip permanent marker, write the full 10-digit phone number of the local public safety dispatcher on every phone in your house that uses your VoIP service. Don't write it on tape or sticky labels adhered to the phone, because they will eventually peel off, and you never know when you'll need that important phone number.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required