What Is VoIP
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VoIP-Based Services

By now you've probably seen ads for companies like Vonage and Packet8. These services promise ultra-cheap voice calling service via your broadband internet connection. Some offer calling packages as low as $9.95 per month. Their secret weapon is VoIP. Voice over IP service providers use the internet to carry voice signals from their networks to your home phone. Because VoIP telecommunication isn't regulated the way traditional phone line telecommunication is, VoIP providers like Vonage can offer drastically lower calling rates.

The catch? You've got to put up with the occasional hiccup in your voice service, caused by the one thing legacy telephone technology has built-in that VoIP doesn't: guaranteed quality. Because VoIP uses packets to transmit data like other services on the internet, it cannot provide the quality guarantees of old-fashioned, non-packet-based telephone lines. But this is changing, too. Efforts are underway on all fronts (service providers, Internet providers, and VoIP solution makers) to adapt quality-of-service techniques to VoIP services, so that one day, your VoIP calls may sound as good as (or better than) your regular land-line calls.

Today, if you want to build a fully quality-enabled private VoIP network, you can. Cisco, Foundry Networks, Nortel, and other network equipment makers all support common quality-of-service standards, meaning corporate networks are only an upgrade away from effective convergence of voice and data.

But it will be quite some time before the internet itself is quality-enabled. Indeed, the internet may never be fully quality-enabled. This hasn't stopped enterprising network gearheads like me from trying to connect calls over the internet, of course. Hey, if Skype works so well, why can't corporate phone calls? Enterprise phone administrators have found that it is actually very easy to equip mobile users with VoIP phones to place calls on the company phone system by connecting to it over the internet--from hotel rooms or home offices--but the quality of these calls is sort of hit or miss, like a cell phone when you drive through a "dead zone" in the cell network.

What's Next for VoIP?

A host of brand new, VoIP-enabled cell phones will soon be ready for action. Imagine driving to work, receiving a call on your cell phone from a client, and then continuing that call on the corporate Wi-Fi network as you walk into the front office. all without any interruption to your call-in-progress. The cell network will just "hand off" the call to your Wi-Fi network. This sort of technology exists today, and will be a commonplace feature of corporate phone systems in years to come.

Cost savings, uber-slick telephony features, network convergence--VoIP is the technology at the root of all these trends, and you should expect to see a lot more news about VoIP in the coming months and years. If you haven't used Voice over IP products yet, try out a broadband phone service like Broadvox Direct or Vonage, and download a copy of Skype or the Gizmo Project, two excellent VoIP PC calling applications.

To learn more, you can visit or browse O'Reilly's growing selection of books about IP telephony, including the book that's been dubbed the "Voice over IP of reason:" Switching to VoIP.

Ted Wallingford is lead consultant and co-founder of Best Technology Strategy LLC, and is the author of O'Reilly Media's Switching to VoIP and VoIP Hacks.

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