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March 2010 | Volume 13 / Number 3
Packet over Wireless

How to Dial an HD Voice Call

Every server on the Internet has a unique address, kind of like a phone number. For example, Google's (News - Alert) is Short, simple and easy to enter on a phone keypad. So when you want to get to the Google Website, all you need to do is punch that number into your browser address bar, and bingo, you're there. Try it now -- you'll find it's much easier than all the complications of typing

You disagree? You think it's easier to type Then why are you so attached to the idea of phone numbers, when you could call people using their email addresses? Especially considering that calls made using email addresses are cheaper and sound better.

You probably already know that when a VoIP call is routed over IP from end to end, without traversing the PSTN at any point on its route, it can deliver HD voice audio quality by using a wideband codec. If you are under the impression that achieving this end-to-end connectivity requires network peering and ENUM databases, you are mistaken. It can be done far more simply. All you need to do is dial your calls using email addresses rather than phone numbers. Email addresses used like this are called SIP URIs, which stands for session initiation protocol universal resource identifiers.

Try it now; call a friend using his or her email address. OK, there are two reasons that didn't work. First, your friend neglected to add a SIP SRV record to his or her DNS entry; second, your phone doesn't give you a way to dial by SIP URI.

Both of these barriers are relatively easily remedied. IP desk phones like those from Polycom actually already allow you to dial by SIP URI, as do softphones like Counterpath's Bria or Google's Gizmo5 (News - Alert). Soon we'll see add-ins for email programs (including on smartphones) that give you the option of “call” along with “reply” and “forward.” As for the DNS entry, that only takes a few minutes to do. I added a SRV record pointing my domain to my SIP service provider (OnSIP), and now calls made to my email address ring on my desk phone, and complete in HD voice. IT

Michael Stanford (News - Alert) has been an entrepreneur and strategist in VoIP for more than a decade. (Visit his blog at

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