October 27, 2004

Numbering and Addressing in VoIP: Wag the Dog?

Lately there have been many discussions and announcements on numbering and addressing in VoIP. The industry is fixated on using E.164 numbers as the addressing mechanism in VoIP even though it creates problems or recreates the PSTN business models; then others follow with attempted partial solutions. We should look at the fundamental issue and address it so that we maintain the promise of VoIP – autonomous communication between the end-points.

As I understand it, Vocaltec used IP addresses when it introduced its VoIP software in 1995 and migrated to E.164 number when it introduced gateways and interconnection to PSTN. In any event, true to its pedigree, H.323 used E.164 numbers as addresses. But SIP used URI based construct for its addressing scheme. Recognizing the flexibility of URI scheme, other protocols like H.323 and MGCP adopted the scheme.

Even though URI allows for alphanumeric characters, FWD restricted the user name part of it to only numerical characters; the domain part was assumed to be fwd.pulver.com. (I remember Pulver taking enormous efforts to point out that FWD does indeed use URIs.) The limited user interface of the standard telephone is the reason for the numerals only restriction. Subsequently, SIPPhone used NANP like structure for their address, with 747 (SIP) as the area code (which was unused at that time). Of course SIPPhone number is not E.164 address because the NANP administrator did not assign it to SIPPhone. Similar scheme was used by other SIP providers. Interconnecting to each other creates a problem because it is not clear how the caller can specify the domain name. The solution is a typical Bellheaded solution – use of access codes. There is only one reason for placing numerals only restriction – limited user interface of the terminals.

When commercial service providers entered the scene, they used valid E.164 numbers because they wanted to accept calls from PSTN (after all there is money to be made from incoming calls). This creates a problem while interconnecting to pther VoIP providers. It is not transparent from the address whether one is terminating in PSTN or in IP. So a simple solution is to interconnect through PSTN. (A cynical explanation is there is money to be made from incoming calls.) Now DUNDi is being proposed to address this problem. This is a technical solution; but I am not sure whether it will be accepted on business grounds, if it means loss of access charges revenue.

Shouldn’t a Nethead try to eliminate the basic restriction rather than come up with adhoc,(even if clever) fixes? How come a Nethead turns into a Bellhead when placed in the “voice” environment?

Now some try to console the incidental benefits of using E.164 address. We are told that it provides a strong identity infrastructure. Even if this true, it does not provide the derivative benefits even in PSTN. Such protections do not easily traverse national boundaries and since the PSTN calling card rates are so low, the economical barriers are very low for people to do mischief across national boundaries. Now that the PSTN allows interconnection from PSTN, PSTN itself has lost the strong identity.

So there is only one reason for sticking to E.164 numbers - the industry is lazy or risk averse in trying to change the UI of the terminal. So as advocates of VoIP, we should strive for improved UI for the terminals and insist on URI based dialing (which will marginalize the service providers). Oh, by the way, do everything to encourage your circle of friend to migrate to VoIP. This means you should not subscribe to additional virtual numbers, because this will take away the economical motivation to get VoIP.

Against this background, there is a proposal called GNUP. It introduces another Naming authority. The interesting aspect of this proposal is to use this one has to use Peerio discovery algorithm. I would imagine this involves royalty payment of some sort. Looks like everybody wants to emulate Bill Gates.

Posted by aswath at October 27, 2004 05:20 PM
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Interesting. The question I keep asking myself is whether consumers really care about the numbers. In the IM world they care about their handle and which one they are using at a given time. Numbers are less personal and don't share the same type of "emotive" information. Are numbers really sustainable. IM systems work fine without numbers at least within their community walls. Within those environments consumers have many more opportunities to create their own profiles and with that control their reputations.

From a consumer perspective I find it hard to believe that numbers have a 50 or even a 20 year future. Voice dialing is already here.

Numbers and area codes have purposes. However right now their primary function is to let the consumer know whether it is long distance or local. It works as a charge prompt. When the costs are a simple flat rate like now to 21 countries then voice requests for connections will have an even bigger incentive. For it won't matter where in the world or on what device they are.

So... what if the system just enabled consumers to identify themselves and made sure it was unique? Will they get that from Peerio? Skype still has that component centralized... although the API will enable new forms of caller ID sharing.

I'm probably off topic. However the numbering discussions appear too complicated. A simpler consumer solution in a better application that still allows some perhaps lower quality interconnect may well provide a better solution.

It feels like the numbers and interconnects are adding unnecessary admin burdens to the system. That may be ok in the short-term. In the long-term it is a potential breakpoint.

People aren't numbers and we do want identities. Perhaps that is where the discussion should shift?

Posted by: Stuart at October 29, 2004 12:10 PM

Stuart: you're basically hitting the nail on the head.

One of the main issues is that for every system to uniquely identify who a user is, and properly route a call to them, a central authority is needed to do this identification. It's a major gold rush. The only reason why this gold rush is happening, is because people want to keep using numbers to dial other people. Well at least industry pundits want us to believe as much.

But we don't need to resort to numbers, or reinvent yet another central authority to uniquely identify "something".

This battle has already been fought in the past, which finally culminated to a nicely distributed system federated by an international body, ICANN: the domain name name registry and DNS. This entire system is what enables e-mail URIs: hollandct@earthlink.net . SIP judiciously sought to capitalize on this system: my e-mail address can just as easily be my SIP address: sip:hollandct@earthlink.net . Just about *ANY* ISP on the planet can offer SIP routing to their members.

The problem is, many VoIP companies and Telcos are seeking to retrofit and confine SIP within the realm of a Telco's narrow concept of VoIP. When in fact, VoIP and SIP ought to remain pure internet applications.

I find it okay for someone such as Vonage to offer transparent integration with the PSTN, *because* its mission in life is to offer a more cost-effective way to make and receive calls "in the old world". A vonage system leverages VoIP to achieve costs savings it passes down to the customer, while always remaining an integral part of the "PSTN world": Your vonage number *IS* a *REAL* PSTN number.

But as we're building out NEW SIP-based voice systems, building a foundation on yet ANOTHER NUMBERING SCHEME, and relying on yet ANOTHER central federating entity, is, in my mind, thoroughly asinine. We're moving into an age of Internet applications, not "PHONE" applications. VoIP is only the most popular application of SIP. Video conferencing is just another logical application of SIP. Online text messaging will also, one day, leverage SIP. From this point, how much sense does a number make? Are you really calling someone's "phone number" or rather their "internet address".

Raise your hand if you think initiating an instant messaging session, a video conferencing session, or calling "chris at hollandct@earthlink.net" makes more sense than calling XXX XXX 524 7460 ?

As far as practical aspects go, Aswath and I both agree there is no technical reason why we should stick to the clumsy, limited user interface of a traditional phone to make calls. Already, most mobile phones have built-in address books, that are sync'ed one way or another, whether it's "online", or through a USB or bluetooth-connected computer. I rarely ever type a number in my t610.

Who's likely to use VoIP without an internet broadband connection? Who's likely to have an internet connection without a computer?

There's plenty of room for handheld devices to improve. Mobile phones will, hopefully, help. RIM is headed that way.

That kinda was the reason behind my Xmas Wish post ( http://chrisholland.blogspot.com/2004/10/my-xmas-wish-ultimate-handheld-device.html ) :)

Let end-users manage identities. Keep control in the hands of the user.

Posted by: chris holland at October 30, 2004 06:52 PM

I raise my bith hands (given the current political atmosphere here in US).

Chris, don't forget that even PSTN cordless phones these days allow for quickly adding an entry to its address book. I can easily see their OS allowing URIs to be stored and sent to a companion ATA.

Posted by: Aswath at October 30, 2004 08:11 PM

SIP should be just like email, whether you are jsmith@aol.com or john@smith.com in the US, you can email fjones@yahoo.com or fred@jones.com in Germany without the need to use peering, National, International etc numbers.

Throughout the world there has been a smallish group of www.Intertex.se IX66 (Router/Firewall/SIP Server/Proxy & PBX Opt) users, for whom the SIP world has been simple for the last two years. Using service providers SIP addresses, but in most cases using their own domain, hosted on their IX66 SIP just works for voice, text, video and presence.

Posted by: David Boyce at October 31, 2004 10:03 AM

holy crap Aswath! you've just gotten comment-spammed! congrats! :)

Posted by: chris holland at November 8, 2004 05:52 PM

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