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December 01, 2009

The Perfect Network Architecture

Years ago, when one of the founding fathers of SIP, and now senior vice president of Google, Jonathan Rosenberg, would present his thoughts on network architecture, he would project a picture of an hour glass and talk about its impact.
 
Rosenberg’s analogy was right on and today I will use Alan Johnston’s & Henry Sinnreich’s SIP Tutorial slide to once again depict the hour glass figure of the Internet (see diagram below as well as my video blog, here).
 
It’s this ability to mask everything that made it possible for the Internet to ubiquitously bring applications to people using dial-up, broadband and any other method we could think of. The “masking” of the inner workings of the network is important.
 
 
We could make the statement that all of IMS is really trying to make the carrier’s network more capable to the Internet. And obviously it is not a pretty picture.
 
 
However, the important point about this slide is not the layer 2 connectivity, but the commitment to support SIP as the application protocol.
 
This is what makes 4G so exciting.
 
But we have a real challenge. When the Internet started connecting to the cell phone, it used a gateway with a Wireless Access Protocol [WAP]. Its role was to deliver the Web in a presentable manner to a smaller screen and low bit rate. It was not particularly good and people referred to it as a walled garden.
 
As the ability to add more speed to the connection between the cell phone and the Internet increased the impact was to deliver the Web more seamlessly.
 
But the carriers are looking to be more than just a dumb pipe. If you have to put all that effort in to getting IMS set up to make it so that you could support applications, being told the Web is the ultimate app store is kind of a let down. When you look at the applications at the app stores, a majority of them are Web apps.
 
How can a carrier complement the applications developer?
 
The carriers are trying to make available certain services such as location, security and billing. Now the reality is that the Web has made apps ubiquitous, so connecting to the carrier’s application store is more about being noticed (and yes, billing helps).

So the carriers see the need for a network API to blend their layer two and backend support to application as shown in the diagram at right.
 
Gone is the walled garden. Back when I worked on the first class 5 soft switch we would draw a seesaw about Web developers vs. telephone developers. We generously estimated we had about 2,000 people who could program a class 5 switch. We then estimated that conservatively there were 2 Million Web developers.
 
Getting the attention of the application developer is going to take a lot for the carrier, but as we move to 4G, a case can be made that the carrier’s information can improve some services.
 
David Isenberg would tell us that the network should be a dumb pipe. If you are an application developer the question will be: Who pays? Are you strong enough as an application to be viral and be independent of the network provider? Or does the carrier offer some recognition and capabilities that compliment your applications?
 
These are the discussions I have continually had with my colleagues in various forms. It’s the framework that drives the decisions being made strategically in device, network and application development.
 
The 4GWE Conference, to be held Jan. 20 to 22 in Miami, will address the critical issues related to the evolution to the 4G wireless broadband network. 4GWE will kick off with a full day SIP Tutorial on Jan. 19. The tutorial will be lead by Henry Sinnreich and Alan Johnston and will include an introduction to SIP and its associated protocols such as RTP (Real-time Transport Protocol) and SDP (SessionDescription Protocol), client-client server and peer-to-peer SIP systems.
 
Various issues of working over the Internet, especially NAT (Network Address Translation) traversal will be presented as well as SIP-specific solutions such as the STUN/TURN and ICE protocols. SIP security issues will also be presented. Examples of various SIP-based communication applications are provided, in the areas of telephony, presence, instant messaging and multimedia will be discussed as well.
 
Register for the 4GWE Conference now.

Carl Ford is a partner at Crossfire Media.

Edited by Michael Dinan


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