SIP — The Promise, The Reality and The Potential

At eComm 2008 and Spring VON I had the opportunity both to listen to presentations by, and to have personal discussions with, Brough Turner of NMS Communications. If there is one authority on telecommunications infrastructure, back office and the business side of routing calls around the world, Brough is the person. He understands the backhaul issues; he understands the business environment that can both encourage and inhibit the launch and evolution of new telecommunications services.

Last week he was asked to provide a guest post for SIPCenter, SIP, in time, where he talked about the issues around deploying SIP and its failure to live up to the promise for it when it launched in the late 1990’s. A few days later, in a reprise on his own blog, SIP Revolution, massively delayed — but there’s hope, Brough pointed out where he could see more promise for SIP, through a new PSPSIP initiative. He talks about how SIP was initially perceived as facilitating direct end-to-end connections supposedly bypassing costly infrastructure but, in practice, has become embedded into centralized PBX’s and servers, thereby removing the cost advantages. "SIP has been adopted for use in the IP Multimedia Subsystem (IMS), but this completely warps the original SIP vision." Yet through P2PSIP, there may be a route to realize some of the original vision.

Some of Brough’s comments:

The biggest change in telecommunications in the past 12 years has been the global deployment of three billion mobile phones, all based on conventional circuit-switching and Intelligent Network technology — nothing to do with SIP. And arguably, the most interesting telephony service enhancement, after mobility, came from Skype with its seamless integration of presence, instant messaging, wideband audio and video. But Skype is based on proprietary protocols, not SIP. Finally, VoIP technology has helped drive down the cost of international calling, but using MGCP, H.248 &/or H.323 protocols much more than SIP, at least so far. ……

SIP assumes it’s possible to make end-to-end connections over the Internet and therefore a SIP session can know about and use globally valid IP addresses. That was a naive assumption, even in 1996-1999 when SIP was being defined. The real Internet contains firewalls, network address translators (NATs) and other "middle boxes." They are not going away, it’s only getting worse over time. Today, applications must be aware of and able to work around middle boxes and other network problems. ……

Actually, there is some reason for optimism. The advent and widespread adoption of Skype showed what was possible and suggested how one might distribute central services among peers, potentially avoiding the need for an explicit service provider. The past few years have seen rising interest in peer-to-peer SIP which has resulted in an IETF working group under the name p2psip. Their goal is "to leverage the distributed nature of P2P to allow for distributed resource discovery in a SIP network, eliminating (or at least reducing) the need for centralized servers."

Hat tip to Jon Arnold’s Is SIP Living up to its Potential? for directing me to these posts. One of Jon’s points:

Skype chose to use a proprietary protocol instead of SIP, and has proven by far to be the most popular web-based voice/IM application we’ve ever seen. It’s conventional wisdom to knock Skype for being a walled garden that won’t integrate with the other IM platforms, but when it comes to VoIP, Skype has proven its ability scale better than anyone. I guess this begs the question – could Skype have been as successful (let’s leave profitability aside here) if they had used SIP instead? Would love to hear your thoughts on this one.

Interesting to note that Skype is one of the heavier users of SIP — for its SkypeIn and SkypeOut connections. And, as Jonathan Christensen (who was heavily involved with SIP during his five years at Microsoft) pointed out during a panel at eComm 2008, instead of supporting its initial promise for the transmission of rich multimedia, SIP today remains largely a voice services interconnection protocol.

Tags: Brough Turner, SIP, Skype, Jon Arnold, Jonathan Christensen, SkypeIn, SkypeOut, IMS, eComm 2008, SIPCenter

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About Jim Courtney

Bringing over thirty years' experience in the sales, marketing and management of cutting edge technology businesses.
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