SIP FORMAT GAINS MOMENTUM AS WIRELESS DEVICE PROTOCOL

Any doubts that session initiation protocol, or SIP, would be displaced by an emerging IP voice technology appeared to go out the window last week at the Voice on the Net show in San Jose, where a host of vendors lined up behind new technologies that will port SIP to the wireless environment.

Of particular significance was Microsoft, which announced that the next version of its Windows CE .net operating system would include a SIP-based voice-over-IP application interface layer. In addition, the new CE — Version 4.2 — will include a user interface that other vendors can customize.

“We think this shows the industry one of the ways that SIP can really be used in mainstream applications,” said Scott Horn, director of Microsoft's Embedded and Appliance Platforms Group.

In typical Microsoft fashion, the company used VON to demonstrate several applications, including a CE-based handset that warehouse workers can use to track inventory and communicate with others via voice over a Wi-Fi network.

Eight vendors already have committed to developing Microsoft-based applications, including BCM Computers, Casio Computer, Hitachi, NEC Infrontia, Samsung Electronics and Tatung. Another company, Symbol Technologies, plans to integrate push-to-talk technology into Pocket PC mobile computing units.

Microsoft's support of SIP comes at an important time for SIP vendors. It was less than two years ago when the company first threw its support behind SIP with the release of Windows XP (see figure). At the time, most felt that Microsoft's marketing muscle would help launch the VoIP market into the stratosphere. However, the company backed off slightly following the release of XP.

“Sometimes having the big gorilla on your side only works when they're moving in the right direction,” said one telecom carrier executive at VON who was still skeptical of Microsoft's latest move.

However, the current rush into Wi-Fi has SIP vendors salivating over a wireless market that is rich in potential but still unproven in real value.

“We're seeing some interesting [business] models, but it's still in the early stages,” Horn said.

Of course that hasn't stopped a number of other SIP vendors from placing bets in the wireless market.

“We're adding more and more hooks into the 3G world,” said Jeff Liebl, vice president of worldwide marketing and product management at Ubiquity Software, which has a SIP-based applications development platform. “The reality is that you can't ignore SIP anymore.”

Carriers worry about how integration with their current wireless networks will work and are predictably more cautious. Sprint, for instance, may appear to be the perfect candidate to deploy SIP in a macro-wireless or Wi-Fi environment. But the carrier is not jumping in just yet, said Bob Azzi, vice president of engineering with Sprint.

“We have to look at things like how you manage traffic when you cross from one network to another,” he said. “We're not at all locked into any one option. There are too many things out there to explore.”