Microsoft Office Communications Server 2007 Enters Public Beta

As promised three weeks ago, Microsoft's first experimental foray into the click-to-call field of VoIP - its Office Communications Server 2007, due to replace Office Live Communications Server 2005 - has been opened to public beta tests today. Its aim is to integrate voice communication with other Office users as well as with the server itself, directly into Office 2007 applications.

Here is where we start to see Microsoft's plan to become a communications company take shape. With the acquisition of Tellme Networks two weeks ago, Microsoft now has a centralized platform for the delivery of search and other services via voice, worldwide. For potential customers looking to design enterprise telecom networks, this shifts the services logic out of the server room and onto an outsourced platform.

Now, with Office Communications Server entering the picture, the device with which the user directly interacts moves from the telephone to the PC - or, to use Microsoft's term for it, in its recent diagrams, the "OC."

Left behind is the PBX, which under the Microsoft plan becomes completely outmoded. Microsoft's gamble is that today's generic servers are fast enough now to be able to handle voice traffic as well as regular data, and that enterprise customers would be willing to give "unification" a try in order to save thousands, if not tens of thousands, in up-front investment costs...even if in so doing, they become beta testers.

The OC window and conversation window from the latest beta of Office Communicator 2007. (Courtesy Microsoft)

As an "OC," the PC doesn't simply absorb the function of the telephone. Through Microsoft's newest instant messenger client (yes, there's another one), Office Communicator provides a "point of presence" for each user that's linked not just to the machine the user is running on, but to the specific application, the importance of which is subtle but unmistakable. So the application which contains a link to another OC user can open up to reveal a Web conferencing console.

For this to work properly, however, the Session Initiation Protocol which typically links VoIP clients had to be amended. As it was originally conceived, VoIP users might either be contacting other parties either on their dedicated VoIP phones or through their computers, though with computers serving as the consoles. In the Microsoft vision, applications are the consoles. In other words, you're not just calling Warren Buffet but Warren Buffet's open copy of Excel.

And what's extremely important here is this: Should Mr. Buffet call you back, and you contacted him via Microsoft's OC, you would receive his call through that OC and not someone else's brand of VoIP client that uses the old SIP protocols that were application-agnostic. So if you're using a competitor's VoIP client now, it becomes outmoded pretty quickly.

Beta testers will discover this during a tour of OCS 2007's documentation, which includes the following: "The original SIP standard had a design flaw where it was not possible to construct a URI which could be routed to from anywhere (including the Internet) and reach a specific device or User Agent. User Agent is a broad term that includes clients such as Office Communicator as well as gateways such as the Mediation Server. This gap in SIP causes problems when a server or client needs to route to a specific device, for instance the device with which you joined an IM session.

"In Live Communications Server 2003, Microsoft introduced a proprietary SIP extension in the called EPID (End-point Identifier) to address this gap," the documentation continues. "GRUU [Globally Routable User Agent] offers a technically superior alternative to EPID and it is soon expected to become an Internet standard."

Because customers are often wary of Microsoft's past record with "embrace and extend," the company was very, very careful this time around not to get caught introducing an extension on an existing standard without a partner. So to avoid this very tangle, one year ago Microsoft entered into a partnership with Cisco.

Among the technologies these two are sharing is the GRUU protocol, which creates a tag at the end of the old SIP identifier (which was essentially a glorified e-mail address) that routers such as Cisco's won't block, but which will lead directly to specific endpoint applications on the client side.

Just three weeks ago, Cisco issued a new draft of its proposed GRUU to the IETF. One example of a GRUU that Cisco supplies is this: sip:[email protected];gr=kjh29x97us97d. Here, the original SIP protocol address continues to identify what the IETF calls the agent of record (AOR). To this, Cisco appends a semicolon and a gr= parameter, which appears to be a kind of pseudo-random string determined by what the draft calls "the registrar in the domain." You could probably cross that out and enter "Active Directory" instead.

Last September, Cisco and Microsoft issued a joint statement of their intentions to make their respective network security monitoring systems interoperable. And there's that key word regulators these days love to see.

With the cost of IP-oriented voice communications plummeting, there's been plenty of incentive for Microsoft and Cisco to do things by the book - promptly, but carefully. In a time when standards bodies are being taken to task for having slowed to a crawl, members associated with the SIP amendment project have recently praised Microsoft and Cisco for, in effect, showing how interoperability ought to be done. So the GRUU development process has been proceeding without much of a hitch. What remains to be seen is whether the current voice service providers (VSP) are aware of the approaching juggernaut.