Similar to its famous "developers, developers, developers" rant, Microsoft is chanting "software, software, software" as it lays the cornerstones of its unified communications platform.

Microsoft's is an all-software strategy that weaves voice, e-mail, instant messaging, presence, and video conferencing into a suite of communication tools anchored by Office Communications Server (OCS) 2007.

Read Cisco's approach to unified communications.
Watch a head-to-head comparison of Cisco vs. Microsoft UC solutions.

The most dramatic difference between Microsoft's vision and that of the hardware-based unified communications players comes at the junction of the voice and data networks, where Microsoft believes the PBX will die and be resurrected as software. In other words, OCS 2007 becomes you new PBX.

Microsoft's Chief Software Architect Bill Gates in October was blunt in his PBX prognosis. "Once you get software in the mix the capabilities go way beyond what anybody thinks of today when they think of phone calls. This is a complete transformation of the business of the PBX," said Gates at the launch of the company's unified communications platform.

Gates likened the PBX to the mainframe of years ago, an all-inclusive system that lacked flexibility. Gates said moving voice to software would bring efficiencies to workers and IT, and reduce infrastructure and operating costs. (See story on Gibson Gibson Guitars use of Microsoft unified communications products.)

This approach also allows Microsoft to more easily integrate directory services, desktop applications and system management tools.

Click to communicate

The company believes that its voice-enabled unified communications platform will give more than 100 million corporate workers the ability to "click to communicate" by the end of 2010.

Click to see: Diagram of Microsoft's unified communications vision

Gates says megatrends, such as hardware improvements, abundant bandwidth and a digitized economy have "laid the foundation for voice integration via software and unified communications."

Microsoft believes that as the phone call is revolutionized, the change will bring along screen sharing, video, collaboration and the ability to put rich unified communications capabilities into business applications.

In the Microsoft nirvana, all that will remain at the network's edge is a gateway to translate signaling and media between the Public Switched Telephone Network and the Session Initiation Protocol (SIP)-based OCS 2007.