Microsoft will launch a frontal assault on enterprise telephony when it launches OCS (Office Communications Server) 2007 later this month but plans to win over most customers bit by bit over the next few years.

At its San Francisco launch event for OCS on Oct. 16, the software behemoth will also announce availability of new devices that can be used with the unified communications software, said Kim Akers, general manager of unified communications at Microsoft, in an interview Wednesday. At the same time, Microsoft will line up device, infrastructure, and software partners who are part of the "ecosystem" the company will promote as part of its edge in combined voice, e-mail, text, and video. The Office Communicator 2007 client and Office Live Meeting will also debut at the event, which will feature Microsoft Chairman and Chief Software Architect Bill Gates.

OCS will bring Microsoft into a fast-growing market for platforms that put all forms of enterprise communication in one place and will put it in competition with dominant networker Cisco as well as a host of telecommunications switch vendors. Unified communications is intended to let people make calls from within software applications on a PC and easily start up collaborative sessions, including videoconferences, from many locations. Microsoft sees a $45 billion total market for the technologies this year.

One tool to help users get the most out of Microsoft's unified communications technology is the RoundTable, a small tabletop device with a panoramic camera and a directional microphone that can find the current speaker in a meeting. Microsoft previewed it earlier this year.

The RoundTable represents Microsoft's approach to videoconferencing, which has been a major focus for Cisco since the launch of its Telepresence high-definition meeting systems late last year. Both companies think videoconferencing has a big future, Akers said. But while Cisco goes after the top 20 percent of the market with its 65-inch plasma displays and specialized furniture, Microsoft is targeting the other 80 percent with a less expensive system, she said.

"There are a lot of activities that happen inside of an organization that don't require something as rich as Telepresence," she said.

Although Telepresence still is being used primarily for high-level executive meetings, Cisco has started to see a second wave of sales to organizations that are rolling out systems for other employees, Cisco executives said on a webcast on Wednesday.

Also coming from Microsoft on Oct. 16 is a portable conference phone, also previewed earlier this year, and devices coming from hardware partners, Akers said. Vendors of PBXes (private branch exchanges) will also be on hand to talk about interoperability with OCS, along with independent software vendors, she said.

Working with PBXes will be critical to Microsoft's plans. OCS adds VoIP to the messaging features Microsoft already brought together in Live Communications Server. But the company doesn't expect organizations to immediately rip out traditional phone switches to start relying on Microsoft for all their phone calls.

Most organizations upgrade their messaging and voice systems separately, and this is key to Microsoft's customer migration strategy. Enterprises can start using OCS for functions such as presence, instant messaging, and collaboration while keeping their current phone systems for voice calls, Akers said. Along the way, OCS can be integrated with the PBX so that, in some cases, employees may get calls ringing on both their PC softphones and their desktop phones. Eventually, most enterprises plan to migrate to VoIP, but they will be able to make that decision separately from the OCS purchase, as part of their telephony upgrade path, she said.

OCS became available in a public beta test in March. So far the beta software has been downloaded 80,000 times and Microsoft has delivered 170,000 packages of it on discs, Akers said.

Akers acknowledged Microsoft will continue to compete with Cisco and other telephony vendors despite pledges earlier this year by Cisco Chairman and CEO John Chambers and Microsoft CEO Steve Ballmer to cooperate. But engineers from the companies are working together to ensure interoperability, she said.