Microsoft will release public betas of Office Communications Server (OCS) 2007 and its Office Communicator 2007 client this month. They are designed to integrate Exchange with IP private branch exchange (IP PBX) functions as well as new features, like instant messaging (IM) and presence, into a single unified communications solution.

Speaking at the VoiceCon Spring 2007 IP telephony forum in Florida, Microsoft Business Division president Jeff Raikes forecast that within three years the average voice over IP (VoIP) solution will cost half what it does now, and 100m people – twice the number currently using VoIP, by Microsoft’s calculations – will be able to initiate “Click to Call” communications sessions from within Office applications.

Steve Blood, an analyst with Gartner specialising in IP communications, believes Microsoft's forecast of 100m VoIP users in three years is optimistic, given that there are currently only 150m Exchange users in total.

“Companies ultimately will not just use VoIP software clients; mobile and desktop phones are still out there, and click to call involves a high level of integration with OCS and the PBX, which incurs high costs,” Blood said.

Microsoft is comparing the cost of the IP telephony software against high-priced IP handsets from vendors such as Avaya, Cisco and Siemens, which cost up to £500, and not against other IP telephony software clients already on the market.

Blood says that Microsoft will bundle the Office Communicator client with Exchange 2007 and charge a $50 increment per user per desktop for the software, on top of the cost of the Exchange licence.

Jan Dawson, vice president of Ovum's US enterprise practice, believes this will still be cheaper than buying a proprietary IP PBX and messaging platform, however. While Microsoft's use of open standards and interfaces will provide companies with a broader range of compatible hardware.

“The VoIP industry is dominated by the hardware vendors, like Cisco, Nortel and Avaya, but Microsoft is shaking up that model by saying forget about having a separate proprietary PBX and IP telephony server, just buy OCS, which provides the same capabilities at less cost,” said Dawson.