Microsoft's Lync fills gaps in VoIP

"This is an area where Microsoft has been playing catch-up. Everyone asks can Lync replace a PBX Customers may now be willing to consider it," he says.

But they won't trust it without proof, so it may have to be on the market for a couple of years and proven with large-scale deployments by early adopters to win over business telecommunications decision makers. "Telecom tends to be conservative. I'd like to see deployments with 5,000 to 10,000 users," Schoeller says.

How customers look at phasing in UC&

Much of Lync's success may depend on how customers look at phasing in UC&C, says Osterman Research in its white paper, "Microsoft Lync Server 2010 and the Unified Communications Market." The infrastructure that customers already have and the new capabilities they need immediately will have an influence.

"For example, should an organization use its existing PBX as the starting point and then add capabilities like video conferencing, e-mail, mobility and presence into that infrastructure Should it begin with its e-mail system and then slowly add IM/presence, audio conferencing and then finally enterprise voice into the mix Should it choose a middle route and preserve its e-mail and PBX infrastructures as they are now and simply "glue" them together to provide unified communications capabilities" Osterman says.

Microsoft and its competitors are vying for control of the customer's desktops, which will be the key to which UC&C platforms businesses adopt over time, Schoeller says. Cisco's client, for example, supports the Lync backend servers. "Both product sets are lining up more and more side-by-side," he says.