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Microsoft Integration with PBXs

As Microsoft developed its initial Unified Communications strategy, it recognized the need to provide a complete solution and support products and services from other vendors. To that end, Microsoft partnered with various hardware vendors such as Polycom for phones, NET for gateways and Jabra for headsets. Microsoft also made several acquisitions to enhance its software portfolio, including, which became the basis for the real-time voice communications/call control component of its Office Communications Server (OCS) offering.Microsoft made it clear from the beginning that it intended to provide a complete collaboration and communication solution, which includes the role traditionally played by a PBX. Microsoft also recognized that it would not have a complete and competitive call control solution in the short-term (3-5 years) and, even if it did, customers would not scrap a recently purchased phone system. This situation continues even as Microsoft moves to a more complete call control solution as part of its next major release - Wave 14.

Microsoft's UC strategy continues to include support for integrating with other vendors' call control solution and phones. OCS integration with third-party switches means that these switches can work side-by-side with OCS. OCS integration partners include all of the usual suspects - Alcatel-Lucent, Avaya, Cisco, Mitel, NEC, Nortel, ShoreTel, Siemens and others.

In May 2007, Microsoft published the Microsoft Office Communications Server 2007 Telephony Integration White paper, outlining various deployment scenarios, including remote call control (RCC). RCC is the PBX integration mechanism that initially shipped with Live Communications Server 2005 and Office Communicator 1.0, and uses a protocol known as uaCSTA (user-agent Computer Supported Telecommunications Application), a telephony API into OCS.

Unfortunately, Microsoft, its partners and customers have discovered that, in addition to not delivering a compelling user experience, RCC requires a good deal of systems integration work, making it a very expensive solution, often costing more than OCS itself.

Microsoft has been advising customers and partners that it will no longer support RCC for new customers in Wave 14, although it will continue to support customers that have already deployed RCC. Knowing that it has to find a viable alternative to RCC, Microsoft is in discussions with various partners to determine the best approach toward integrating OCS with a customer's existing PBX/IP-PBX. Microsoft is currently evaluating various scenarios and is expected to reach a conclusion soon, and I will be hosting a podcast with Microsoft later this month on to announce the new strategy.

Despite rumors that Microsoft is going to reverse its position and no longer interoperate with other PBXs/IP PBXs, Microsoft is working diligently to ensure that customers can leverage their existing switches with OCS. Of course, Microsoft wants OCS to be the primary phone system in the enterprise, but it understands that it cannot dictate that enterprises get rid of their existing systems.

If your organization is considering Microsoft OCS as part of your UC strategy, you should continue to move forward, knowing that Stay tuned.