Strategically, however, LCS is a fully functional SIP sever, which means it can switch and route phone calls as easily as it can IM sessions. Once everyone has an LCS client there is little need for the IP PBX. In tomorrow's business communications network, pure-play voice has as much value as it did for Vonage in the consumer market.
This tension came out while conducting a roundtable at VoiceCon in March. At the end of the meeting, I asked Karyn Mashima, senior vice president of strategy and technology at Avaya, and Microsoft's Dennis Karlinsky, united communications group, whose presence server will run the enterprise. For a brief moment the facade of vendor companionship dropped and in between the nervious laughter and the jokes about having some more "work to do" in ironing out the details of the relationship, the real answer was provided. Micorosoft and all of its partners are circling one another wanting a bigger piece of that $40 billion pie.
Personally, I find it humorous that after all of the buggy code, the worms and the viruses that Microsoft could consider chasing the enterprise telephony server market. As a provider of presence servers and soft-clients that augment the telephony server, Microsoft will do just fine. But have Microsoft run the telephony core and get ready to do CNTRL-ALT-DELETE on your IP PBX.