Unified Communications and Microsoft
With the release of the much-hyped Microsoft Office Communication Server 2007 last October (2007) Microsoft seems to have announced it’s entry into the Unified Communications race along with main rival Cisco and PBX vendors such as Avaya, Nortel and Alcatel. Microsoft envisages Office Communication Server 2007 (OCS) and the following generations to replace the PBX.
The cool thing about OCS is that it provides “presence” out of the box and integrates seamlessly with address books and directory servers. Users are required to install an OCS client to view presence information, IM and call colleagues. For companies that have a collaboration initiative, Microsoft Office Live Meeting integrates seamlessly with OCS and allows multiple employees to edit the same document, spreadsheet or/and presentation concurrently. Since most companies already use Microsoft Exchange Server, it must be noted that a company’s voicemail needs can be accomodated by simply paying for unified communications to be enabled in Exchange 2007. However, several critics slam Microsoft for several core features missing in their implementations of Unified Communications. These include music-on-hold, call parking, trunk selection when routing to emergency calls and the ability to use site access codes for overlapping extensions. These features are either not supported in the current release or are difficult in their configuration. The biggest drawback that draws the most criticism is the fact that none of the major vendors of VoIP gateways from Cisco Systems, Mediatrix Telecom, Quintum Technologies, Stratus, Welltech Computer and Nortel Networks are currently supported.
On the other hand, while Cisco offers a robust solution, the implementation of basic features is relatively complicated. To get the equivalent of the Microsoft offering, companies are required to purchase Cisco Call Manager, Cisco Meeting Place, Cisco Presence and Cisco Unity.
At the core of the Unified Communications offering is fact that the underlying protocols are simple and easy to implement. Interested vendors could seamlessly implement similar, custom solutions (like Microsoft and Cisco) based on signaling protocols (such as SIP, H.323, MGCP and the Cisco-proprietary SCCP) allowing their low-level implementations to dissect calls between endpoints conforming to the same protocol, while voice can be encoded within a codec (like G.711, G.729) and then transported over an RTP stream (UDP extension).
I believe that eventually companies are going to choose to implement heterogeneous solutions that use a combination of technologies to get the most out of their Unified Communications initiative. I intend to study and post material on these assimilated offerings, so stay tuned 
