After spending some time at our Unified Communications Server booth at TechEd, I decided to write the answers to some of the most common questions people had for those of you who did not have the opportunity to attend this year.

What is the difference between Live Communications Server and Office Communications Server? - Office Communications Server 2007 is simply the next version of Live Communications Server 2005.  As the "Live" name is used by our web properties, we change the name to "Office" to avoid confusion.

What does Office Communications Server do? - OCS provides IM, voice, and video conversation and conferencing support for your organization.  It is a VOIP solution using SIP and can integrate with Outlook, Sharepoint, and Exchange.  This is the 100,000 feet view.

What is new in Office Communications Server 2007? - Voice and video conferencing (you can now host your own Live Meetings), improved PBX support, Speech Server, platform APIs for building apps, improved Outlook and Exchange integration

How can I hook it up to my existing PBX? - You need to deploy a Mediation server (an OCS server role) and deploy a third party gateway (AudioCodes, Cisco, and others)

How does it integrate with Exchange? - We use Exchange for voice mail and archiving IM conversations

Do I need to have Exchange to use Office Communications Server? - No, you will just not be able to use the voice mail and IM archiving features

How does it integrate with Outlook? - If Office Communicator is installed on the machine, you will see presence levels for everyone involved in an e-mail and you can make calls or create conferences by right clicking on an address in Outlook or by selecting call or IM from the message toolbar.  You can also create and track meetings and view your IM conversation history.

How does this compare with Cisco Call Manager? (note: this is just my opinion and does not represent anything official from Microsoft) - Cisco and Microsoft approach the problem from two different perspectives.  Cisco is looking to change your infrastructure ("the color of the wire").  At Microsoft we are trying to change fundamentally how people communicate with each other - and therefore we have integrated heavily with our Office and Sharepoint products.

What are the bandwidth requirements for voice and video? - We continually make adjustments to the video and audio depending on the bandwidth available.  We will try our hardest to make sure we work with what you have.  Therefore there are no solid requirements.

When will this ship? - Sometime this summer

How can I find out more about the soft phones available? - There is more information about devices available at http://www.microsoft.com/presspass/presskits/uc/gallery.mspx