As instant messaging and presence products have become prevalent in corporations, Microsoft  has taken the instant messaging engine out of Exchange 2000 and turned it into a stand-alone product, Live Communications Server 2003.

All IM functionality was removed from Exchange, so if you're looking to upgrade to Exchange 2003 and want to keep the IM, you'll also need to buy LCS. (However, Exchange 2000 licenses covered by Microsoft's Software Assurance program allow you to receive LCS licenses when you upgrade.) We recently tested LCS and found it to be much better than the IM in Exchange 2000, but perhaps too limited for those looking to purchase an IM package as a separate system.

Putting it together

LCS must be installed on a Windows 2003 Server or Advanced Server that is a member server of your Active Directory. Microsoft highly recommends that LCS be on a server other than a domain controller. The installation does an Active Directory schema extension to handle the new data types. Besides the problems we had installing a Service Pack for Windows Server, the LCS installation was straightforward.

The administration tool to manage the LCS is simply a snap-in to the standard Microsoft Management Console, and will launch as a stand-alone application . Although the snap-ins originally are placed on the Windows server, you can install the snap-ins at additional workstations where Active Directory administration is performed.

The installation CD has plenty of documentation that can help you plan your installation, migration or a test deployment. A deployment guide can help you size your hardware, set usage policies and give ideas of a typical installation.

Because LCS relies on Active Directory to hold its objects, it scales just as Active Directory does. As your LCS user base grows, you can install LCS services on multiple servers  that all share the same user information.

Microsoft abandoned the Rendezvous protocol used in its previous IM engine. LCS now uses existing Internet standards, including Session Initiation Protocol, SIP for Instant Messaging and Presence Leveraging Extensions (SIMPLE) and Simple Object Access Protocol . These protocols were added to Windows Messenger 5.0 to let it communicate with other messaging services. Because Windows Messenger is the supported client for LCS, these protocols were used.