We've been using Exchange Server Instant Messaging (IM), but we're moving to Microsoft Office Live Communications Server 2005. How should we go about migrating our Exchange IM user data?
There are four scenarios for migrating Exchange IM users to Live Communications Server 2005. As you evaluate which one is right for you, remember that Exchange IM and Live Communications Server store contact data differently: Exchange IM clients keep their contact lists in the client machine's registry, whereas Live Communications Server clients keep their client lists on the Live Communications Server server. Therefore, the chief difference in migration methods is whether you move this data or make users recreate it from scratch.
The typical migration methods are as follows:
- You can perform an immediate migration (in which you migrate all users to Live Communications Server, without providing any coexistence with Exchange IM) and demand that users recreate their contacts. This method is most appropriate for small organizations or other environments in which users don't have large contact lists.
- You can perform an immediate migration and move contact data by using the scripts in the Live Communications Server migration kit. You can usually use this method to migrate users overnight or over a weekend, making the method suitable for small to midsized organizations or for environments that want to get the additional functionality and security of Live Communications Server sooner rather than later.
- You can perform a gradual migration (in which you permit coexistence between Exchange IM and Live Communications Server until all users are migrated) and import each user's contacts as you migrate those users. This approach spreads out the work required to migrate user contacts, so it's a good choice for larger organizations.
- You can perform a gradual migration but wait to move users' contact data until all users have been migrated, then use the Live Communications Server migration scripts to move all that data at once. This is easier than moving individual users' contact data but requires more careful planning.
Both gradual migration paths depend on deployment of Windows Messenger 5.1 or later, which allows users to communicate by using Exchange IM or Live Communications Server and accommodates migrations by creating a separate contact group for Exchange IM contacts. During the migration, users will be able to communicate with other users through either system, although they won't be able to route messages between Exchange IM and Live Communications Server servers. To find out more about the necessary steps for each of these migration paths (which also apply in Live Communications Server 2003), see "Live Communications Server 2003," October 2003, InstantDoc ID 40610, or visit the Microsoft Live Communications Server 2005 Deployment Resources site (http://office.microsoft.com/en-us/fx011526591033.aspx).