Supported Migration Paths and Coexistence Scenarios

[This is preliminary documentation and is subject to change. Blank topics are included as placeholders.]

The following sections provide an overview of the supported migration path from Office Communications Server 2007 to Office Communications Server 2007 R2 and the supported coexistence scenarios during phased migration. Migration from Live Communications Server 2005 with Service Pack 1 to Office Communications Server 2007 R2 is not supported.

Migration Methods

Migration of Standard Edition Server, Enterprise Edition Server in a consolidated configuration, and Enterprise Edition Server in an expanded configuration, either with or without edge servers, is supported. You can migrate from one topology to a different topology, such as from Standard Edition Server to Enterprise Edition Server in a consolidated configuration.

The following two migration methods are supported:

• Side-by-side migration
  In side-by-side migration, a new Office Communications Server 2007 R2 configuration is built alongside the Office Communications Server 2007 configuration. After the new configuration is fully validated, users are moved from the original configuration to the new configuration. This method requires additional servers during the migration, and system names and pool names are different in the new configuration. During this type of migration, service outage is brief or nonexistent.
• Uninstall-reinstall
  This type of migration is similar to a disaster recovery. All user and configuration data is exported and stored in a backup location. Office Communications Server 2007 is uninstalled, and Office Communications Server 2007 R2 is installed on the same computer, and then all user and configuration data is restored. This migration method does not required additional servers, and the system name and pool name remain the same. During this type of migration, service outage is expected to be longer. This method requires an operating system upgrade from 32-bit to 64-bit.

Migrations can be approached in a phased fashion, starting with the internal network and moving to the perimeter network.

Components external to Office Communications Server must meet certain requirements before migrating, as follows:

• Domain controllers in a forest or domain to be migrated must run at least Windows Server® 2003 with Service Pack 2.
• Any forest or domain that is to migrate to Office Communications Server 2007 R2 must be raised to a domain functional level of Windows Server 2003 or Windows Server® 2008.
• During an uninstall/reinstall migration, the operating system must be upgraded to 64-bit, and Microsoft® SQL Server should be upgraded at least to SQL Server 2005 with Service Pack 2.

Phased Migrations

The coexistence scenarios described in this section support phased side-by-side migrations. Any coexistence scenario not included in this section is not supported.

The following table identifies components that can interoperate.

Coexistence Scenarios

Coexistence Restrictions

Live Communications Server 2005 with Service Pack 1 cannot coexist with Office Communications Server 2007 R2.

The back-end database schema has changed with Office Communications Server 2007 R2, so a new SQL Server instance is required for an Office Communications Server 2007 R2 Enterprise Edition pool. An existing back-end server with the required level of SQL Server 2005 can host an Office Communications Server 2007 R2 Back-End database, but there might be performance limitations for a collocated back-end.

Call Control Server (CCS) requires Office Communications Server 2007 R2 Mediation Server. In side-by-side phased migrations, CCS is disabled until Mediation Server is upgraded to Office Communications Server 2007 R2.

The following Communications Server 2007 components cannot interoperate with Communications Server 2007 R2 pool components. These components must be upgraded when the pool is upgraded.

• Archiving Server
• Administrative Tools