Microsoft® Exchange Server 2007 Administrator's Companion

Transport Architecture

In Exchange Server 2007, Microsoft has completely eliminated the redundant routing group architecture. You might be wondering what is meant by "redundant." In short, in most instances, your legacy routing group topology should fairly closely mimic your network structure or Active Directory topology. Under older versions of Exchange Server, you were forced to create an additional routing layer used only by Exchange Server. Microsoft, with Exchange Server 2007, has eliminated this additional layer by allowing you to use a structure that must already be in place and working in an organization—the Active Directory site topology. In order to support coexistence between a legacy routing group and an Exchange Server 2007 environment, ...