About Sites, Networks, Uplinks, and Regions : About site types
  
About site types
Site types group one or more sites based on their business organization or other functionality. Riverbed creates three basic site types for you: Data Center, Headquarters, and Branch. You can create other site types In addition, to these default site types. When you create sites, you must provide the site type that the site belongs. Site types are the building blocks for QoS profiles and pushing new features in SCC 9.0 and later to SteelHeads.
You must create site and sites types before migrating or configuring QoS. When creating QoS profiles, We recommend selecting site types rather than sites to make QoS more manageable. A QoS profile is a container for QoS rules and classes that apply to a source and destination site type or site. Sites should only be selected when creating exceptions for QoS profiles containing the site types. When you push QoS profiles, only the selected site types or sites in the push are applied to the QoS profiles. For detailed information about migrating QoS policies and configuring QoS, see Managing QoS.
The default site types can’t be deleted or modified.