Evaluating CAL Suites

Client Access Licenses (CAL) suites are collections of client-side licenses for accessing Microsoft server software, such as Windows Server and Exchange Server, and a few Exchange-related online services. Compared to purchasing component licenses separately, CAL suites can in many cases be a more economical option, and they can be leveraged to reduce the cost of migrating to Microsoft-hosted online services. However, buying CAL suites can lead to several forms of overlicensing, especially when purchased through an Enterprise Agreement (EA).

Core and Enterprise CAL Suites

The two types of CAL suites, Core and Enterprise, are packaged in a Russian-doll fashion, with the Enterprise CAL Suite being a superset of the Core CAL Suite. (See the illustration “CAL Suite Components“.) Most of the individual components within the CAL suites are called CALs, but a few are labeled Client Management Licenses (CMLs) and subscription licenses (SLs). All components include version downgrade rights, meaning clients are licensed to access any version of any product included in the suite.