Licensing brief: Base and Additive Client Access Licenses: An explanation
Applies to all Volume Licensing programs
Server software that requires Client Access Licenses (CALs) offers one base CAL and may offer one or more additive CALs. Base CALs license access to server functionality. Additive CALs license access to advanced server functionality and must be licensed in addition to the corresponding base CAL. Both types of CALs are available on a per-user and per-device basis.
This brief replaces a previous version published in April 2013. The content has been updated to reflect the Enterprise CAL Suite components as of August 2015.