In addition to License 6.0, Microsoft is introducing a new Client Access License (CAL) plan called Core CAL. The Core CAL covers all the following Microsoft server-based products: Windows Servers, Exchange Server, System Management Server (SMS), and SharePoint Portal Server (formerly code-named Tahoe). The Core CAL replaces the Microsoft BackOffice CALs in current licensing agreements.
A Core CAL’s price equals the sum of the prices of the individual components less 5 percent. The individual price depends on your license agreement. Microsoft defines an eligible client as "a device that accesses the server within the firewall." This definition eliminates Web clients.
You must enroll in Software Assurance (SA) to be eligible to purchase Core CALs. If you currently use BackOffice CALs, you can’t convert them unless you buy SA, along with a new license plan, and update your server-based products to the current version.