I was reading through the new Visual Studio 2010 Licensing White Paper released a couple of weeks ago. It contains a good explanation and examples of multiplexing scenarios. These sounded very familiar, as some of our clients have implemented these in the past. Just to clarify, these scenarios do not reduce the number of TFS CALs that are required, as some people think. End users or devices that accesses TFS in any way, other than the New Work Items (WIWA) exception, are required to have the appropriate licenses, regardless of whether they are using a direct or indirect connection.
What is Multiplexing?
Multiplexing is hardware and software that reduce the number of users or devices that directly access Team Foundation Server. This is also sometimes referred to as pooling.
An organization implements an intranet Web site that connects to TFS in a way that enables users to add work items, resolve bugs, or trigger builds through the Web site. Even though only one device (the Web server) is directly connecting to TFS, each person who uses the Web site to access TFS for purposes other than creating new work items must have a CAL or be covered under an External Connector License. (A Device CAL may not be used for the Web server because the Device CAL only supports one user logged-into the specified device at any given time.) A CAL is not required for accessing a second Web site that runs on the same physical Web server but does not access Team Foundation Server.
Multiple people simultaneously remote into a server running Terminal Services (or Citrix) to access a development environment. Even though those multiple users are “sharing” one device, each user must have a CAL or be covered under an External Connector License. (A Device CAL may not be used because the Device CAL only supports one user logged-into the specified device at any given time.)