Client Access Licenses
If the workstations in your organization are networked, you likely depend on network server software to perform certain functions, such as file and print sharing. To legally access this server software, a Client Access License, or CAL, may be required. A CAL is not a software product; rather, it is a license that gives a user the right to access the services of the server
Microsoft offers a device-based CAL (Device CAL) or a user-based CAL (User CAL) for purchase. In addition, an External Connector (EC) license is offered for some products as an optional alternative to address specific customer scenarios.
With the User CAL, you purchase a CAL for every user who accesses the server to use services such as file storage or printing, regardless of the number of devices they use for that access. Purchasing a User CAL might make more sense if your company employees need to have roaming access to the corporate network using multiple devices, or from unknown devices, or simply have more devices than users in your organization.
Client Access License based on user
With a Device CAL, you purchase a CAL for every device that accesses your server, regardless of the number of users who use that device to access the server. Device CALs may make more economic and administrative sense if your company has workers who share devices, for example, on different work shifts.
Client Access License based on device
If you want external users—such as business partners, external contractors, or customers—to be able to access your network, you have two licensing options:
- Acquire CALs for each of your external users.
- Acquire External Connector (EC) licenses for each server that will be accessed by your external users.
External Connector licensing
An external user is a person who is not an employee or similar personnel of the company or its affiliates, and is not someone to whom you provide hosted services. An EC license assigned to a server permits access by any number of external users, as long as that access is for the benefit of the licensee and not the external user. Each physical server that external users access requires only one EC license regardless of the number of software instances running. An “instance” is an installed copy of software.
The right to run instances of the server software is licensed separately; the EC, like the CAL, simply permits access. The decision on whether to acquire CALs or an EC for external users is primarily a financial one.