About Licensing

Licensing software with Client Access Licenses can be complicated due to the technical nature of server products and networks. 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.

This overview is for reference purposes only. Before purchasing, you should visit the "How to Buy" section for each product and consult your Microsoft representative or local reseller regarding your specific licensing needs.

User CALs

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

Device CALs

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

External Connectors

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.

Server Licensing Not Requiring CALs

Some server products are available to be licensed on a "per processor" or "per instance" basis.

Per Processor Licensing

Under the Per Processor model, you acquire a Processor License for each processor in the server on which the software is running. A Processor License includes access for an unlimited number of users to connect from either inside the local area network (LAN) or wide area network (WAN), or outside the firewall (via the Internet). You do not need to purchase additional server licenses, CALs, or Internet Connector Licenses.

Software licensed by processor

Specialty Server Licensing

Specialty Server licensing is a commonly used model. Specialty Servers are server-only licenses that also do not require CALs. Specialty Servers require a server license for each instance of the server software running on a server. An example of this is Microsoft Office SharePoint Server for Internet Sites. You can run the instance in a physical or virtual operating system environment. By exception, some products provide more specific use rights.

Specialty Server licensing

Other examples of Specialty Server licensing include Windows Web Server 2008 and Microsoft Dynamics CRM 4.0 Workgroup Server.

For a list of Microsoft Server products and their applicable CALs, see the Product CALs tab.

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