The Windows Server 2008 External Connector (EC) license is an optional licensing alternative to address a specific customer scenario. If you would like to allow your business partners or customers to access your network, you have two licensing options:
Acquire Windows CALs for each of your external users.
Acquire External Connector (EC) licenses for each instance of the Windows Server 2008 software that will be accessed by your external users.
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 using the server software. An EC license can be acquired for servers running Windows Server 2008 Standard, Enterprise, Datacenter, and Windows Server 2008 for Itanium-Based Systems editions. It is not applicable to Windows Server 2008 Web Server or Windows Small Business Server.
Microsoft Windows Server 2008 builds on the success and strengths of its Windows Server predecessors while delivering valuable new functionality and powerful improvements to the base operating system. New Web tools, virtualization technologies, security enhancements, and management utilities help save time, reduce costs, and provide a solid foundation for your information technology (IT) infrastructure.