When users log on to a Communicator Web Access Web site, they are actually logging on to an Internet Information Services (IIS) virtual server. A virtual server is a mechanism that allows a single computer to host multiple Web sites. For example, a server could host the Web site https://im.contoso.com in addition to the Web site https://im.fabrikam.com. Communicator Web Access uses two types of virtual servers: internal virtual servers (that is, designed for users located behind the organization’s firewall) and external virtual servers (that is, designed for users located outside the organization’s firewall).

When you install Communicator Web Access, you must create at least one virtual server on the computer where the software is installed. After you create the virtual server, you can use the Communicator Web Access snap-in to perform the following administrative tasks: