Authentication
The server uses authentication plug-ins to verify the identity of the client. Identity is usually established by comparing client credentials to a list of credentials stored in a database. For example, the authentication plug-ins included with Windows Media Services verify client credentials against a Windows-based user account database.
Protocols are used to pass credentials on a network. Windows Media Services includes plug-ins that support anonymous, NTLM, digest, and Kerberos authentication protocols because these are the protocols understood by Windows Media Player. It is possible that players by other manufacturers support other protocols.
Authentication plug-ins can be installed at either the server or publishing point levels. If you install at the server level, all clients attempting to connect to the server are authenticated. If you install at the publishing point level, all clients attempting to connect to that publishing point are authenticated. If you install an authentication plug-in at both levels, only the plug-in installed at the publishing point level is used.
You can build your own plug-in to handle authentication protocols not supported by Windows Media Services or to implement a custom user account database such as a SQL Server database. For more information, see Creating Authentication Plug-ins.