About Internet Authentication Service

Internet Authentication Service (IAS) extends the operating system's network authentication capabilities by making it possible to implement plug-in DLLs that provide enhanced session control and accounting. IAS implements the Remote Authentication Dial-In User Service (RADIUS).

The IAS API allows you to write plug-in DLLs that use your own network authentication methods for scenarios such as controlling the number of end-user network sessions, using a state server, and connecting to domain authentication databases and Active Directory services.

IAS supports the RadiusExtensionProcess2 API in Extension and Authorization DLLs and supports RADIUS Proxy.

**Windows XP/2000:  **

• Extends the remote access authorizations currently provided by IAS.
• Plug-in DLLs are able to add their own authorizations when sending an Accept response back to an authenticating client.
• Extensibility added via the RadiusExtensionProcessEx API as well as support for Authorization DLLs.

IAS was first included in Windows 2000 and can also be installed on machines running Windows NT Server 4.0 with SP5 and later from the Windows NT 4.0 Option Pack for Microsoft Commercial Internet Service (MCIS).

The About section covers the following topics:

• RADIUS Authentication and Accounting
• Implementing DLLs to Extend IAS
• RADIUS Accounting Packets
• Working with a State Server

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Build date: 10/1/2007