About the Web Proxy Service

The Web proxy service (W3proxy) is a Windows 2000 service that supports requests from any browser that conforms to standards of the Conseil Europeen pour la Recherche Nucleaire (CERN). The Web proxy service allows Web access to nearly every desktop operating system, including Windows NT, Windows 95, Windows 98, Windows 2000, Macintosh, and UNIX.

The Web proxy service works at the application level on behalf of an HTTP client requesting an Internet object retrievable through one of the protocols supported by the Web proxy service: FTP, HTTP, HTTPS, and Gopher. Web proxy protects all Web browser access. The Web proxy service operates with a Web proxy client, which can be any client computer that uses CERN-compliant applications and is configured to use the Web proxy service of ISA Server.

Unlike Microsoft Proxy Server 2.0, which implemented the Web proxy as a Web (ISAPI) filter loaded by the local Internet Information Services (IIS) Web server, Web proxy now runs as a Windows 2000 process (W3proxy.exe). The process can be initialized by starting the Web proxy service. IIS Server can be installed on an ISA Server computer, but this is not required. For more information on IIS and ISA, see Internet Information Services Separation.

You can use the secure Web publishing feature of ISA in conjunction with Internet Information Services (IIS) or other Web servers to publish to the Internet without compromising the security of your internal network. ISA uses Secure Web publishing and reverse hosting to send requests to Web-publishing servers connected behind the ISA proxy computer. ISA server's Web proxy (W3proxy) service supports the use of Secure Sockets Layer (SSL), and also supports Web (ISAPI) filters.

The Web proxy service includes the ISA cache, described in About the ISA Server Cache.