“Since the early days of the Internet, HTTP-based applications have enjoyed the definition of a proxy mechanism that allowed hosts operating in private networks to reach hosts in public networks. These applications would connect to the local proxy on its listening port (8080 is the accepted default) and issue the request in a specific form so that the proxy could handle it correctly.

The proxy would then mediate between the internal client and the external server so that the communication would be carried out in accordance with their needs and the policies dictated by the proxy administrators. This mechanism is known officially as a CERN proxy, in reference to the organization that defined the HTTP protocol and HTTP proxy mechanisms.

Currently, it’s commonly referred to as an HTTP proxy or a Web proxy, but the meanings are identical – a mechanism that mediates between the HTTP client and server. This process works very well and even includes the ability to authenticate the user by means of specific HTTP request/response sequences. Figure 01 illustrates this process for a directly-connected client…”

Check out the rest of this great article by ??? at:

http://technet.microsoft.com/en-us/library/ee291341.aspx

HTH,

Tom

Thomas W Shinder, M.D., MCSE
Sr. Consultant / Technical Writer

Prowess Consulting www.prowessconsulting.com
PROWESS CONSULTING | Microsoft Forefront Security Specialist
Email: tshinder@isaserver.org
MVP — Forefront Edge Security (ISA/TMG/IAG)