Introduction

The primary use of proxies is to allow access to the Web from within a firewall (Fig. 1). A proxy is a special HTTP server that typically runs on a firewall machine. The proxy waits for a request from inside the firewall, forwards the request to the remote server outside the firewall, reads the response and then sends it back to the client.

In the usual case, the same proxy is used by all the clients within a given subnet. This makes it possible for the proxy to do efficient caching of documents that are requested by a number of clients.

The ability to cache documents also makes proxies attractive to those not inside a firewall. Setting up a proxy server is easy, and the most popular Web client programs already have proxy support built in. So, it is simple to configure an entire work group to use a caching proxy server. This cuts down on network traffic costs since many of the documents are retrieved from a local cache once the initial request has been made.

Current proxy methodology is based on the earlier gateway code written by Tim Berners-Lee as part of libwww, the WWW Common Library. Kevin Altis, Ari Luotonen and Lou Montulli have been the principle designers behind the proxy standard.

Lou Montulli, author of Lynx, made the first libwww changes to support proxying in collaboration with Kevin Altis. Ari Luotonen maintains the CERN httpd . Ari has made the server side of the proxy standard a reality and integrated caching into the proxy server

Ari Luotonen - Kevin Altis