Lee County Public School System's Technology Initiative

All INTERNET traffic to and from the school browsers passes through the Microsoft Proxy Server at Lee High School. The proxy server provides several functions. First, it caches all material requested by browsers on the WAN. It does this both passively and actively. Passively, if a web page is requested it is cached by the proxy for a period of time, determined by the server’s logic. Then, if the same page is requested by another browser, the local copy of the page on the server is supplied and bandwidth on the INTERNET feed in not used. On Web pages that the content changes frequently, the proxy server determines at what interval the content changes, then during slow utilization periods, it goes onto the Web and obtains an updated copy. This is in anticipation that there will be a need for this Web page in the future. In other words, it monitors content changes along with anticipated usage by the Lee County users. This is called active caching. Currently we are getting about a 34% hit rate at peak usage periods. This implies considerable savings on our INTERNET bandwidth costs.

The most important feature of the proxy server is its ability to create a firewall protecting an organization’s network from outside intrusion. It does this by caching everything coming into the network and delivering it locally using private I/P addresses. INTERNET routers do not support the private I/P address ranges. This gives a level of protection to machines who are identified by a private I/P address. Private I/P addresses can be designated without a governing agency’s approval, hence, far less administrative overhead is involved in maintaining machine identities.

Additional functions of the proxy server include Net usage logging and I/P address filtering. These are discussed further in the section entitled inappropriate site management. The logging feature is also used to develop usage statistics.

If security was implemented utilizing user names and passwords, the proxy server would make this possible. This feature is not activated on the Lee County System.