The ntl architecture is designed to deliver the best performance to the customer through the use of cached content. This minimises network traffic and speeds up processing on ntl’s servers.

There are three main cache areas within ntl’s TV Internet architecture:

1. Set Top Box cache (locally on the STB)
2. The DTV Liberate/Apache Proxy server cache
3. The Inktomi Internet Proxy server cache

• Use HTTP 1.0 Header server directives to control caching, all ntl’s network devices will obey these
• Don’t use cache control tags in the HTML page as only the STB will obey these
• Don't deliver static content using CGI scripts, the presence of ? in the URL will prevent caching
• Don’t use HTTPS unnecessarily for non-secure items, HTTPS items will not be cached
• Don’t prevent all pages from caching if this is not absolutely essential to the whole site’s functionality