System, method and apparatus for use in monitoring or controlling internet access

摘要

An apparatus method and system are described for categorising Uniform Resource Locators (URLs) when accessing the Internet 20 from a client 12 . A request message 500 is generated to request categorisation of a specified URL, and a category is provided in a reply message 600 . The specified URL and the category are added to a category cache. In a second or subsequent instance of a URL request referring to the specified URL, the category is determined from the category cache. This reduces communication traffic in a network such as the Internet 20.