Supporting functions Web Gateway also provides functions, such as web caching or progress indication that do not themselves filter web objects, but support the filtering process in different ways. Functions supporting web filtering Some of the functions that support web filtering are implemented by rule sets of the default rule set systems. Rule sets for other functions can be imported from the library. Web caching A web cache is provided on the appliance for storing web objects to speed up responses to client requests. Progress indication Progress indication is a process that shows a user who has started the download of a web object the progress made in downloading the object. File opening File opening is performed on Web Gateway to make files available for inspection and filtering that cannot immediately be accessed, for example, because they are nested in an archive or have been encrypted or compressed. Bandwidth throttling You can limit the speed for uploading and downloading data to the appliance in a process known as bandwidth throttling. Next-hop proxies Next-hop proxies can be used as an additional means of forwarding requests received from the clients of an appliance to their destinations.