Proxy servers have long been used to provide a level of content caching to improve performance and protection for users accessing the internet. Typically specific details of the proxy server are entered into the settings of the user’s preferred web browser. More often now these settings may be automatically downloaded by the way of a proxy configuration script. As more and more content has moved to be encrypted via https and is more likely to be dynamically generated, the ‘success’ rate of proxy cache hits has dropped meaning they are no longer very effective in many cases.
A variant of the standard proxy is the Transparent Proxy (also known as an intercepting or inline proxy) which intercepts communications at the network layer without any special client configuration. These devices are sometimes used by network carriers such as mobile phone operators as it gives them control over content. The problem with transparent proxies is that they have to work without creating any impact on the communication between the client and the server which is a complex task. The result is that unusual problems may be seen with web pages not loading correctly or protocols being blocked because the transparent proxy does not support them.
Whenever using a mobile network (or any provider where the path to the internet is not explicitly known) for a critical event or launch it is important to test any applications or websites prior to the event to ensure they work correctly.