On a BIG-IP® system with an SWG subscription, you can customize URL categories and URL filters any time after the initial download of the URL database has completed. Customizing URL categories and URL filters is completely optional.
With regularly scheduled downloads, URLs are added to the URL database on an ongoing basis. With predefined URL filters, if they completely serve your needs, you do not need to configure more.
Secure Web Gateway (SWG) supports HTTP and HTTPS-based instant messaging protocols. As a result, when you use the Instant Messaging URL category to block messages, SWG can block messages to ICQ, for example, but cannot block messages from applications that use non-standard ports or tunneling over HTTP, such as, Yahoo Messenger, Skype, Google Talk, and so on.
Similarly, SWG cannot block messages from file-sharing and peer-to-peer protocols that do not use HTTP or HTTPS; most of these protocol types do not use either HTTP or HTTPS.