Analyzing network traffic to discover the type of application that sent the data. In order to prioritize traffic or filter out unwanted data, deep packet inspection can differentiate data, such as video, audio, chat, voice over IP (VoIP), email and Web. Inspecting the packets all the way up to layer 7 (see
OSI model), it can be used to analyze anything and everything within the packet that is not encrypted. For example, it can determine not only that the packets contain the contents of a Web page, but also which website the page is from. See
packet filter.