Deep packet inspection (DPI) is a technique that has seen success in traffic management, security, and network analysis. Different from purpose-built network solutions with DPI capabilities, a general DPI solution provides deep packet inspection for different applications. As network operators, Internet service providers (ISPs), and corporations alike are increasingly dependent on the efficiency of their networks and the applications that run on them, the need to manage bandwidth and control the complexity and security of communications becomes paramount. DPI provides exactly the means for such purposes. User organizations that seek better network management and compliance should view DPI as an essential technology.