Transmission Control Protocol/Internet Protocol (TCP/IP) tracks the address of nodes, routes outgoing messages, and recognizes incoming messages. Current networks consist of several protocols, including IP, Internetwork Packet Exchange (IPX), DECnet, AppleTalk, Open Systems Interconnection (OSI) and LLC2. This wide diversity of protocols results from application suites that assume their own particular protocols. Collapse from this wide variety is inevitable, but users will only be able to reduce this diversity, not eliminate it. Most users will collapse networks into two main protocols: IP and IPX. Installed-base applications and the pain of change will prevent a total reduction to a single backbone protocol.