One of the two fundamental communications protocols used in the Internet (see TCP/IP). IP is a connectionless, unreliable network layer protocol, which conveys packets from any computer in the network to any other. Currently version 4 (IPv4) is the most widespread, with version 6 (IPv6) beginning to appear. IPv6 offers a greater number of addresses, allowing more computers to attach to the Internet, simpler connection, and provisions to ensure quality of service for multimedia traffic.