1977-78 ==== In 1977, Cerf and Kahn split their original "TCP" network protocol (a combined layer 3-4 protocol) into a stack of separate protocols: "TCP" (Transmission Control Protocol, for layer 4), and "IP" (Internet Protocol, for layer 3) -- in order to accommodate real-time apps such as voice, thus allowing other layer 3 (network layer) protocols such as UDP to be used along with TCP. They called the end result, "TCP/IP version 3." A year later (1978), an updated version "TCP/IPv4" was introduced, which is still the Internet standard today. The Internet is planned to run on "IPv6" soon -- for increased address space (from 32 bits to 128 bits). Key personnel at that time: Dr. Vint Cerf and Dr. Robert Kahn.