In 1972, Vint Cerf and Bob Kahn, both of whom were part of the core ARPANET
group, collaborated on what they called the Internetting Project. They wanted to link
different networks together so that a host on one network could communicate with a
host on a second, different network. There were many problems to overcome: diverse
packet sizes, diverse interfaces, and diverse transmission rates, as well as differing
reliability requirements. Cerf and Kahn devised the idea of a device called a gateway to
serve as the intermediary hardware to transfer data from one network to another.