BBN Technologies is the current official name of a firm that was originally Bolt, Beranek and Newman and is often referred to as just BBN.
Originally, BBN was a consulting company founded in 1948 by two MIT and one Harvard professor, all specialists in acoustics. Their first contract was acoustical consulting for the design of the United Nations Assembly Hall in New York.
Later, they became heavily involved in computing and in military contracting. For many years, they had a close relationship with DEC; BBN were the buyer for PDP-1 serial number one, and later the implementers for DEC's TOPS-20 operating system. They also had close relations with MIT, and such notable MIT professors as John McCarthy, Marvin Minsky and Seymour Papert worked at BBN.
BBN also implemented and managed the original ARPANET; one of the most basic protocols was called BBN 1822. When the second generation system was designed — with TCP and IP used and 1822 eliminated — BBN were involved in implementing that as well.