On October 29, 1969, the ARPANET came to life with the first message being sent from a mainframe computer at UCLA to a mainframe computer at Stanford Research Institute.
BBN won the contract to build and operate the Interface Message Processors (IMPs), the forerunners to today’s modern routers. IMPs were computers with specialized interfaces and software the size of a refrigerator and cost about $100,000 in 1969 U.S. dollars.
Steve Crocker at UCLA had been working on the IMP software and wanted to solicit opinions from others working on the project. In a memorandum entitled “Host Software”, he asked others in the development of the ARPANET for their opinions and ideas concerning the IMP software. Needing to track documents of this type, he chose the modest phrase “Request for Comments”, along with the number “1” indicating the first number in the sequence. This type of memorandum, more commonly known by its acronym RFC, became the method the early developers of the ARPANET chose to discuss and document standards. At the time there were a very limited number of people working on the development of the ARPANET, so the process was much more informal than it is today.
Today, the Internet is a much different place and there is a formal structure used to propose, develop, and implement Internet and TCP/IP standards. RFCs are still the official document used, following a process managed by the IETF.