by Darius Kazemi, Jan 6 2019

In 2019 I'm reading one RFC a day in chronological order starting from the very first one. More on this project here.

Syncing with BB&N

RFC-6 is from April 10th, 1969 and titled “Conversation with Bob Kahn”. This puts it one day after the reported publication of RFC-2, but two months before the publication of RFC-5. Yes these things are chronologically out of order, which I was not expecting. I think it has to do with the fact that RFCs were formalized well after these first ones were written so there's a lot of backdating and that kind of thing.

This RFC consists of notes on an informal conversation Steve Crocker had with BB&N's Bob Kahn (known as the co-inventor of TCP/IP).

The technical content

This is a very short document but the main point is that BB&N was willing to convert characters to 8-bit ASCII for transmission over the network.

Crocker also briefly summarizes the kinds of messages that can be sent between HOSTs and IMPs, and presumably this was important information to have confirmed by someone at BB&N (the makers of the IMP).


The conversation happened “yesterday” which means it must have happened on April 9th, the date of publication of RFC-2. We know Kahn hadn't read any of the RFCs yet because this RFC closes with the note “I also summarized for Bob the contents of Network Notes 1, 2, and 3.” “Network notes” were what they were calling RFCs casually back then. RFC-3 was probably not published at this point but Crocker was its author and could have easily summarized his work in progress to Kahn.

Also interesting is how rapidly these early RFCs came out and how much emphasis there was placed on a kind of dialogue, or at least documenting the dialogue. As Elizabeth “Jake” Feinler would reminisce in RFC-2555, with the RFC system “a swath was instantly cut through miles of red tape and pedantic process. Was this radical for the times or what!!”

Further reading

ASCII was formalized as an information encoding standard in 1961 and President Johnson signed a memorandum saying US federal computers needed to use ASCII to communicate in 1968. Since ARPA was a US military network I guess it made ASCII the only real choice for the job. From the memorandum:

All computers and related equipment configurations brought into the Federal Government inventory on and after July 1, 1969, must have the capability to use the Standard Code for Information Interchange and the formats prescribed by the magnetic tape and paper tape standards when these media are used.

Full memorandum text is here.

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About me

I'm Darius Kazemi. I'm a Mozilla Fellow and I do a lot of work on the decentralized web with both ActivityPub and the Dat Project.