by Darius Kazemi, July 21 2019

In 2019 I'm reading one RFC a day in chronological order starting from the very first one. More on this project here. There is a table of contents for all my RFC posts.


RFC-202 is titled “Possible Deadlock in ICP”. It's authored by Steve Wolfe and Jon Postel of UCLA and dated July 26, 1971.

The technical content

The UCLA folks have once again found a bug in the Initial Connection Protocol. (The first time was reported in RFC-143. The issue at hand is that if both sides of a connection send a “request for connection” at the same time, then both will simply wait for the other to reply, forever. The authors suggest a minor tweak to the ICP to avoid this.

Note that this condition is present in the old ICP defined in RFC-123 and not the new one recently proposed in RFC-197.

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About me

I'm Darius Kazemi. I'm an independent technologist and artist. I do a lot of work on the decentralized web with ActivityPub, including a Node.js reference implementation, an RSS-to-ActivityPub converter, and a fork of Mastodon, called Hometown. You can support my work via my Patreon.