RFC 1149, a 1990 internet spec, sent IP packets on paper taped to pigeons' legs, and a Norwegian Linux group made it work

David Waitzman of BBN wrote it in the same deadpan format as every other Request for Comments, the documents the internet’s plumbing is actually specified in. The title is “A Standard for the Transmission of IP Datagrams on Avian Carriers,” and it calls itself “an experimental, not recommended standard.”

The frame format is where it gets good. “The IP datagram is printed, on a small scroll of paper, in hexadecimal, with each octet separated by whitestuff and blackstuff.” A band of duct tape holds it on. “The bandwidth is limited to the leg length,” and the maximum packet size, the MTU, “paradoxically, generally increases with increased carrier age. A typical MTU is 256 milligrams.”

The receiving end is a person with tape remover and a scanner: “Upon receipt, the duct tape is removed and the paper copy of the datagram is optically scanned into a electronically transmittable form.”

Every caveat reads like a real networking spec, because it was written to. The birds have “an intrinsic collision avoidance system.” There’s “built-in worm detection and eradication.” Lost packets are fine, since “IP only guarantees best effort delivery, loss of a carrier can be tolerated.” And the last line of the section: “Audit trails are automatically generated, and can often be found on logs and cable trays.”

The Bergen test went sideways in the most pigeon way possible. The neighbor had a flock out flying, and the group wrote that “Our pigeons didn’t want to go home at once, they wanted to fly with the other pigeons instead.” After about an hour, a couple of birds broke off and headed home to cheering.

Decoding was manual. The packet “was carefully removed from the leg, unrolled and scanned,” then the OCR got checked by hand, since the gocr software “did have problems recognizing F’s.” Two birds came back with no packet at all, because the other end was so busy “they forgot to shut the pigeon cage.” The group’s verdict: “I guess this is a new record for ping times…”

Waitzman wasn’t done, either. On April 1, 1999, he published RFC 2549, “IP over Avian Carriers with Quality of Service,” with service classes named “Concorde, First, Business, and Coach” and the note that this is “the only networking technology that earns frequent flyer miles.”

Bergen’s write-up ended by asking for “other implementations, so that we can do interoperability tests.” The group’s RFC 1149 page still lists just two posts, the planning minutes and that report, so the interoperability test is still waiting on a second flock.