RFC 1149's April Fools protocol IPoAC proposed carrying internet traffic by what?

RFC 1149’s April Fools’ protocol IPoAC proposed carrying internet traffic by avian carriers.

IPoAC stands for “IP over Avian Carriers,” a humorous networking proposal written by David Waitzman and released on April 1, 1990. Instead of wires, radio links, or fiber-optic cables, the scheme imagined birds—especially homing pigeons—transporting packets between predetermined locations. Data would be written onto a physical medium carried by the bird.

The joke was presented in the formal style of an Internet Engineering Task Force Request for Comments, complete with technical discussion of routing, packet loss, storms, predators, and latency. A later RFC, 2549, added “Quality of Service,” and RFC 6214 adapted the idea for IPv6.

IPoAC was even tested in practice. In Bergen, Norway, in 2001, nine packets were sent by pigeon over roughly 5 kilometers; only four responses arrived, producing about 55% packet loss. Thus, “avian carriers” is the canonical answer, while pigeons are the best-known example rather than the protocol’s formal answer.