The Internet Was Designed With a Narrow Waist

The article argues that the Internet's "narrow waist" concept, a shared abstraction that solves an interoperability problem, avoids O(M × N) code explosions in favor of O(M + N) code, and that software design should deliberately engineer such waists more often. It cites IP as the Internet's narrow waist, which allows applications on top to run over many physical transports below, and notes that web authors never had to change anything as the author moved across dial-up, Ethernet, DSL, wireless and cell networks. The author says most software code is glue and that byte streams and text are essential narrow waists, while the Unix and Web designs are equally inconvenient for every programmer. The post also traces the idea's history, mentioning a 1979 attribution to John Aschenbrenner, a 1994 National Research Council book, and Jon Postel's late-1970s hourglass diagram for IP.