Hot potatoes and postmen: how packet switching became ARPANET’s greatest legacy

Abstract

ARPANET demonstrated that packet switching was an effective routing principle for computer networks, accelerating the evolution towards the current network paradigm, in which packetization is found in almost all forms of digital communication. The decision to use the packet switching principle was crucial to the development of the Internet and computer networking broadly, and in popular literature, packet switching is often attributed to three originators: Paul Baran, Donald Davies and Leonard Kleinrock. This paper does not concern itself with who invented packet switching, but rather, who had the greatest influence on the risky and highly consequential decision to base the ARPANET design on this previously untested technology. A close examination of the available documentation, including two newly re-emerged documents, indicate that Paul Baran had a much more substantial influence on the decision to use packet switching for ARPANET than most retellings of Internet history portray. The findings also show that Donald Davies’ role in the adoption of packet switching as a dominant principle for digital communication may have been less impactful than depicted in current literature and that Kleinrock may have played a significant role in bringing packet switching to the ARPANET, influenced by interactions with Baran.