List of packet-switched networks

This list of packet-switched networks is divided into three overlapping eras: early, isolated, networks before the introduction of X.25; the X.25 era when many postal, telephone, and telegraph (PTT) companies provided public data networks with worldwide reach; and the modern Internet era, which initially competed with the OSI model.

The work of Donald Davies in the late 1960s on data communication and computer network design became well known in the United States, Europe and Japan. This was the "cornerstone" that inspired numerous packet switching networks in the decade following.