Tymnet

Tymnet was an international data communications network developed and operated by Tymshare. It was based at the company’s headquarters in Cupertino, California.^[1] The network used packet-switching techniques, including statistical multiplexing, and connected host computers at companies, educational institutions, and government agencies through synchronous leased lines and programmable terminal interfaces.^[2]

The business consisted of a large public network that supported dial-up users and a private network that allowed government agencies and large companies (mostly banks and airlines) to build their own dedicated networks. The private networks were often connected via gateways to the public network to reach locations not on the private network. Tymnet was also connected to dozens of international public gateways via Tymnet II protocol and other public networks in the United States and internationally via X.25/X.75 gateways.

As the Internet grew and became almost universally accessible in the late 1990s, the need for services such as Tymnet migrated to the Internet style connections, but still had some value in the Third World and for specific legacy roles. However the value of these links continued to decrease, and Tymnet shut down in 2004.