Tymnet

Tymnet was an international data communications network over which the computers of large corporations, universities, research institutions, banks and national authorities communicated.

The Tymnet itself used various protocols for dial-up, such as X.25, Synchronous Data Link Control( SDLC) or the asynchronous techniques. In addition, subscribers could dial into the Tymnet using dial-up lines. The Tymnet itself used data packet switching and could control throughput rates with variable packet lengths. The data packets themselves could contain data from multiple users. Individual user groups could set up their own dedicated networks within the Tymnet, most of which were connected to public networks via gateways.

The Tymnet concept was outdated in terms of technology and could not hold its own against the emerging Internet. For this reason, it was shut down in 2004.