What Is Telnet

Computer History Notes - Herong's Tutorial Notes

∟1974 - Internet by Vinton Cerf

∟What Is Telnet

This section provides a quick introduction of Telnet application that allows you to log into a remote computer over the Internet as a text based terminal.

What Is Telnet? - Telnet is an Internet application that allows you to log into a remote computer over the Internet as a text based terminal.

The Telnet protocol that supports the Telnet application was actually developed on physical networks before the Internet age. The Telnet protocol was proposed by C. Stephen Carr in 1969 in "RFC 15 - Network Subsystem for Time Sharing Hosts" at https://tools.ietf.org/html/rfc15.

The diagram below from the above RFC shows how a user from University of Utah can establish a terminal access to the computer host at Standford Research Institute:

  Teletype
  Terminal        ______                                 ________
  _________      |      |     ______          ______    |        |
 |         |     | USER |    |      |        |      |   |SERVING |
 |         |-----| HOST |----|      |---//---|      |---| HOST   |
 |_________|     |  A   |    |      |        |      |   |  B     |
                 |______|    |______|        |______|   |________|
                University                               Stanford
                 of Utah                                 Research
                                                         Institute

 Figure 1:  User accesses distant serving HOST via shunt
            subsystem in his own Host computer.