Telnet

Telnet (sometimes stylized TELNET) is a client-server application protocol that provides access to virtual terminals of remote systems on local area networks or the Internet. It is a protocol for bidirectional 8-bit communications. Its main goal was to connect terminal devices and terminal-oriented processes. The name "Telnet" refers to two things: a protocol specifying how two parties are to communicate and a software application that implements the protocol as a service. User data is interspersed in-band with Telnet control information in an 8-bit byte oriented data connection over the Transmission Control Protocol (TCP). Telnet transmits all information including usernames and passwords in plaintext so it is not recommended for security-sensitive applications such as remote management of routers. Telnet's use for this purpose has waned significantly in favor of SSH. Some extensions to Telnet which would provide encryption have been proposed.