Protocol Telnet

Telnet is a bi-directional client server network protocol. It primarily aims to offer communication facility to its customers which is bi-directional in nature and is quite interactive. This network generally involves the use of a virtual terminal connection. This connection consists of an 8-bit byte data connection which is then connected to the Transmission Control Protocol (TCP).
Telnet is based on a trustworthy transport which is primarily connection oriented. The protocol establishes a connection with one of the ports of Transmission Control Protocol and the server application of Telnet is listening.
SANS Institute, which is established as an expert in the field of computer security recommends that one should not use this network protocol ,Telnet, in case of remote logins. This should be completely discontinued at all given times due to several reasons. The different reasons are that no encryption of data is happening when the data is being sent over this connection. This is also true for passwords. Therefore, there is a possibility that one may use the password for unauthorized purposes. Any individual has access to a switch, hub, router or gateway located on this network can easily obtain the login and password information. Additionally no authentication of the communication is possible on this network.