TELNET Protocols

The TCP/ IP protocol  suite  includes a simple textual  remote terminal protocols called  TELNET  that allow  a user to log into  a computer across an internet. TELNET  establishes  a TCP connection and then  passes keystrokes from the internet user  keyboard directly to the remote computer as if they had been  typed on a keyboard attached to the  remote machine. TELNET also carries textual output from the remote  machine back  to the user screen. The service is called transparent  because it gives  the  appearance that the  user keyboards and display attach directly to the remote machine.

TELNET  offers  three  basic  services. First  it defines  a network  virtual terminal that provides a standard interface to remote systems. Client  programs do not  have to  understand the details of all possible remote systems  they are built to use the standard interface. Second  TELNET  include a mechanism  that allows  the client  and server to negotiate options   and it provides a set of standard  option (  e ,g one of the option controls whether data passed across the connection uses the standard7 bit ASCII  character set  or an 8 bit  character set). Finally TELNET treats both ends  of eh connection symmetrically. In particular. TELNET does not  force client input  to come from a keyboard  not does  it force the client to display output  on a screen. Thus TELNET  allows  an arbitrary program  to become  a client. Furthermore either  end can negotiate options.