TELNET: Advantages and Disadvantages

This page explores the advantages and disadvantages of TELNET. It details both the benefits and drawbacks of using TELNET.

What is TELNET?

TELNET, short for teletype network, allows users to connect to and log on to other hosts on a network from their computer using login credentials (username and password).

Introduction:

• Telnet uses the TCP protocol for connections.
• The Telnet service operates on port 23 of the host machine.
• The Telnet client acts as a terminal, accepting keystrokes from the keyboard, interpreting them, and displaying output on the screen.

When a client computer makes a TCP connection to port 23 of a host machine, the Telnet server answers. The Telnet server interacts with applications on the host machine and aids in the terminal emulation process.

• Once a connection is established, both ends of the TELNET connection are assumed to originate/terminate at the NVT (Network Virtual Terminal). The NVT is a network-wide terminal and is host-independent. Therefore, neither the server nor the client in the connection needs to maintain information about each other’s terminal characteristics, as they both perceive each other as an NVT terminal.
• Telnet is used to run command-line programs, shell commands, scripts, and batch files over a telnet connection.

Benefits or Advantages of TELNET

The following are the benefits or advantages of TELNET:

• It can be used to send and receive information.
• It aids in the administration of network elements.
• It supports user authentication.
• All Telnet clients and servers implement a Network Virtual Terminal (NVT).
• Automation test facilities are used by remote computers on a shared basis. This reduces costs by centralizing costly test equipment/facilities at selected locations for all users across the world.

Drawbacks or Disadvantages of TELNET

The following are the drawbacks or disadvantages of TELNET:

• User IDs and passwords are transmitted without encryption. This poses a security risk in the Telnet protocol, as eavesdropping and snooping are easier for intruders or hackers.
• It’s not possible to run GUI-based tools over a Telnet connection because it is a character-based communication tool. It cannot transmit cursor movements or other GUI information.
• It is a very inefficient protocol.
• Each keystroke requires several context switches before reaching the other end.
• It is expensive due to slow typing speeds.