Remote login however uses simple desktop sharing software to give you “remote control”.

For accessing your computer and all of its software and hard drive files from any internet connected device anywhere in the world.

Remote login works exactly the same way as desktop sharing.

In desktop sharing there are two separate parties.

The host computer and remote user to share desktop.

The host computer allows a remote user to view the content of the host computer’s desktop over the internet.

The host computer can also hand over keyboard and mouse controls to the remote user.

With remote login your home or work computer is the host and you are the remote user.

Principle of NVT

The NVT has a “Printer” (or display) and keyboard.

The keyboard produces outgoing data which is sent over the Telnet connection.

The basic characteristics of an unless they are modified by mutually agreed option are:

• The data representation is 7 bit ASCII transmitted in 8 bit bytes.

• NVT is a half duplex device operating in a line buffered mode.

• The NVT provides a local echo function.

• In Time-sharing environment, When a user wants to access an application program or utility located on a remote machine, then it is called Remote Login. The TELNET client and server programs are used.
• The mechanism to access a remote computer is complex. This is because every computer and its operating system accepts a special combination of characters as tokens. For example, the end-of-file token in a computer running the DOS operating system is Ctrl+z, while the UNIX operating system recognizes Ctrl+d.
• TELNET solves this problem by defining a universal interface called the Network Virtual Terminal (NVT) character set.

• Via this interface, the client TELNET translates characters (data or commands) that come from the local terminal into NVT form and delivers them to the network.
• However, the characters cannot be passed directly to the operating system because the remote operating system is not designed to receive characters from a TELNET server: It is designed to receive characters from a terminal driver. The solution is to add a piece of software called a pseudoterminal driver, which pretends that the characters are coming from a terminal. The operating system then passes the characters to the appropriate application program.
• The server TELNET translates data and commands from NVT form into the form acceptable by the remote computer.