Multiplexing
- Multiplexing (or muxing) is a way of sending multiple signals over a single communications link at the same time in the form of a single.
- OR it can be defined as "To combine multiple signals (analog or digital) for transmission over a single line or media."
- A common type of device combines several low-speed signals for transmission over a single high-speed connection.
- Multiplexing is done by using a device called multiplexer (MUX) that combines n input lines to generate one output line i.e. (many to one).
- Therefore multiplexer (MUX) has several inputs and one output.
- At the receiving end, a device called demultiplexer (DEMUX) or (demuxing) is used that separates signal into its component signals. So DEMUX has one input and several outputs.
- The receiver recovers the separate signals, a process called demultiplexing (or demuxing).
- The technique to combine two or more data streams in one session is called Multiplexing. When a TCP client initializes a connection with Server, it always refers to a well-defined port number which indicates the application process.
- The client itself uses a randomly generated port number from private port number pools.
- Using TCP Multiplexing, a client can communicate with a number of different application process in a single session.
- For example, a client requests a web page which in turn contains different types of data (HTTP, SMTP, FTP etc.) the TCP session timeout is increased and the session is kept open for longer time so that the three-way handshake overhead can be avoided.
- This enables the client system to receive multiple connection over single virtual connection. These virtual connections are not good for Servers if the timeout is too long.
