Piggybacking is a concept used in computer to enhance communication between devices. In piggybacking concept sender sends a user data packet with the acknowledgement (ACK) if an acknowledgement (ACK) is going in the same direction. In a real example, if someone is going in the same direction as you want to go then you can ask for the lift by which there will be so many advantages like reduction in the road traffic, lesser pollution, etc. In the same way, piggyback also work.
In the piggybacking technique, the receiver acknowledges the reliability of communication. Efficient usage of available channel bandwidth is the main advantage of piggybacking technique.
How does piggybacking work
To explain how piggybacking work we are going suppose there are two computers over an IP network, computer A and computer B. They are communicating with each other with a reliable Stream Control Transmission Protocol (SCTP) protocol. Computer A has sent a data packet and now waiting for acknowledgement from computer B. Computer B will wait for some time to receive the data packet and then send the user data and acknowledgement in a single network message. In case there is no piggybacking supported then computer B will only send an acknowledgement. This technique saves bandwidth but increases the timing of the process.
Advantages and disadvantages of piggybacking
The main advantage of piggybacking is a better use of bandwidth. The cost get reduces if someone is paying to use a network based on messages. With the piggybacking technique the underlying cable and router, intermediate switches, etc. will become less loaded.
The main disadvantage of piggybacking is blocking of acknowledgement for some time. By blocking the acknowledgement connection can be slow down or may cause a service problem. Piggybacking use a very small duration timer to avoid this type of situation.