Advantages of Piggybacking | disadvantages of Piggybacking
This page covers advantages and disadvantages of Piggybacking in data communication. It mentions benefits or advantages of Piggybacking and drawbacks or disadvantages of Piggybacking.
What is Piggybacking?
The process of carrying the acknowledgement along with the data on the same channel is known as piggybacking. Let us understand how it works with following example of two users communicating with each other.
In data communication, transmitter transmits the data packet and waits for acknowledgement from the other end before it
starts transmitting the next packet. This can be achieved in two ways as follows.
Method #1 : There will be two separate channels, one channel is used for transmission of data in forward direction and the other channel is used for transmission of ACK in the reverse direction.
Method #2 : There will be single channel used for transmission of data/ACK but one at a time.
The method #1 reduces bandwidth efficiency by utilizing entire channel for ACK. Moreover method #2 introduces delay between successive packet or frame transmissions.
The above mentioned drawbacks are avoided by transmitting ACK along with data packet. Hence problems encountered in both the methods can be avoided.
Benefits or advantages of Piggybacking
Following are the benefits or advantages of Piggybacking:
➨It offers efficient use of available channel bandwidth. It saves bandwidth to greater extent. In first method above, both the channels between A and B can be used for data + Ack transmission/reception.
➨The transmitter (say A) need not have to wait for ACK separately as it receives previous packet's ACK along with next data packet from the other end (say B). This improves latency of data transfer between A and B.
Drawbacks or disadvantages of Piggybacking
Following are the drawbacks or disadvantages of Piggybacking:
➨It increases additional system complexity.
➨The more delay in waiting for ACK by data link layer often leads to retransmission of the packet.