The receiver waits
until its network layer passes in the next data packet. The delayed acknowledgement is then
attached to this outgoing data frame. This technique of temporarily delaying the acknowledgement so
that it can be hooked with next outgoing data frame is known as piggybacking.
Piggybacking is a
technique used for efficient utilization of bandwidth. The acknowledgment for
previous segment is sent along with the data request/transfer of current
segment.