acknowledgment becomes more critical when sending a large amount of information, such as a large data file that was divided into multiple packets for transmission. this is necessary because of the limits set on packet sizes by lower-lever protocols.

in a large network, packets might end up taking different routes to the destination. some might get lost in the process or be delayed and arrive in the wrong order a connection-oriented protocal uses packet sequence numbers to verify packet order and acknowledges the receipt of each packet. the lost or improperly delivered packets, which are not acknowledged as a successful receipt, can be retransmitted.