The problem of acknowledgment schemes in store-and-forward packet-switching communication networks is addressed. The performance of systems with end-to-end acknowledgment (ETE Ack) and hop-by-hop acknowledgment (HBH Ack) are compared in terms of packet delay and channel utilization. It is shown that a system with an HBH Ack scheme performs significantly better in terms of delay or channel utilization, when the number of hops that a packet traverses is large and/or when the probability of successful packet transmission over the channel is low.