A communication protocol system is provided for reliable transport of packets. A content addressable memory hardware architecture including an acknowledgment coalescing module in communication with a content addressable memory (CAM). The acknowledgment coalescing module coalesces multiple acknowledgement packets as a single acknowledgement packet to reduce the overall numbers of the packet transmission in the communication protocol system. In addition, the acknowledgment coalescing module may also provide a piggyback mechanism to carry acknowledge information in a regular data packet. Thus, the need to generate a new acknowledgement packet may be eliminated. Accordingly, the network congestion and latency may be reduced, and the communication and transmission efficiency are enhanced.