Simulation-Based Comparisons of Solutions for TCP Packet Reordering in Wireless Networks

The objective of this paper is two-fold. First, we compare the performance, through computer simulations, of some solutions for TCP packet reordering in wireless networks. Second, we present an alternative method to improve the connection goodput in wireless networks through link-layer retransmissions and applying the solutions to TCP packet reordering. Some link-layer retransmission approaches do not attempt to maintain in-order packet delivery. This leads to some segments, which belong to the same TCP flow, to arrive at their destination out of order. Thus, the problem of high channel error rates in wireless networks becomes the problem of packet reordering due to link-layer retransmissions. We performed a simulation study to evaluate the performance of four solutions for TCP packet reordering, namely, RR-TCP, TCP-DCR, TCP-DOOR, and TCP-PR, under the scenarios of an infrastructure-based wireless network and a multi-hop wireless network. We also compared them with SACK TCP and TCPW. Our simulation study reveals that TCP-PR outperforms all of the other five algorithms, enjoying a greater connection goodput and fewer false fast retransmissions.