TCP Performance and Behaviors with Local Retransmissions

TCP has been the dominant transport protocol over the global Internet, and its performance over a hybrid wireless/wireline network has attracted much attention in recent years. This paper investigates the end-to-end TCP performance, in terms of normalized throughput, effective goodput, and packet delay, over wireless lossy links with local retransmissions. The results reveal that local retransmissions can increase the normalized TCP throughput in different wireless bandwidth, delay, and error settings, at the cost of a decrease in effective goodput and an increased packet delay. The performance observation is explained by the explored TCP endpoint behaviors, including the spurious timeout and duplicated acknowledgment. Analysis shows that spurious timeouts with local retransmissions are rare due to the conservative TCP timeout algorithm. However, spurious duplicated acknowledgments have negative impact and a further improvement with the D-SACK proposal is evaluated.

• Type: Journal
• Year: 2002
• Where: TJS
• Authors: Jianping Pan, Jon W. Mark, Sherman X. Shen
• Keywords: Local Retransmissions, Packet Delay, Spurious Timeouts, TJS 2002