A Timestamp based Detection of fast retransmission loss for improving the performance of TCP NewReno over wireless networks

Abstract

NewReno is the most widely deployed TCP protocol in today's internet. When NewReno operates in wireless networks, the performance of NewReno degrades significantly. Frequent retransmission timeout is one of the well-know problems of the performance degradation of TCP NewReno over wireless networks. In wireless networks, a retransmission timeout is unavoidable, when the fast retransmission of a lost packet fails to reach the destination particularly due to the changing level of congestion and bit error rate in wireless channel. There have been many schemes developed for reducing the retransmission timeouts. However, these schemes have no mechanism to detect the loss of fast retransmitted packets. In this paper, we introduce an efficient mechanism based on TCP NewReno, called T-DLRP (Timestamp based- Detection of the Loss of fast Retransmitted Packets) which is able to detect fast retransmission loss and react accordingly without waiting for retransmission timeouts even multiple loss of packets in a single window of data and the loss of its fast retransmission. T-DLRP consists of three schemes, called FRL (Fast Retransmission Loss)-Detection, FRL-Differentiation and Immediate fast recovery. Through extensive simulations using qualnet 4.5, we evaluate the performance of TDRLP and demonstrate that our mechanism achieves 40–90% performance improvement than key existing TCP schemes over wireless networks especially when the network co-existed with packet loss and retransmission losses.