Internet Congestion Control

Chapter 4

Congestion Control in Broadband Wireless Networks

This chapter discusses congestion control in broadband wireless networks. This work was motivated by finding solutions to the performance problems that TCP Reno has with wireless links. Because the algorithm cannot differentiate between congestion losses and losses caused by link errors, decreasing the window size whenever a packet is lost has a very detrimental effect on performance. This chapter describes TCP Westwood, which solved this problem by keeping an estimate of the data rate of the connection at the bottleneck node. Thus, when Duplicate ACKs are received, the sender reduces its window size to the transmit rate at the bottleneck node (rather than blindly cutting the window size ...