How network asymmetry affects TCP

Several emerging wireline and wireless access network technologies exhibit asymmetry in their network characteristics. For instance, cable modem netwo rks exhibit significant bandwidth asymmetry, while packet radio networks ex hibit media access asymmetry. A high degree of asymmetry can have an advers e effect on the performance of feedback-based transport protocols. In this article we study the effects of bandwidth and media access asymmetry on the performance of the TCP protocol. We identify the fundamental reasons for t he mismatch between TCP and asymmetric networks, and then present several t echniques to address this problem.