A simulation-based study of TCP dynamics over HFC networks

New broadband access technologies such as hybrid fiber coaxial (HFC) are li kely to provide fast and cost effective support to a variety of application s including video on demand (VoD), inter-active computer games, and Interne t-type applications such as Web browsing, ftp, e-mail, and telephony. Since most of these applications use TCP as the transport layer protocol, the ke y to their efficiency largely depends on TCP protocol performance. We investigate the performance of TCP in terms of effective throughput in a n HFC network environment using different load conditions and network buffe r sizes. We find that TCP experiences low throughput as a result of the wel l-known problem of ACK compression. An algorithm that controls ACK spacing is introduced to improve TCP performance. (C) 2000 Elsevier Science B.V. Al l rights reserved.