The throughput degradation of Transport Control Protocol (TCP)/Internet Protocol (IP) networks over lossy links due to the coexistence of congestion losses and link corruption losses is very similar to the degradation of processor performance (i.e., cycle per instruction) due to control hazards in computer design. First, two types of loss events in networks with lossy links are analogous to two possibilities of a branching result in computers (taken vs. not taken). Secondly, both problems result in performance degradations in their applications, i.e., penalties (in clock cycles) in a processor, and throughput degradation (in bits per second) in a TCP/IP network. This has motivated us to apply speculative techniques (i.e., speculating on the outcome of branch predictions), used to overcome control dependencies in a processor, for throughput improvements when lossy links are involved in TCP/IP connections. The objective of this paper is to propose a cross-layer network architecture to improve the network throughput over lossy links. The system consists of protocol-level speculation based algorithms at transport layer, and protocol enhancements at middleware and network layers that provide control and performance parameters to transport layer functions. Simulation results show that, compared with prior research, our proposed system is effective in improving network throughput over lossy links, capable of handling incorrect speculations, fair for other competing flows, backward compatible with legacy networks, and relatively easy to implement.
Bibliographical noteFunding Information:
received the M.Sc. and Ph.D. degrees in electrical engineering from the University of Man- chester, England. Currently he is a professor in the School of Computer Science at the Uni- versity of Oklahoma. He is Co- Editor-in-Chief of Computer Communications Journal, and serves on the editorial boards of IEEE Communications Maga- zine, Telecommunications Sys- tems Journal, Wireless and Optical Networks Journal, and Real Time Imaging Journal. He has guest edited many special issues in various journals, and organized special sessions in conferences. He was technical co-chair of HPSR 2003 and the SPIE Quality of Service over Next-Generation Data Networks Conference (2001, 2002, and 2003). He also serves on the technical program committee of many national and international conferences including IEEE INFOCOM, IEEE GLOBECOM, and IEEE International Conference on Computers and Communication Networks. His current research interests are in wireless, satellite, and mobile networks, QoS for next-generation Internet, broadband networks, multimedia over high -speed networks, TCP/IP over ATM, multiprocessor systems, and image processing. He is a coauthor of the book TCP/IP over ATM Networks. He has taught many short courses to industry in the area of computer and telecommunication networking. His research has been supported by state and federal agencies like NSF, NASA, U.S. Air Force, Ohio Board of Regents, and DITARD (Australia). He has over 130 refereed publications in the above areas, most of which can be accessed at http://www.cs.ou.edu/*atiq.
- Network architecture
- Speculative execution
- Transport control protocol (TCP)
- wireless networks