High Bandwidth-delay Product Networks Research Articles

Performance of TCP extensions on noisy high BDP networks

Experiments on high bandwidth delay product (BDP) networks assist in the design and understanding of future global networks. This paper describes the results of experiments with different implementations of TCP on a high speed ATM/SONET network over high delay and noisy channels. Comparisons are also made with host/traffic configurations over various smaller BDP systems, experimental comparisons of three different implementations of TCP; TCP Reno, TCP new Reno, and TCP SACK as a function of bit error rates (BER) and round-trip times (RTT) are presented.

Performance evaluation of TCP extensions on ATM over high bandwidth delay product networks

Practical experiments in a satellite network environment assist in the design and understanding of future global networks. This article describes the practical experiences gained from TCP/IP on ATM networks over a high-speed satellite link and presents performance comparison studies of such networks with the same host/traffic configurations over local area and wide area networks. These comparison studies on the LAN, WAN, and satellite environments increase our understanding of the behavior of high-bandwidth networks. NASA's Advanced Communications Technology Satellite (ACTS), with its special characteristics and high data rate satellite channels, and the ACTS ATM Internetwork (AAI) were used in these experiments to deliver broadband traffic. Network performance tests were carried out using application-level software (Netspec) on SONET OC-3 (155.52 Mb/s) satellite links. Finally, we experimentally study the performance, efficiency, fairness, and aggressiveness of TCP Reno, TCP New Reno, and TCP SACK end hosts on ATM networks over high BDP networks.

Performance evaluation of Forward Error Correction in ATM networks

If the packet loss rate in a network is higher than the loss rate requested by an application, the transport protocol must make up for the difference in loss rate. In high bandwidth delay-product networks the latency introduced by retransmission-based error recovery schemes may be too high for applications with latency constraints. In this case, Forward Error Correction (FEC) can be used. FEC allows recovery from loss without retransmission. The amount of loss recovered strongly depends on the loss behavior of the network. FEC works best if losses are dispersed in time. We use simulation to study the loss behavior of an output buffered multiplexer for three different traffic scenarios. Our results show how the loss behavior of the multiplexer is affected by the traffic mix and the statistics of the sources. The more bursty the sources, the higher the loss rate and the higher the probability that losses will occur in bursts. Based on simulation results, we develop a mathematical model for the performance of FEC and compute the effectiveness of FEC for the three traffic scenarios. FEC is not effective for the two homogeneous traffic scenarios. However, FEC reduces the loss rate for the video sources by several orders of magnitude for a heterogeneous traffic scenario consisting of video and burst sources.

A simulation study of forward error correction in ATM networks

If the packet loss rate in a network is higher than the loss rate requested by an application, the transport protocol must make up for the difference in loss rate. In high bandwidth delay-product networks the latency introduced by retransmission-based error recovery schemes may be too high for applications with latency constraints. In this case, Forward Error Correction (FEC) can be used. FEC allows recovery from loss without retransmission. The amount of loss recovered strongly depends on the loss behavior of the network. FEC works best if losses are dispersed.We use simulation to study the loss behavior of an output buffered multiplexer for three different traffic scenarios. Our results show how the loss behavior of the multiplexer is affected by the traffic mix and the statistics of the sources. The more bursty the sources are the larger the loss rate and the higher the probability that losses will occur in bursts. We then investigate the effectiveness of an FEC scheme that can recover a fixed number of lost packets within a block of consecutive packets. For a heterogeneous traffic scenario consisting of video and burst sources, this scheme reduces the loss rate for the video sources by several orders of magnitude.