Modeling of TCP Reno with Packet-Loss and Long Delay Cycles

Abstract

The Transport Control Protocol (TCP) is the dominant transport layer protocol in the Internet Protocol (IP) suite, as it carries a significant amount of the Internet traffic, such as Web browsing, file transfer, e-mail, and remote access. Therefore, huge efforts have been devoted by researchers to develop suitable models that can help with evaluating its performance in various network environments. Some of these models are based on analytical or simulation approaches. This chapter presents a description, derivation, implementation, and comparison of two well-known analytical models, namely, the PFTK and PLLDC models. The first one is a relatively simple model for predicting the performance of the TCP protocol, while the second model is a comprehensive and realistic analytical model. The two models are based on the TCP Reno flavor, as it is one of the most popular implementations on the Internet. These two models were implemented in a user-friendly TCP Performance Evaluation Package (TCP-PEP). The TCP-PEP was used to investigate the effect of packet-loss and long delay cycles on the TCP performance, measured in terms of sending rate, throughput, and utilization factor. The results obtained from the PFTK and PLLDC models were compared with those obtained from equivalent simulations carried-out on the widely used NS-2 network simulator. The PLLDC model provides more accurate results (closer to the NS-2 results) than the PFTK model.