Abstract

Despite the larger performance and higher throughput compared to transmission control protocol (TCP) Reno, TCP Vegas still has a few obstacles to be deployed in new networks, such as 4G LTE systems (4th Generation, Long term evolution). One of these obstacles is the Vegas congestion control that is not used in all available bandwidth capacity of the network path and which causes minimization in packet quantity transferred from source to destination. However, many researches have shown unfair treatment of TCP Vegas connections when they compete with Reno connections. So, Vegas need more developments and more modifications to be efficient over bidirectional links with unbalanced traffic, and on wireless links. TCP-Vegas is a congestion control algorithm that reduces queuing and packet loss, and thus reduces latency and increases overall throughput, by carefully matching the sending rate to the rate at which packets are successfully being drained by the network. This paper presents results from a series of simulation experiments designed to study TCP Vegas performance in LTE network model using NS-2 network simulator. The characterization and analysis of Vegas behavior performed using the main two parameters, alpha and beta, to configure the congestion window (cwnd) phases. After used multiple values, the configuration results show that TCP Vegas perform better than TCP Reno.

Key words: Transmission control protocol; TCP-Vegas, cwnd, long term evolution (LTE), NS-2.