Correlation Analysis of Data Rate and Router Buffer Size on TCP Performance using OPNET Simulator

TCP/IP is a dynamic window based protocol that is used over the Internet. Its widely use is mainly based on its high dynamic nature of adaptability to any kind of network capacity. Since the development of TCP as an internet standard, special attention has been drawn to its behaviour over different network environment. Many TCP performance studies have been conducted on single TCP connection and multiple TCP connections through a sequence of finite router buffer capacity and data rates. However, the result of these works on TCP performance behaviour cannot be generalized because performance of TCP is dependent of the network environment. Each network environment has set of network elements, and application traffics generated at a particular period of time. Therefore, it becomes necessary to study the performance of TCP behaviour in any kind of network environment. Particularly, in a network environment of multiple TCP connections with UDP traffic flows. The paper studied the state of TCP behaviour in a network environment that establishes multiple TCP connections with UDP traffic flows, over a limited router buffer size and wireless link data rate. Using selected test cases, performance matrix of interest are observed, the reason for the unwanted behaviour are identified and estimate alternatives to avoid the problematic behaviour were identified.