Experimental study and performance analysis of real time applications over differentiated services capable networks

The research reported in this dissertation, focuses on the delivery of QoS by Differentiated Services enabled networks to MPEG-2 compressed video and Distributed Interactive Virtual Environments (DIVE) applications. Video based services will be among the most popular high-bandwidth applications running in the future through Internet. DIVE based services are emerging as powerful tools for use in distributed simulation environments and are expected to be used in developing applications for the support of several very promising business sectors; among them e-commerce, telelearning/tele-training and networked games. MPEG-2 video and DIVE applications are highly sensitive to delays and losses. Our objectives were to: (i) assess the ability of Differentiated Services networks to support such applications; (ii) determine what algorithms are most suitable; (iii) find where certain algorithmic parameters should be placed for best performance; (iv) identify potential weaknesses and propose solutions. We performed our research by developing a Linux based Differentiated Services capable network, and by conducting extensive sets of experiments and measurements. As the reader will find out, we succeeded in all the objectives. Performance of the applications and network behavior were successfully measured. "Mechanisms", affecting performance in a negative way, were discovered and solutions were proposed. We also demonstrated the ability to provide advanced networking solutions using off-the-self computing equipment (regular PCs) and open source operating systems (Linux in our case). Such low cost solutions could be very beneficial for supporting the needs of small size business and of tomorrow's "intelligent home". (Abstract shortened by UMI.