Title of Dissertation: Supporting Distributed Multimedia Applications on ATM Networks

Title of Dissertation: Supporting Distributed Multimedia Applications on ATM Networks Debanjan Saha, Doctor of Philosophy, 1995 Dissertation directed by: Professor Satish K. Tripathi Department of Computer Science ATM o ers a number of features, such as high-bandwidth, and provision for per-connection quality of service guarantees, making it particularly attractive to multimedia applications. Unfortunately, the bandwidth available at ATM's data-link layer is not visible to the applications due to operating system (OS) bottlenecks at the host-network interface. Similarly, the promise of per-connection service guarantees is still elusive due to the lack of appropriate tra c control mechanisms. In this dissertation, we investigate both of these problems, taking multimedia applications as examples. The OS bottlenecks are not limited to the network interfaces, but a ect the performance of the entire I/O subsystem. We propose to alleviate OS's I/O bottleneck by according more autonomy to I/O devices and by using a connection oriented framework for I/O transfers. We present experimental results on a video conferencing testbed demonstrating the tremendous performance impact of the proposed I/O architecture on networked multimedia applications. To address the problem of quality of service support in ATM networks, we propose a simple cell scheduling mechanism, named carry-over round robin (CORR). Using analytical techniques, we analyze the delay performance of CORR scheduling. Besides providing guarantees on delay, CORR is also fair in distributing the excess bandwidth. We show that albeit its simplicity, CORR is very competitive with other more complex schemes both in terms of delay performance and fairness. Supporting Distributed Multimedia Applications on ATM Networks by Debanjan Saha Dissertation submitted to the Faculty of the Graduate School of The University of Maryland in partial ful llment of the requirements for the degree of Doctor of Philosophy 1995 Advisory Committee: Professor Satish K. Tripathi, Chairman/Advisor Professor Ashok K. Agrawala Assistant Professor Michael Franklin Assistant Professor Richard Gerber Professor Joseph JaJa Professor Armand Makowski c Copyright by Debanjan Saha 1995 Dedication To my parents. ii Acknowledgements I would like to express my earnest gratitude to my advisor, Professor Satish Tipathi, for motivating me to do a Ph.D., arranging for my funding, and supervising this thesis with care and interest. He has been the ideal advisor, one who allowed me to explore the space while providing me with experience and insight which I often lacked. I will always be grateful to him for believing in my abilities and for being on my side at every step of the way. Many thanks to Professor Ashok Agrawala for his support and encouragement. A special thanks to Professor Richard Gerber for his interest in my work and for many exciting and enlightening discussions we had during my stay in Maryland. I thank the members of my thesis committee, Professors Armand Makowski, Joseph JaJa, and Michael Franklin for carefully reading my thesis and making suggestions for improvement. I would like to thank Drs. Dilip Kandlur at IBM Research, Dipak Ghosal at Bellcore, T.V. Lakshman and Hemant Kanakia in AT&T Bell Labs for their help during di erent stages of my dissertation research. A very special thanks goes to Sarit Mukherjee, Pravin Bhagwat, and Manas Saksena for their constructive criticism of my work and for many late night debates which in uenced my brain waves. I am particularly grateful to Jennifer Yuin, Ibrahim Matta, and Krishnan Kailas for reading di erent parts of the thesis and for suggesting numerous improvements. I would like to thank the members of the Systems Design and Analysis Group, particularly Cengiz Alaettinoglu, Sedat Akyurek, Sanjeev Setia, Dheeraj Sanghi, Bao Trinh, Chia-Mei Chen, Partho Mishra, and Frank Miller for creating a wonderful atmosphere for research. Thanks to Nancy Lindley for making my life in the department a lot less complex than it would have been. I would like to thank all my friends, particularly Kateel Vijayananda, Shailendra Verma, Shuvanker Ghosh, Stayandra Gupta, Gagan Agrawal, Kaustabh Duorah, Greg Barato , Sibel Adali, Claudia Rodriguez, and Koyeli Dey, for making my life inside and outside school a lot more fun. Although my parents are on the other side of the Atlantic, they have been a constant source of encouragement. Without their support, this thesis would not have been complete. Finally, I would like to thank a sweet mu n for her love and a ection which will never fade in my memory. iii Table of