On the Provision of Scalable Networked Services

			 Mostafa H. Ammar

              The Networking and Telecommunications Group
	               College of Computing
		  Georgia Institute of Technology
		        Atlanta, GA 30332


Networked services are at the heart of the on-going information revolution.
As the demand for these services increases it becomes important for 
a service to be scalable.  That is, a service provider should be able to
handle a large number of users with low per-user cost and still maintain 
good user-perceived service quality.  Our work considers two techniques 
for making a service scalable: 1) the use of group (or multicast) 
communication combined with request batching at the server and 2) the 
use of server replication.  To illustrate our efforts investigating 
the first technique, we will first discuss our work on the provision 
of highly scalable Web service using multicast communication. We also
overview our work in the development of end-to-end protocols for 
multicasting video to a heterogeneous set of receivers.  With the second 
technique, when a service is replicated to improve its scalability, 
the user is faced with the problem of determining the best server 
to access.  We present a summary of our work on the design and 
implementation of the ``anycasting'' communication paradigm to support 
the server location function.



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Biographical Sketch:


Mostafa H. Ammar received his Ph.D. Degree in Electrical Engineering 
from the University of Waterloo in Ontario, Canada, 1985. His
S.M.(1980), S.B.(1978) degrees were acquired in Electrical Engineering and 
Computer Science at the Massachusetts Institute of Technology, 
Cambridge, MA.  Dr. Ammar is currently an Associate Professor in 
the College of Computing at Georgia Tech.  He has been with Georgia Tech
since 1985.  For the years 1980-82 he worked at Bell-Northern Research (BNR), 
in Ottawa, Ontario, Canada, first as a Member of Technical Staff 
and then as Manager of Data Network Planning.

Dr. Ammar's research interests are in the areas of computer network
architectures and protocols, multipoint communication, distributed computing 
systems, and performance evaluation.  He is the co-author of the textbook 
"Fundamentals of Telecommunication Networks," published by John Wiley and Sons.  
Dr. Ammar is the holder of a 1990-1991 Lilly Teaching Fellowship and
received the 1993 Outstanding Faculty Research Award from the College
of Computing. He is a member of the editorial board of 
IEEE/ACM Transactions on Networking and Computer Networks and ISDN Systems 
Journal. He is also the co-guest editor
of an upcoming issue of IEEE Journal on Selected Areas in Communication
on "Network Support for Multipoint Communication".
He is the Technical Program Co-Chair for the 1997 IEEE International
Conference on Network Protocols.

Dr. Ammar is a Senior Member of the IEEE and a member of 
the ACM and a member of the Association of Professional Engineers 
of the Province of Ontario, Canada.