Loss-free Smoothing of Constant Bit Rate Flows
		   in Connection-Oriented Networks

Khosrow Sohraby
Computer Science Telecommunications
University of Missouri - Kansas City

Constant Bit Rate (CBR) traffic is expected to be an important traffic
source in high-speed networks. Such sources usually have stringent delay
and loss requirements and in many cases, they should be delivered exactly
as they were generated.

In this talk, we examine networks consisting of number of nodes. We
carefully examine the individual flows in the network showing that they
satisfy a certain bounding property which can be used to determine the
minimum smoothing delay and smoothing buffer in guranteeing loss-free
play-out of individual flows.  The smoothing buffer plays-out the flows
periodically as they were generated at the entry to the network.

In a homogeneous environment, where the period of all the flows are the
same, we show a smoothing delay equal to the period of flows and a
play-out buffer of at most two cells (packets) is sufficient to avoid
buffer underflow and overflow.  This holds independently of the number of
CBR nodes in the network.  In a heterogeneous environment, we provide
simple and efficient algorithms for the determination of the parameters of
the smoothing buffer.

=========================== Bio of Khosrow Sohraby =====================
KHOSROW SOHRABY
received B.Eng and M.Eng degrees from McGill University, Montreal, Canada
in 1979 and 1981, respectively, and Ph.D degree in 1985 from the
University of Toronto, Toronto, Canada, all in Electrical Engineering.
His current research interests include design, analysis and control of
High Speed computer and communications networks, traffic management and
analysis, multimedia networks, networking aspects of wireless and mobile
communications, and large-scale computations applied to computer and
communications networks.

During 1984-1986 he was a research associate at the L'institute national
de la recherche scientific - INRS Telecommunications, Montreal, Canada. In
1986 he joined AT&T Bell Laboratories, Holmdel, NJ as a Member of
Technical Staff in the Teletraffic Theory and System Performance Analysis
Department. In 1989 he joined IBM T.J. Watson Research Center, Yorktown
Heights, NY as a Research Staff Member in the Communications Systems
Department.  While at IBM research, he was an adjunct faculty at
Polytechnic University and Columbia University in the Department of
Electrical Engineering teaching undergraduate and graduate courses in
telecommunications. He joined the Computer Science Telecommunications
Program at the University of Missouri-Kansas City in 1994 as professor.

Dr. Sohraby has served on the technical program committee of many IEEE
conferences and workshops.  He served as the technical program vice-chair
of IEEE INFOCOM '94 and the technical program chair of IEEE INFOCOM '95
and the chair of 10th Annual IEEE Workshop on Computer Communications.