Thursday March 28, 2002
Noon - 1:00 p.m.
Wean Hall, 8220
DVSR: A High-Performance Protocol to Tame the
The Resilient Packet Ring (RPR) standard is under development as a new
technology for high-speed metropolitan backbone networks. A key performance
objective of RPR is to simultaneously achieve high utilization, spatial
reuse, and fairness, an objective not achieved by current technologies
such as SONET and (Metro) Gigabit Ethernet nor by legacy ring technologies
such as FDDI. The core technical challenge for RPR is the design of a
bandwidth allocation algorithm that dynamically achieves these three properties.
The difficulty is in the distributed nature of the problem - that upstream
ring nodes must
inject traffic at a rate according to congestion and fairness criteria
downstream. Unfortunately, the proposed algorithms in the current draft
standards have a number of critical limitations that result in permanent
wide-ranging oscillations, throughput loss, and slow convergence. In this
talk, I will describe the technological challenges and goals of networking
at the "metro-edge". Moreover, I will introduce Distributed
Virtual-time Scheduling in Rings (DVSR), a new bandwidth allocation algorithm
for packet rings that overcomes the limits of state-of-the-art protocols.
Finally, I will present the results of our implementation and measurement
study on a Gb/sec network processor testbed.
Ed Knightly received the B.S. degree from Auburn University in 1991, the
M.S. degree from the University of California at Berkeley in 1992, and
the Ph.D. degree from the University of California at Berkeley in 1996.
Since 1996, he has been an assistant professor in the ECE/CS Departments
at Rice University. He is an editor of the Computer Networks Journal,
IEEE/ACM Transactions on Networking, IEEE Transactions on Multimedia,
and previously, IEEE Network Magazine. He served as co-guest editor of
IEEE Network Magazine's special issue on integrated and differentiated
services for the Internet. He served as co-chair and on the steering committee
for IWQoS, as the finance chair for MOBICOM, and on the program committee
for numerous networking conferences including INFOCOM, IWQoS, MOBICOM,
and SIGMETRICS. He received the National Science Foundation CAREER Award
in 1997 and the Sloan Fellowship in 2001. His research interests are in
the areas of quality-of-service, scheduling, admission control, and media
access protocols in wireless and wireline networks.
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