**** Columbia Network Research Center Seminar ****

Title:    On The Impact of Aggregation on The Performance
          of Traffic Aware Routing
Speaker:  Prof. Roch Guerin
          UPenn
When:     February 28, 2001 - 10 am
Where:    Interschool Lab, CEPSR Building, 7th floor
          Columbia University
          Refreshments will be served

This talk discusses the impact of traffic aggregation on the performance
of routing algorithms that incorporate traffic information.  The focus
is on two main issues.  Firstly, we explore the relationship between the
average performance of the network and the level of granularity at which
traffic can be assigned to routes.  More specifically, we are interested
in how average network performance improves as the ability of the
routing protocol to split traffic arbitrarily across multiple paths in
the network increases.  Secondly, we focus on the impact of traffic
aggregation on short-term routing behavior.  In particular, we explore
the effects of traffic aggregation on traffic variability, which
directly affects short-term routing performance.  Our analysis is based
on traffic traces collected from an operational network.  The results of
this study provide insights into the cost-performance trade-offs
associated with deploying routing protocols that incorporate traffic
awareness.

This is joint work with A. Sridharan (U. Penn), S. Bhattacharyya,
C. Diot, J. Jetcheva, and N. Taft (all from Sprint Labs).

Roch Guérin received the ``Diplôme d'Ingénieur'' from the École
Nationale Supérieure des Téléecommunications, Paris, France, in 1983,
and his M.S.  and Ph.D.  from the California Institute of Technology,
both in Electrical Engineering, in 1984 and 1986 respectively.  He
joined the department of Electrical Engineering of the University of
Pennsylvania in 1998, where he is the Alfred Fitler Moore Professor of
Telecommunications Networks.  Before joining the University of
Pennsylvania, he was with the IBM Thomas J.  Watson Research Center,
Yorktown Heights, New York, where he was managing the Network Control
and Services department when he left.  His current research interests
are in the general area of Quality-of-Service support in high-speed
networks, and in particular QoS routing, scheduling, and buffer
management mechanisms.  He is also interested in service verification
issues and service aggregation techniques for scalable service
deployment.

Dr.  Guérin is the editor of the ACM SIGCOMM Computer Communication
Review, an editor for the Journal of Computer Networks, and an area
editor for the IEEE Communications Surveys.  He was guest editor of a
JSAC issue on Internet QoS published in December 2000.  He has also been
an editor for the IEEE/ACM Transactions on Networking, the IEEE
Transactions on Communications, and the IEEE Communications Magazine. 
He was the chair for the IEEE Technical Committee on Computer
Communications from 1997 to 1999, and was elected a member-at-large of
the Board-of-Governors of the IEEE Communications Society in 1999.  He
served at the General Chair for the IEEE INFOCOM'98 conference, and will
be the Technical Program co-chair of th ACM SIGCOMM'2001 conference.  He
was the Program Chair of the First IEEE/Russian POPOV Society Conference
on Internet Technologies and Services held in Moscow in October 1999,
and has been active in the organization of many other conferences and
workshops.  In 1994 he received an IBM Outstanding Innovation Award for
his work on traffic management in the BroadBand Services Network
Architecture.  His email address is:  guerin@ee.upenn.edu.