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Roch
Guerin Dept. Elec. & Sys. phone: 215 898-9351 |
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Current ·
Recent ·
Past |
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Journals |
Where Do I Come From?
(Short one-page bio
in pdf format)
I grew up in
a suburb of Paris, France, called Saint
Cloud and
went to high school in
I did my undergraduate studies at ENST, Paris, and actually spent my last year in Toulouse in the South-West of France in the Satellite Communications Systems department (don't ask me why, but it was fun). I did my undergraduate thesis on "Jamming Resistant Multiple Access Methods for Satellite Systems."
After finishing my undergraduate studies, I attended Caltech, where I received both my MS (1984) and Ph.D. (1986) from the Electrical Engineering department. My Ph.D. was supervised by Prof. Edward Posner and was entitled "Queueing and Traffic in Cellular Radio" (sorry, no link. That was way too long ago...).
After graduating from Caltech, I joined the IBM T.J. Watson Research Center, where I worked on many aspects related to quality of service in broadband networks for over 12 years. When I left I was the manager of the Network Control and Services department (sample of projects I was involved in while at the IBM T.J. Watson Research Center).
I joined the department of Electrical and Systems Engineering at the University of Pennsylvania in October 1998 as the Alfred Fitler Moore Professor of Telecommunications Networks.
In 2001, I
co-founded Ipsum Networks (now part of Iptivia)
with Raju Rajan, a former colleague from my days at the
I was elected IEEE Fellow in January 2001 and served as a Member-at-Large on the Board of Governors of the IEEE Communications Society until the end of 2002. I was an editor for the IEEE/ACM Transactions on Networking and the IEEE Transactions on Communications, served as the chair of the Technical Committee on Computer Communications of the IEEE Communications Society from 1997 to 1999, and was the General Chair of the IEEE INFOCOM'98 conference.
I became an ACM Fellow in 2006, served as the Editor of the ACM SIGCOMM Computer Communication Review (CCR) until the end of 2001 and returned as an area editor for CCR from 2005 to 2006. I was Program co-Chair of the ACM SIGCOMM'2001 conference and General Chair of the ACM SIGCOMM 2005 Conference, and Program co-Chair, together with Olivier Bonaventure, of the 2007 ACM CoNEXT conference. I have also been on SIGCOMM's Technical Advisory Committee from 2001 till 2005.
I served on the Scientific Advisory Board (Scientific Council) of France Telecom for two consecutive terms from 2001 till 2006, and on Samsung's Technical Advisory Board in 2003 and 2004.
Courses
I Have Recently Taught or Currently Teach
Email
me in case you want access to some of the course material I used, as our course
portal is currently not allowing external access…
· Networking Theory and Fundamentals (TCOM 501 - Spring'04-05): An entry level graduate course on the basic analytical techniques used in the design and modelling of networking systems.
· Advanced Networking Protocols (TCOM 502 – Fall'04, Spring'05-08): An entry level graduate course on a range of protocols and technologies used in networking. The courses covers everything from addressing, to packet forwarding and lookup techniques, to routing protocols for which it provides an in-depth treatment of RIP, EIGRP, OSPF, IS-IS and BGP, as well as a general discussion of multicast protocols ending with a review of PIM-SM and SSM. Topics such as MP-BGP and MPLS/BGP VPNs are also discussed. The course ends with a brief introduction to various efforts for introducing service differentiation in modern networks, and reviews both the underlying mechanisms for enforcing differentiation and the signalling protocols (RSVP and RSVP-TE) used to configure them.
· Introduction to Networks and Protocols (TCOM 400/500 - Fall'05-07): An introductory combined upper level undergraduate and entry level graduate course on networks and protocols. The course introduces the basic mechanisms and technologies involved in enabling modern end-to-end communications with an emphasis on packet networks. The course follows a bottom-up approach roughly along the various layers of the OSI model but focusing primarily on layers present in IP networks, and using examples derived from current network technologies and applications. The course by nature emphasizes breadth over depth in any specific topic, but provides a solid foundation on which students interested in pursuing further studies in networking can build.
General Research Interests
·
My
general area of research is networking, although I have also been looking at a
number of application level issues that arise when applications need to
communicate over a packet network. In the networking area, I still have a couple
of projects related to Quality-of-Service (QoS), with a focus on scalable and
flexible mechanisms that require minimum configuration and interactions between
the network and users. However, in general and in spite, or rather because of
many years investigating QoS topics, I have reached the conclusion that the
large majority of QoS solutions turn out to be more expensive than the
resources they are trying to manage. Hence, the bulk of my current activities
are directed at what I would characterize as “Robust Networking.” What I
mean by that are a set of techniques that allow you to design networks and
network mechanisms that can ensure efficient operation across a broad range of
operational characteristics. For example, in the traffic engineering area, this
means identifying routing schemes that are tolerant of link and node failures
as well as changes in traffic patterns, in the sense that they result in “good”
overall network performance even in the presence of such perturbations. In the
more traditional QoS area, this means devising mechanisms that support service
differentiation across a broad range of traffic characteristics, i.e., are not
heavily dependent on the proper configuration of policers. I am also interested
in extending the concept of robust networking to the wireless setting, where
the combination of greater limitations on resources and the more dynamic nature
of users and of the network infrastructure itself, creates a new set of
problems. One area of recent interest is that of leveraging diversity as a
means for improving robustness in large-scale networks (see the presentation “Size
Does Matter! From the Age of Closed-Loop to the Age of Open-Loop” given at NeXtworking’07 – 2nd
COST-NSF Workshop on Future Internet, April 2007, Berlin, Germany, together
with the accompanying one-page
abstract for additional details).
Current
and Recent Activities in the Multimedia and Networking Lab
The
Multimedia and
Networking Lab has
a number of ongoing projects that typically involve a mixture of analysis and
experiments. The experiments are often carried out using a testbed consisting
of multiple routers, hubs, and switches from different vendors. In particular,
part of the testbed has been built using equipment generously donated by 3COM, IBM, and Lucent. Most of the projects carried out in the lab
are supported through NSF grants, as well as
through additional support from industrial partners such as Sprint Labs, Nortel Networks, and Siemens.
Current Projects
On the Economic
Viability of Network Architectures. This is a joint
project with Prof. Kartik
Hosanagar from the Wharton Business School and Profs. Andrew Odlyzko and Zhi-Li Zhang from the University of
Minnesota, which is funded by NSF under the FIND initiative (NSF grant
CNS-0721610). The project has three main
thrust areas aimed at assessing the economic viability of new network
architectures:
1.
Investigate
and quantify the potential benefits of key proposed architectural features such
as virtualization, integration, and diversity;
2.
Explore
when and why the existence of a formidable incumbent (today’s Internet) can
affect the emergence of new technologies;
3.
Develop
models that account for how the openness and flexibility of a network
architecture can foster the adoption of new technology, and its ultimate
success.
Related
Publications
·
Y.
Jin, S. Sen, R. Guerin, K. Hosanagar, and Z.-L. Zhang, “Dynamics of Competition between
Incumbent and Emerging Network Technologies.” Proc. ACM NetEcon’08, Seattle,
WA, August 2008.
A Framework for
Manageability in Future Routing Systems.
This
is a joint project with the
Related
Publications
·
K.-W.
Kwong, R. Guerin, A. Shaikh, and S. Tao, “Improving Service
Differentiation in IP Networks through Dual Topology Routing.” Proc. ACM CoNEXT'07, New York, NY, December
2007.
·
H.
Peterson, S. Sen, J. Chandrashekar, L. Gao, R. Guerin, and Z.-L. Zhang, “Message-Efficient
Dissemination for Loop-Free Centralized Routing.” ACM Computer Communication Review, Vol. 38,
No. 3, July 2008.
·
S.
Ray, R. Guerin, K.-W. Kwong, and R. Sofia, “Always Acyclic Distributed
Path Computation.” Under submission.
Distributed Uplink Scheduling in CDMA
Networks. This is a project in collaboration with Ashwin Sridharan and partially
funded by Sprint Labs, which explores
issues that arise in CDMA networks when devices (mobiles) are afforded some
level of independence in making transmission decisions, instead of being under
the tight control of a base station.
Giving mobile devices some flexibility in deciding when to transmit and
at what rate is increasingly desirable because of the diversity of applications
they are now capable of running and that exhibit a broad range of communication
requirements. However, allowing devices
to make individually controlled transmission decisions may affect global
system performance, and one of the goals of this project is to explore this
trade-off in a number of different settings.
Related
Publications
·
A.
Sridharan, R. Subbaraman, and R. Guerin, “Distributed Uplink Scheduling
in CDMA Networks.” Proc.
Networking'2007,
Towards
Large-Scale Flat Networks. This is a
project sponsored by and in collaboration with Siemens. Flat networks like Ethernet have many
advantages in terms of simplicity and flexibility, e.g., plug-&-play and
little or no configuration requirements.
However, they suffer from a number of potential scalability
limitations, which have limited the scope of their deployments and promoted the
use of (hierarchical) routed solutions to build large networks, the Internet
being a case in point. This work is not
aimed at replacing the Internet with one big flat network, but it explores
various issues aimed at improving the scalability of flat networks. In particular, it targets two important
factors that affect scalability: (i) reliance on broadcast for address
discovery; and (ii) loop prevention during path changes.
Related
Publications
·
S.
Ray, R. Guerin, and R. Sofia, “A Distributed Hash Table
based Address Resolution Scheme for Large-scale Ethernet Networks.” Proc. ICC’07,
·
S.
Ray, R. Guerin, and R. Sofia, “Distributed Path Computation
without Transient Loops: An Intermediate Variables Approach.” Proc. ITC’20,
Recent Projects
Data
plane aggregation.
This
work was supported through NSF grant ITR-0085930 and
aimed at developing a better understanding of the relations that exist between
QoS provided as some aggregate level, e.g., a service class as in the
Differentiated Services model, and the actual QoS that individual users experience.
Of particular interest are models that allow explicit evaluation of individual
QoS measures, and their use in identifying characteristics of user traffic that
can result in significant differences between individual and aggregate QoS
measures. This led to the development of
models that allow the evaluation of the loss probability experienced by
individual connections and when and why it differs from the aggregate loss
probability. The environment that is assumed consists of a single FIFO queue
where all the individual users belonging to the same service class are
multiplexed. A separate but related perspective is that of
security, namely, understanding the extent to which a single (or a few) user
can affect the performance of many other users. In that context, we
investigated the extent to which more sophisticated attack schemes can defeat
existing mechanisms, and used that understanding towards developing better
defenses.
Related Publications
·
Y.
Xu and R. Guerin, “Individual QoS versus
aggregate QoS: A loss performance study.” IEEE/ACM Trans. Netw. Vol.
13, No. 2, April 2005. For a short
version, see also the proceedings of INFOCOM'2002, New York, NY, June
2002.
·
Y.
Xu and R. Guerin, “On Evaluating Loss Performance
Deviation: A Simple Tool and Its Practical Implications.” In
Proceedings of 2nd
international workshop on QoS in Multiservice IP Networks (QoS-IP 2003),
Milano, Italy, February 2003.
·
Y.
Xu and R. Guerin, “On the Robustness of
Router-Based Denial-of-Service (DOS) Systems.” ACM Computer
Communication Review, Vol. 35, No. 3, July 2005.
·
Y.
Xu and R. Guerin, “A Double Horizon Defense Design
for Robust Regulation of Malicious Traffic.” In Proceedings
SecureComm 2006, Baltimore, MD, August 2006.