Ramana Kompella - Systems and Networking Group - UC San Diego

Ramana Kompella
9168 Regents Rd, Phone: 858-453-5992
Apt B,
Email: ramana@cs.ucsd.edu
La Jolla, CA 92037.
Homepage: http://sysnet.ucsd.edu/∼rkompell
Education
University of California, San Diego
•
Ph.D., Computer Science and Engineering
– Advisors: Prof. George Varghese and Prof. Alex C. Snoeren
– Thesis: Fault localization and measurement in backbone networks
La Jolla, CA
Jan 2003 - Jun 2007 (expected)
Stanford University
Stanford, CA
•
M.S., Computer Science and Engineering Sept 1999- Jun 2001
– Advisor: Prof. Nick Mckeown
– Research topic: High-speed packet buffers
Indian Institute of Technology (IIT)
Bombay, India
•
B.Tech., Computer Science and Engineering Jul 1995- Apr 1999
– Advisor: Prof. S.S.S.P. Rao
– Thesis: Algorithms and architectures for packet classification.
Research Interests
Fault Localization, Measurement and Security, Router Architectures, Wireless and Sensor Networks.
Research Experience
UC San Diego
•
Graduate Student Researcher in Computer Science & Engg. Department
La Jolla, CA
Feb 2004 - Present
Scalable measurement architecture. In ongoing research, I am designing an architecture in which
end-to-end measurements are composed from individual link- and router-level passive measurements. Each
router keeps track of measurements such as delay, loss, available bandwidth, etc., along internal forwarding
paths (e.g., from a given ingress to egress router interface), and also measurements across router-to-router
links. Together, these measurements can be used to compute for all the end-to-end paths. Using this
approach, we remove the need for active measurements that inherently interfere with the very metrics they
attempt to measure and also suffer from O(n 2 ) scalability problem, where n is the number of measurement
end-points.
Scalable router functions. I have worked on the design and implementation of many scalable primitives
for various router functions such as measurement, monitoring and fair queuing. For scalable DoS attack
detection and monitoring, I have devised a data-structure that detects protocol incompletion attacks (e.g.,
Syn flooding, scanning) in the network with only a small amount of high-speed memory [5,7]. I have also
designed a measurement primitive that uses a variety of sampling techniques to independently tune memory,
CPU and reporting bandwidth requirements of a router even in the presence of adversarial traffic mixes [6].
Cooperative scheduling in wireless networks. In this research project, I have designed and architected
a cooperative scheduling protocol that allows multiple wireless nodes to share the wireless channel according
to a globally consistent scheduling policy [9-12]. For example, if a video streaming server and a laptop are
sharing wireless access in a home network environment, the scheduling policy could be to give the video
streaming server all the bandwidth it requires with the remaining given to the laptop. Such policies are

difficult to implement using current 802.11 a/b/g wireless devices. The cooperative scheduling protocol uses a
novel 2 1 2
stage pipeline architecture. In this architecture, nodes estimate their traffic requirements, then
exchange this information to agree on a transmission schedule (in terms of number of packets each node can
transmit within the given time frame). However, the channel access itself is regulated through the normal
distributed coordination function (DCF) of the 802.11 protocol.
AT&T Labs - Research
Florham Park, NJ
•
Summer Intern Jun 2004 - Sep 2004 and Jun 2005 - Sep 2005
Fault localization. Faults are common in backbone networks; fast and accurate fault localization is critical
for both reliability as well as manageability of the network. I have developed a general risk-modeling
methodology that relies on creating dependencies between observable symptoms and likely root-causes [1]. In
this methodology, we apply inference algorithms to output a compact and accurate set of root-causes for a
given set of observed symptoms. Using this methodology, I have built two systems—link- and path-fault
localization systems—that have been deployed in a large tier-I network for over a year.
Stanford University
Stanford, CA
•
Member of High-Performance Networking group Jan 2000 - Jun 2001
Fast packet buffers. All packet switches and routers require packet buffers to hold packets during
temporary episodes of congestion. As a typical rule of thumb, a buffer size of approximately link speed times
the round-trip time is used in these switches and routers. As link speeds increase to OC-768 (40 Gbps) and
beyond, current SRAM memories are technologically infeasible while DRAM memories are too slow to handle
packet read/writes at wire-speed. In our architecture, we propose a way to combine the DRAM and SRAM
memories such that the hybrid memory architecture operates at SRAM speeds but with DRAM capacities
[13,14]. Moreover, our architecture provides deterministic worst case as opposed to statistical guarantees
other approaches provide. The work resulted in a company called Nemo Systems acquired by Cisco Inc., in
May 2005.
Industry Experience
Chelsio Communications Inc.
Sunnyvale, CA
•
Member of Technical Staff Dec 2002 - Jan 2004
Hardware TCP engine. At Chelsio, I worked on a 10Gbps TCP hardware engine as an ASIC design and
verification engineer. I designed and implemented modules (in Verilog) for performing direct data placement
and remote DMA (using ISCSI and IWARP standards) after terminating TCP sessions in hardware. In
addition, I also invented novel algorithms for performing fast flow identification using a combination of
hashing and TCAMs instead of using TCAMs alone.
SwitchOn Networks Inc. (acquired by PMC-Sierra Inc.)
Santa Clara, CA
•
Design Engineer Mar 2000 - Oct 2001
Packet classification processor. I was part of the team that designed and architected a flexible platform
to perform high speed packet classification called ClassiPI. ClassiPI employed an SIMD (single instruction
multiple data) architecture for performing parallel matching of packet classification rules. However, unlike
power-hungry TCAMs, the architecture effectively combined decision trees and hardware parallelism to
reduce the power consumption while remaining comparable to TCAM’s performance. The architectural
details of ClassiPI can be found in the paper I have co-authored with colleagues [16]. The algorithms I have
invented have also resulted in two patents (nos. 6,691,168 and 7,043,494).
Teaching Experience
UC San Diego
La Jolla, CA
•
CSE 123A Sep 2006 - Dec 2006
– TA for the under-graduate course on computer networks.
– Lead discussion sections on both covered as well as additional lecture material.

Stanford University
Stanford, CA
•
CS 244 Jan 2000 - Mar 2000
– TA for the graduate course on computer networks.
– Lead discussion sections and homework reviews.
Publications
Fault Management in Large Scale Networks
1. Ramana Rao Kompella, Alex C. Snoeren, Jennifer Yates, Albert Greenberg, “Fault Localization via Risk
Modeling”, under review in IEEE/ACM Transactions on Networking (ToN).
2. Ramana Rao Kompella, Alex C. Snoeren, Jennifer Yates, Albert Greenberg, “Detection and Localization of
Network Blackholes”, to appear in IEEE Infocom, Alaska, USA, April 2007 (Infocom 2007).
3. Ramana Rao Kompella, Albert Greenberg, Jennifer Rexford, Alex C. Snoeren, Jennifer Yates, “Cross-layer
visibility as a Service”, in the Proceedings of Fourth ACM Workshop on Hot Topics in Networks, College
Park, MD, Nov 2005 (HotNets 2005).
4. Ramana Rao Kompella, Jennifer Yates, Albert Greenberg, Alex Snoeren, “IP Fault Localization via Risk
Modeling”, in the Proceedings of the 2nd Symposium on Networked Systems Design and Implementation,
Boston, May 2005 (NSDI 2005).
Scalable Router Functions (Security, Scheduling, Measurement)
5. Ramana Rao Kompella, Sumeet Singh, George Varghese, “On scalable attack detection in the Network”, to
appear in IEEE/ACM Transactions on Networking, April 2007 (ToN 2007).
6. Ramana Rao Kompella, Cristian Estan, “The Power of Slicing in Internet Flow Measurement”, in
Proceedings of ACM/USENIX Internet Measurement Conference, Berkeley, CA, October 2005 (IMC 2005).
7. Ramana Rao Kompella, George Varghese, “Detecting DoS attacks in the Network”, in Proceedings of the 2nd
ACM/USENIX Internet Measurement Conference, Taormina, Sicily, Italy, October 2004 (IMC 2004).
8. Ramana Rao Kompella, George Varghese, “Reduced state Fair Queuing for Core and Edge routers”, in
Proceedings of the 14th ACM International Workshop on Network and Operating Systems Support for
Digital Audio and Video, Kinsale, County Cork, Ireland, June 2004 (NOSSDAV 2004).
Wireless and Sensor Networks
9. Ishwar Ramani, Ramana Rao Kompella, Sriram Ramabhadran, Alex C. Snoeren, “Efficient Cooperative
Scheduling in 802.11 Wireless Networks”, UCSD Technical Report CS2005-0830, La Jolla, CA, July 2005
(UCSD TR 2005)
10. Ramana Rao Kompella, Sriram Ramabhadran, Ishwar Ramani, Alex C. Snoeren, “Cooperative Scheduling
via pipelining in 802.11 Wireless Networks”, in the Proceedings of ACM SIGCOMM Workshop on
Experimental Approaches to Wireless Network Design and Analysis, Philadelphia, PA, August, 2005
(SIGCOMM E-WIND 2005).
11. Ramana Rao Kompella, Alex C. Snoeren, “Practical Lazy Scheduling in Wireless Sensor Networks”, in
Proceedings of the First Conference on Embedded Sensor Systems, November 2003, Los Angeles, California,
USA (SENSYS 2003).
12. Ramana Rao Kompella, Alex C. Snoeren, “SPARTA : Scheduled Rate and Power Adaptation in Wireless
Networks”, Extended Abstract in ACM SIGCOMM, August 2003, Karlsruhe, Germany (SIGCOMM 2003).
Deterministic Memory Designs for High Performance Routers
13. Sundar Iyer, Ramana Rao Kompella, Nick McKeown, “Designing Buffers for Router Line Cards”, Stanford
University HPNG Technical Report, TR02-HPNG-031001, Stanford. Also under review in IEEE/ACM
Transactions on Networking, Nov, 2002 (ToN 2002).

14. Sundar Iyer, Ramana Rao Kompella, Nick McKeown, “Analysis of Memory Architecture for Fast Packet
Buffers ” in the IEEE Workshop on High Performance Switching and Routing, Dallas, May 2001 (HPSR
2001).
15. Sundar Iyer, Ramana Rao Kompella, Nick McKeown, “Techniques for Fast Packet Buffers”, Gigabit
Networking Workshop, Anchorage, Alaska, April, 2001 (GBN 2001).
Packet Classification Architectures
16. Sundar Iyer, Ramana Rao Kompella, Ajit Shelat, “ClassiPI : An Architecture for Fast and Flexible Packet
Classification”, in IEEE Network Special Issue on Fast IP Packet Forwarding and Classification for Next
Generation Internet Services”, March-April 2001 (IEEE NETWORK 2001).
Presentations and Posters
1. “Cross-layer visibility as a Service”, presentation in Fourth ACM Workshop on Hot Topics in Networks,
College Park, MD, Nov 2005 (HotNets 2005).
2. “The Power of Slicing in Internet Flow Measurement”, presentation in ACM/USENIX Internet Measurement
Conference, Berkeley, CA, October 2005 (IMC 2005).
3. “Cooperative Scheduling via pipelining in 802.11 Wireless Networks”, presentation in ACM SIGCOMM
Workshop on Experimental Approaches to Wireless Network Design and Analysis, Philadelphia, PA, August,
2005 (SIGCOMM E-WIND 2005).
4. “IP Fault Localization via Risk Modeling”, presentation in the 2nd Symposium on Networked Systems Design
and Implementation, Boston, May 2005 (NSDI 2005).
5. “Detecting DoS attacks in the Network”, presentation in 2nd ACM/USENIX Internet Measurement
Conference, Taormina, Sicily, Italy, October 2004 (IMC 2004).
6. “Reduced state Fair Queuing for Core and Edge routers”, presentation in 14th ACM International Workshop
on Network and Operating Systems Support for Digital Audio and Video, Kinsale, County Cork, Ireland,
June 2004 (NOSSDAV 2004).
7. “Practical Lazy Scheduling in Wireless Sensor Networks”, presentation in the First Conference on Embedded
Sensor Systems, November 2003, Los Angeles, California, USA (SENSYS 2003).
8. “SPARTA : Scheduled Rate and Power Adaptation in Wireless Networks”, Poster presentation in ACM
SIGCOMM, August 2003, Karlsruhe, Germany (SIGCOMM 2003).
Patents (Pending and Issued)
1. “IP Fault Localization via Risk Modeling”, with Jennifer Yates, Alex C. Snoeren, Albert Greenberg, (Pending
- Filed Nov 2005).
2. “Fast, Deterministic Exact Match Look-ups In Large Tables”, with Deepali Joshi, Ajit Shelat, Amit
Phansalkar, Sundar Iyer and George Varghese, (Patent No. 7,043,494 - issued May 9, 2006).
3. “Method and Apparatus for High-Speed Network Rule Processing”, with Sundar Iyer, Moti Jiandani, Ajit
Shelat et al, (Patent No. 6,691,168, issued Feb 10, 2004).
4. “Implementing Lookup Methods, with bounded deterministic delay, using only content addressable memory
and hashing techniques”, with Asgeir Eiriksson, Chelsio Communications Inc. (Pending - Filed Jun 2002).
5. “Algorithm and Design for Deterministic Route Lookups”, with Sundar Iyer, Ajit Shelat, George Varghese,
PMC Inc., (Pending - Filed Jul 2001).

Awards and Grants
• Graduate Student Researcher position since January 2003.
• Travel grant to present poster in ACM SIGCOMM 2003, Karlsruhe, Germany.
• Travel grant to visit ACM NOSSDAV 2004, Kinsale, Ireland.
• Travel grant to visit ACM/USENIX NSDI 2005, Boston, MA.
• Top 0.07% among more than 100,000 examinees in the Joint Entrance Examination (JEE) for entrance into
the Indian Institutes of Technology (IIT).
Professional activities
• Program Committee Member of Mock SIGCOMM 2006 held at University of California, San Diego, April
2006.
• Reviewer for major networking and systems conferences including ACM SOSP, ACM/USENIX NSDI,
USENIX OSDI, ACM SIGCOMM, IEEE ICC, IEEE Infocom, IEEE/ACM Transactions on Networking,
IEEE Transactions on Dependable and Secure Computing.
References
Prof. George Varghese
Professor, Dept. of Computer Science and Engineering,
University of California, San Diego,
EBU3B 3130
9500 Gilman Drive, M/C 0404
La Jolla, CA 92093-0404
Email: varghese@cs.ucsd.edu
Phone: (858) 822 0424
Prof. Alex C. Snoeren,
Assistant Professor, Dept. of Computer Science and
Engineering,
University of California, San Diego,
EBU3B 3114
9500 Gilman Drive, M/C 0404
La Jolla, CA 92093-0404
Email: snoeren@cs.ucsd.edu
Phone: (858) 822 2289
Dr. Albert Greenberg
AT&T Labs - Research
Room A161; Building 103
180 Park Avenue
Florham Park, NJ 07932
Email: albert.greenberg@hotmail.com
Phone: (201) 404 4756
Dr. Jennifer Yates
AT&T Labs - Research
Building 103
180 Park Avenue
Florham Park, NJ 07932
Email: jyates@research.att.com
Phone: (973) 360 7036