I was a PhD student
with the Computer Networks Research Group. Since Aug. 2005,
I work at Bell Labs
Research in Bangalore, India
. Before that
I received a BE in CSE from REC (now
NIT), Trichy
in India in 1998, a MS in Computer Systems Engineering
from Boston University and arrived at UMass in
Fall 2000. Here is my CV.
research
measurements-in-the-middle: My thesis research revolves around
the question of how to infer end-to-end properties of a TCP connection
(such as loss and delay) based on passivemeasurements taken
at a single
point in the ``middle'' of the connection's end-end path. Given a
carefully chosen point of
observation, one can observe and analyze millions of TCP connections,
which originate and terminate from a highly diverse crossection of end
points in today's Internet. However this approach also poses several
interesting inference problems since the measurement point has a very
limited view of the end-end path. As part of this work, we have
developed techniques to
identify and classify by cause packets that are
out-of-sequence in a TCP connection, such as retransmissions (indicator of
end-end packet loss), and other anomalies such as packet reorderings, and
replications.
infer and keep track of the round trip time (RTT) of
the TCP connection, an estimate of end-end round trip delay.
infer and track TCP sender properties such as its
congestion window, implementation of the TCP congestion control algorithm and
factors that affect the rate of the connection.
These techniques are implemented in a tool called
tcpflows And the work is described in the
following papers:
AS graph topology: Our work has explored aspects of the
"hierarchical" structure of the Internet graph. Firstly, we have looked
into this in the context of the logical (commercial) relationships
between ASes, and how these relationships can be used to place an
AS in an hierarchical structure. Secondly, we have applied the notion
of the existence of a "logical" hierarchy to construct simple
algorithms that decompose and reveal a graph's inter-connection
structure. Applying these techniques to the Internet-AS graph,
and other power-law graphs we have studied the physical
inter-connection structure of these graphs, and whether they have
"hierarchical" properties.
When I was at BU,
I worked at Prof. Mark Karpovsky's Reliable Computing
Lab.
I helped write code for a simulator. This was to evaluate
wormhole routing algorithms for multiprocessors n/was with
irregular
topologies. Here
are
some papers about this work.
work experience
I have also worked out of
school as a research intern. I spent Summer 2001 and
Spring 2003 at Sprint ATL,
Burlingame,
CA, working with Gianluca
Iannaccone
and Christophe Diot
on end-end path inference problems in the context of passive
measurements. And in the summer of 2000 before I arrived at UMass, I
worked at HP-Labs, in Palo Alto
with
Martin Arlitt
on characterizing WWW client sessions.