[Nets-seminars] Talk Friday 8th June UCL electronic Engineering

[Richard G. Clegg]

Tommorow's talk (8th June) is at 16:00 in GS/302. The speaker is Raul 
Landa from UCL Electronic Engineering.

ENVISION: The Large-scale Geography of Internet Round Trip Times

This is the second of two talks arising from research in the EU project 
ENVISION. In this talk we present a model for the analysis of Internet 
round trip times (RTT) and its relationship with other geographic and 
network properties. This model is based on a novel RTT dataset 
comprising ∼19 million measurements between ∼54 thousand measurement 
points. Our first contribution is a procedure for the geographic 
analysis of RTT that allows the recovery of large-scale routing 
information. We accomplish this by investigating RTT on the basis of 
disjoint, large-scale geographic components. By applying a novel 
median-based, least-squares fitting algorithm to traffic flows between 
these components, we analyse their RTT\distance behaviour and compute a 
large-scale routing excess that quantifies the extra distance beyond the 
great circle that packets traverse when they flow between large-scale 
geographic areas. Our second contribution is an information-theoretical 
analysis that allows us to determine the amount of information that a 
given subset of geographic or network variables (such as RTT or great 
circle distance) gives about any other variable of interest. We then 
provide bounds on the error that can be expected when using this subset 
of variables to estimate the value of the variable of interest.

-- 
Richard G. Clegg,
Dept of Elec. Eng.,
University College London
http://www.richardclegg.org/