Purpose
<span style="color: #000000"> The purpose of this study is to investigate the effectiveness of tiering</span> for TULIP
. (i.e we have a set of primary landmarks tier0 which will narrow down the location to a particular region*[1] and then more denser secondary tier1 landmarks can be used to get more accurrate results). Currently we are looking into two regions North America and Europe. We are trying to build heuristics which will enable us to find the region of a particular host.
North America
We selected 4 landmarks in North America for our study( SLAC, BNL, Ampath-Florida,TRIUMF-Canada). We pinged a set of know geographical sites from PingER database in US, Canada and Mexico. We also calculated the physical distances between them. The figure below shows the distribution. It appeared that all hosts were within 80ms of one another of the 4 monitors and 98.84 are < 70ms.
Here are graphs of data seen from four landmarks
