Extra
We began our analysis with the fixed alpha values, but now we are heading towards another dimension in TULIP which is calculating the distance based on the RTT's. We start our work by pinging each landmark to another landmark as we already have landmark latitudes and longitudes we can easily find the distance between the two. These results  are in the form of  tsv file containing the records for landmark source to landmark destination their rtt and distance an example of this file is given below

Landmark Source

Landmark Destination

RTT

Distance

icfamon.rl.ac.uk

csplanet02.cs-ncl.net

19.242

83.02

planetlab1.cs.vu.nl

csplanet02.cs-ncl.net

22.986

357.77

host4-plb.loria.fr

csplanet02.cs-ncl.net

33.77

548.47

After getting these results, I then edited the available schema of TULIP database and added a  new table to cater for this change. The schema for new table is given below:

Field 

Type

Null

Key

Default

Extra

ipv4Add_f

varchar(50)

YES

 

NULL

 

ipv4Add_t

varchar(50)

YES

 

NULL

 

rtt

varchar(50)

YES

 

NULL

 

distance

varchar(50)

YES

 

NULL

 

This table is then populated with recently collected data with the help of perl script "rttdistinput.pl"deployed at:

/afs/slac.stanford.edu/package/pinger/tulip
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