Google

And finally academic session over. Done with all vivas and related stuff. Next will be exams likely in June. Time for me to get ready for travel. :)   Anyways an interesting topic for today’s post - Google Public DNS. Lot of us are familier with popular (and free) DNS resolvers 8.8.8.8 and 8.8.4.4. I have covered reason in previous posts on why it tends to fail with Content Delivery networks like Akamai which rely on anycasting at bottom DNS layer and simple unicasting on application servers. Anycasted DNS nodes point to application servers based on various factors like distance, load, cost etc out of interesting algorithms these CDN networks use for load & cost management.   Anyways today’s post focus is not CDN issues with these resolvers but Google Public DNS itself. Are these servers located in India and everywhere else where Google has PoPs?   Let’s do a simple trace to get forward path from Airtel to Google’s 8.8.8.8:

Just wrote a quick script to pull dump of Picasaweb albums backup on my server & further to Amazon S3. Overall I have good trust on Google for data but it’s always a poor idea to leave all eggs in single bucket.

OK here’s the script (poorly written code. Literally spent 10mins on this, thus suggestions to improve my coding are more then welcome!)

 #!/bin/bash

Destination=<PUT YOUR DESTINATION HERE!>
google picasa list-albums | cut -d"," -f1 » $Destination/tmp/album_list.txt

cat $Destination/tmp/album_list.txt | while read album

do
          google picasa get “$album” $Destination/tmp
done

FileName=PicsBackup-`date ‘+%d-%B-%Y’`.tar
tar -cpzf $Destination/$FileName $Destination/tmp
gpg –output $Destination/$FileName.pgp -r –always-trust –encrypt $Destination/$FileName
s3cmd put $Destination/$FileName.pgp s3://YOUR-AWS-S3-BUCKET-ADDRESS-HERE

rm -r $Destination/tmp/*
rm $Destination/$FileName
rm $Destination/$FileName.pgp

How to use

Simply download Google Cli scripts, and get your Google account working with the installed stack. Also if you need Amazon S3 backup support then install & configure s3cmd. Once you have both of these configured with your account, simple give executable bit to the script & run!

Yesterday it was reported across networking community that Google’s prefixes were having issue due to an Indonesian ISP Moratel AS23947.

Quick analysis

From data logged by routeviews it seems like it wasn’t exactly a prefix hijack. AS23947 did not originated prefixes but rather had a route leak leading to path leak of AS23947 > AS15169. 

Here’s a view of global routing table for Google’s prefix 216.239.32.0/24 at 15:57 GMT on 4th Nov:

Yesterday I had a discussion with a friend from Airtel after long time. For some strange reason discussion topic was changed to old statements from Bharti Airtel’s executives that companies like Google, Facebook, Yahoo etc should pay to ISPs like Airtel for “data interconnection”. The argument goes more for Google then any other company. Statements from Airtel can be found here and here. 

The argument?

Companies like Airtel who have built a “physical infrastructure” feel that companies like Google should pay to them since they are putting so much of traffic on their networks. Airtel feels that services like YouTube take significant amount of bandwidth and thus requires and infrastructure from core, middle mile to edge part of network and all that needs significant investment. Similarly there was another argument from Mr Sunil Mittal about fact that Facebook is enjoying on top of infrastructure which ISPs like Airtel have created.

I usually find that Gmail phone performs lot better then Skype for calls to PSTN. Usually latency on Skype is high as compared to Gmail phone in India (in US it was almost no difference).

I looked around today and here’s bit of test data I collected by calling couple of numbers from Skype & Gmail phone & monitored UDP traffic to collect information about destination servers which is very likely IP-PSTN gateway.