To explore how Exponential backoff works, I wrote this script that helps check if the system is connected to the Internet of not. Another reason for making the script is, I was fed up with my ISP resetting my connection, since I'm on ssh, it kept timing out and the only way to find/notify disconnection was through Dropbox, and it takes forever.

Exponential back-off states that:

Given a uniform distribution of backoff times, the expected backoff time is the mean of the possibilities.

That is, after c collisions, the number of backoff slots is in

[0, 1, ..., N], where N = 2c - 1 

and the expected backoff time (in slots) is:

(1/(N+1))*(n∑i,i=0), where (n∑i,i=0) = ((n*(n+1))/2)

The script checks if the system is connected, by getting www.google.com. If true, backs off for x seconds, if false backs out for y secs.

On a successful:

• connection-after-disconnection
• disconnection-after-connection

the script send a notification using notify-send.

PS: Do remember, this will silently run in the background :)

• python3
• notify-send
  • install using sudo apt-get install notify-osd

• check socket timeout issue and fix
• clean and make code legible
• Implement backoff of both disconnection and connection
• make notifications audible
• back it as a shell callable
• Way to get kill the script form terminal, one command

I'm open to all suggestion and feedback.

Also, I have a very faint feeling I'm doing it wrong, if so, please do let me know