[cheeseprocedure]

packagecloud's in-depth writeups on the Linux networking stack are a great read:

https://blog.packagecloud.io/eng/2016/06/22/monitoring-tunin...

https://blog.packagecloud.io/eng/2017/02/06/monitoring-tunin...

The illustrated guide to receiving data is also solid:

https://blog.packagecloud.io/eng/2016/10/11/monitoring-tunin...