Boxes and Lines — Intro

Abel Lawal
3 min readMar 7, 2021

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Who Am I?

My name is Abel Lawal, I am a cloud engineer. I have worked in technology for almost 5 years, before that I was in retail, running my own business selling watches and watch parts for almost a decade. The common theme my entire work-life has been that I really enjoy learning about and gaining an understanding of technology, then sharing that knowledge with others. I have always measured my understanding of a technology by how simply I could explain it to others. Whether that is explaining how watches use atomic technology to keep your watch accurate or how an AWS EC2 instance uses Virtual Private Cloud(VPC) Firewall(FW) to send traffic to the internet.

Why “Boxes And Lines”

One day after a particularly trying day at work. I was attempting to explain to my girlfriend the events of the day while showing her an architecture diagram and she joked “It’s all boxes and lines anyways”, and the name just stuck...

What is “Boxes and Lines”

Architecture diagrams are a valuable tool in understanding technical solutions. Modern solutions are comprised of different technologies that interact in an ever more complicated and obscure way. Almost every project I have ever worked on in any capacity, has an associated architecture diagram.

But when I look at an architecture diagram, I can’t help but ask myself what does it leave out and does that omission matter. What assumptions are being made, about me as the viewer and my level of understanding. They say a “picture is worth a 1000 words”, but even in that statement there is an assumption that the viewer speaks the same language and more specifically knows those thousand words.

Simplified VPC FW Architecture

As a concrete example, the above diagram illustrates an AWS EC2 instance using VPC FW to send traffic to the internet. However, the diagram leaves out the implicit router present in every AWS VPC. The route table that the implicit router associates to traffic that originates in the private subnet. The default or user defined stateless Network Access Control List (NACL) that dictates what traffic can leave and enter the private subnet. The diagram assumes that the audience knows that for an EC2 to be “in” the private subnet, that the primary etho0 Elastic Network Interface(ENI) that is associated with the EC2 instance must be deployed to the private subnet.

That’s just taking a slightly deeper look at the first box and line, the same exercise could be done for every box, but the question is how far down the “rabbit hole” do you go before you stop adding value and start adding noise.

This second diagram is technically more complete but loses the simplicity and elegance of the first even though they both detail the journey a packet takes from an EC2 to the internet using VPC FW.

“Boxes and Lines” attempts to be journey to the middle. Each blog post will start with an architecture diagram, and then take a deeper look at the technology presented in it. Striving to understand not just what the architecture and technology it contains does, but how it does it. While attempting not to get lost down the rabbit hole. I will cover topics in technology that interest me — Automation, Virtualization, Linux and Networking and the beautiful enigma where they all collide, the Cloud.

Thanks for taking the time to be on the journey with me, I am not sure where we will end up. But in the words of my favorite author

“Journey before destination”.

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Abel Lawal

Cloud Engineer who draws "boxes and lines" for a living