Cheat sheet of data networking part 1

A lot of data networking is conceptually self-similar thanks to the layered approach.

Broadly speaking (from Grandma’s point of view), if <-> denotes exchanging or swapping,

  • Physical interface1<-> Physical interface2 is repeating
  • Physical port1 <-> Physical port2 is bridging
  • MAC1 <-> MAC2 is routing
  • IP1 <-> IP2 is NATting, load balancing
  • TCP/UDP port1 <-> TCP/UDP port2 (along with IP1 <-> IP2) is PATting
  • SSL/TLS ON/OFF <-> SSL/TLS OFF/ON is a security gateway
  • Application1 <-> Application2 is an application gateway, for example, gmail

Once you look at the “data plane” like such symbol swapping, it becomes very simple game.

Especially, if you start putting tuplets together like:

Ingress {Source, Destination} * {Physical segment, MAC, IP, Port, SSL/TLS and encryption, Application} <->

Egress {Source, Destination} * {Physical segment, MAC, IP, Port, SSL/TLS and encryption, Application}

It gives a nice product matrix. Once I learn how to put tables on WordPress, I will upload some and ask for your help to fill in the rest of details.

Understand that symbol swapping is the simplest thing a networking product does. Building such symbol swapping tables is one of the hardest jobs and that is where the concept of “control plane” kicks in. I will leave that discussion to experts.

Interestingly, the above is not the complete picture of networking products. It has only two interfaces – Ingress and Egress. There are some products (called caches) which (may) have three interfaces. Some day I would like to write such a table for caches also.

And then, layering is not the only concept in networking. There is also encapsulation. It leads to wholly another class of products called tunnels, like MPLS, IPSec and SSL-VPN. Making a table of such technologies also will be fun.

Do you want to embark on this journey?




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