Our "Tech Talks" series features analysis from our experts into the way entertainment technology works and is evolving over time.
Vari-Lite's Jon Hole recently gave an introduction to understanding subnets for ESTA's Protocol magazine. Here's a short excerpt from the article:
“This is happening, so get on board!” was my attempt to drum up enthusiasm within a group of students, to whom I was providing balls of string and plastic cups to illustrate the strengths and weaknesses of different lighting control protocols. We were covering terminology such as “analogue” (signals represented by a continuously variable value, such as 0-10V), “digital” (signals represented by a series of discrete values, such as DMX512), “unidirectional” (functioning in one direction, also such as DMX512), “bi-directional” (functioning in both directions, such as RDM), and “half-duplex” (functioning in both directions but not simultaneously, also such as RDM).
Creating tin can phones (with plastic cups) is a successful approach when looking for an interactive and fun way of introducing such terms, along with their associated pros and cons, that the group can personally identify with. However, transition these discussions onto common networking terms and more-than-often I’m met with blank expressions and head scratching. Daisy chaining, splitters, and DMX addresses are easy, even logical, when compared to star topologies, network switches, IP addresses, and subnet masks. I needed a “tin can phone” approach to networking, but didn’t have one.
What are subnets?
As I think back to those university lecture theatres, there’s a clear purpose to such rooms. Their size and layout make it ideally suited for lectures in a way that other meeting rooms, classrooms, and sports halls don’t. I was standing in a realised concept of “subnets.” Let me explain. Imagine you’re standing in an arena, alongside thousands of silent spectators. You could shout a friend’s name and, assuming they’re also in the arena, you start communicating with them. When others in the arena do the same, the room quickly becomes too noisy for successful communication. So how can you efficiently talk to your friends, whilst simultaneously allowing others to talk to theirs?
In fear of stealing a catchphrase, we need to build a wall.
Read the full article in Protocol magazine.