Meet the Manager

Sig-Net describes every device by what it does, not what it looks like. There are four roles — Manager, Sender, Node and Visualiser — and a single physical box can play any combination at once. We'll start with the Manager because everything else depends on it.

What a Manager is for

A Manager is the brain of the network. It does the patching, the configuring, the talking-to-RDM, the discovery, the onboarding of un-provisioned gear. If you've ever opened the patch screen on a console or fired up an RDM controller app on a laptop, you've met a Manager.

In Sig-Net's vocabulary, the Manager has the keys — literally. It holds K0, the root key for the whole network, and from K0 it derives everything it needs to authorise any command on any device.

Two flavours: Equal and Guest

This is the bit worth understanding, because it solves a very real problem in our industry: how do you let a touring console drive a house rig without handing them the keys to the building?

An Equal Manager has the master key. It can do anything: patch fixtures, change IPs, run RDM, onboard or factory-wipe a node. Multiple Equal Managers can co-exist on the same network — that's how main-and-backup desks work. If the main desk dies mid-show, the backup already knows how to derive the management keys for every fixture and can immediately add a replacement moving light, repatch a universe, do whatever it needs to.

A Guest Manager has a deliberately limited set of keys. The house exports them as a small JSON file (Km_global, Ks and Kc, but not K0 or the per-device keys), drops them onto the touring console, and the touring console can:

• See every fixture on the rig.

• Stream DMX to the rig.

• Read RDM responses.

But it cannot:

• Change a fixture's IP address.

• Send any RDM SET commands.

• Onboard or factory-wipe anything.

Crucially, this isn't a software lock that someone could reverse-engineer their way around. The cryptography simply makes the unauthorised packets fail. There's no override.

What a Manager does day-to-day

When a Manager is alive on the network, it's quietly doing four things:

It's polling. Every few seconds it shouts a discovery packet, and every Node within range answers with "I'm here, this is who I am, this is my change-count". If a Node's change-count is higher than what the Manager remembers, the Manager fetches the new settings.

It's configuring. Every label, universe assignment, port direction, IP setting, failover behaviour and DMX timing parameter is something the Manager can SET.

It's RDM-ing. Sig-Net wraps standard RDM commands inside its own packets and routes them to the right fixture, with built-in flow control so consoles don't flood a gateway's RDM queue.

It's onboarding. New, factory-fresh gear arrives in "Beacon Mode" with no key — it sits there chirping a heartbeat that says "please add me". The Manager is the role that hands over K0 and brings it into the show.

What happens without a Manager

Nothing dramatic. Senders keep streaming, Nodes keep outputting, the show carries on. Nodes will start broadcasting "lost" notifications so any Manager that comes online later can find them, but the rig doesn't blackout.

Next post: the Sender — the role that streams the show.

This series is based on v1.0 of the Sig-Net spec - visit Sig-Net.net for any updates.