AES70 (Open Control Architecture)

showstack / protocols / aes70-oca

AES70 (Open Control Architecture)

Also called OCA, Open Control Architecture, AES70.

Open Control Architecture, standardised by the AES as AES70, is an object-oriented model for controlling and monitoring media network devices. It carries gain, mute, routing, presets, sensors and status over TCP, and carries no audio of its own.

Audio controlPaid specAudio Engineering SocietyReported

Stewarded by Audio Engineering Society (AES), developed by the OCA Alliance.

Control Small, urgent, must arrive

Small messages that either repeat constantly or fire once. Bandwidth is almost never the problem.

What kills it. Latency and loss on the messages that fire once. A repeating level survives a dropped packet; a GO does not.

The four flows, and why the model is worth having →

What goes wrong

There is no universal port. OCP.1 runs over TCP but the port is chosen by the device: the d&b DS100, for example, listens on 50014. Read the specific product manual before writing a firewall rule.

AES70 is control only. It does not move audio, so it always sits alongside AES67, Dante or ST 2110, and a device can be reachable for control while its audio path is dead.

"AES70 compatible" says nothing about which objects a device exposes. Two compliant products can share almost no controllable parameters, so check the device's actual class tree, not the badge on the box.

The standard is split into parts (framework, class structure, protocols). Buying one part does not give you a working picture, and the parts are priced separately for non-members of the AES.

What speaks AES70 (Open Control Architecture) (3)

Product	Direction	Notes
d&b audiotechnik 40D installation amplifier d&b audiotechnik	bidirectional	Control and monitoring.
d&b audiotechnik D80 d&b audiotechnik	bidirectional	R1 remote control speaks OCA (AES70) to the amplifier over Ethernet.
L-Acoustics LA7.16i L-Acoustics	bidirectional	Control and monitoring.

Open source implementations

AES70.js — JavaScript, GPL-2.0-only
NanoOcp — C++, GPL-3.0-or-later

Typical use

Amplifier and DSP control from a third party controller or show control system
Monitoring device health, temperature and fault sensors during a run
Recalling presets and scenes across mixed-vendor loudspeaker systems
Vendor control apps that need one model across a whole product range

Sources

AES70 standards category (latest published edition) — Audio Engineering Society primary
AES70 Standards and Specifications — OCA Alliance primary
AES Standards Store (AES70 pricing and access) — Audio Engineering Society primary
Open Control Architecture (history and publication date) — Wikipedia
NanoOcp — OCP.1 over TCP, DS100 default port 50014 — Christian Ahrens

Understand the mechanism

How software talks to software Numbers that stand for signals

Something wrong, or missing?

Known gaps on this entry: default_ports. If you can source one of them, that is a ten minute pull request.

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