AVB Connectivity

Network Control

The 12Mic is an AVB endpoint device that can be configured with the IEEE Standard for Device Discovery, Connection Management, and Control Protocol for IEEE 1722™ Based Devices, in short: ATDECC.

This device does not provide an ATDECC controller for other devices on a network. To establish an AVB connection between devices, a separate controller is required.

There are several ATDECC controllers available for download from different manufacturers that support the commands required to

  • identify the device,

  • adjust its sample rate and clock source, and

  • create connections to or from it.

The RME Digiface AVB includes an ATDECC controller.

Many other configuration options of the 12Mic are at this time not implemented in generic ATDECC controllers. These can be inspected and controlled on the device itself, with the web remote, or using a JSON API.

Audio Streaming

The 12Mic has nine outgoing and nine incoming stream ports. Eight ports can be configured to contain 1-8, 12 (at up to 96 kHz) or 16 (at up to 48 kHz) audio channels in AAF or AM824 format. The ninth port supports only the clock reference format (CRF) and is exclusively used for clocking, not for audio streaming.

In order to establish a connection (stream) between two AVB devices, the following conditions must be fulfilled:

  1. There must be a physical connection between the devices.

  2. All switches between the devices must be certified AVB switches (or compatible).

  3. An ATDECC Controller is required to find the devices and to connect them.

  4. Talker and listener must support the stream format and channel count.

A stream between two AVB devices is deterministic, has a fixed latency, and reserved bandwidth.