About AES67
AES67 is a technical standard developed by the Audio Engineering Society (AES) with interoperability guidelines for Audio-over-IP (AoIP). It is supported by major AoIP vendors like Wheatstone, Telos, Ravenna, Dante and others, and supports the streaming of audio between these different systems. Tieline codecs are used to transport audio between AES67 compatible networks and studios and using AES67 inputs and outputs facilitates inter-studio routing of high quality AoIP.
The AES67 standard defines requirements for synchronizing clocks using IEEE 1588-2008 Precision Time Protocol (PTPv2). It also defines setting of QoS media traffic priorities and initiating media streams using standard internet protocols. The standard also defines the audio sample format and sample rate, the number of supported channels, plus latency, buffering and the size of IP data packets. It does not define device discovery, connection management and media configuration protocols.
Introduction
The codec is AES67 compliant and therefore capable of connecting to AoIP networks such as:
1.Wheatstone WheatNet-IP (using optional WheatNet-IP card installed at purchase).
2.Wheatstone in AES67 mode.
3.Axia Livewire+
4.RAVENNA
5.Dante in AES67 compatibility mode.
AES67 compatibility makes it simple for different devices to use common configuration settings and stream audio between them. Similar to how different brands of codecs are configured to connect using SIP for interoperability, AES67 compliant audio products can stream audio between each other using common streaming configuration parameters. The codec is also compliant with ST 2110-30 for system timing/synchronization and PCM digital audio transport. This allows the codec to operate in live production, playout and other media applications, where real-time audio, video and ancillary data needs to remain independent yet co-timed, allowing independent streams to be synchronized. The SMPTE ST 2110 standards are based on AES67 so can work together. The configurable elements include:
1.Audio Sampling Rate
2.Audio Sampling Depth.
3.Packet Time.
4.Number of Channels streamed.
In addition, the SDP values defined in ST 2110-30 provide standard order for individual channels within the IP packets. E.g. for stereo and surround sound channels. Plus, ST 2110-30 also defines a set of six compliance levels for devices receiving audio streams. The codec supports A, AX, B and BX.
Level |
1 millisecond Packet Time |
125 microseconds Packet Time |
||
48 kHz |
96 kHz |
48 kHz |
96 kHz |
|
A |
1 to 8 |
|
|
|
AX |
1 to 8 |
1 to 4 |
|
|
B |
1 to 8 |
|
1 to 8 |
|
BX |
1 to 8 |
1 to 4 |
1 to 8 |
1 to 8 |
C |
1 to 8 |
|
1 to 64 |
|
CX |
1 to 8 |
1 to 4 |
1 to 64 |
1 to 32 |
Note: Only the AoIP 1 port on the codec rear panel can be used to connect to WheatNet-IP networks. All AoIP configuration settings are configured in the AoIP menu in the HTML5 Toolbox Web-GUI.
