Un protocole de réseau audio optimisé pour le live

Le concept de réseau audionumérique apporte un grand nombre de nouvelles fonctionnalités en son live. Comme il suffit d'un seul câble réseau pour transporter simultanément les données d'un grand nombre de canaux audio, le nombre de câbles nécessaire est considérablement réduit par rapport à une configuration analogique. Et là où, en analogique, l'assignation des canaux demande des connexions physiques indépendantes pour chaque canal, elle s'effectue de façon virtuelle et très souple dans un réseau audio. La transmission de données numériques n'est pas affectée par les bruits de fond ni par la dégradation de signal inévitables sur les lignes analogiques, ce qui permet de maintenir une qualité de signal optimale dans tout le système. Nous vous présentons ici un protocole de réseau audio idéalement adapté au monde du spectacle vivant : le Dante.

Dante is based on standard IP network technology, and is capable of handling a large number of channels with high quality and low latency. It also allows redundancy for extremely high reliability.

Dante offers the kind of system design and layout flexibility required by today’s live sound applications.

Dante compatible products: CL series digital mixing consoles, QL series digital mixing consoles, R series I/O racks, and more.


Dante Network Design Points

When creating a Dante network using CL series mixing consoles, QL series mixing consoles, R series I/O rack units, and Dante-MY16-AUD cards, be sure to use gigabit capable network devices (cables, switches, etc.). Network device selection will be covered in more detail later.

Dante makes it easy to setup up primary and secondary networks for redundancy when failsafe reliability is required. Failure of a device or connection in one network will not interrupt the audio signal. CL series consoles, QL series consoles and R series I/O units can also be linked using a simple daisy-chain configuration that directly connects console to I/O via a cable without the need for switches.

Dante networks feature high-precision synchronization, right down to the phase of the clock, and latency between devices can be fixed at a specified value. In a system that includes CL series consoles, QL series consoles and R series I/O racks, system latency can be set to between 0.25 and 5 milliseconds. Please note that the minimum latency setting will be determined by the number of hops on the network (devices and switches). Setting a lower latency can result in noise and dropouts. When latency is critical in larger systems that implement switches and redundancy, it is important to design the network to eliminate unnecessary hops and thereby minimize the number of hops overall.


Dante with AES67

AES67 is an audio-over-IP interoperability standard established by the Audio Engineering Society (AES) in September 2013. In February of 2014 udinate announced that Dante would be updated to support AES67. In response to this, Yamaha updated Dante equipped products with device and Dante firmware updates that added AES67 support. AES67 allows communication with Ravenna, Q-LAN, Livewire, and other audio networks, for significantly improved system expandability.

Dante with AES67 compatible products: CL series digital mixing consoles, QL series digital mixing consoles, R series I/O racks, and more.

Using AES67 with Dante: an Introduction

Andy Cooper, manager for pro audio application engineering, introduces the new AES67 audio networking standard, explaining when it's needed, how it works with Dante, and showing some system examples.

Yamaha Dante devices with AES67 Guide

Cables

The network cables listed below have been tested and confirmed to be suitable for use in Dante networks. However, the maximum cable length over which reliable data transmission can be achieved will depend on cable characteristics, termination quality, and the operating environment.

- CAT5e or higher cable.

- Check maker specifications for maximum cable length.

- Use STP (Shielded Twisted Pair) cable for maximum resistance to electromagnetic interference.

If cable characteristics are unknown, use a cable checker to ensure that the cable meets TIA/EIA-568-B requirements.


Tested and confirmed cables

Brand Product Code Length Diameter Note
Link CUS LK CAT6 STP 100m 8.5mm Flexible for touring
CAE-Groupe Giga-Audio 100m 6.7mm Flexible for touring
Resistance to rain and UV
Klotz RC5SB 100m 6.6mm Flexible for touring
TACHII T-SB5E202W-4P 100m 8.0mm Sold only in Japan
YMH-18C-1 (multi-core) 85m 19.5mm
Belden 74003PU 80m 6.65mm Flexible for touring
Resistance to rain, UV, temperature, abrasion, oil
TMB ProPlex PCCAT5EP 75m 7.1mm Flexible for touring

*Disclaimer

The maximum cable length for Dante is tested and suggested by Yamaha. We use a Fluke DTX-1800 cable analyzer to check if it conforms to TIA/EIA-568-B (CAT5e) with the length, and then checked that the Dante system with CL5 and Rio3224-D works perfectly without audio dropouts for over 12 hours. However, this list does not guarantee 100% safe operation due to the individual variability, termination quality, and other environmental conditions of and around the cable. If you are unsure, we recommend that you check your cables with a cable analyzer. Please note that the suggested Max. length is appropriate for Dante devices using 1Gbps data transmission, and may be shorter than the length suitable for 100Mbps transmission.

Network Switches

With the exception of basic daisy-chained setups, Dante networks will require one or more network switches that meet the conditions described below.

- Non-blocking gigabit switch.

- Energy efficiency functions such as EEE must be defeatable.

- Intelligent switches that allow management (setup and monitoring) are recommended.

- Strict priority queuing with 4-queue Diffserv (DSCP) QoS recommended.

Depending on system requirements it may be necessary to consider maximum cable lengths between switches, bandwidth optimization, and other parameters in large networks. Information is available here.


Media Converters

When long-distance transmission between network devices (switches) is required, fiber optic cable can be used. Rather than using independent media converters when switches are used, it is preferable to add GBIC or SFP modules to the switches when such capability is provided. Cut-through mode is preferred over store-and-forward mode.