In the audio industry, we often hear that a certain audio product supports the "Dante protocol". What exactly is the "Dante Protocol"? What are the advantages of this transmission protocol? This article will provide a specific explanation of this.
1. What is the "Dante Protocol"?
The Dante protocol is a modern high-performance digital media transmission system running on standard IP networks. That is to say, it is a technology that uses IP data structure to transmit real-time audio signals in Ethernet, providing a low latency, high-precision, and low-cost solution for point-to-point audio system connections. It was developed by Audinate in 2003 and, like traditional CobraNet technology, is a product that integrates hardware, software, and communication protocols.
DANTE can allow audio signals to be transmitted freely over Ethernet using TCP/IP, and can maintain accurate signal restoration during this process. The following Figure 1 reflects the working mode of DANTE network connection:
2. What are Dante's advantages?
Dante technology allows for sending and receiving multiple audio channels simultaneously on an Ethernet cable, while avoiding the complexity and limitations of early solutions. Dante's low latency and strict synchronous playback can meet the most stringent requirements of audio systems, and has excellent compatibility with existing IT devices. The difference between Dante and traditional products is that it has crossed the two-layer network communication protocol and fully adopts the more advanced and convenient IP three-layer communication protocol. It can also directly transition to the AVB (AudioVideoBridging) protocol through firmware upgrades, which is a very important step.
3. How many audio channels does the Dante protocol support?
Gigabit network: Supports 512 ✕ 51248KHz/24Bit audio channels on a single link, which means a total of 1024 bidirectional channels. For 96KHz/24Bit audio data streams, the Channel capacity is halved.
Baimeganet: Supports 48 ✕ 48KHz/24Bit audio channels on a single link, which means a total of 96 bidirectional channels. For 96KHz/24Bit audio data streams, the Channel capacity is halved.
The Dante protocol supports two audio sampling rates, 48KHz and 96KHz, which vary depending on different manufacturers and series of products.
4. What is the delay between the two audio nodes in the network when using Dante?
In principle, two audio contacts are directly connected using a gigabit network, and the network is very perfect. In this case, a single audio data is collected and transmitted through its own IP packet. Dante has measured the same delay as the gigabit network standard, both of which are 83.3 μ S (0.08ms).
The following table shows the number of transmission audio channels that the network can withstand (including the total sum of unicast and multicast) and the corresponding network delay when the network utilization reaches about 90% when a basic audio signal is transmitted at one or more times oversampling (2 times is 96KHz sampling, 4 times, 8 times, etc.).
From the above table, it can be seen that the Dante system can automatically adjust the available network bandwidth for different network bandwidth and channel transmission needs, and use as much free bandwidth as possible to reduce transmission delay while ensuring network transmission security.
5. What is the performance comparison between Dante and EtherSound?
Dante has no topology limitations and installation complexity; The Dante protocol supports a maximum sampling rate of 192KHz, supports up to 1024 channels of bidirectional transmission on a single link, and has a minimum latency of 83.3 μ s. The EtherSound protocol only supports a maximum sampling rate of 96KHz, a maximum of 512 channels on a single link, and audio data streams can only pass through HUB or Switch in one direction, with a minimum delay of 125 μ s. So Dante surpasses EtherSound in performance. And Dante can provide fault backup, which is a very obvious advantage for on-site activities.
6. Performance comparison between Dante and CobraNet?
CobraNet protocol is a networked audio transmission technology developed by PeakAudio in the United States in 1996. So far, CobraNet has been widely recognized as the "ancestor" of all networked audio technologies, regarded as an effective audio protocol, and will continue to serve the industry well. Although supported by over 50 CobraNet product manufacturers, CobraNet has not yet become an industry standard.
The CobraNet protocol supports a maximum sampling rate of 96KHz, with 128 audio channels for bidirectional transmission on a single link, and does not support routing. The minimum latency is 1/3ms, and the data performance is still inferior to that of the Dante protocol. And there is no fault backup for the CobraNet protocol.
7. Understanding Dante and AVB
Due to the fact that communication protocols such as CobraNet and EtherSound are independently established protocol standards by various manufacturers, although some of them follow Ethernet protocol standards, they are not truly international standards. Therefore, there are certain obstacles to the setting of universality and compatibility in the future (such as communication between CobraNet devices and EtherSound devices). In this case, the IEEE 802.1 Standards Committee, the audio and video bridge working group of IEEE, issued the AVB (AudioVideoBridging) technical standard.
The introduction of AVB is to fill the loopholes in this field, and it is released in accordance with ISO standards and specifications, and provided to manufacturers for free use. So after the introduction of AVB, the phenomenon of a hundred schools of thought competing for communication protocols should gradually disappear, and it is no exaggeration to say that the introduction of AVB can be called a new era in the audio and video industry.
AVB allows multi-channel audio and video streams with different sampling rates to be transmitted between different networks and distances, and supports standard timing and clock signals. All AV devices refer to a unified time base for collaborative playback.
AVB eliminates network buffering latency. When transmitting data through the network, reliability is superior to time, and short delays are acceptable in data transmission. However, the asynchronous audio and video caused by delays in audio and video transmission is unacceptable. Queue and forwarding rules ensure that different AV streams pass through the network at specified delays and identify non AVB devices. The AVB protocol can identify non AVB devices in the network.
Although the current firmware version of the Dante protocol is a transitional version, it is still a self proclaimed transport protocol. Due to Dante's protocol architecture fully complying with AVB specifications, during system upgrades, Dante only needs to update the firmware versions of all network cards to automatically upgrade to the AVB system without changing any hardware devices. This also makes Dante protocol one of the few products currently fully compatible with AVB and put into commercial use.
