In part 1 I introduced the essential features of a network protocol suitable for the distribution of Pro Audio. In part 2 I will offer a very brief overview of the competing systems currently available offering a little detail, relating them to the seven layer network model, highlighting whether they are open or proprietary systems and offer some context on how the differences between these systems make them more or less appropriate for use in different applications.
What Systems Are Available?
Dante - Layer 3, Proprietary. Rednet is an example of a Dante system. Widely supported by manufacturers such as Yamaha, Focusrite and Lab Gruppen. Dante has established itself as a highly visible audio solution and with Rednet, Focusrite have made early inroads into the studio market.
AVB - Layer 2, an open format. AVB is a set of standards and while companies such as Avid, Sennheiser and TC Electronic have implemented AVB in their products, other Cat5 systems can use the same AVB standards in their particular implementations, for example Dante and UMAN both provide support for AVB.
HyperMac/SuperMac/AES50 - Layer 1, SuperMac is the 100 Meg AES50 specification. HyperMac is a newer Gigabit implementation. It is proprietary to Klark-Tecknik and is used by Midas, AES50 is used by Behringer
Cobranet - Layer 2, Proprietary, Cobranet has been around since 1996 and although it has relatively long latency, is popular for distribution around large installed sites. BSS soundweb is a popular system using Cobranet.
Ethersound - Layer 2, Proprietary, has been around since 2001. Low latency and widely supported in PA and studio systems by manufacturers such as Digico and Yamaha.
A-Net - Layer 1, Proprietary, familiar to many studio users as the format used by Aviom headphone systems
REAC - Layer 1, Proprietary, developed by Roland for use in their V mixer system and with Cakewalk.
Livewire - Layer 3, Proprietary, used extensively in radio, particularly in the US. Licenced by Axia Audio.
UMAN - Layer 3, Proprietary, this system is a professional media network designed for a wide range of uses, one of which is audio.
Ravenna - Layer 3, Open, primarily targeted at the broadcast market Ravenna is being seen as an open source rival to Dante. Lawo use this system extensively. Genelec and Pyramix also support this technology. AES67 is the new AES standard for audio over IP and is based on Ravenna. This ratification by the AES is a significant advantage for this format and makes it one to watch.
Waves SoundGrid - Layer 2, Proprietary. This system is well known to the Pro Tools community. it is an example of Cat5 audio being put to a slightly different use. This gigabit only system enables extremely low latencies between host and the sound grid server.
There are other formats available, examples would be Rocknet, Optocore and Omnoe. A related technology which takes an alternative approach is SonoNet which is a wifi audio distribution system used by Sonos for their wireless domestic audio products. Interestingly SonoNet is an example of a L2 wireless network which is not WiFi (802.x). It does with wifi what layer 2 formats do with ethernet, using the hardware and procedures for data transfer but running its own proprietary format. Another interesting development is MADI TP. MADI TP runs MADI over twisted pair Cat5 cable. This hybrid approach takes a proven technology (MADI) and creates a hybrid approach of MADI send and receive with IP data packets running on the same cabling and infrastructure. This allows reliable audio transmission via MADI with control data over IP down the same cable.