Livewire (networking)
| Livewire+ | |
|---|---|
 | |
| Manufacturer Info | |
| Manufacturer | Axia Audio, a brand of The Telos Alliance |
| Development date | 2003 |
| Network Compatibility | |
| Switchable | Yes |
| Routable | Yes |
| Ethernet data rates | Fast Ethernet, Gigabit Ethernet |
| Audio Specifications | |
| Minimum latency | 0.75 ms[1] |
| Maximum sampling rate | 48 kHz[2] |
| Maximum bit depth | 24 bits[2] |
Livewire+ is an audio-over-Ethernet system that was created by Axia Audio, a division of The Telos Alliance. The original Livewire was introduced in 2003. Its primary purpose is routing and distributing broadcast-quality audio in radio stations. Livewire is interoperable with other RAVENNA standards-based systems and equipment.[3] Livewire was superseded by Livewire+, which enables full AES 67 interoperability. Designed as a superset of functionality utilizing common protocols and formats, Livewire+ is available as an open standard through Axia's Livewire+ Partner Program.
To date, there are over 80 Livewire+ Partner companies. Over 6,000 studios have been installed with Livewire+ worldwide, and there are over 60,000 individual Livewire+ devices in the field.[4]
History
Before the advent of Livewire, the infrastructure of analog radio plants consisted of miles of multiconductor audio cable wired to walls full of punch blocks at each end. Installation and maintenance was time consuming and expensive. Telos founder and president Steve Church set out to find a better way.
He looked to computer networks for inspiration. If data could be divided into packets and routed on a single Ethernet cable, why couldn't the same thing be done with broadcast audio? There were many hurdles, such as latency, lost packets, and prioritizing audio over other traffic on the network. One by one, these and other problems were solved. The theory was put into practice, and workable products were developed.[5]
Livewire made its debut in 2003 at the NAB Show in Las Vegas. The original Liveweire-capable products included the SmartSurface console, Studio Engine, analog, AES, mic and GPIO nodes, as well as the Router Selector node.[6]
The NAB premiere of Livewire marked the dawn of Audio over IP (AoIP). The concept caught on, and before long, other manufacturers were making their own AoIP broadcast equipment. Soon, there developed the need for a standard so AoIP gear from different manufacturers could communicate with each other. Telos worked with other manufacturers to develop the AES67 standard for AoIP interoperability. The Telos Alliance is a founding member of the Media Networking Alliance, which promotes adoption of the AES67 standard on behalf of the pro audio industry.[7] Livewire+ was developed to bring the original Livewire protocol into AES67 compliance.
Benefits
Livewire+ provides routing of audio from 'anywhere-to-anywhere' using multicast sources and destinations of uncompressed PCM or AAC audio that is globally visible on a LAN. Distribution is via 8-conductor cables and RJ-45 connectors. These are smaller than the standard XLR interconnects, and improve flexibility while reducing the amount of wiring required for installations.[8]
Protocol
The following table lists ports and protocols used in Livewire systems.[9][10][11]
| Port | Protocol | Multicast Address | Purpose | Notes |
|---|---|---|---|---|
| 67, 68 | UDP | BOOTP Server/Client | Remote IP address assignment | |
| 93 | TCP | Livewire Routing Protocol | Also provides transparent passing of custom messages, similar to the Ancillary Data Transmission feature of AES3 | |
| 123 | UDP | Network Time Protocol | ||
| 514 | UDP | Syslog | Activity logging to a syslog receiver. | |
| 2055 | UDP | 239.192.255.4 | Multicast-based GPIO (CMsg2 protocol) | GPIO commands, GPIO node → console-type endpoint |
| 2060 | UDP | 239.192.255.4 | Multicast-based GPIO (CMsg2 protocol) | GPIO commands, console-type endpoint → GPIO node |
| 4000 | UDP | Livewire Advertisement and Source Allocation Protocol | Verbose advertisement and source allocation requests | |
| 4001 | UDP | 239.192.255.3 | Livewire Advertisement and Source Allocation Protocol | Periodic and verbose announcements;
Source allocation state announcements and responses |
| 4002 | UDP | 239.192.255.3 | Engine Supervision Protocol | |
| 4010 | TCP | Livewire Control Protocol | ||
| 4011 | UDP | 239.192.255.4 | LWCP for Accessory Modules | Module → Console |
| 4012 | UDP | 239.192.255.3 | LWCP for Accessory Modules | Console → Module |
| 5004 | UDP | 239.192.x.x | RTP Livewire Audio | Last two address octets pertain to Axia channel ID, e.g. 9999 = 39 15 (hex 27 0F) |
| 7000 | UDP | Livewire Clock | One device assigns itself as LAN-wide reference, all other devices slave to it | |
| 9997 | TCP | Protocol logging | Debug protocol logging for Element |
References
- ↑ "Best Practices in Network Audio" (PDF). Audio Engineering Society. 2009. Retrieved 30 July 2015.
- 1 2 Introduction to Livewire+ (PDF), The Telos Alliance, May 2015, retrieved 30 July 2015
- ↑ Axia Debuts Livewire Limitless License, Radio, 2011-04-07, retrieved 30 July 2015
- ↑ "Axia Livewire+ Partners". Retrieved 29 July 2015.
- ↑ "Steve Church Remembered". Retrieved 30 July 2015.
- ↑ Personal communication, Clark Novak, The Telos Alliance, 30 July 2015
- ↑ http://www.medianetworkingalliance.com/
- ↑ Matt Rockwell (2011-07-01). "Axia Audio Element Leads New Studio". Radio World. Retrieved 30 July 2015.
- ↑ "Configuring Windows Firewall for use with the Axia IP-Audio Driver" (PDF). The Telos Alliance. 31 October 2006. Retrieved 30 July 2015.
- ↑ "Axia IP-Audio Driver for Windows, rev. 2.5 manual" (PDF). The Telos Alliance. August 2010. Retrieved 30 July 2015.
- ↑ Steve Church; Skip Pizzi (10 September 2012). Audio Over IP: Building Pro AoIP Systems with Livewire. CRC Press. pp. 4–. ISBN 978-1-136-03057-4.