Audio over Ethernet

In audio and broadcast engineering, Audio over Ethernet (sometimes AoE—not to be confused with ATA over Ethernet) is the use of an Ethernet-based network to distribute real-time digital audio. AoE replaces bulky snake cables or audio-specific installed low-voltage wiring with standard network structured cabling in a facility. AoE provides a reliable backbone for any audio application, such as for large-scale sound reinforcement in stadiums, airports and convention centers, multiple studios or stages. In audio and broadcast engineering, Audio over Ethernet (sometimes AoE—not to be confused with ATA over Ethernet) is the use of an Ethernet-based network to distribute real-time digital audio. AoE replaces bulky snake cables or audio-specific installed low-voltage wiring with standard network structured cabling in a facility. AoE provides a reliable backbone for any audio application, such as for large-scale sound reinforcement in stadiums, airports and convention centers, multiple studios or stages. While AoE bears a resemblance to voice over IP (VoIP) and audio over IP (AoIP), AoE is intended for high-fidelity, low-latency professional audio. Because of the fidelity and latency constraints, AoE systems generally do not utilize audio data compression. AoE systems use a much higher bit rate (typically 1 Mbit/s per channel) and much lower latency (typically less than 10 milliseconds) than VoIP. AoE requires a high-performance network. Performance requirements may be met through use of a dedicated local area network (LAN) or virtual LAN (VLAN), overprovisioning or quality of service features. Some AoE systems use proprietary protocols (at the lower OSI layers) which create Ethernet frames that are transmitted directly onto the Ethernet (layer 2) for efficiency and reduced overhead. The word clock may be provided by broadcast packets. There are several different and incompatible protocols for audio over Ethernet. For example, using category 5 cable and 100BASE-TX signaling at 100 Mbits/second, each link can generally transmit between 32 and 64 channels at a 48 kHz sampling rate. Some can handle other rates and audio bit depths, with a corresponding reduction in number of channels. AoE is not necessarily intended for wireless networks, thus the use of various 802.11 devices may or may not work with various (or any) AoE protocols. Protocols can be broadly categorized into Layer-1, Layer-2 and Layer-3 systems based on the layer in the OSI model where the protocol exists. Layer-1 protocols use Ethernet wiring and signaling components but do not use the Ethernet frame structure. Layer-1 protocols often use their own media access control (MAC) rather than the one native to Ethernet, which generally creates compatibility issues and thus requires a dedicated network for the protocol.