SoundGrid 301 Part 4: Understanding SoundGrid’s Layer 2 Ethernet Protocol


Please note: Completing SoundGrid 201 is a prerequisite to taking the SoundGrid 301 test.

When we developed SoundGrid, our priorities were to allow users to easily create a network of IO devices and achieve consistent low latency at the same time. For these reasons we chose the Layer 2 ethernet network protocol, which does not have restricting requirements like, for example, the Layer 3 Ethernet protocol.

The Layer 3 Ethernet protocol, which some ‘audio-over-IP’ networks use, requires various firewall and security permissions. Additionally, in Layer 3, each node in the network needs a unique IP address, which tend to complicate network traffic and connections.

A SoundGrid network does not use IP addresses. Instead, it uses Point-to-Point Protocol (PPP) and connects device MAC addresses directly with no interferences, firewall permissions, or IP addresses.

MAC Address stands for "Media Access Control Address," (it is not related to Apple Macintosh computers). It is simply a hardware identification number that uniquely identifies each device on a network. Every device connected to your SoundGrid network has a MAC address to help you easily identify devices. This allows SoundGrid to be a simple, plug-and-play system.

To make SoundGrid even more efficient, we use both unicast and broadcast protocols. All audio goes through Unicast, all clock and other SoundGrid data go through broadcast.

The network broadcasts all the inventory items to all connected hosts, 10 times a second, so all network operators can see all devices after they are connected.