The Roland Digital Snake System uses the REAC (Roland Ethernet Audio Communication) interface for data transfer through a standard Ethernet cable. If an S-4000D or S-4000SP is not being used to split the audio, an Ethernet switching hub must meet the requirements below.

Important Note: A 3rd party switching hub can be used to split audio (output audio) only. If additional digital snakes are needed to increase input capacity, an S-4000M Merge Unit is required:
https://proav.roland.com/global/products/s-4000m/

Ethernet Switching Hub Requirements:

• 1000BASE-T transmission speed (IEEE802.3ab, Gigabit Ethernet)
• Support for 100BASE-TX devices (IEEE802.3u, Fast Ethernet)
• Bi-directional (full-duplex) communication
• Connect REAC devices only to switching hub ports that support 100BASE-TX.
• REAC calls for unmanaged gigabit switches only. Be sure to only use an unmanaged gigabit switch and not use a managed gigabit switch.
• Multicast should be on
• If straight Ethernet cables are being used, the switcher must have support for MDI/MDI-X. This is an auto-sensing protocol that allows switches to manage data over standard straight and crossover cables.
  
  * Consult the switching hub's documentation for information regarding it's specifications and whether or not it meets these requirements.
  
  Note:
• The transmission protocol for REAC is based on 100BASE-TX (Fast Ethernet). To transfer 40 channels of digital audio, REAC uses the full bandwidth of this protocol. However, some 100BASE-TX switching hubs cannot handle this amount of data traffic. Gigabit Ethernet switching hubs can handle a larger amount of data traffic, so we recommend them for use with REAC devices (just be sure that the Gigabit switching hub you use supports 100BASE-TX devices).