Eos-Family software can communicate with other devices via OSC (Open Sound Control). OSC is a network protocol that uses either UDP (User Datagram Protcol) or TCP (Transmission Control Protocol).
When using OSC via UDP, the user defines which ports to send and receive messages; for example, Port 8000 for receiving (RX) and Port 8001 for transmitting (TX). The 3rd-party device would have these values reversed - it would receive on Port 8001 and transmit on Port 8000.
When using OSC via TCP, Eos listens for incoming connections on port 3032. TCP is bi-directional, so there is no separate in/out port like with UDP.
In Eos v2.9.0 and higher (including v3.0.0 and higher), Users can define other TCP ports they want to have open on the Eos software via Setup > System Settings > Show Control > OSC. These ports will be either OSC v1.0 (Packet Length) or v1.1 (SLIP) based on the setting in the Eos Shell > Settings > Network > Interface Protocols.
When defining other TCP ports, ETC recommends choosing ports outside the well-known range of 0-1023. The preferred range is 4703-4727 or higher; the highest allowable port# is 65535 (due to a bug, it may be limited to 65534 in some software versions)