AbletonOSC uses a fixed port pair: commands arrive on 11000, replies go out on 11001

AbletonOSC listens for incoming OSC messages on UDP port 11000 and sends all replies to UDP port 11001 on the same IP address as the originating message. This asymmetric port arrangement means a client must bind a listener on port 11001 to receive responses. Replies are sent to the last IP address that sent a message — a deliberate simplification that means only one client IP can receive listener/beat-update push messages at a time. When building a Python client, this requires two sockets: one for sending (to 11000) and one for receiving (on 11001). Tools like SuperCollider’s NetAddr or Max’s udpsend/udpreceive must be configured to match this port split.

Examples

Python client setup: send socket → (‘127.0.0.1’, 11000); receive socket bound to (‘0.0.0.0’, 11001). In Max/MSP: [udpreceive 11001] to receive replies, [udpsend 127.0.0.1 11000] to send commands. The run-console.py utility automates this pairing.

Assessment

A student connects to AbletonOSC and sends /live/song/get/tempo but receives nothing. What is the most likely cause? On which port should they bind their receive socket?