Hi, I did not try liblo yet, but it would be the alternative, if I cannot figure out how to get it working with pyOSC. Why so offensive? I expect nothing! I ask for help, if you dont want to, then dont. Anyway... I am reffering to this version of PyOSC: https://gitorious.org/pyosc/devel/commits/python3 I have a python3 app, that calls a class OSC_Communication. address = localhost, port = 9001 class OSC_Communication(object): def __init__(self, address, port): self.osc_server = ForkingOSCServer((address, port)) self.register_osc_callbacks() #__________________________________________________________________________________________________ def register_osc_callbacks(self): self.osc_server.addMsgHandler("/test", self.test_callback) self.osc_server.addDefaultHandlers("", "/info", "/error") print ("Registered Callback-functions are :") for addr in self.osc_server.getOSCAddressSpace(): print (addr) #_________________________________________________________________________________________________ def test_callback(self, path, tags, args, source): print("test") #__________________________________________________________________________________________________ as simple as it is, it does not receive any OSC message. The addressing is correct and the messages are sent. I checked with puredata and printed messages correctly. Wireshark captured messages correctly as well. So, what am I missing? Regards, Ck