osc only working when receiver opened first

beginners
#1

My two openframework applications only communicate when the receiver is opened first. Otherwise I get no messages.

receiver:

  
  
void trackingDataReceiver::init(int _oscPort){  
	receiver.setup(_oscPort);  
}  
  
//--------------------------------------------------------------  
void trackingDataReceiver::update(){  
	if(receiver.hasWaitingMessages()){  
		while(receiver.hasWaitingMessages()){  
			// get the next message  
			ofxOscMessage m;  
			receiver.getNextMessage(&m);  
			//parse message  
			if(m.getAddress() == "/trackingPacket"){  
				trackingData.clear();  
				trackingDataPacket tempPacket;  
				int blobCount = m.getNumArgs()/6;  
				for(int i=0; i<m.getNumArgs(); i+=6){  
					tempPacket.id = m.getArgAsInt32(0+i);  
					tempPacket.x = m.getArgAsFloat(1+i);  
					tempPacket.y = m.getArgAsFloat(2+i);  
					tempPacket.size = m.getArgAsFloat(3+i);  
					tempPacket.distFromCam = m.getArgAsFloat(4+i);  
					tempPacket.speedX = m.getArgAsFloat(5+i);  
					trackingData.push_back(tempPacket);  
				}  
				timer.set();  
			}  
		}  
	}  
}  
  
//--------------------------------------------------------------