Cancel Loopback of data


I’m a beginner in embbeded system programming and XBee. Recently I’m using two 802.15.4 XBee to establish a unicast communication. But how can I actually disable the loopback of data packets, as shown in the figure below?

Any guidance and advices would be much appreciated.

Just figured out that I need to take out the loopback jumper to prevent this. The problem is solved! Thank you very much~!