In this example, UDP is implemented on top of RPL. An LLN comprises a UDP server, which accepts available packets, and several UDP clients, which send packets periodically to the server through single-hop or multi-hops. Using this sample, you will learn the basic idea of RPL and operate UDP communications easily without manipulating lower layer functions.
Create cooja mote1 for udp-server.c
Create sky mote2 for udp-client.c