SurferTim:
It works without internet. The function title is technically incorrect. It receives a packet, then sends a response to the address from which it received the packet. It is like a UDP "server". If you want to see how a UDP "client" works, check out the NTP example.
can I use same code at both sides and just change the IP so i can use both as a transceiver ?
and are you sure it doesn't require internet ? because I made a search and the term UDP always related to internet