I notice that UDP does not car about client and server, you just make a UDP packet with ip and port to send the data! But do the Arduino at the other end (on a other network, i'm transmitting over internet) need port forwarding..i know that with tcp/ip the server need it..but for UDP there's no definition of server..there's no answer. there's no definition of client too..
how the data will get to the arduino at the other end if there's a router and other machine connect to on it's home network(LAN)?