Asio UDP echo server example

Simple Asio UDP echo server using WiFi STA or Ethernet.

Example workflow

Wi-Fi or Ethernet connection is established, and IP address is obtained.
Asio UDP server is started on port number defined through the project configuration
Server receives and echoes back messages transmitted from client

Open the project configuration menu (idf.py menuconfig) to configure Wi-Fi or Ethernet. See "Establishing Wi-Fi or Ethernet Connection" section in examples/protocols/README.md for more details.
Set server port number in menuconfig, "Example configuration".
Run idf.py -p PORT flash monitor to build and upload the example to your board and connect to it's serial terminal.
Wait for the board to connect to WiFi or Ethernet (note the IP address).
You can now send a UDP message and check it is repeated, for example using netcat nc -u IP PORT.

See the README.md file in the upper level 'examples' directory for more information about examples.