Ciao woah, thank you for your feedback. The protocol is now in its 0.3 release so is now under development, but it is structured in a 2 layer model, with Strategies or Data link layer and PJON protocol layer or in OSI protocol and transport layer. It is optimized to be extensible, configuration driven and with a low overhead. If you are interested in the protocol specification take a look to the latest (0.3)
https://github.com/gioblu/PJON/blob/master/specification/PJO...