Your use case does not match LoRaWAN. For LoRaWAN one device is always a gateway and the other always a node. If both devices have a permanent IP connection there is no need for LoRaWAN.
Also, packet forwarders will not talk to other packet forwarders, a packet forwarder never sends any data without the back-end telling it to do so and the back-end does not push data to a gateway if it has not seen data from a node arriving. (And then it might send a reply packet to that node)
Using plain LoRa (or with your own protocol) sounds a lot more achievable. If you do so, please choose a frequency not being used by TTN (or other LoRaWAN providers) in your vicinity.