GWP is the first protocol widely used by LoraWAN. It started out as a proposal from Semtech to prove the concept. Essentially GWP is just JSON wrapped in UDP.
It has become apparent that there is a need for a GWP proxy, not only to provide access for multiple gateways. but also to provide debugging. Using this GWP proxy it was possible to discover a design flaw in interoperability between the RAK2287 software and The Things Network. In the protocol specification it makes use of a ‘temp’ variable in the ‘stat’ data structure. Which RAK Wireless implemented.
The Things Network silently discarded the entire packet and reset the last seen counter. The result from this was the gateways current GPS position was also discarded, and incoming packets from devices would not be stamped with the GPS co-ordinates.
The GWP proxy can be found on GitHub. https://github.com/Scobber/GWP-Proxy
Because this was a quick implementation, it lacks some features. It will provide bi-directional communications. and all output is visible on STDOUT.
The RAK2287 Gateway can be found:
Packet Forwarder Protocol
Github Issue https://github.com/RAKWireless/rak_common_for_gateway/issues/19