When configuring a MultiTech Gateway for TTN, MultiTech’s lora packet forwarder is replaced by TTN’s poly-packet-forwarder.
I’d like to understand what’s going on inside of the TTN poly-packet-forwader. I could find the source code for Semtech’s lora packet forwarder here. Where can I find the source code for the TTN poly-packet-forwarder? Is it open sourced?
A quick search on our Github would probably have taken you here: https://github.com/TheThingsNetwork/packet_forwarder
Although most guides use the poly forwarder, most people won’t need the poly forwarder and can just use Semtech’s. We hope to move away from the packet forwarder entirely (we don’t like using unreliable transport over the public Internet) and are therefore working hard on a replacement 
The version used for the MuliTech gateways is based on the sources @htdvisser refers to with a few modifications. You can find the source at my github repository (sub dir poly_pkt_fwd)
@htdvisser: if you look back at last years conversations on this forum you will find messages relating to the poor performance of the gps packet forwarder as supplied by MultiTech at that time, that was why I started building the poly forwarder for the MultiTech gateways. (The standard packet forwarder does not send position information so gateways using it will not show on the map)