Hi Johan,
I've only recently discovered your project so apologies if these are issues that have been addressed previously.
1/ Is this design for a single region/city roll-out of lorawan? or is the intention to scale to a single global network to allow unconstrained roaming of nodes and applications?
2/ It seems there are too many components in between the nodes and the application. The Handler and Application are tightly knit and could be integrated (or treated as such from a network perspective). Could the functionality of the Network Server be incorporated with the Router?
3/ Once the Router has consulted the Broker to find the route to the Handler/Application do the data packets need to be sent via the Broker? Why not send them direct from the Router to the Handler/Application?
4/ What are the plans for transport layer security between these network objects? IPsec or TLS?
I have some thoughts on scaling that I will write up separately.
Aled