[router] Write down first sketch of interfaces between router and side components
[router] Write down first sketch of interfaces between router and side components

LoRaWanSoFa/ttn,mgranberry/ttn,TheThingsNetwork/ttn,LoRaWanSoFa/ttn,jvanmalder/ttn,jvanmalder/ttn,mgranberry/ttn,TheThingsNetwork/ttn,mgranberry/ttn,jvanmalder/ttn,TheThingsNetwork/ttn