As we understand that data flows from Sensor-1 and 2 to TTN through Gateway-1 and to Thingsboard.
While registering the devices in TTN, we create an application and adds the devices. There is a separate option for registering the gateway.
I am not understanding what is the link between devices and gateways. How does sensor-1 sends data through gateway-1? Or how can we restrict that sensor-1 sends data only through gateway-1?