The combination of DevEUI AND AppEUI uniquely identifies the entity able to process the JoinReq frame?

TTN V2 to V3 Upgrade
1

I have a LoRaWAN 1.0.2 device (A) and I can give this device a DevEUI=02E8EB4E2C220B4F and AppEUI=0000000000000000 with my Arduino sketch.
In the TTS CE console I enter the same DevEUI and AppEUI.
This setup works, and I can receive sensor data from device A in the TTS CE console.

I have a LoRaWAN 1.0.2 device (B) and I can give this device a different DevEUI=A207BE18CC660ABB and AppEUI=0000000000000000 with my Arduino sketch.
In the TTS CE console I enter the same DevEUI and AppEUI.
This setup works, and I can receive sensor data from device B in the TTS CE console.

According to LoRaWAN 1.0.x specification, the AppEUI is a EUI-64 identifier that uniquely identifies the entity able to process the JoinReq frame.
In the example above the AppEUI are both 0000000000000000.

My question is:
Does this mean in the TTS CE the COMBINATION of DevEUI AND AppEUI uniquely identifies the entity able to process the JoinReq frame?

2

That combination with the AppKey provides the credentials required to process the join request. In TTN this combination is set on a virtual device (part of an application) and the information of that virtual device will be used to generate a response frame.

In TTS(CE) you will not be able to register the same DevEUI and JoinEUI/AppEUI for two different devices. That is why it is extremely important people use allocated unique EUIs and do not start using random values that might collide with EUIs provided by a hardware vendor from its range.

3

Jac, thanks for your confirmation. I was not 100% sure of it.