Do not bother getting a grandstream product.
I spent an extra 3 hours working on 2 of them.
Both had an incorrect mac address on their label.
I’d bet there are thousands of others with the same problem.
Correction: I did not know that there are 2 mac addresses per unit.
So when trying to configure using a mac address, only one of the addresses is marked on the box or device.
It would be better if the lan and wan macs were specified.