We used to do radio management like the following diagram.
Blue is a VLAN which we are using to route between the two POPs, and red is a VLAN used for device management at the POP on the left.
If the router at the remote side had issues, you were at least able to confirm it was the router, and not the link in the middle.
We would run OSPF over the blue VLAN, but red was basically an access VLAN solely for management devices.