We have an issue between two of our locations (L1 and L2). Each location has two HDX 8000 endpoints (E1 and E2). All calls are point-to-point from L1 to L2.
When calling from L1 E1, calls to one of the L2 endpoints work normally, while calls to the other endpoint result in no incoming video to L2 and no FECC from L1 to L2.
When calling from L1 E2, the same issue occurs, but with the other L2 endpoint. So, the result is that each calling endpoint can reach one destination endpoint, but fails to the other endpoint.
In theory, routing and firewall rules should be the same for all endpoints at these locations, but clearly something is different. We've tried opening up the firewall completely between the locations with no effect. Any ideas where to look next?
You are probably on the right path looking at the network between the locations. When you look at the local stats do they show you receiving video frames? If not then for sure the network is blocking them.