A bit more information on this:
Perhaps similar -
Using Real Presence Desktop I called a conference host while wired to my router. With this I had a 10. X IP address and I could not see the other end, though they could see me. (We had audio both ways)
After disconnecting the Ethernet wire and using wifi (same router) I was assigned a 192. X IP address and called from that -- with this we had full audio/video, (albeit with many lost packets).
We repeated this experiment a couple of times