I have 2 obi200 devices at home on the same LAN. 1 freephoneline number on each obi200. Everything works except the two phones can not talk to each other. The phone rings but cannot hear each other. If I call the obi number of the other phone, there is no problem.
Perhaps forwarding your RTP ports would solve the problem.
1) Use your router to assign a static IP to each ATA.
2) Navigate to Service Providers >> ITSP Profile X >> RTP. Set each ATA to use a different LocalPortMin and LocalPortMax range, for example, 20000-20010 for the first OBi and 20011-20020 for the second.
3) Use your router to forward the UDP ports 20000-20010 to the first OBi's IP address, and 20011-20020 to the second OBi's IP address.
4) Test to see if the problem is solved.
Alternate solutions: use the OBi's dial plan to route calls to the other ATA's phone number via OBiTALK. Or, try to use voip3.freephoneline.ca - if that works, file a ticket with FPL and advise that you have no audio unless you use voip3.
Thank you so much.
The port forwarding solution does work.
Is there any security concerns of port forwarding?
I'm unaware of a way to attack an OBi ATA via its RTP ports; doesn't mean it's not possible or will not one day become possible though.
If you are particularly security-conscious, with some routers, you can restrict port forwarding to traffic from a specific IP. I know this works with Tomato; haven't tested it with other routers.
Example:
OBi A LocalPortMin 20000 LocalPortMax 20010 IP 192.168.1.10
OBi B LocalPortMin 20011 LocalPortMax 20020 IP 192.168.1.20
Forwarding rules:
From 192.168.1.20 20000-20010 UDP To 192.168.1.10
From 192.168.1.10 20011-20020 UDP To 192.168.1.20