You can try pointing IPKall directly to the OBi.
You point IPKall to your public IP address and UserAgent port number of the OBi SP trunk used for Circlenet like this:
anything @ xx.xx.xx.xx:5061
xx.xx.xx.xx is your public IP address
5061 points to SP2
If you block scanners by using a UserID, setup IPKall like this:
UserID @ xx.xx.xx.xx:5061
If you don't know your public IP address go here:
http://whatsmyip.org/In your router you have to port forward the UserAgent and RPT ports to the OBi's IP address.
The range of RTP ports can be found here:
Service Providers -> ITSP Profile X -> RTP
LocalPortMin: xxxxx
LocalPortMax: xxxxx
That's 99 port numbers, so use Port Range Forwarding in your router.
If your ISP assigns dynamic public IP addresses and you have a power outage your public IP address might change.