On the remote OBixxx:
Define a Speed Dial like:
pp(aaaaaaaaa*1)
Change aaaaaaaaa to the OBi number of the OBi202
On the OBi202:
Voice Services -> OBiTalk Service
Add the following to the beginning of the InboundCallRoute:
{bbbbbbbbb>(<1:>):li},
Change bbbbbbbbb to the OBi number of the remote OBi
If the only rule in the OBiTalk InboundCallRoute is "ph" without the quotes, change it to:
{bbbbbbbbb>(<1:>):li},{ph}
Dial the speed dial number from the remote OBixxx and you will get dial tone from the line port on the OBi202.
Use OBi Expert to make the above InboundCallRoute change.