You can route calls from the OBi202 over the OBiTalk network to the OBi110 and then out the Line port. Make the following configuration changes with OBi Expert:
OBi202:
Physical Interfaces -> Phone1 and 2 Port
PrimaryLine: OBiTalk Service
Add the following to the beginning of the OutboundCallRoute:
{(1xxxxxxxxxx):sp1},{(<200123456*>xx.|222222222):pp},
Replace 200123456 with the OBi number of the OBi110
Voice Services -> OBiTalk Service
DigitMap: (xx.S3)
InboundCallRoute: ph,ph2
OBi110:
Voice Services -> OBiTalk Service -> InboundCallRoute:
{510123456>(xx.):li}
Physical Interfaces -> Line Port -> InboundCallroute:
ph,pp(510123456)
Replace 510123456 with the OBi number of the OBi202