Morgen,
We use an OBi202 with a two line portable phone for our Home phone service.
I configured the following OBi202 configuration settings using OBiTalk OBiExpert Mode.
Voice Services > SP1 Service > X_InboundCallRoute > {ph1}
Calling Features > CallForwardOnBusyEnable [x} {Checked}
CallForwardOnBusyNumber ph2(#)
Physical Interfaces > PHONE1 Port > PHONE Port > Calling Feature
CallWaitingEnable [ ] {NOT Checked}