I'm sharing my notes on:
OBi202 Configuration for the Main # with two phones to:
1) Ring only Ph1 for a single call, Call Waiting Disabled on Phone 1.
2) Ring Ph2 only for a 2nd Call using "Call Forward Busy Line".
Using ObiTALK configure:
Phone 1 Phone 2
Primary Line for Outgoing Calls Route to: SP1 SP1
Phone Rings on Incoming Calls from: SP1
Enter ObiTALK "Expert" Configuration.
Locate: Physical Interfaces – PHONE 1 Port.
Uncheck – Calling Features – CallWaitingEnable Default Block
Locate: Voice Services – SP1 Service.
Uncheck – CallForwardOnBusyEnable Default Block
Check – CallForwardOnBusyEnable Block on the Left
Uncheck – CallForwardOnBusyNumber Default Block
Add – CallForwardOnBusyNumber Ph2(#)
See: Topic: Obi202 - Using two-line phone with one Google Voice number
http://www.obitalk.com/forum/index.php?topic=6046.0