My Obi202 has two phones connected, and at my voip service provider I have two DIDs (one on a sub-account). Only the phone being called should ring, but when either number was called both phones rang. After my voip service provider vetted my settings in their control panel as correct, I found the solution in the Obi202 Settings Wizard:
In Voice Services > SP1 Service, change X_InboundCallRoute from "ph,ph2" to "ph". Then in SP2 Service change X_InboundCallRoute from "ph,ph2" to "ph2".
I had failed to notice that there's a comma instead of a period in the default setting for X_InboundCallRoute (ph,ph2). The comma means "ring ph and ph2".
I hope this helps anyone with the same problem.