Hi Briankelly,
By default, OBi110 assumes call is connected as soon as you finish dialing on LINE port, that is why you hear the ringback instantly, while the actually PSTN ringback comes a little bit late. OBi110 also provides advance setting on PSTN dialing, please go to
Physical Interface -> LINE port -> DetectOutboundConnectMethod
From there, you can choose OutboundConnectMethod to be "Detect Speech", the ringback will be ended as soon as the actual comes through LINE port. Please have a try, and see if you get better experience,
Thank you,