I was playing around with my OBi202 conference calling feature this evening, which is described on page 146 of the OBiDeviceAdminGuide.pdf. When one flashes the hook and dials a number to add a 3rd party to the call, the AdminGuide explains that you can flash back to the original caller while the to-be-added party's line is still ringing: "We refer to [this] case as an early conference, where the second conferencee is still ringing; the other 2 parties may converse while hearing ringback tone in the background until the 3[rd] party answers." This is almost how it works for me, except that on my OBi neither party in the original call hears the background ring tone. When the third party answers, if they answer, they are indeed bridged onto the call.
I suppose this is OK if you understand how it works, although I think having the background ring tone is the preferable implementation. It does raise the question of how long the 3rd party's call setup attempt will go on if they never answer their phone and you forget you've tried to add them onto the call.
Is this consistent with the way it works for the rest of you, or do you hear ringtone in this situation?
Inquiring minds want to know.