Just got my OBi110, set it up with my Google Voice and so far everything works fine.
I searched this forum and the documentation of how exactly one can use the phone jack and couldn't find an answer.
Can someone, in simple words, explain how in real world one would connect their "phone" (besides the one connected through the "line") and what it would do?
Perhaps an example would demonstrate it best.
Phone port is for one or more traditional phones.
Line port goes to your telco, presuming you have plain old telephone service still.
With such a setup, you can use your traditional phone to dial out either by the LINE or SP1 or SP2.
MRTT
In addition to using the line in connected to a traditional POTS phone service it is a handy way to add other voip providers like (MJ, NetTalk etc.) or using another ATA with other voip providers to chain all of them to use one phone.