using POTS mainly

[Ruslan]

I am deciding to purchase OBi110, which will be connected to a POTS line and GV.
How to OBi distinguish if the call needs to be made through the POTS line or a VoIP service?
In my case most of the calls will be made through POTS line (no VoIP used).

Should I enter some prefix or something so device will know what service to use?

(didn't find answer in the data sheet on the web site...)

[RonR]

By default, an OBi110 will use the LINE Port (PSTN line) for outgoing calls.

To use the SP1 Service or SP2 Service instead, dial **1 + number or **2 + number.

[Felix]

By default, an OBi110 will use the LINE Port (PSTN line) for outgoing calls.

By default are the operating words here. You can easily set up pretty much any way you want. for example, I set up my dad that 7-digit numbers go through POTS; numbers starting with 1 go through GV, and numbers that start from 2-9 and not 7 digits (that is, international) go through CallWithUs. You are limited only by your imagination... and by clarity of what you actually want 

[Ruslan]

"set up my dad that 7-digit numbers go through POTS; numbers starting with 1 go through GV, and numbers that start from 2-9 and not 7 digits (that is, international) go through CallWithUs. "
@Felix, can you please point me to the docs where calling plans got described? I am okay with regexes.
Thank you.

[RonR]

OBi Device Administration Guide