I assume you have an OBi110 and the Line Port is connected to the Land Line.
Do you have a VOIP provider and is it defined on SP1?
Assuming your VOIP provider is on SP1.
All domestic calls routed to the line port.
International calls routed to SP1.
Physical Interfaces -> Phone Port
Add to the beginning of the DigitMap:
011xxxxxx.S3|
It should look like this:
(011xxxxxx.S3|......Current Rules........)
Physical Interfaces -> Phone Port
Add to the beginning of the OutboundCallRoute:
{(<011:00>xxxxxx.):sp1},
Physical Interfaces -> Phone Port -> Primary Line: PSTN Line
This is the default.
Physical Interfaces -> Line Port -> DigitMap:
(xxxxxxx|1xxxxxxxxxx)