single stage dialing is only possible from another endpoint (Obi device or Obion app).
for an app,
click on the softphone number in your account, above your Obi device in the list. Select the "Obi Voice Gateway" that you want to use with that softphone number. You log into the app using your Obitalk credentials and that softphone number becomes the Obi number for that app. Since you have already selected the default gateway for that softphone, you just dial a 10 digit number and it is routed through the default gateway using the configuration of the device.
If you have sp1 as the default line in the device then that is the line that will be used to route the call from the app. You can edit the call route to change the path of the calls from the app if you want. So if you route through sp2 then sp1 will still be available for incoming & outgoing calls from the Obi itself.
From another Obi device,
The Obi device has to belong to the circle of trust for the other one in order to access it's service.
Single stage dialing from one device to another is accomplished by using a speed dial setting. You put the Obi device in your speed dial list and then append that speed dial location with * before the desired number.
example: obi in speed dial location 2. Press 2* + 10 digit # to dial direct through the second Obi using it's configuration.
this will be most popular for overseas calling.
Calling from a regualr phone number,
If you are calling from a regular number you will have to access the Auto Attendant and use 2 stage dialing. your number has to be in the circle of trust in order to acces the AA.