xxxx-xxxx or 9xxxx-xxxx inside SP:
just call 8-digit number no extension no 011
xx-xxxx-xxxx (long distance)
call literally 0800-xxx-xxxx, ignore the error messages
there is a secret code which Vilma knows, the IFT will pay
You have to dial fast; a delay in 2-3 seconds between button presses may lead to disconnection.
This makes dialing very inconvenient.
Fortunately, there is a way to dial automatically, or at least almost automatically.
First, have to determine the IP of the telephone, by pressing the Setup Key and navigating to Network. You find something like this: 22.214.171.124 (just an example)
"28078" → "38384000"
This sets SPEED DIAL No 2 to this number: 38384000
Sample script is available here.