Is?:
Status -> SP2 Service Status -> Status : Registered
(Your original post said it shows Connected but it should show Registered.)
Assuming you have the VoIP provider on ITSPB, is?:
Voice Services -> SP2 Service -> X_ServProvProfile : B
With this DigitMap, you should be able to dial 1 + area code + number OR 81 + area code + number.
81 + area code + number should be sent out SP2 in either case.
Do you have PHONE Port -> PrimaryLine set to SP2 Service or are you dialing **2 in front of (8)1xxxxxxxxxx?