I was with ViaTalk for over 2 years, and all their "quick dial" numbers had to be pre-fixed with *
So I would dial *123 for voicemail, *01 for my first fast-dial contact, etc.
If I create an outgoing call route with "142", with VoiPO, I cannot use 11-digit dialling when calling the Seattle area (1-425-xxx-xxxx).