I have a Switchvox with 8 Port Digium card servicing two related business with independent lines(phone numbers) that they want to keep separate. What Outgoing Call rules will allow me to have one office use their lines and the other office use their Lines ONLY. This is especially needed on the outgoing call rules. Switchvox by default seems to take the first line available regardless of grouping. I have tried to use 9 prefix for one office and 8 prefix for the other office but is still taking first available line regardless of group association. Any assistance?