Do you need long distance service for DSL?

Yes, if the fax is being sent to a long distance number. You dial a fax number on a fax machine exactly the same way that you would dial the same telephone number on a landline telephone at the same location. If the phone line you have the fax machine connected to cannot call long distance, then the fax machine will not be able to send a fax to a number outside your local calling area.