If you have a Belgacom ADSL (and only Belgacom) and that ADSL uses the phone line for support, you must first ask Belgacom (Tel: 080 033 800) to change your ADSL fixed line to a DSL line without Fixed line (raw copper). Indeed, in the other case your line will be cut following the number portation . Without broadband, you can not start with internet telephony. Belgacom will give you a date they will make the change. Communicate us that date and we will then transfer your number the same day avoiding any interruption of service.