I have had such bad experiences with Centro Grande and Swisscom in recent years that I can unfortunately no longer consider this company. I therefore now rent my Internet connection from Init7, and my IP telephone provider is Sipcall. The Gigaset is connected (directly) to a Fritz!Box. There are a few problems with this, but basically it runs out-of-the-box. The probability that the Gigaset SL450 HX will run on a Swisscom/Pirelli Centro Grande is close to ZERO.