Dear HenrykG
No limitations with these devices are known to us. It is important to make sure that in the use of Vivo Casa on the latest technology (Voice over IP http://bit.ly/MHA1e6) no ISDN fixed network devices can be used. Do you have any additional questions about devices from other manufacturers? Contact us by phone and we will check the possibilities for an individual support with you, such as through our Amico Team: http://bit.ly/NxEbpP.
Kind regards
KatrinM
Swisscom