- Remote powering of the end device (router or fixed-line telephone) is not possible. (Calls are not possible in the event of power failure.) Call forwarding can be set up in the Customer Center(opens in new tab) if there is no connection.
- Telephones with a dial plate (impulse dial) can no longer be used.
- “Telealarm” devices cannot be used.
- Alarm systems (with analogue telephone connections for alarms) need to be IP-enabled to continue using them.
- Carrier Preselection (pre-selecting other telephony providers) is no longer supported. However you can use different telephony providers on a call-by-call basis.
- ISDN: Several telephone numbers can be used with fixed network telephony (IP). The ISDN network and ISDN devices are no longer supported with an Internet box (these are only supported as part of the universal service with a Centro Business).
- Rented devices (fixed-line telephone): If you switch, the existing rental agreement for the device may be cancelled. In this case Swisscom will let you keep the device. However, it will no longer provide any further maintenance or warranty services.
- Additional telephony services no longer supported: charge display during and at the end of connection, COLR (suppress connected line identification), COLP (display connected line identification), reject reverse charge calls, call back when busy, change end device during call, call transfer, call forwarding, prevent call offering for non-authorised calls (PCONAC)
- SLA Plus and SLA Premium (Service Level Agreements, i.e. specific contracted service agreements with Swisscom).