Are Gigaset phones compatible?
Yes, all Gigaset DECT phones are compatible because they have GAP. However, Gigaset has also equipped some devices with additional functions, such as central phone book, HD voice quality, wake-up call, etc.. , which have been defined with the additional DECT standard CAT-iq 2.0.
With the Sunrise Internetbox from Sagemcom, the blocking is carried out via this.
https://www.sunrise.ch/content/dam/sunrise/residential/hilfe/internet/Sunrise_Home_Handbuch_Sunrise_Internet_Box_neue_firmware_d.pdf
Instruction from page 88.
I have three Gigaset SL450HX in a network. Entries in the phone book are transferred via Bluetooth (not automatically). I don't know if more handsets can be added - but I assume that this should not be a problem. For more information see: http://gse.gigaset.com/fileadmin/legacy-assets/CustomerCare/Manuals/SL4xx/SL450/A31008-M2701-B101-1-19_13-03-2017_de_AT-DE-LU.pdf
The Gigaset works with routers with conventional DECT protocol. This has nothing to do with the Internet provider, but depends on the router or telephone exchange installed in your home.
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.
We had no problems. First deregister the old handsets according to the DX800A instructions and then register the new SL450HX.
This has worked for us for half a year without any problems.
Greetings