If several telephones are registered on your Internet-Box, you can use them to make free calls between these phones. You don’t need more than one phone number for this. You can, for example, assign the number 201 to your handset in the living room. You can then dial the internal number 201 on the phone in the bedroom to call your phone in the living room. You can assign the internal short numbers to the individual telephones in the web portal (http://internetbox.home or 192.168.1.1).
Making or forwarding calls internally with a Centro Business 2.0 (HD-Phone Nyon, Gigaset SL360HS and Gigaset CL660HX) is also free of charge and does not require additional telephone numbers. However, you do need an additional phone number/line to forward calls on an IP-Phone (e.g. Yealink T46G, Sarnen HD-Phone) with inOne SME Office.
Internal forwarding is possible only from a cordless HD-Phone to another cordless HD-Phone or to an analogue telephone that is connected to phone port 1 or 2 on the Internet-Box.