The interface (for example DECT, LAN, FON 1) limits the maximum number of calls that can be conducted over the FRITZ!Box. You can conduct four calls over the internet. Below you will find the number of calls possible with each type of interface. To find out how many calls you can conduct with your devices, you will have to calculate a little. We have given you a couple of calculation examples.
If you conduct a call with an IP telephone, two additional calls can be made using the other interfaces.
If two IP telephones are being used to conduct calls, no additional calls can be conducted.