FRITZ!Box 7581 Service - Knowledge Base
Maximum number of calls over the FRITZ!Box
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 five 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.
1 IP telephones
Two connections are established when you conduct a call with an IP telephone configured for the "LAN/WAN" port: The internal connection between the IP telephone and the FRITZ!Box, and the connection to the external party. You can therefore conduct a maximum of two simultaneous calls with IP telephones, and the number of possible calls is reduced.
If you conduct a call with an IP telephone, three additional calls can be made using the other interfaces.
If two IP telephones are being used to conduct calls, one additional call can be conducted using the other interfaces.
2 DECT devices
You can conduct a maximum of three calls at the same time using cordless telephones that are registered with the FRITZ!Box's DECT base station.
If calls are being conducted with three cordless telephones and an IP telephone, you cannot conduct an additional call using the other interfaces.
If calls are being made with three cordless telephones and an analog telephone, the integrated answering machine or the fax can accept an additional call. You cannot conduct an additional call with an IP telephone.
3 Analog devices
One call can be conducted with each of the analog devices connected to the "FON 1" or "FON 2" port.
4 Integrated answering machine and fax function
The answering machine and the fax can each accept one call. All other callers hear a busy signal, even if you set up more than one answering machine. You cannot send a fax while receiving a fax, and you cannot receiving a fax while sending one.