FRITZ!Box 7390 Service - Knowledge Base
Number of telephony and DECT devices that can be used with the FRITZ!Box
You can use different types of telephony devices, for example telephones, fax devices, answering machines, or PBXs, with your FRITZ!Box. Your line type determines how many devices can be used.
1 DECT devices
2 IP telephones and IP door intercom systems
3 Analog devices
4 ISDN devices
You can connect up to eight devices at the same time, for example a telephone or PBX, to the "FON S0" port on the FRITZ!Box by means of an ISDN hub or S0 bus cabling. The FRITZ!Box can provide power to one ISDN device. The other ISDN devices must use their own power supply.
The ISDN service indicators you can use depends on whether you use your landline or the Internet (VoIP) to make the call. You can use the following ISDN service indicators when making calls over the Internet (VoIP), on an analog landline or an ISDN line:
- Voice (service indicator 1)
- Audio 3.1 (service indicator 4)
- Telephony (service indicator 16)
- Fax G2/G3 (service indicator 17)
When making calls on an ISDN line, you can also use the following ISDN service indicator:
- Data (service indicator 2)