Technical specifications Interfaces 4 x gigabit LAN (10/100/1,000 Base-T) Wireless access point compliant with IEEE 802.11ac, n, g, a 1 x USB 3.0 and 1 x USB 2.0 for printers and storage media 1 x gigabit WAN Internet Wireless router for the connection to a cable/DSL/fiber optic modem or 4G/3G dongle Use of existing Internet connections via LAN and wireless LAN Support for IPv6 Stateful Packet...
> https://en.avm.de/products/fritzbox/fritzbox-4040/technical-specifications/
Callers hear a fax toneCallers hear a fax tone when they call you. The telephones connected to the FRITZ!Box do not ring or only ring a couple of times and you cannot answer the call. Cause A fax (external fax machine, integrated fax function of the FRITZ!Box, or fax software) answers the call immediately, so you cannot answer the call with a telephone. Simply proceed as described below. After...
> https://en.avm.de/service/knowledge-base/dok/FRITZ-Box-7690/1199_Callers-hear-a-fax-tone/