Using an ADSL/VDSL FRITZ!Box just as a DECT base station and PBX

[jfraga]

I have a fiber Internet connection and my router has two FXS ports.

I was wondering if I could connect the DSL/TEL port of an old ADSL/VDSL FRITZ! Box (7340, 7360 or 7390) in order to use it just as a PBX and DECT base station (and potentially network switch as well).

Is it mandatory to use an ADSL splitter in between, or will the FRITZ! Box be able to receive/make landlines without a splitter?

 

[the other]

Hey there,
In case you mean using another fritzbox as an IP client, here is a link by the manufacturer
https://en.avm.de/service/knowledge...up-the-FRITZ-Box-for-use-with-another-router/

That way you can use dect as well as lan ports 2 to 4. Dns, dhcp and such will be managed by your router. To connect the boxes a lan cable is enough. Connect lan port #1 of routing cable fritzbox to lan #1 of IP client fritzbox.

 

[the other]

Hey there,
Forgot to mention: you can even use it as a WLAN access point.

 

[jfraga]

Hey there,
In case you mean using another fritzbox as an IP client, here is a link by the manufacturer
https://en.avm.de/service/knowledge...up-the-FRITZ-Box-for-use-with-another-router/

That way you can use dect as well as lan ports 2 to 4. Dns, dhcp and such will be managed by your router. To connect the boxes a lan cable is enough. Connect lan port #1 of routing cable fritzbox to lan #1 of IP client fritzbox.

Thank you.
I expected that to be possible. My main doubt has to do with the phone/PBX service. I'm wondering if I can manage to get the FRITZ! Box to make/receive landline calls by connecting a phone line to its DSL/TEL port. Mind I don't have an ADSL connection. Just a fiber connection and a router which provides two FXS ports.

 

[Stationary]

If your device has FXS ports, these would usually be RJ11, please correct me if I am wrong. In such case, these ports are normally meant to connect terminal analogue devices, like an office phone or a fax machine. The ingress port of the Fritzbox box is RJ45. I would guess that if your device provides FXS ports it will have already split an incoming signal.
Hence, one small consideration, if you wish to give it a try: the Y-Cable that used to be delivered with Fritzboxes for use with external splitters only provided 3 RJ45-connectors, no RJ11-connector was present on that cable, see image below.
If you have a Fritzbox at hand and don‘t need to buy one first, you might try to buy 1-2 meters of telephone cable, a RJ11-connector and a RJ45-connector and prepare a cable by yourself, the RJ11 needs to be connected based on how the FXS is wired, the RJ45 on the other end should probably be wired on 3 and 6, for receiving an analogue signal.

 

[jfraga]

That is a very relevant piece of information, @Stationary. My device has RJ11 plugs indeed.
Thank you so much.