New to VOIP - loud "no service" tone on extension sockets

[LukasD]

My landline switched over to VOIP today but I'm still on FTTC broadband.  The master socket is in my bedroom but I need the phone's base unit downstairs in the living room using the extension socket.  So I'm running a cable from the green Tel port on the router to the master socket and then plugging the phone in downstairs.

This works but the problem is that there's still an audible "no service" tone on the line at all times.

Is there something I can change in the wiring to get rid if it?  Or will it eventually shut off on its own?

[Jayach]

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@LukasD wrote:
This works but the problem is that there's still an audible "no service" tone on the line at all times.

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First question, is the "no service tone" still there if the phone's base, (I presume DECT?) connected direct to the TEL socket?

[LukasD]

No.  When plugged directly into the router there is only a normal dial tone.  When plugged into the extension there's both the dial tone plus the no service tone.  It seems like even though the phone service has been terminated the handset is still picking up a connection to the network.

I know the solution with FTTP is to disconnect the A & B wires from the master socket, leaving only the internal wiring.  But of course with FTTC I still need that connection.

[CrimsonLiar · Accepted solution]

You'll need to disconnect the extension wiring from the master socket and wire the extensions into the router, what you are currently hearing is exactly what would be expected from feeding the phone signal back into a socket.

[Jayach]

As @CrimsonLiar says what you need to achieve is know as VRI (Voice Re-Injection)

If you search for that on your favourite search engine, you should find lots of help

[LukasD]

Alright, I've snipped the end off of an old microfilter and connected that into the extension wiring, with an RJ11 cable running to the router.  It's a bit messy but it seems to be working ok.