I'm in the UK. We have a master phone socket downstairs, and an
> upstairs extension that taps into the main socket by the use of a
> splitter plugged into the main socket. The extension plug is an RJ14,
> but the splitter's socket is an RJ11 (2 pins instead of 4).
> On the downstairs socket, we can use a phone, yet on the upstairs one,
> we can't -- we just get no dialtone. But here's the weird thing --
> the ADSL connection works fine when the modem's plugged into the
> upstairs socket. Any ideas why that might be? I thought the extra
> two pins on the RJ14 were superfluous when you only have one phone > line.
Sounds to me like it's not a normal splitter, but it's your ADSL filter.
Use filter on your main socket and ensure that any telephone extensions come out of the Phone part of the splitter.
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