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Broadband dropping out with incoming voice calls

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Broadband dropping out with incoming voice calls

I was wondering if anyone could help me with a problem with my BB connection.

I have recently wired in a phone extension socket, from the BT master socket something I have done a few times before with no problems.

Upon connecting my router via a filter the router connects to plusnet with no problems. Unfortunately as soon as the phone rings (which is connected to the filter as well) the router loses connection.

It connects again when the phone stops ringing even if someone answers it. Bit of a mystery to me this one, anyone got any ideas?

Thanks


J Coleman
10 REPLIES
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Broadband dropping out with incoming voice calls

Have you exceeded your ren? Faulty filter? Some old phones draw to much current and cause it try another phone. How have you connected to the bt box? does it happen if the router is in the master box or just the extention?
chymorva
Grafter
Posts: 275
Registered: 29-08-2007

Broadband dropping out with incoming voice calls

Hi,
The filter filters out the interference caused by the phone and so all phones must be connected through filters. The ADSL signal passes straight through the filter so it makes no difference whether the router is connected via the filter or not (other than the plug size is different).
Hope this helps.
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Broadband dropping out with incoming voice calls

In answer to your questions:

I have not exceeded the REN, I only have one extension which comes off the master socket. The phone is connected to the extension socket via a filter and the master socket has a sky box connected (without a filter) The phone (and filter) I am using is quite an new one and has worked in a similar installation before in a different house.

From reading your comments it sounds like I need another filter for the sky box. I'll get another filter and try that. However I thought the filter merely filters out the noise from the ADSL to enable a clear telephone line not the other way round as stated.

Thanks for your help guys
Community Veteran
Posts: 38,216
Thanks: 913
Fixes: 54
Registered: 15-06-2007

Broadband dropping out with incoming voice calls

I confirm. The Sky box must have a filter.
chymorva
Grafter
Posts: 275
Registered: 29-08-2007

Broadband dropping out with incoming voice calls

Quote
... However I thought the filter merely filters out the noise from the ADSL to enable a clear telephone line not the other way round as stated.

No. The ADSL signal passes straight through the filter, the filter filters out the interference caused by the phone.
shellsong
Grafter
Posts: 2,191
Registered: 03-08-2007

Broadband dropping out with incoming voice calls

Surely the filter is a form of crossover circuit-- low pass to the phone and high pass to the ADSL modem because you don't want interconnection in either direction!
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Broadband dropping out with incoming voice calls

The ADSL filter is a cross-over unit that feeds the high frequency data to ADSL and the low frequency to the telephone. The pulses that BT send to ring the handset can mess with the high frequency components hence the dropouts.
N/A

Broadband dropping out with incoming voice calls

Thanks for your help, it is all ok now, although I've disconnected the sky box for the time being until I find my spare filter.
chymorva
Grafter
Posts: 275
Registered: 29-08-2007

Broadband dropping out with incoming voice calls

Quote
The ADSL filter is a cross-over unit that feeds the high frequency data to ADSL and the low frequency to the telephone. The pulses that BT send to ring the handset can mess with the high frequency components hence the dropouts.


Sorry, but I have to disagree Shockedops:

Most ADSL filters/splitters (call them what you will) have one input (from the phone line) and 2 outputs (one marked Phone, the other marked ADSL).
The circuit to the Phone is a low-pass circuit so that:
(i) the higher frequency ADSL signal is not heard on the telephone, and
(ii) high frequency spikes caused by the telephone do not interfere with the ADSL router/modem.
The circuit to the ADSL is normally a straight-through connection.
This means that you do need a filter at each socket where a telephone (or fax,sky box, etc..) is fitted, but not necessarily where the router is fitted.

On my own setup, I have a DIY extension kit plugged into the master BT socket in the hall. At the other end of the extension cable is an ordinary BT socket in the study where I used to have my dial-up modem plugged into. I now have my router connected to it. Back in the hall I have my filter plugged into the back of the DIY extension plug/socket and my phone is connected to this filter.
So, as you can see, the filter is nowhere near the router and is there purely for the phone.
I have a rock solid connection with only the occasional restart on the router. Cheesy
chymorva
Grafter
Posts: 275
Registered: 29-08-2007

Broadband dropping out with incoming voice calls

Quote
Quote
... However I thought the filter merely filters out the noise from the ADSL to enable a clear telephone line not the other way round as stated.

No. The ADSL signal passes straight through the filter, the filter filters out the interference caused by the phone.


Sorry if I have caused confusion over this Shockedops: . Reading my post again I can see it can be taken both ways :!:

What I meant was that there is normally no filtering applied to the ADSL socket on the filter, only a low pass filter to the phone socket (which stops the phone from interfering with the signal at the ADSL socket and also stops the ADSL signal from appearing at the telephone).
Hope this is a little clearer :?