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Two telephone sockets, one number, slow ADSL


Two telephone sockets, one number, slow ADSL


I am new to Plusnet and have found my 2Mbps connection incredibly slow. The BT speed test scored typically between 350 and 700 kbps. My Mac is connected to a socket upstairs (self install), whilst the phone is connected to a socket downstairs (same telephone number).

When I brought my filter and iBook to the downstairs socket with the phone, the speed went to 1.7 Mbps. When I brought my phone upstairs to my computers, the connection speed was 1.6 Mbps. However, if I return the phone downstairs and the computer upstairs then the connection is rotten again.

What gives? Is there some effect of having two sockets in different parts of the house in use at the same time that causes slow connections? Or have BT made a pig's ear of adding the new (upstairs) socket, which they did a couple of weeks ago?

For what it's worth, I am using a Belkin wireless ADSL modem/router (without using the wireless bit yet).

I look forward to your replies...

Thanks in advance,

Community Veteran
Posts: 14,469
Registered: 30-07-2007

Two telephone sockets, one number, slow ADSL

Are you using an ADSL filter/splitter on your phone? If not, you should be.

See ADSL: Wiring and Filters for correct use of filters and ADSL modems when you have extension sockets.

If you connect your ADSL modem upstairs and unplug the phone downstairs, does it get any faster than 250->700K?

The fact that you get good speeds when connected to your master socket (the one downstairs) could indicate there is a possible wiring fault with your extension. If this was fitted by BT then you need to contact BT faults and explain what the problem is you are having, explain it is a BT fitted extension and can it be investigated.

Two telephone sockets, one number, slow ADSL

Thank you very much for this.

The thought had actually occurred to me after I had posted the message. I had wondered if there would be high frequency leakage through the telephone line and I was about to ask whether I needed two splitters. Now I know, and for that I thank you very much.