Broadband/phone extension line max length

  Midsman2005 17:17 01 Sep 2006

Dear Forum,

Does anybody know what the approximate maximum extension line length, from the phone socket to the PC modem, can be for adsl without badly effecting speed, connectivity, reliability, etc.


  rawprawn 17:21 01 Sep 2006

I don't know the maximum, but I have about 15m with no adverse effect.(ADSL)

  anskyber 17:25 01 Sep 2006

rawprawn's experience is repeated elsewhere. there is sometimes a difference of opinion in terms of whether you extend the BT line then split with the filter close to the modem or the other way around.

The easiest is the former.

  Diversion 17:43 01 Sep 2006

Iv'e got a 15m extention on my PC and I am supposed to be on a 1Meg connection, but my readings only show 512Kb connection. But my connection is unlimited and uncapped, so I don't argue with the loss of bandwidth.

  Stuartli 17:43 01 Sep 2006

I use a Linkskys 10m ADSL data cable from the splitter/filter on the Master Socket to my ADSL Modem Router (it replaced a USB modem) - speeds in both cases are well up to expectations.

The cable was around £7.50 but it can be acquired cheaper online; other lengths are also available.

  DieSse 17:50 01 Sep 2006

When you think how far you are from the exchange, you'll realise that quite a few more metres won't make any difference.

But you must use good quality cable - poor quality (and much "extension" cable isn't much cop) will affect things, as will too many plugs/sockets.

I always used round, white, multi strand multi-core cable - I could buy reels with 4 wires, and I usually joined the wires together in pairs as well. Never had a single problem including some very long runs (20-30m).

So better to wire in a proper socket near the computer, with good wire, then just a regular short lead from socket to modem.

  rawprawn 17:50 01 Sep 2006

I don't know your ISP, but I'm with Tiscali and got a free upgrade from 512kb to 1mb, and nothing happened (No increase in speed) I complained and suddenly I am up to 1mb

  FelixTCat 17:51 01 Sep 2006


There is no practical advantage in spitting the adsl and voice signals at the master socket and then running unshielded cable to your modem.

I don't know whether adsl data cable is shielded, but if it is it would be a good solution. Otherwise, consider moving your modem to the master socket and running ethernet cable, which is shielded.



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