Telephone extension cable - any good for broadband?

cahjubb

Hi, I'm getting broadband over the next couple of days, and although eventually I'll get a wireless router, I'm using the provided router and cables. I'd appreciate some advice and info.

My exchange is only "up to" 1.5mb, so if I use a telephone extension cable to get to the telephone point and microfilter, will this reduce the speeds? What quality of RJ11 lead should I look for, or how do I minimise any reduction in speed?

Thanks for any help, HJ.

Little_John

unless you extending it by another 1000m then you shouldnt really have a problem. I would proberbly buy a standard phone extention and run it like another phone socket rather than running a long cable to the modem/router.

espresso

Little_John wrote: »

unless you extending it by another 1000m then you shouldnt really have a problem. I would proberbly buy a standard phone extention and run it like another phone socket rather than running a long cable to the modem/router.

Unfortunately not true. Most phone extensions that are sold do not use twisted pair cable and although this is fine for voice and dial-up, broadband will suffer. For broadband only one twisted pair is required, connected to terminals 2 and 5 from the master to and other extensions sockets. See this thread for more info on improving BB speed.

Little_John

Useing the twisted pair on 2 and 5 only provides a sheilding effect by the other pair of wires.

BT sockets only need 2 and 5 to work wire 3 is for thering capacitor and only needed on the master socket. Twisitn wires only makes a difference when your talking high bandwidth 100mb (cat5) and 1000mb (cat6) where the cable has a slightly different twist to cat5 and they use a few other tricks with dividers etc to allow the higher transfer speeds. dont forget 10mb is capable down the old coaxial cable and ADSL isnt even up to that speed yet. and 1.5mb isnt going to be affected by not useing a twisted cable. the reel or 2 pair cable I have I don't think is twisted or if it is it is only lightly twisted.

Millionaire

I use an standard extension cable from my main socket in the lounge to my pc in my bedroom. Have no problems with the broadband speed at all.

espresso

Little_John wrote: »

Useing the twisted pair on 2 and 5 only provides a sheilding effect by the other pair of wires.

Wrong again - the other wires in the cable have no effect, as they are not connected.

BT sockets only need 2 and 5 to work wire 3 is for thering capacitor and only needed on the master socket. Twisitn wires only makes a difference when your talking high bandwidth 100mb (cat5) and 1000mb (cat6) where the cable has a slightly different twist to cat5 and they use a few other tricks with dividers etc to allow the higher transfer speeds.

We are not talking about Ethernet here, so that is all irrelevant.

dont forget 10mb is capable down the old coaxial cable and ADSL isnt even up to that speed yet.

Co-ax has nothing to do with ADSL, so again irrelevant.

and 1.5mb isnt going to be affected by not useing a twisted cable. the reel or 2 pair cable I have I don't think is twisted or if it is it is only lightly twisted.

What is important with ADSL, is achieving the highest possible signal to noise ratio and this is why a noise canceling twisted pair is beneficial, when trying to achieve the best ADSL speed. Cheap and nasty phone extensions will work but will not give the best possible signal to noise margin.

Another option would be to use the standard RJ11 router cable into the master socket and then to use an RJ45 Ethernet cable to extend the ADSL to the PC.

Conor_3

Ho hum...

IN THE REAL WORLD, it doesn't cause any issues, even if you're on a marginal connection.

Also, using copper wire instead of the aluminium stuff that seems prevalent would be more beneficial than worrying about it being twisted pair or not.


As Little John said, if you were talking about 100MBit speeds, then you'd have a point.

espresso

Conor wrote: »

IN THE REAL WORLD, it doesn't cause any issues, even if you're on a marginal connection.

In the real world it does make a significant difference, especially on a marginal connection. One of the original posters questions was "how do I minimise any reduction in speed?"

:rolleyes:

Example 1:
A small improvement in the noise margin from 5.8db to 6.1db resulted in a speed improvement of over 38%. i.e. line sync of 3776 Kbps to 5248 Kbps. See here

Example 2:
See here

Conor wrote: »

As Little John said, if you were talking about 100MBit speeds, then you'd have a point.

These are actual examples of real world improvements on ADSL, not 100Mbit networks, so stick driving your truck conor! Ho hum!

Little_John

Firstly your going on about not using an extension cable as it isn't twisted then when I point out that the twisting really only comes in to effect on higher bandwidth like 100/100mb connections. so why do you then say the other pair dint matter as they are not connected? so what difference does it make if the cable is twisted or not? only data cable uses pairs twisted round each other voice doesn't and the fact everything before his master socket is voice cables it isn't going to make any difference sticking a twisted cable on his side.

Using a 10m extension will not make the slightest bit of difference to the speed, his exchange is already on its a**e at 1.5mb. There is nothing the user can do to reduce the chances of a drop in speed, why not go and use O2 free cables or even gold contacts? just to reduce the chances of the copper or brass contacts reducing the connection quality?

espresso

There is no point discussing this with people who 'think' that it makes no difference when, real world signal to noise margin tests, prove that it does! Did you read the examples? I don't think that you understand for example, why disconnecting the bell wire makes any difference to the achieved ADSL speed but it does - fact.

espresso

Another example of a phone extension resulting in loss of ADSL speed here just in case you still believe that in the real world of ADSL it "will not make the slightest bit of difference to the speed".