Telephone extension wiring

[DuncM]

Hello.

I am trying to fit a telephone extension. I currently have one telephone plugged into the only box inside the house which works fine. When I opened up the box there are four wires inside.
Orange,
Black,
White
Green.
The telephone cable that I have bought has four wires also but these are.
Orange with a White band.
White with an Orange band.
Blue with a White band.
White with a Blue band.

Which wires do I connect to each other? I have connected the new extension socket as it has a colour coded diagram on it to help.
I will be plugging in a wireless router to the extension.

Any help will be greatly appreciated.

 

[3george]

Have a look at this site....it has proved useful to me in circumstances such as this...

http://www.rob-r.co.uk/other/UKphonecatwiring.htm

 

[JimLoskot]

it should be a master socket and there should only be 2 wire connected inside it. It sounds like it is an extension socket which is possibly connected to a hidden master sockt somewhere else. does this sound feasable?
Unless of course you have only taken off the front part and there is already a wire in for an extension that has been removed but the wire left in.

basically there are 3 parts to a master socket (NTE5), the back which screws to the wall, then the middle section where 2 wires attach onto screws which comes straight from the external phone line, then there is the face plate which plugs into the middle piece and has 4 IDC connections for attaching extension sockets to.
Worth getting or borrowing an IDC tool to ensure the connections are done properly

 

[bernardgreen]

Have a look at this site....it has proved useful to me in circumstances such as this...

http://www.rob-r.co.uk/other/UKphonecatwiring.htm[/QUOTE]

While this site is mainly correct there is one error. Using CAT5 cable for the internal telephone cable carrying ASDL can reduce the quality of the ADSL signal and not improve it.

ADSL transmissions are designed to work as well as possible over the twisted pair cable CW1308 of telephone systems. CW1308 has a low number of twists per metre compared the CAT 5 which has many more twists per metre. This means that the charactoristic impedances of the two cables are very different at ADSL frequencies.

If the signal has to cross from CW1308 to CAT 5 it faces a change of impedance and this will degrade the signal to some extent. In cases where the incoming ADSL is already poor quality due to the distance from the exchange then the impedance mis-match between CW1308 and CAT 5 will have a significant effect of the quality of the ADSL signal.

Changing from CAT 5 to CW1308 has been known to make a significant improvement to the signal.

 

[drgl]

I'm afraid if that were true then you need to ask the question why Pressac(BT licenced) use what is basically CAT5 spec cable (minus 1 pair) for the BT ADSL extension kits?

 

[Paul_C]

I'm afraid if that were true then you need to ask the question why Pressac(BT licenced) use what is basically CAT5 spec cable (minus 1 pair) for the BT ADSL extension kits?

Because, apparently, they don't know any better.

 

[drgl]

BT spec the cable, not Pressac. I would hope BT know what performs best on their network! They aren't using CW1308 on the vDSL extensions for the very same reason.

 

[bernardgreen]

I'm afraid if that were true then you need to ask the question why Pressac(BT licenced) use what is basically CAT5 spec cable (minus 1 pair) for the BT ADSL extension kits?

Can I refer you to http://www.run-it-direct.co.uk/ADSLEXinstructions.pdf where the instructions for the kit show only one pair in the diagram and make not reference to any other pairs in the cable.

basically CAT5 spec

How basic is basic. Twisted pair is the basic spec for both CAT5 and CW1308. The variations between them are in the number of twists per metre, inter conductor capacitance and other parameters which determine the charactoristic impedances of the two specifications. Suggested reading "Insertion Loss" and "reflection losses due to impedance mismatches to the link segment"

 

[drgl]

I've got the kit sat in front of me Bernard, it has 3 pairs with the same number of twists as CAT5. Of course the kit only mentions 1 pair, only 1 pair is required! Would you like a picture of it posting up as you seem to doubt everyones word?

 

[bernardgreen]

I do not doubt what you say is correct about the type of cable used in the kit you have.

It does seem a bit odd that a company would use 3 pair when only one pair is required. Unless they were using 3 pair with fitted plug for some other product and decided it was cheaper to use the same cable with plug for the ADSL extension kits rather than creating a new sub-assembly stock item.

 

[drgl]

Agree it is odd as would be cheaper still to just use 4 pair I would imagine. In any case the cable is white so probably made to spec, I'm guessing a single pair may be problamatic to make to keep the tight twists. The latest from the manufacturers is they are using CAT6 spec cable for the vDSL extensions, or at least they will when BT decide what they are doing. BT themselves have said you can not use CW1308 cable for vDSL extensions. Seems odd as that is the specification of cable from the exchange but that is what they are saying.

 

[Paul_C]

I would hope BT know what performs best on their network!

One might hope so, but I'm afraid that these days BT has reached the point where technical expertise is often not what it used to be, or what it should be. Look at the instructions in the link Bernard provided. There's a reference to connecting the extension kit with an RJ45 plug. I must admit that I get peeved at the widespread incorrect usage of the term to refer to computer network connections, but in this case it's not even that very common misuse of RJ45 to refer to an 8-position plug & jack, as the ADSL connection at the master is RJ11 using the smaller 6-position connectors. There's also the curious statement about an ADSL extension not being longer than 50m/164 ft. So long as the proper cable and connection methods are used, there's no particular reason why such a limit should apply: My line runs some 23,000 ft. from the exchange, so even if I put an extra 200 to 300 ft. extension on for some reason, it's not going to make a huge difference.

The latest from the manufacturers is they are using CAT6 spec cable for the vDSL extensions, or at least they will when BT decide what they are doing. BT themselves have said you can not use CW1308 cable for vDSL extensions. Seems odd as that is the specification of cable from the exchange but that is what they are saying.

Things change a little with vDSL though, as the DSL won't be provided by copper all the way from the exchange. To get the higher speeds, the link is fiber to the local distribution cabinet where the remote DSLAM will be located, thus reducing the length of copper cable carrying the DSL signal to a minimum.

I haven't followed the latest news, but I would guess that the plan is to use suitably specified cable (instead of "regular" telephone cable) for the drop to the house from the DP.

 

[drgl]

I would hope BT know what performs best on their network!

One might hope so, but I'm afraid that these days BT has reached the point where technical expertise is often not what it used to be, or what it should be. Look at the instructions in the link Bernard provided. There's a reference to connecting the extension kit with an RJ45 plug. I must admit that I get peeved at the widespread incorrect usage of the term to refer to computer network connections, but in this case it's not even that very common misuse of RJ45 to refer to an 8-position plug & jack, as the ADSL connection at the master is RJ11 using the smaller 6-position connectors. There's also the curious statement about an ADSL extension not being longer than 50m/164 ft. So long as the proper cable and connection methods are used, there's no particular reason why such a limit should apply: My line runs some 23,000 ft. from the exchange, so even if I put an extra 200 to 300 ft. extension on for some reason, it's not going to make a huge difference.

The latest from the manufacturers is they are using CAT6 spec cable for the vDSL extensions, or at least they will when BT decide what they are doing. BT themselves have said you can not use CW1308 cable for vDSL extensions. Seems odd as that is the specification of cable from the exchange but that is what they are saying.

Things change a little with vDSL though, as the DSL won't be provided by copper all the way from the exchange. To get the higher speeds, the link is fiber to the local distribution cabinet where the remote DSLAM will be located, thus reducing the length of copper cable carrying the DSL signal to a minimum.

I haven't followed the latest news, but I would guess that the plan is to use suitably specified cable (instead of "regular" telephone cable) for the drop to the house from the DP.

Paul, I'm afraid the term RJ45 is used, it's incorrect but so is calling a vacuum cleaner a hoover! RE: the length this is probably to do with interference issues, there is no kit from them longer than 30m anyway so a mute point (& the longer the run from the exchange the more likely an internal extension will matter, they have to draw the line somewhere). (BTW, I have run ADSL over a 90m run of CAT5 and seen no speed drop off at all).

Re:vDSL, fibre to the cabinet still relies on copper for the final loop, there are no plans at present to replace this with new copper, no point as FTTH would be more cost effective (trails of this have been done with new faceplates obviously). The cabling spec. refers to internal house wiring for vDSL & this is NOT CW1308 spec. BTW, you are wrong on the ADSL connection at the master jack, the NTE2000 & NTE2005 uses an 8 way "RJ45" connector NOT RJ11(which is why the extension kit has an RJ45 plug on it!)

 

[Paul_C]

Re:vDSL, fibre to the cabinet still relies on copper for the final loop, there are no plans at present to replace this with new copper, no point as FTTH would be more cost effective (trails of this have been done with new faceplates obviously). The cabling spec. refers to internal house wiring for vDSL & this is NOT CW1308 spec.

If there are no plans to replace the subscriber loop from the cabinet, then I really don't see the point in specifying CAT5 or CAT6 cable for the internal wiring. Admittedly though in this case the impedance change on the cable probably wouldn't matter too much given that the signal strength is going to be pretty high with the DSLAM so close by.

BTW, you are wrong on the ADSL connection at the master jack, the NTE2000 & NTE2005 uses an 8 way "RJ45" connector NOT RJ11(which is why the extension kit has an RJ45 plug on it!)

I've been used to using the filters which do have a 6-position jack, but on checking a BT/OpenReach one, I see that it is in fact an 8-position, so I stand corrected (but I still get peeved at the improper use of the term RJ45).