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Your Internal Cable

With regard to your Internal Telephone Wiring there are many factors which can decrease your Signal to Noise Ratio (SNR). Some wiring problems might just cause an odd dip every night which goes un-noticed but others can cause wild fluctuations which can lead to frustrated Internet users! This is because your internal wiring has the potential to pick up a lot of noise, which causes the fall in your SNR.

One of the main things to check is the cable used for your internal telephone lines. It needs to be a twisted pair cable. Some people have decided to save the few pounds by using non-twisted pair cable, like bell or alarm wire, to wire up their extension sockets. The reason twisted pair cable should be used is the twists in the pair of cables you need for your telephone line helps reduce noise picked up as it travels through your house. You should at least use internal grade twisted pair telephone cable (CW 1308), but I would recommend Cat 5e network cable. If the wiring is hidden Cat 6 would be even better as you then have more options available in the future but it is too thick to run along skirting boards or under carpets and does not bend round 90 degree corners well.

In any case it will need to be solid core cable and not stranded cable. This is because the type of connections usually used in telephone wiring are designed to use solid core cable. Solid core cable is where the actual cable (the metal part under the sheath) is one long solid piece of metal. Stranded cable has lots of long, very thin strands of metal running the length of the cable. It makes for more flexible cables but Stranded cables will not work properly when using the usual telephone wiring connectors.

Connection Types

The main type of connection you are likely to find in telephone wiring is called an Insulation Displacement Connector (IDC Connector). An IDC connector basically has two blades which, using a punch tool, you insert the cable between. As the cable slides to the bottom of the connector the blades get closer together which bites into the outer sheath of the cable and grip into the actual metal part of the cable.

When done correctly, and it really is not too difficult, you get a very good contact which allows for a good flow of current through the connection. When using IDC connectors you can only place two separate cables in the same connector so you have to run your sockets in series (one socket following the next) or you need to come up with some other distribution point. If you knock them around too much the connections can start to make their way loose.

The other type of connection you might see is the screw connection. This is where a small screw holds the cable down in a hole, similar to a chocolate block, and it is sometimes used. Using screw terminals is generally not always the best way to get all you can through that connection and the cable is known to break under the strain of the screw so the IDC connection is the preferred choice, even though using an IDC punch down tool scares some people.

Whichever type of connector your wiring uses the Internal Telephone Wiring side only uses connections 2, 3 and 5. Any other connectors, except the A and B connectors which are on BT's side, are usually redundant.

The Master Socket

The Master Socket is the socket with certain components built into it and you must have one somewhere in your telephone system. The Master Socket that BT used to use looked exactly the same as any extension socket which meant the only way to tell the difference was take it apart and look to see if it had that big long round thing (or the ring capacitor, whichever is easier to remember).

 

 

NTE5

However, more recently BT have been installing a socket called an NTE5. This socket is recognizable by the horizontal split half way up and the actual socket is lower down on the box. Your internal wiring should be connected to the bottom section so if you remove it you should have disconnected all your internal wiring. When you remove the bottom section you will notice that there is another telephone socket underneath. This is the BT Demarcation Point, also referred to as The Test Socket. This is because with all internal wiring disconnected a BT engineer can use this socket to see what signal is being received at the point of entry. All of the wires on BT's side are hidden away behind the back section along with all the Master Socket components.

If you do not have a newer type NTE5 I would recommend getting BT to install one as it makes things easy to work with compared to the older style of sockets, some can be quite a mess. It can be a little expensive but if you have Broadband problems it makes things a whole lot easier to troubleshoot. Getting it changed before you have a problem can be beneficial as a lot of ISP's are telling people, for good reason, to use them when troubleshooting connection problems. Although it can seem annoying their are other options than moving your computer and router to the hallway, like moving your router to the hallway and using a long network cable to your computer, which as it goes would be the best solution all round.

If your Broadband connection suddenly dies this test socket can give a lot of useful information to your router which can help tell you whether it's a problem you are responsible (for paying) to get fixed. It is certainly cheaper being able to work out yourself that it's your internal wiring that's the problem rather than having a BT engineer tell you, just before giving you a bill.

Apart from the ease and troubleshooting benefits of the NTE5 socket you can also use it to help deal with the problem of filtering, internal wiring and routing of the Broadband signal to any specific socket by swapping the bottom section for a Filtered Faceplate.

The Ring Wire

You may hear about the simple wiring tweak you can do by removing the ring wire. In telephone wiring, usually 3 wires are used. When looking at the phone sockets these wires are connected to connections 2, 5 and 3. One pair, which is usually the Blue / White stripe and White / Blue stripe pair, should be used for connections 2 and 5. This means that connection 3, which usually gets connected using the Orange / White stripe wire, is on an open pair. i.e. even if the second wire of the pair is connected to one of the remaining connections, as there is nothing being sent down any of these connections the ring wire, which is the one supplied by connection 3, is the only wire of the pair being used.

Why is this important? This is important because if both sides of the pair are not being used, rather than help shield against noise, it acts more as a big ariel. Because the frequency range that ADSL uses falls within the same frequency ranges as AM radio, you do not want the ring wire acting as an ariel. The ring wire will pick up the 'noise' from the radio stations which will decrease the total SNR, which can limit your speed, sometimes quite significantly.

This is not just limited to radio stations though. As your telephone cables travel through your house they will run past many sources of electrical equipment which may be emitting some electrical interference which will be picked up with the ring wire, so removing it can be beneficial for speed and stability.

Removing the ring wire is a very simple task and can be carried out by following the instructions below: -

NTE5 Standard Faceplate before Note the two Orange wires inserted in the second IDC terminal up with the unused wires placed above the back of the socket	NTE5 Standard Faceplate after Note the two Orange wires have been removed from the second IDC terminal up and placed with the other unused wires

With an NTE5 to remove the Ring Wire unscrew and remove the lower half of the socket. The extension cabling should be connected to the front half that you have just removed. Turn the faceplate around and pull any cables connected to terminal number 3 up, do not pull them down the length of the wire, to disconnect them from the NTE faceplate. Do not cut them in case you ever want to reconnect them. If you have screw terminals unscrew terminal 3 and remove the wire. Tidy the wires away into the faceplate and reconnect it to the NTE5.

Old Style Master Socket before: Note there is only one Orange Ring Wire. There is no Ring Wire from the Drop Cable but if this were an extension socket both cables would use the Orange Ring Wire	Old Style Master Socket after: Note the Orange Ring Wire that was connected to terminal 3 on the lower right of the picture has now been removed and placed with the other unused wires

Removing the Ring Wire on old style Master sockets and extension sockets is essentially the same except on old Style Master sockets the incoming wire, from the BT side, does not have a ring wire. This is good as you are not supposed to touch this side. If you have extensions then there will probably be ring wires from all cables.

Firstly unscrew the front of the socket and lift it off. As in with the NTE 5 you want to disconnect all wires connected to terminal three either by unscrewing or lifting the cable up out of the IDC connector. Tidy the cables into the socket and replace the front of the socket.

This is in essence a ten minute job to remove the Ring Wire from your master and any extension sockets and the amount of times I see this dramatically improve the figures of a line is un-believable. With this ring wire removed you need to make sure you have a microfilter before every telephone, which you should have anyway, as the filter produces the ring signal at it's socket which the telephone plugs into.

NTE5 Filtered Faceplates

Filtered Faceplates are covers that replace the front half of the BT NTE5 socket and house an internal Microfilter. This part of the BT master socket is the part of the wiring you are allowed to touch but be aware, if you cause problems on this side of the wiring and need a BT engineer to fix it, it is likely to cost.

NTE5 Filtered Faceplate

These devices are usually used to completely separate the Broadband signal from the telephone line at the point of entry. You can then have a filtered telephone line running through the house and the Broadband connection is located at the BT Master socket, fully optimized to receive as little noise from the internal wiring as possible.. Usually in this configuration, if you have a good quality Filtered Faceplate, your internal telephone wiring will not affect the line too much as long as the cable running to the extensions is of a decent quality.

Filtered FacePlates can also be used to send filtered telephone signals to all of the extensions except one. This one you could supply through an un-filtered connection on the Faceplate. Then as long as you ensure this uses good quality cable, the ring wire is not connected and you are using a good quality socket and microfilter on the other end this could be one solution if you really need to get the Broadband signal to a socket closer to computer.