NTE5 master Socket and back Box

Telephone Master Socket

The telephone Master Socket sometimes called an NTE5 telephone master socket was introduced in 1986, it is mainly used for single analogue telephone line installations on the PSTN (Public Switched Telephone Network). One of its most important functions is to serve as a demarcation point, the point at which responsibility changes from your service provider to you the customer. This is achieved with a two part face plate configuration, all customer owned wiring is attached to the detachable half of the NTE5.

The main body of the NTE5 houses its own special telephone socket, this socket serves as a test point once the  detachable half has been removed. When directly connected to your telephone line via the test point you are able to start some simple diagnostics of your service related problems.

Providing that no additional wiring has been added to the supply side before the NTE5, then the test socket will serve as an reliable point of testing. Using the test point allows you clearly identify the origin of most faults.

One popular reason for being interested in the NTE5 & its associated wiring is to ensure that you are able obtain the best possible broadband performance that your line can support. As such there are some additional factors that maybe worth noting.


IDC connection as used in most mater socketsScrew terminal connectionThe connection method used for the wires inside the socket can be either screw or Insulation Displacement Connector (IDC) terminals. The IDC method is the preferred choice of professional installers mainly because of speed & the very reliable connection created. Subject to using the correct method of installation & tools the IDC method will actually create an efficient mechanical weld that meets the required standards of line quality for services such as broadband. (Note IDC connector modules are designed to have an optimum capacity of two wires per connection point. Whilst it is possible to connect a third wire this will alter the mechanical characteristics of the joint, which can have a negative effect on voice and broadband services)



This can cause interference, however it can be removed on a standard broadband enabled line with simple internal wiring configurations subject to local filters on all connected devices. Many new NTE5 telephone master sockets now come with a bell wire filter fitted to reduce this type of interference.


Weather conditions such as wind & rain can compound the effects of a degraded joint, the same effect can also be experienced by tree branches touching the line. Even birds perched on the line can often make things worse.


Weather conditions such as heavy rain & very low temperatures can compound the effects of a degraded joint, similar compounding effects can sometimes be caused by tree roots or burrowing animals. Another source of potential problems are ground works being carried out for building or road works.

JOINT BOXESIDC crimp joint

External joint box

BT 66 External joint box

Some external joint boxes attached to customer premises have connecting wires pass through a screw terminal joint. This can be a source of corrosion & high resistance type faults. Both of which can have a negative effect on the line & broadband services. Petroleum jelly filled connectors when correctly installed, can solve this problem. 


THE EXTERNAL NTEExternal NTE telephone joint box

Contains a set of master socket components, putting another set of master socket components on the network will often create a fault after a period of time. Due to the nature of the required wiring for Infinity Fibre type broadband installation, the components in an external NTE may need to be bypassed to ensure quality & continuity of service.


When installing extension sockets always use the correct type, do not connect your modem/router with poor quality extension cables. Some extension cables can cause interference on your line and cause slow broadband faults. In the event that you choose not to have a telephone extension professionally fitted, you may want to consider locating your router at your master socket and use a wireless connection.


Internal grade telephone cable should always have a minimum standard of CW1308, internal grade cable should not be used outside as its life span will be significantly reduced. External grade cable should always have a minimum standard of CW1128, this type of cable is graded to withstand hash environmental conditions.


When fitting new doors & windows or flooring always check to see how your existing wiring may be effected, you may need to have cables re-routed. Try to avoid cables being routed beneath window or door frames.

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Affordable Technical Help In The Home & Small Business


Affordable Technical Help In The Home & Small Business


Affordable Technical Help In The Home & Small Business


Affordable Technical Help In The Home & Small Business


Affordable Technical Help In The Home & Small Business