ADSL Wire up a Master socket and a router.
A Master socket must be the first socket your telephone line connects to when it comes into your premises. You should only have 1 master socket on your line. Each approved UK phone will have a REN number underneath it. In its simplest terms, This REN number is a measure of how much power the device takes. So a phone may have REN1 and a fax machine REN2 and a router REN1. You must not let the REN number exceed 4 for a single line.
This is the same for FTTC connections.
Telephone master phone socket with a removable lower part is also known as an NTE5.Customers are not permitted to remove the lower casing however you may remove the lower faceplate. If your phone line or internet fails, you may be asked to remove the lower faceplate and connect a telephone to the socket beneath. This is important as it will help to identify whether or not the problem is caused internally or externally. An internal fault is chargeable.
The good old Mark 2 is one of the best, it was well built and easy to work with. All the parts were well screwed down and when you left one of these working – it stayed working.
The Mark 4 and 5 were similar design but easier to work with and the Mark 5 could be worked on without tools.
Which filter is best?
In any case, there was little or no gain in internet performance to be had from any filter. So what marked a good filter from a bad one was the audio quality down a telephone line. Some of the older cheaper filters would cause the internet to cut off when a connected handset was lifted.
Connecting your router.
Your router should be connected from its RJ11 socket to the RJ11 socket on your telephone master socket. The RJ11 socket is the smaller of the two sockets on the filter.
The RJ11 cable on the right has the same sockets on each end and only 4 contacts.