I have an older house that we restored around 2000. We installed five jack points in various rooms and it was my understanding that there was a master connection to the copper telecom input and the other jacks were connected to it. This setup worked perfectly.

About five years ago we changed to fibre. For this installation there is a plain white box fixed to the side of the house where the fibre (previously copper) incoming line is terminated. There are two outputs from this box; one is a blue wire that disappears under the house, which I suspects is connected to the previous copper 'master' jack, and the other goes inhone line through the garage to the home office where the ONT is wall-mounted and connected to the Vodafone Ultra Hub. There are two phone connections piggy-backed off Phone 1 on the Ultra Hub, one going to a cordless phone in the home office, the other through an analog line back underground too the master connection in the house. This setup has also worked perfectly until a couple of days ago.

At that point the phones all started to display 'Check TEL line' or 'Check phone line'. All phones were dead.

I called Vodafone Faults who tested quite extensively and were sure that the signal was incoming to the Ultra Hub. As a last resort I connected the office phone, without the accompanying piggy back, directly to the router  Phone 1 and was able to confirm dial tone and make/receive calls.

However when i reconnect the piggy back to the house the error message reappears. This means the fault is somewhere in the old copper-based star network between jack points in the house.

I am wondering therefore whether the fault may be in the mysterious white box that has the wire leading under the house to the master connection. And, if this is the case, is it something for Chorus to sort out? i don't understand what this connection does. Can anyone explain how this setup works (I am not a tech but would like to understand how it works)?