New Fibre Installation

I have searched around but cannot find the answer to my query so I hope someone can point me in the right direction or comment.
I have been reviewing fibre deals for when my contract ends with another provider.
At present we have broadband with two computers, both upstairs in seperate rooms.
One computer is connected via modem plugged into a "secondary" phone socket in that room.
The other computer is connected by wireless to the network via a D Link USB Wireless Adapter.
Reading up on the fibre installation I read that the modem must be connected to the telephone master socket which is downstairs.
Will this lead to any problems as the computers must stay upstairs.
Any comments welcome.

To get the best speeds the master is the best place for the modem, options

1. Keep option at modem, but run an Ethernet cable upstairs to connect to the router (maximum distance 100m)
2. More common, make sure provider orders the free data extension kit when ordering and have a data extension socket installed up to 30m from the master socket.

Thanks MrSaffron
So there is a modem at the master socket then a router, I call them all modems, upstairs as now and I assume this will act as the setup now with the computer in the other room still using the USB adapter.
My present contract runs to November but I have been looking around and
Plusnet from which my query arose do supply the extension kit.
So really its an extra device downstairs with an extension lead but more or less the same upstairs.
Have I got this right?.
THanks
John

Yeap more or less right

If you opt to get the data extension kit fitted, the the existing NTE downstairs will have a faceplate filter attached, and then the installer will run the data extension kit to the position upstairs. This will then feed the Openreach VDSL modem, and from this is short ethernet cable to the router.