data extension cable

[#1]

Hi, FTTC install due later this week...
Currently I have my master socket in a bedroom upstairs, a room it shares with my 5 month old child.  So far, not a problem, but I can see that changing soon enough.  The master socket connects to my ADSL modem, and then a I run a CAT5e from there into another bedroom, where I put everything else (computers, wifi routers etc etc).
As I can see the new service comes in two parts, a BT VSDL modem, and then a router.... I wondered about the Data Extenion cable.
As my CAT5e is already run nice and discretely I wondered if I could make use of it, above and beyond the following:
Fallback plan:  BT VSDL modem plugged into Master socket and located next to it.  CAT5e cable run through to Netgear router supplied by plusnet, in a different room.
My question is, Can I use the CAT5e cable to put the BT VSDL modem in a different room?  Photos I've seen suggest the master socket has an RJ11 connector, not RJ45,  is this the case?  What does the "Data Extension Kit" consist of?  Would that allow me to use my own RJ45?
Sorry, for the questions, just seems a nice opportunity to get the kit out of the kids room.

[#2]

Quote from: phil4

Fallback plan:  BT VSDL modem plugged into Master socket and located next to it.  CAT5e cable run through to Netgear router supplied by plusnet, in a different room.

I think that is your best option.

[#3]

i agree with jelv, I have done this with a 30m cat5e with no problems (the wifi was terrible over the same distance). Unless its an issue, theres no real point in moving the modem if your cat5e is already in place as BT wont/cant use it, instead they'd use their own supplied cable to extend the distance from the socket to the modem.

[#4]

Thanks both, was hopeful I guess, but I'd rather modem worked than have BT tacking stuff to skirting etc.