This topic

Plastering behind CSP and ONT

honister — Wed, 06 May 2026 15:01:12 GMT

Hello,

I would like to replaster a room where the fibre cable comes into the house. There is the box where the fibre comes in from outside (is this called a CSP?) that then goes into the ONT box via a green plug in cable.

CSP (?) on the left and ONT on the right

I'm not so fussed about the ONT box because it is just held in by screws so I can deal with that but how do i remove the CSP and the plaster behind it. Is this going to need a visit by open reach?

Re: Plastering behind CSP and ONT

chrisjp — Wed, 06 May 2026 15:10:02 GMT

It's unusual for the CSP to be fitted inside the house. It's usually fitted outside on the wall to which the ONT is fitted inside, so the CSP to ONT cable just goes through the wall.
I suspect that the screws holding the CSP to the wall will be inside the box under the cover, so you'll have to remove the cover to get at them, which is probably not an action approved by Openreach.
Still, I cannot imagine that Openreach will want to make a visit just to do this, and then make another visit to put it back.

Re: Plastering behind CSP and ONT

chrisjp — Wed, 06 May 2026 18:49:33 GMT

To add to my previous posting, now that a picture has appeared, the box that you have called the CSP doesn't look to me like the weatherproof box that normally sits outside. I'm not sure what the white oblong box is - perhaps another forum member can enlighten us?

Re: Plastering behind CSP and ONT

iniltous — Wed, 06 May 2026 19:01:58 GMT

The box in question is a (quite uncommon) internal CSP

Re: Plastering behind CSP and ONT

36ULW — Wed, 06 May 2026 19:24:43 GMT

Take the front off the Internal CSP am there should just be 2 screws securing it to the wall, most likely using the same kind of raw plugs that’s holding the ONT on the wall.

Re: Plastering behind CSP and ONT

honister — Thu, 07 May 2026 14:58:04 GMT

thanks mate, how careful do i need to be with it once its off?

Re: Plastering behind CSP and ONT

36ULW — Thu, 07 May 2026 18:21:31 GMT

Just avoid pulling fibre out of it.