Anyone here knows the ins and outs of a fibre CSP box?

Would I be correct in assuming that, as of the date of this forum message, a residential full-fibre Openreach connection, approaching the property from a pavement duct that ends about a metre from the property’s front housewall, will consist basically of a Customer Service Point (a so-called CSP box) mounted on the housewall and, indoors, a modem referred to as an ONT, measuring approx 82mm x 89mm?

On the assumption that I’m correct and up-to-date about that, does anyone here know whether the incoming fibre cable in the aforementioned duct will always serve the one property at a time, eg. where semi-detached properties are involved, as is the case here, will the respective installations require one CSP per property/household, or does the one CSP somehow cater for the two properties together? The CSP to which I refer is a grey box that measures 14cm wide x 15cm tall and which is fitted to the housewall and, as I understand it, one end of the indoors pigtail needs to pass through a hole in the housewall, and thence through the back of the CSP, to where it's then fusion-spliced to the external cable. (Obviously, by ‘cable’, I mean ‘fibre’). In other words, if I have full-fibre installed and then at some later date my semi-detached neighbour also then opts for it, will he/she have to have a separate CSP fitted? I’ve been looking at the logistics of the hole-drilling and, from what I’ve measured and worked out, it’d be impossible to drill concealed holes for both the properties whilst having only one 14cm of CSP width to play with, especially with the party wall taken into account. Locally, I’ve found only one case that’s remotely similar, and in that one anyway only one of the two semi-detached properties had opted to have a full-fibre installation.

For a number of practical reasons relating to electronic kit that resides indoors, directly on the other side of the housewall, I plan to drill my own hole myself, doing that some weeks or months well before the OR engineer’s visit. And there are other minor preparatory building works I’ll need to do too, so that the OR operative will be able to get the incoming cable from the duct exit point in the garden fully to the housewall.

The hole I’d drill through the wall would be a 10mm diameter one; the length of the hole would have to be about 10” (25cm). After lining it with an 8mm OD metal tube, approx 6mm would be left for the OR engineer to pass through it the internal pigtail, which I’d guess would be more than enough. The OR operative would fix the CSP box to the wall, siting it over the hole as necessary.

Each property will have its own fibre cable, CSP and ONT. If the existing copper lines for the two properties uses a shared duct then that would be the route for the two new fibre cables.

Oh good, that'll make everything pretty straightforward.

The existing copper lines in fact use a single multiple-pair cable emerging out of the duct end in the garden. That then goes up the housewall for about a metre, into a small grey Openreach 'breakout' box from which the two copper line connections emerge, one for me and one for my neighbour. These then pass into our respective properties, effectively ending up at our NTE5 master sockets. When fibre's installed the practise seems to be to sometimes shift the copper box slightly out of the way on the housewall but still retain it and its cable connections, presumably until Dec 2025 comes around and it's all then redundant. In any event, the neighbour may want to continue with his copper line right up until that date arrives. So it kinda makes sense.

The duct currently has a drawrope installed in it, ready to pull through the fibre cable when the time comes. It's a 50mm plastic duct that's been in use for about 30 years, and I'm hoping that OR won't have too much trouble pulling in the fibre cable with the copper one still in it. They did, after all, manage to install the drawrope.

The only extra bit of advice I would give you is remind the guy (or girl) who pulls your fibre cable through (with the existing draw rope) to attach another draw rope as well so he (or she) leaves a draw rope ready for when your neighbour eventually switches.

Edited by PCJM40 (Fri 13-Oct-23 17:31:29)

Good idea, PCJM40. Thanks for the tip, and thanks also for pointing out that it's basically 'one CSP per household'. Much appreciated.

Here is more detail on the possible entry and exit points for the CSP
CSP Demarcation Box User Guide

Here is more detail on the fibre cable between the CSP and the ONT which can be run externally before entering the property
Inside/Outside Cable

Those links to the Dexgreen info are well-appreciated by yours truly, and probably by many others, and the information imparted by the articles are, in my view, top drawer. Good old Dexgreen! Allows the householder to plan ahead, see what the options are for OR, in collaboration with the householder, to mount and install the various parts.

Having read all about the CSP from the links given here several days ago, I changed my plan from drilling through the housewall brickwork for a rear entry to the CSP, to drilling instead a spot on the housewall just to the left side of the CSP. I'd gathered that OR operatives had found it tricky to make the rear-entry one, and having seen the pic of the CSP's innards and where the various rear-entry knockouts are, I myself can understand why. (An important point there is that any hole in the wall, inside the CSP, should, for reasons of keeping water and moisture from easily getting into the room on the other side of the wall and also to meet the requirement for the indoor/outdoor's fibre to be wound on to the bobbin in the opposite direction to that of the 'neighbourhood' cable' fibre so that they meet head-on and can then be fusion-spliced, these two things work against each other; the problem disappears if you bring the inside/outside cable through instead to the side of the CSP and it entering the CSP almost flat against the wall, in the same sort of manner as the neighbourhood cable).

Seeing, from these PDFs, that the so-called inside/outside cable's outer sheath is 5mm OD and that the core fibre of it can withstand more bending than I initially anticipated, I think it'll be fine in my case for the inside/outside cable to come through instead just to the left of the CSP box, though I still wonder whether I should cover (with the OR operative's agreement of course) the short outdoor loop of it with some flexible conduit, in order to mechanically protect it from the local wildlife (squirrels, magpies, foxes). In recent times I've had to make a repair to the outer jacketing of my copper telephone/internet cable at much the same position on that housewall that was damaged by that very means. Also, any and all exposed cables on that housewall tend to get a lot of UV bombardment, as the wall faces due south.

Addendum: It's beginning to look as though, in my case where the neighbourhood cable is arriving at the property via an underground duct (rather than aerially from a pole dropwire), the neighbourhood cable will be either of blown fibre or of CommsScope fibre. The one finished example I found locally had a 6mm OD cable for the neighbourhood one but, who knows, OR might simply use cables and other components that are readily at hand, rather than sticking to particular marques/parts? Having just read about the inside/outside pigtailed cable, at one point I wondered whether a common single-fibre cable is now used for both the inside/outside cable and the one I keep referring to as the 'neighbourhood' one, ie. the 5mm inside/outside.

Edited by viteranio (Wed 18-Oct-23 17:05:43)

In reply to a post by viteranio:

the neighbourhood cable will be either of blown fibre or of CommsScope fibre.

It won't be blown fibre at the CSP for a new deployment, normally a flat ROC type cable with a connector at the other end for connection to the CBT.