Fibre install query

I just put in order for Fibre to be installed for the first time at my house in a few weeks time.

I have been reading that the fibre modem itself needs to be near master phone socket and as a result will need power. The location of my phone socket is in a hallway and is, straight line distance, about 4 metres away from the nearest electrical socket inside the living room on the opposite side of the hallway.

My current ADSL setup has the combined modem and router in an upstairs office connected to the downstairs hallway phone socket via an extension. This arrangement will no longer work since the modem has to be downstairs. I will install the new router in place of the old one in the office and then run an ethernet cable downstairs to the fibre modem.

On the day of the fibre install, will it be sufficient for me to simply provide a double electrical socket (for modem and router) extension reel for the engineer and then worry about a more permanent solution later? Or will the engineer want to see something finalised and safer on the day before he leaves?

So you mean put the modem next to the master socket permantly but provide electricity by an extension? The OR installer should be quite happy with that.

He "may" offer alternatives which may or may not be better!

The installer should install the modem where you want it, rather than where the master socket currently is. This is one of the advantages of an engineer-install.

Yes, on the day I would want to supply the engineer with an electrical extension reel running across the hallway (and thus can be tripped over if not careful). However, afterwards I will arrange for a tidier and safer electrical supply to be available to the modem.

In fact, the phone socket itself is about 2 feet away from a small cupboard containing the gas and electrical meters plus fuse box. A few years back when I had a house alarm installed the control panel for it was placed on a wall near the cupboard. Electricity for it was supplied to it via a new cable that the installer fitted directly into the fuse box.

I plan on having the fuse box hijacked once again and have it feed to a new wall mounted electrical socket outside of the cupboard. If the OR engineer is satisfied with that idea then I will arrange for that to be done a day or so after he has installed the fibre modem + router install with the extension reel.

Batboy,

Are fibre modems like ADSL modems in that it is preferable to have the distance between it and the phone socket minimised in order to obtain higher syncs speeds?

Yes, but remember the line comes from the cab so another few metres won't matter that much.

That's a good point. I think I will go ahead with what I planned but hold off on the fuse box hijack until I move the modem upstairs and see how much the sync is/isn't affected.

Do as you suggest and see what happens. BatBoy is right about the extras few metres not contributing much to attenuation. However, a house is an electrically noisy environment - central heating, fridges, freezer, TVs and more all of which can affect the detected line noise and thus the maximum speed.

The BT Tech only requires a working 230v supply with a BS1363 compliant socket so the extension will be fine.

until I move the modem upstairs and see how much the sync is/isn't affected.

Is very different to your original plan:-

I will install the new router in place of the old one in the office and then run an ethernet cable downstairs to the fibre modem.

If you plan on having the modem upstairs you want to either have the master socket moved or have a data extension cable installed by the OR installer.

The data extension kit has to be ordered by the ISP but there is no cost. Better to do this than move it yourself.

Why? Installing a Data Extension is a simple task and the OP can route the cable as required rather than the route teh OR Tech will take. 2 pair or 4 pair Cat5e; two IDCs punch downs at the master and a suitable RJ socket at the remote end.

My install is booked for Tuesday. I will be providing the same scenario as for my ADSL router at present - a structured wiring socket to my house LAN, and an extension lead that connects back to the house UPS.

If the engineer objects to the extension lead, there is a socket on the wall - but I'd rather have the modem on the UPS along with the rest of my network infrastructure. I can always move the wall wart later!


The connection from the existing ADSL router, which is unfirewalled, is carried over a dedicated VLAN to my firewall / router (a small 1U rack server running pfSense). It will be a simple configuration change to tell pfSense it has PPPoE rather than a routed IP block on its WAN interface.

My intention is to add RFC 4638 support to pfSense (mostly a matter of adding it to the FreeBSD PPPoE code) to allow the same 1500 byte MTU I use with my current PPPoA based ADSL setup. Both network switches involved and the network interface in the pfSense box support jumbo frames, so all the necessary hardware is in place.

I would install unterminated Cat5 or Cat6 between the master and the preferred location, before the installation day. Leaving about half a metre spare at each end.

The engineer should be willing to resite the master using it.

If you still want a phone socket in the hall, he wil probably be prepared to backwire through the same cable to provide that. If not, DIY yourself afterwards - as long as there is sufficient loose wire remaining at the sockets.

I sort of regret getting my master socket moved, although it was the right thing aesthetically I've now not been able to rule out that 3 or 4 meters of CAT5 being the cause of my reduced speed - just something to bare in mind if the OPs not bothered about a large lump of plastic stuck on his wall

Also a data extension is simple enough to wire in afterwards - picture guide in my sig, but if the CAT5 or better still CAT6 cable is there beforehand the engineer can use it to wire in a data extension.

My understanding is that BT Openreach's practice is not to backwire through the same cable - pre-NTE and post-NTE signals should not be in the same cable.

In some situations where there is only one cable in place, an engineer may be persuaded to backwire, but may refuse to do so.


When we had Home Highway installed, we wanted the Highway NTE upstairs by the computers, which meant backwiring to what was now a secondary socket downstairs using spare pairs in the existing cable.

When we had Highway removed to be replaced by two PSTN lines (one with ADSL) I had already run some unterminated Category 5 solid core cable. This allowed the engineer to use the existing cable for the two incoming pairs, and he wired the extensions using the cable I supplied. I would have been equally happy if he'd left it to me to reinstate the extensions - I had my punch-down tool and outer insulation stripping tools at hand.


If you are running cables in advance of requesting the master being moved upstairs as part of an FTTC installation and retaining a voice socket downstairs, I'd run two Category 5 (or better) solid core cables before the engineer visit. This allows network side and extension side to be separated. One cable is used to carry the incoming pair and effectively becomes BT property as it's network side. The other cable is used to connect the extension socket(s) and is your property.

In reply to a post by David_W:

My understanding is that BT Openreach's practice is not to backwire through the same cable - pre-NTE and post-NTE signals should not be in the same cable.

In some situations where there is only one cable in place, an engineer may be persuaded to backwire, but may refuse to do so.

I think I fairly strongly implied that - just trying not to write a book at the time . OR engineer views seem to vary.
...

If you are running cables in advance of requesting the master being moved upstairs as part of an FTTC installation and retaining a voice socket downstairs, I'd run two Category 5 (or better) solid core cables before the engineer visit. This allows network side and extension side to be separated. One cable is used to carry the incoming pair and effectively becomes BT property as it's network side. The other cable is used to connect the extension socket(s) and is your property.

Very sensible, unless the OP would find that rather ugly.

In reply to a post by BatBoy:

Yes, but remember the line comes from the cab so another few metres won't matter that much.

But also remember that the cable that comes from the cab is going to be better quality than internal cable, so adding a few meters inside equals to many more meters than it would do if it was outside.

Really? A few metres of new Category 6 cable is likely to be of much better quality than an ageing overhead drop.

However, the internal cable will be in a much more hostile environment from an EMC perspective. From the perspective of minimising noise on the DSL side, it is best to keep internal wiring to a minimum.

In reply to a post by greenglide:

until I move the modem upstairs and see how much the sync is/isn't affected.

Is very different to your original plan:-

I will install the new router in place of the old one in the office and then run an ethernet cable downstairs to the fibre modem.

I guess I should have clarified in that I meant my original plan in so far as letting the engineer deal with a non-permanent electrical extension reel for the install on the day. Everything else, as in the router and (potential) modem relocation, would still be a post install change by myself.

Since the data extension that you mentioned is simply a 2/4 pair CAT5E then it's something I'm more than comfortable with installing should I decide to relocate the modem at a later date.

Thank you RobertoS and David_W, your posts have given me more food for thought.

Just spotted the "solid core" bit. I'm not too sure about that, but I'm no expert on Cat5/6 specifications/construction and suitability for specific applications.

Solid core is used for infrastructure cabling and is normally terminated in punchdown IDCs.

Stranded is more flexible and used for patch leads and normally terminated in a through crimp - such as a RJ45 plug.


If a stranded cable is inserted into an IDC terminal, it is possible that the strands move an flatten out resulting in the insulation not being cut or several strands can be severed and a bad joint formed which may work for a short while and then fail.

Putting solid core into an RJ45 plug can result in the terminal slicing through the insulation and not having a permanent contact with the conductors again it may work but fail after a short while.

I have seen many examples of both types of problem.

Thanks for that.

So solid core is still twisted pair? That was my main worry.

Provided it is Cat5/5e/6 &c

Not everybody has overhead drops. It is common knowledge that FTTC suites underground lines better because the cable used is better quality.

And there was me thinking it was because the sunlight doesn't get to them and cause reflections. D'oh!

Oh, better quality. Better quality copper?

In reply to a post by robertcrowther:

Not everybody has overhead drops. It is common knowledge that FTTC suites underground lines better because the cable used is better quality.

Since when? And how? The insulation may be different to cope with damp rather than sunlight but they are both normally 0.5mm diameter twisted pair.

In reply to a post by BatBoy:

Oh, better quality. Better quality copper?

Better quality copper and better quality shielding, that's why if you look in comparison the underground cable is way thicker than overhead cables.

I thought they're thicker because they carry more cables so more cross-talk.

And there is no shielding

You are plain wrong on this.

I work with this stuff every day.

The underground cable that comes into my house is like an armoured cable, no idea what it's like where it joins the rest though.

There is shielding on Mainside cables but as FTTC is not reliant on Mainside cables it's not relevant.

"Mainside cables" and just want is that when at home ?

Do you mean E side cable ? if so it stll has no shielding as such just a lot fatter as a lot more prs in it.

You obviously have never opened up one of those joints then Bert. If you had, you would notice you were working on a 'mainside' estimate and the first thing you would see is the continuity wire that is either riveted or soldered onto the shielding.

Edited by deleted (Tue 08-Jan-13 17:50:39)