Networking and Broadband

Networking and Broadband Internet

After the last open event (29th August), Adrian asked me to write up a proposal for electronic communications (networking, telephony, etc.) for houses and across the K1 site. I’m considering some options and I’d like to put forward this straw-man proposal as a first attempt to put something together, and to get your feedback and ideas.

Note: there is much information about home networks and broadband infrastructure for new builds in PAS 2016.

Onsite Network

I think it would be a good idea to offer very high speed broadband (gigabit speed) on the site, over a 10GB fibre local area network (LAN). This is easily technically achievable in a new build, will enourage tech-savvy residents (particularly with links to the Science and Business parks) and will facilitate interesting uses such as:

  • free phone calls and videoconferencing across the site;
  • meetings, remotely looking after relatives, neighbours and pets;
  • kids playing multiplayer games across the site;
  • significantly faster broadband Internet than commercial offerings (maybe).

It is entirely up to the residents of each house to determine how they use this, and buy any additional hardware; I propose that we put in the infrastructure (cabling) to make it possible.

Broadband Utilities

If each house has its own independent broadband connection, then the speeds available between houses will be much lower. However I think it’s a really good idea to have it anyway (see below under Broadband for reasons why). I think we should provision BT telephone lines and their Fibre to the Premises (FTTP) products, and Virgin Media in addition.

I’ve made enquiries to BT Ipswich about getting connected to FTTP, and to Virgin Media’s New Developments Team, but I suspect they won’t be able to tell us much until we have planning permission. At least I hope that we’re now on their radar and they will be able to factor us into their rollout plans.

Site Network

I propose that we run four fibre pairs to each house: one each for audio, video and data networks, and one spare (or possibly for BT to use). (While they can in theory share a single fibre pair, they tend to interfere with each other, typically causing annoying dropouts in audio conversations and video to stop and buffer while a download is in progress. And BT would want their own fibre if they use it at all.)

For the fibre between houses (back to the common house), I think the longest run is probably:

  • 10m to the south side of the lane,
  • 100m either way (east or west) to the end of the lane,
  • 10m each side inside (common house and home).
  • Total: 130m of fibre.

That gives us a choice between 10GBASE-SR and 10GBASE-LRM fibre interfaces. It seems that both work with OM3 fibre. 8 core OM3 costs about £0.90/metre and the average distance (with the nearest houses requiring about 30m and the furthest 130m) would be 80m, or £72 per house.

Home Network: Entry

These would be brought to a utility cabinet in the home, probably shared with electricity and maybe gas. (This is the “digital cupboard” referenced in PAS 2016). In that cabinet would be a shelf and two power sockets (and lighting if it’s large enough to need it).

The presentation of the home cabling and associated equipment should be accommodated in a primary distribution space, as specified in BS EN 50174-2, which is secure (lockable).
This space should be located in for example an under-stairs cupboard, or a similar location.
The primary distribution space should be provided with two-twin gang switched 13A sockets

Here we can install whatever equipment we need to service the home:

  • Ethernet switches can be installed to route traffic through the house (converting fibre to ethernet);
  • an ADSL or cable modem router;
  • a wireless access point;
  • a VoIP adaptor, Sky box, or Sonos sound system;
  • backup or home server/firewall;
  • whatever else might be required but desirable to keep hidden (and quiet).

We might want to make this cupboard lockable to reduce the risk of theft, and of young fingers getting overly involved with it.

Any such equipment is the responsibility of the homeowner to purchase, install and maintain, although we’d probably have some standard recommended equipment and an IT working group (I offer to be part of this) which helps people to install and use it.

PAS 2016 says:

BS EN 50173-4 requires that cabling be implemented in a star configuration from a home distributor (HD) located in a “primary distribution space” which is separately specified in BS EN 50174-2. Exceptionally for large buildings, additional star points [secondary home distributors (SHDs)] may be used to serve areas of the building not easily served by the primary star point. Where possible the demarcation point [BT or Virgin master socket] should be co-located with the HD [in the digital cupboard].

Home Network: Distribution

Within the house, I propose that we provide multiple connection points. Each point would contain:

  • Two CAT6 ethernet ports (one for VoIP/analogue phone, one for data);
  • Two HDMI ports (HDMI 1.4 with built-in Ethernet)
  • Four coaxial ports (TV, radio and satellite/Sky+)
  • Two analog telephone lines (e.g. one for home, one for business)

This would come out into two recessed double wall sockets to accommodate all of the above (with 4 euro modules each). Most rooms would have two of these points, approximately on opposite sides. I’m not sure whether to fit any in bathrooms or not. All would run back to the patch panel in the utility cupboard for interconnection there, where they would be labelled.

None of this would be energised by default. It would be up to the household to decide which of these ports they want to connect, and how.

I expect that each cable run would be approximately 20 metres in length on average. For a two bedroom house, I guess there would be 10 points:

  • Two bedrooms with two points each
  • One living room with two points
  • One kitchen with one point
  • One attic with two points
  • One garage with one point

Very approximate costs for a 2 bedroom house (these are retail prices and with bulk purchasing they will probably be significantly lower):

  • 2 x 20m x 10 points CAT7 (Ethernet) at £2/m: £800
  • 2 x 20m x 10 points HDMI at £6/m: £2400
  • 1 x 20m x 10 points satellite (Sky+/HD dual RG6) at £0.50/m: £100
  • 2 x 20m x 10 points coaxial (TV RG6) at £0.20/m: £80
  • 2 x 20m x 10 points analogue telephone at £0.10/m: £40
  • Total: £3420

Shared Broadband

The onsite network (LAN) would not actually require Internet connectivity to bring significant benefits. However it could be extremely useful. It’s possible that we can offer a better quality of service than a for-profit Internet provider.

It’s probably unwise to try to share a normal home Internet connection (ADSL, VDSL or Virgin Cable) between multiple users, as there just isn’t a lot of bandwidth. Heavy users will cause problems for lighter users, and possibly take the whole site over a bandwidth quota, into traffic management or excess usage charges.

Two possible approaches are:

  • Light users share a single 300mbps fibre connection from a commercial provider, with a bandwidth quota, and heavy users get their own, separate connection.
  • We get a fast leased line (1 GBps) shared between all users, with a fair use policy.

A leased line would cost about £1000 per month. Shared between 40 people that’s actually quite affordable, and would give us better Internet access than any commercial broadband provider (especially faster upload speeds) and the ability to run servers from home and from the common house. But if it’s not well taken up, it becomes a liability because the costs don’t scale down. We’d also need to install and manage a bandwidth management system to share the bandwidth fairly between users, and enforce quotas.

I think it’s safer not to install any such system at the moment, but merely the fibre optic cables to homes, and consider building the local network which will be relatively cheap (a few thousand pounds) and enable all kinds of interesting interactions that aren’t currently possible over the Internet. A shared Internet connection be added at any time later.


The proposal above for home networking requires installing a lot of copper! And most of it probably won’t be used. But it’s hard to know in advance what will be used. I strongly suspect that in future, everything will run over Ethernet or HDMI. But right now, I’m pretty sure that most people will want traditional analogue phones, and either satellite or TV. Each house could choose its own cables from the set above, but that makes the system tailored to the resident, which reduces the impact it could have on resale value, or forces people to install unsightly cables in future.

It might not be necessary or useful to run satellite or TV points to every room. I don’t know whether multiple satellite boxes can share a single dish, or how many people would want it. I suspect that most people will get their cable TV (Sky, BT YouView or Virgin Media) over an Internet connection in future. We might not even want to see satellite dishes or TV antennas on the site.

HDMI is difficult to run over long distances. Cables over 45ft (15m) are unlikely to be certified as compliant, although they will probably work. Generally you can’t terminate it yourself, it has to be purchased at the correct length with moulded connectors. This makes it quite expensive, and we’d have to survey the houses very carefully to work out exactly what length to install where, before buying the cables.

We might want to skip the HDMI completely, which means that each TV and audio device would have to be connected to an antenna, an Ethernet device or a Sky+ box in the same room. This would save a lot of money and hassle on cabling, but the system would be much less flexible.

It’s almost certainly over-engineered. I’m interested to know what members think they’re likely to use, or not use. I specified CAT7 cable (Class F, capable of 10-GB Ethernet) but only CAT6 wall ports, because it’s not easy to get CAT7 wall ports at the moment, and they’re much easier to replace than the cable! Alternatively we could drop to cheaper CAT6a, which also supports 10-GB but is less future-proof and supports only shorter distances.

We could add fibre to the home wiring. We might choose to install cheaper OM1 cable (good for up to 33 metres at 10GB speed) and either not to terminate it at all, or fit LC connectors that are available as Euro modules. I strongly suspect it won’t be useful in the next 10 years, but it might be after that, and it’s cheap to add.

I haven’t included any audio cables. I don’t think audio works well over long cables, good quality cable is expensive, and it’s quite possible that people would want speakers in different positions (e.g. in the ceiling). But I could definitely include it.

What about wireless? As PAS 2016 says, “Wireless provides convenience, and offers the possibility of connecting to the internet from any place in the dwelling, provided there are no wireless deadspots. However, cabled medium is required to connect wireless routers to the Internet. Wireless connectivity is assumed in this PAS to provide a supplementary method of connectivity to broadband services, used in conjunction with cabled media.” I would add that wireless has much lower bandwidth (speed) and reliability than wired infrastructure (cables), and I would always prefer to use wired for anything except a portable device.

I think the most flexible approach would be something completely different: install cabling ducts all around the homes, with wall sockets at the ends in rooms, and people can install whatever cables they want into them. This might actually be more future-proof, but I don’t really understand the costs well.


Finally, apart from Copper Ethernet and Internet I’m not an expert on any of this. I may well have made mistakes in the specification above.

There’s a very useful NSRC guide to campus networking that was recommended to me by Brian Candler, who is a consultant for CityFibre.


Virgin Media

From: “Thorogood, Neville” <>
Subject: RE: New build in North Cambridge

Thanks for the details Chris.

It appears that the nearest network we have to your proposed site is on the opposite side of King’s Hedges Road, therefore we would need to complete a full survey for us to determine feasibility. In this instance full site plans will be required before we can undertake any survey. Also, the developers full name and postal address is required in order for us to create a business case.

I look forward to receiving the plans and required information when available. I have attached our new build developers guide as requested.

Zen Internet

From: Darren Shaw <>
Subject: RE: Zen Internet Leased Lines & EFM Enquiry 14/09/2013

Here is a quote, while not specific to you should give you an idea of what is possible. I would expect this cost to decrease in the next 12 months, as bandwidth is always becoming cheaper.

CW12 4TR



Ethernet 100Mbps/1Gbps (Premium Bandwidth)

1 Year Contract

3 Year Contract




CISCO 867VAE-K9 Secure Router, ADSL circuit for backup/monitoring , Cisco 3560V2-24TS Layer 3 switch with IP Services IOS, GLC-LH-SM SFP, GLC-T= SFP, Cisco Catalyst Fibre lead 9/125 LC-LC 2.0mtr Switch



Monthly Circuit Rental

£1573 per month

£1573 per month

Total Contract Value



CW12 4TR



Ethernet 500Mbps/1Gbps (Premium Bandwidth)

1 Year Contract

3 Year Contract




CISCO 867VAE-K9 Secure Router, ADSL circuit for backup/monitoring , Cisco 3560V2-24TS Layer 3 switch with IP Services IOS, GLC-LH-SM SFP, GLC-T= SFP, Cisco Catalyst Fibre lead 9/125 LC-LC 2.0mtr Switch



Monthly Circuit Rental

£3950 per month

£3857 per month

Total Contract Value



A 100Mb on 100Mb would probably be around £1000 pm with no upgrade path

For further info on our SIP service please have a look at the following link:

If you need anything else please let me know

Kind regards
01706 902173

Joe’s View

I think the idea of a 10GB sitewide network is great although having got it it in place it seems a shame to not use it for a common internet connection. However I agree that each house should be provisioned for individual broadband and analogue phones.

While the fibre  could be used to also deliver TV it might be better to consider some sort of integrated reception system so there could be one satellite dish feeding every household. We could then chose to subscribe to whatever TV package suited us, or none at all. I’m sure Virgin do something similar for cable TV

As for the wiring inside the house it’s difficult to think what might be useful in five or ten years time. I agree with Ethernet ports in every room since it’s well established. I’d be glad to ditch the homeplugs. I’m less keen on having HDMI ports given the cost and how it’s changing relatively quickly.

Wireless should probably be left up to each household. Sitewide wireless is expensive and anyway it couldn’t be installed until the place is built.

I also think that your last point is very important. That the houses should have ducting which is reasonably accessible so obsolete or broken wiring can be easily replaced.

My response to Joe

I agree that it would be a shame not to have fast, shared Internet access over the LAN. However I think it’s only economical if we agree that everyone pays for it, whether they use it or not. Otherwise:

  • 100mbps fibre = £1000 / 40 houses = £25 each (really cheap)
  • 100mbps fibre = £1000 / 10 houses = £100 each (really expensive)

We’d also need to deal with the issue of some users making excessive use of the service to the point where it interferes with other users.

If we’re not able to agree on either of these things then it’s much safer to not use the network for shared Internet access. Hopefully we will get BT to install FTTP and we’ll be able to get 330 megabit broadband for around £40 per month. This is actually pretty good.

We may at some point choose to build a site-wide wireless network. It certainly doesn’t have to be done now, or before the houses are built. Having the LAN between houses will make it possible. Each householder can access their own individual broadband connection over the sitewide wireless network and the LAN.

I think provisioning BT and Virgin services into the houses at build time is the safest option:

  • We might be kicking ourselves in a year or two if we haven’t done it;
  • We’ll never get FTTP unless we do it at the start;
  • As Lautaro says, we can’t have BT engineers drilling holes in the passive houses.

Hopefully (fingers crossed) we can come up with an agreement to share a 100mbps leased line, for example for 2-3 years, everyone pays for it, and we make it run as well as we can. If someone thinks it’s a terrible service, and we can’t fix it, then they’ll still have the option to get their own broadband independently.

I don’t know of any way to distribute TV over fibre. I was thinking it would be useful to have a separate fibre for video, but I think you’re right that it’s unnecessary, and BT also won’t use our fibre (they prefer single-mode instead of cheaper multi-mode fibre). So we could just run 2 pairs (4 fibres) to each house: one pair for LAN/internet/general use and one for special applications (maybe voice/video, maybe TV over internet or something like that in future, but basically spare for the time being).

Agreed on ducting. I hope we can find a good way to make it easily accessible and not intrusive.

Lautaro’s View

I think an integrated reception system is a good idea as Joe says, however I also think that whatever is chosen needs to allow for the option of Freeview so people don’t have to pay for anything other than the Freeview box/TV if they don’t want to. 

I’m not sure how the options you outline, Chris, are set up, but I guess it’s important that we don’t have Virgin or Sky engineers drilling holes into individual dwellings to set up their services as it would end up breaking the Passivhaus seal – is this already considered under your proposals? The integrated reception system might help.

On the HDMI, the cost does seem high.

My response to Lautaro

Interesting point. I don’t know of any way to get freeview to houses except for each house (that wants it) having an antenna on the roof. Is anyone familiar with TV distribution in blocks of flats or anything like that? It would probably run over coax, so we can add coax to the spec for wiring back to the common house in case we find a way to use it, and also coax up to the roof/attic so that people can install their own antenna if necessary.

My plan was that BT and Virgin would install cables to each house’s distribution point (digital cupboard) during the build process, so the connection points would be inside (under the stairs) which is the ideal place from which to connect them to the rest of the house.

From there, we could run dual coax to a few points (e.g. the living room, master bedroom and the attic) and you could attach a Sky box at one of those points (I’m not sure if you can have multiple Sky boxes per dish), or a Virgin Cable TV box or a Freeview box at any or all of them.

Agreed on the high cost of HDMI. So far I’ve heard two opinions against HDMI and none in favour. PAS 2016 also doesn’t mention HDMI at all; it only specifies Ethernet connectivity within the house. It might be a niche application. I’m aware that HDMI either doesn’t run at all over CAT6, or doesn’t run reliably, or only with expensive equipment, so it seems that anyone who wants to use HDMI will need separate cables for it. If the ducting is accessible then people can add their own HDMI cables, when and where they need them, which is more economical.

One thought on “Networking and Broadband

  1. This is a great piece of work which presents us with a good range of options and food for thought.
    As an IT person (I currently work as a Business Analyst), I can understand most of it although I did get a bit lost on some of the detail and there are probably some other members who will struggle with the level of technicality. I appreciate that this level of technical detail is required in putting together an options document and costing he various estimates but I’m wondering if it would be possible to add a couple of paragraphs to explain what the options provide in terms of “real life”?
    On the subject of shared TV signals, I had a quick look on the web and there are specialist providers that offer a range of services in this field e.g. or (these are not recommendations, just the first two I looked at)

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