One of Liberty Global’s principal UK engineers and technologists, Stephen Scott, has recently posted a series of new videos that offer a refreshingly detailed insight into the inner workings of Virgin Media’s Hybrid Fibre Coax (HFC) and Fibre-to-the-Premises (FTTP) based broadband ISP and TV network.
Most of the videos like this that we see from other operators tend to be all flash and little substance, often consisting almost entirely of joyful background music (i.e. the type that becomes irritating after 10 seconds) and an endless stream of cringe worthy self-praise. As such it’s rare to see anybody producing one that actually provides a truly useful insight into how the underlying network is setup and actually works.
The good news is that Stephen has done a series of three genuinely useful and informative videos – charting everything from the Headend (data centre) sites to their DOCSIS based Hybrid Fibre Coax (HFC) and Fibre-to-the-Premises (FTTP) based broadband lines at a high level. Admittedly these will make more sense if you already have a basic grasp of the technology, but they’re worth the time to view.
We’ve tried to keep these in the correct sequence below, with the first video in the series being focused on the headend (data centre) sites, which the operator uses to serve cabinets and, ultimately, customers in surrounding areas.
We’ve been informed that the aforementioned videos are now in the process of being taken private because, we’re told, they were only ever intended to be used for internal training purposes (probably shouldn’t have uploaded them to YouTube then.. aye). While the decision is understandable, we think it’s very disappointing as they really were very well presented and informative.
This is excellent! Well done Virgin Media! Hopefully other providers will follow their lead.
A company that cannot even connect fibre across one very minor road in a large town, because it’s too costly, has no credablity when it come to rolling out fibre to the door. Especially as it takes them 6 months and a lot of customer hassle before they say that Virgin media are too self centred, not customer based, and so profitable they just pay compensation rather than address problems. So the excellent coverage promised will lead to yet more inequality as the easy cheap installations go ahead This company does not deserve a government contract until they become more transparent.
Good, informative article. LUX reply is stupid. Virgin is a business and there will be some situations where it is uneconomical to install. As to virgin’s continued use of coaxial, it is a legacy. They have taken an “Evolutionary” approach to their fibre roll out rather than “Revolutionary” as a result they are still tied to some older technology. Virgin are not perfect by any means, and I to have had my arguments with them, but there are worse companies out there.
It would be great if Open Reach did something similar as would love to know how they lay FTTP from exchange to the street and then to the home.Do they go via street cabinets. Do they run hub and spoke model etc. What is the capacity and contention at each connection or level as VM describe. I think it’s 2,5gb over 30 properties at the street level but no idea next level up
Is that 2,5 gbs figure for Opeanreach? It can be even less, 2,4 down and 1,2 up up to 64 adresses with GPON (not XGSPON) that Openreach us using.
I agree it would be good if someone technically competent at OR did some technical videos.
The VM ones are really good although bear in mind that VM need to go on the offensive before they are strangled by all the FTTP that is rapidly enriching their customer base.
VM are being forced to act rapidly as upstream is going to become the battle ground and however much GPON is disliked OR’s 220mb/s upstream on a 1G plan is a lot better than VM’s 50Mb/s offering. Standing still is not an option for VM.
There was a video, but they made it private.
It’s hub and spoke, and it doesn’t use the street cabinets(*). It’s all in underground chambers or on poles.
OLT —– fibre aggregation node — splitter node —-< CBTs (up to 32 ports)
It even bypasses most local exchanges: the OLTs are in larger "head end" exchanges.
(*) Except in a few rare, ultra-rural locations, where a cabinet contains a "subtended head-end": essentially a small remote OLT.
Openreach FTTP is much simpler and completely passive, only the kit at each end needs power. Virgin is still very much tied to COAX with their FTTP arriving outside the property then converted to DOCIS and and then feeding COAX. This would be like FTTP on Openreach arriving outside the property, then terminated in a box that then feeds VDSL (or G.FAST signals) to the customers master socket over the last few meters of telephone cable, which ironically was essentially what G.FAST was specified to be more or less.
OpenReach use GPON with a 32:1 split, but usually keep 2 spare on the splitter, so really 30:1.
GPON can be done at 128:1 though.
I’m not sure what the relevance of 64:1 is? OpenReach don’t use that anywhere.
I’m not aware of any UK networks that use GPON at 64:1
Phil: The RFoG VM use is nothing like sticking a VDSL / G.fast modem outside a property.
The fibre isn’t carrying digital signals. It can have digital signals overlaid but for now it’s a simple conversion of AM / Amplitude Modulation over fibre to AM over coaxial.
The presence of the coaxial itself is meaningless. That short a length of it can happily carry 5 GHz of spectrum – more than enough to carry 40 Gbit/s.
If someone took the Openreach ONT under my stairs and moved it into a weatherproof box outside, as it done in the United States for instance, it would not impact me in any way. Same story here. Whether the fibre coaxial conversion is in the home or on the wall outside doesn’t matter.
This can be adjusted by replacing the ONT with one with a tap so it handles RFoG outside then sends fibre and coax into the property, replacing the drop fibre run entirely or replacing the ONT with a splice and taking the fibre into the property.
It’s not a big deal. What VM have done is perfectly reasonable and common among cable companies. No different from how some of their coaxial networks are vastly superior to others but running hugely separate products doesn’t appeal.
Openreach’s FTTP network is far simpler and more compact. As others have mentioned there are no cabinets involved and many exchange buildings are not involved in FTTP, the fibre goes back to a headend in a large telephone exchange.
The equipment that makes up an Openreach FTTP headend (inside an exchange building) is also very compact. The plan is to close most telephone exchange buildings leaving about 1/5 of the amount we have now.
OpenReach have done a similar video, from exchange to premise with all the above and in ground details – only available to see if you are a BT Wholesale or OpenReach CSP.
I know VM have their issues around customer service, and I wouldn’t want to be caught in an over utilized area (at least wouldn’t until 3.1 AQM kicks in to mitigate) – but it is really great that they are investing in new cable technology. I will never forget the day I got my first cable modem in replacement of my 56k dialup line. It was a 128k sub with a CableTel DOCSIS 1.0 modem and it blew my mind. I’ve never really lost fascination with DOCSIS since then. So definitely watching these videos!
P.s. I’m a very odd person lol.
Great to see a bit more insight into the network!
Great videos thanks for the links Mark
Wow that was actually really interesting. I’ve played about with some DSL kit many moons ago at KCOM, and I’ve messed about with Satellite mux’s for Sky, but I’ve got only a basic understanding of cable systems. It was really interesting to see the kit. It looks like they took some pride in their head end and data centre setup.
Thank you for posting these, very interesting.
I have a new respect for virgin media since being forced to work from home in march 2020. Since then, touch wood, i haven’t had a single issue with my internet service.
My only wish is that faster upload speeds were readily available on their normal packages
I like the videos I was right all along know one believed me even Virgin Media so called FTTP uses Coax cable. Only the main difference is as with Openreach and CityFibre FTTP it’s in your house tour router. But with Virgin Media’s FTTP it’s from the front your house wall it’s FTTP and to your Virgin Media Box and Virgin Media Modem it’s coaxial cable.
No-one apart from anyone who reads this site, who has seen a Virgin Media ONT, read their forums, their website, etc, etc.
That there’s coax from the ONU/T and they use RFoG isn’t new information. They rely on the coax to power the ONT, fibre isn’t so hot at carrying electricity.
They don’t use ONTs they use external termination boxes or ONUs and it’s in house coaxial cable they use
When the likes of Openreach and CityFibre have an Ethernet cable from their ONT to the router you believe its true fibre, but Virgin Media has coaxial cable from their ONT you say it’s “so called FTTP”. Hmmm.
I know tell me about it that’s Virgin Media for you. I would rather use CityFibre or Openreach at least FTTP to you door from optical network terminal aka ONT then Ethernet to to the router
This is all crap, how about fixing my very slow Buisness broadband speed???? I pay for 350mb, lucky if I get 150mb!!!!! For years you know you’ve had issues with fixed IP’s and GRE tunnels!!!! How about fixing what us Buisness customers are paying for???? Over a year my complaint has been open, the chief executive office is a waste of time let’s hope Ofcom does better with you muppets!!!
Perhaps someone who spelt business incorrectly three times consecutively, shouldn’t be in it?
They’ve got a point though. When I was on a business contract with them, I paid the same as a residential customer, yet I had a lower upload speed (10mbit compared to 35) and I was supposed to have an SLA with them, yet when I made complain they were supposed to resolve it in 48hrs they didn’t even respond to it. I mean what’s the point in an SLA when you don’t even bother to reply to your business customer?
If you’re on their HFC network and you go for the business option, the only thing you’re supposed to have that’s better than the residential option is the SLA, but Virgin can’t even honour that.
I also subscribed to 350mbit, which was way more than enough for my needs, but I often suffered from getting 100mbit instead of 350, and that wouldn’t have bothered me so much because for download, I could live with that .. but when it didn’t work, or when the upload (which actually did matter more) didn’t even do 10mbit and they couldn’t even be bothered to respond to an SLA complaint, well .. you get the idea.
Virgin is great when it works, when it doesn’t, they couldn’t care less. And business? on VM? Well lets just say, roll on Openreach FTTP for business (and residnetial). VM is about to get a massive rude awakening and is going to have to up their game massively.
RFoG? LMAO … 1000mbit … 50mbit upload. LULLLLLZZZZZ
You’re not better than anyone else because you vote for Labour either. I’d love to know if there is any difference between red and blue currently to be completely honest.
VM took over three months to connect me even though I already had a cable outside my building for the last 20 yrs, shameful service
You got the order of the videos backwards
Interesting post. More like it please, covering the other common technologies used.
Am I the only one who thinks the entire setup is overly complicated?
A lot less complicated than it used to be. The phone line stuff is just being wrung out until voip is fully integrated. The FPMs and RPMs are a lot smaller and easier then they used to be, they are passive now, basically splitters where as before they were amplified. The new CMTS as mentioned is starting to integrate VOD, and the long term plan would be a full IP network where the CMTS does the lot. The transmode/ciena stuff is backhaul/core stuff anyway, pretty standard kit across all carriers. Over time I can see consolidation and some smaller site closers, especially why R-PHY takes off
Indeed. It was way more complex before CCAP was introduced.
The only way to simplify more is to move more intelligence into the field.
That is happening, alongside moving CMTS into the cloud as virtual machines in Docker containers.
How would you propose to make it simpler? Which components aren’t required?
Building networks is hard. Building affordable, high-performance networks at scale is really hard.
Some of the messiest cabling I’ve seen in a data centre, I’m not surprised they have failures in the network, for a company the size of Virgin too. Seems cost cutting is in use. No point spending all that money on equipment if you don’t think off and look after the cabling.
I remember when a Telewest employee used to do a monthly post/report in what the had upgraded and changed that month, and what was in the immediate future, then what was in the long-term plan.
Went into great detail, explained it well and did not sugar coat it. If mistakes happened, they were detailed.
Do Virgin not do fibre to an ONT then? Or am I wrong in thinking the coax would restrict bandwidth?
The ONT on FTTP areas is outside the property and converts it to a standard Cable for inside, so the same hardware can be used.
No restriction until broadband is sold in multiples of 10Gbps.
All well and good but we’re my 1gbps
On ports 1 and 2 of my ONT.
Did any you guys watch the videos it’s FTTP to your house and coaxial cable inside your house and it’s not Optical network terminal ONT. It’s external network box’s ONU Stans for optical network unit
ONT, ONU… Different names for the same thing: The box where the fiber is terminated. ITU-T calls it ONT, IEEE calls it ONU. SCTE calls the RFoG box for R-ONU.
ONT and ONU are interchangeable when they both connect to the end user’s premises and terminate the fibre.
An ONU that serves a single premises is also an ONT.
A switch that takes fibre in and copper out which then goes to a series of apartments per Hyperoptic / FTTB is an ONU.
Well I would love to give an opinion but these videos have now been blocked and made private so someone wasn’t happy about this being shared with the public I guess.
I also suspect that thee video’#s may show the background workings, but what about localised distribution methods and the typical setups across the UK, its still a misconcept for most that Virgin delivers fibre the the cabinet and then coaxial to the home…. which they don’t.
That’s covered in the videos, they mention amplifier cascades. It also doesn’t matter. As long as the signal is high enough quality whether there’s fibre to the nearest cabinet or fibre 3 cabinets away it’s not an issue.
I didn’t say there was any issue between the two setups, just that it’s likely going to be different for most customers, anyway, haven’t seen and cannot see the videos so whatever.
I don’t know why I even commented because I’m past giving a **** about it any more and the responses I get or see on these comments sections makes me wanna hurl sometimes.
I fail to see why you’re getting into such a mood. For the record the majority of people are on a network which has fibre to a node cabinet with coaxial cable to their premises via one or more distribution cabinets, for the others (a small but growing minority) it’s fibre to the premises.
Shame they took the videos down. 🙁
Virgin has a massive Intranet but yes let’s use Youtube.
@Anna – Ex VM employee here. Their Intranet always only ever hosted text/images. Any videos were always hosted on Vimeo so seeing YouTube is a surprise.
Shame they’ve gone down! Was really interested in learning about how these sorts of networks work. Any chance anyone managed to get a copy before they went and would be able to share them?
I downloaded all three videos…
Yes I too would be interested if anyone could send me a copy please!
I too would be interested in a copy.
@Roger_Gooner if you wouldn’t mind uploading them to google drive or mega that’d be much appreciated! Cheers
Woud love to get these too!
I’m not a fan of VM but for anyone who want’s to watch them their cached on Waybackmachine still and here they are on filefactory as well 🙂
http://filefactory.com/folder/4872b3d7fdb4835c
The videos now say private content which is no longer accessible?
Can’t be a proper VM engineer as he closed the cab at the end
Good videos on BT FTTC.
https://www.youtube.com/watch?v=ziqgASrHeP8
OK, So I’m watching these videos…. as I had guessed they would they don’t really concur with reality or even the practices that Virgin Media preach.
The HFC video says the a distribution cabinet feed 12-60 users but actually in many areas, Birmingham being one of them, cabinets are configured with 96 ports on average, this is without ports being split to add in customers in MD Units, cabinets also cascade to more than just 3/4 but that’s not technically what was said.
Also, inside an Omni box, even though a isolator can be fitted, this is not Virgin’s practice at all, as they have for many years put isolators in wallboxs and now feature them as part of the newer modular fittings, I will also add that Virgin will never fit a service in a way shown in anybodies home, unless it has been done prior to vacancy in a new build…. and Virgin say that have a policy of not used 3rd party cabling to connect services….. (So if your refurbishing your home and decide to put high quality RG6/WF100/CT100 coaxial cabling into the walls to feed rooms with cable/tv/satellite services, be assured that Virgin’s terms of service will be against you, so get Sky as they are open to customers having a say in their homes)
I cannot fault the videos on FTTP (RFoG) or the Headend, though can understand ideally too much info may have been given in the headend video, I’ve learnt a little bit about the distribution of the FTTP network and quite chuffed to have done so…. But I wish the the HFC video was very much a misrepresentation of what actually happens on the network isn’t what customers can expect in their homes.
Thanks @SymetricalAccess for the link to the video’s, much appreciated.
Really interesting look. Didn’t realise coax was capable of 40Gps along short distances. The VoD stuff seems so overbuilt for the future of internet streamig. When I got my first VM VoD stuff in 2006 it was pretty impressive then – you got the original bitstream of the show you wanted to watch as it was broadcast. But with todays internet it’s no longer needed.
The amount of wasted power that also goes into DRM is frustrating. All the stuff makes its way through anyway, but the market still demands providers and manufactuers waste resource on DRM
Is there anyone able to share these video’s still? Keen to see them if possible. You can email me john -at- omail.icu