How Does Fibre Broadband Work?

(Denis Cooper) #21

the diagram on this picture will probably help you see how the different connection types work

Unless you are using FTTP you will be going over some form of co-ax connection. As mentioned by others you need to look at both upload and download speeds you are being quoted. Upload speeds will affect things like backing up to cloud services (iCloud, oneDrive, Dropbox etc), uploading photos videos to facebook, youtube etc, if you are using smart home devices, CCTV - viewing your stream remotely.

Download is when you are pulling something from a remote server, such as viewing webpages, streaming films, streaming music etc.

There are many things that can and will affect speed you truly get, down to the time of day, the number of people, your position in the cab, contention at the isp, distance, the type and quality of the cables to your property.

(Allie) #22

Or upload 4K content. Also that’s only on the most expensive package. You can get the same speed for a lot less money elsewhere.


Where? I had 210Mbps down and 12Mbps up on virgin for about 50 quid a month. I miss it.

(Allie) #24

Sky fibre max gives you 18 up (50% faster) for a lot less than that! It’s only 63 down so depends on your exact needs but I’d take the better upload any day in this case.

(Andre Borie) #25

I get 20 mbps on Virgin for about 42/month. It would be very hard to find another consumer-grade plan that can beat this upload speed. It’s not even an issue about price, just that 90% of phone lines are so bad that there’s no way your modem will manage to sync at 20Mbps or more even if they technically offer higher upload speeds. At least Virgin is somewhat guaranteed (HFC either works or doesn’t, it does not degrade like DSL), so if you can get a connection you are more or less sure to get 20Mbps upload or whatever your plan offers.

I understand you don’t like Virgin (and frankly I don’t either), but I think it’s the lesser evil compared to DSL, so personally I wouldn’t steer people towards DSL given that most properties have horrible phone wiring and unless you’re an expert you won’t find out what speeds/reliability you’ll get until after you sign up for a contract (how convenient for the carriers).

(EJ) #26

Would you recommend Sky fibre overall, Allie?

(Simmy) #27

20mb upload here on BT for £35
Not that it means anything for me though

(Andre Borie) #28

Up to 20Mbps, since this is DSL the real speed will be determined by line quality.

(Dave) #29

I’ve got DSL and Virgin (I work from home, don’t ask).

Virgin gives me measured throughput of 385 Mbps down and 20.6 Mbps up which exceeds their specification for the product. The cabinet is right outside my house but as @Rjevski said it doesn’t make much difference for Virgin cable broadband.

The VDSL2 line syncs at 60 Mbps and 20 Mbps and gives me measured throughput of 55.6 Mbps and 18.5 Mbps. I believe I am about 300m from the street cabinet and given where it is the actual line length (as it won’t be a straight line) is about 50m more maybe (I should have asked the engineer).

The difference between the technologies is that the tests show lower jitter on the DSL line, but it isn’t something I notice in use. Apparently the lower jitter can help with online gaming and if you are remotely accessing a server and using the command line. I’m told that a gamers dream is to have cable broadband speeds over DSL technology (I wouldn’t know) :slight_smile:

(Simmy) #30

Yeah im synced at 75/20


Cable and DSL both have benefits and drawbacks, but overall cable is the better technology from a throughout perspective. Newer standards are capable of full duplex speeds in the Gigabit range, not that Virgin have anything like this yet.

The main problem in the UK is that Virgin Media is the only cable provider, and their network management leaves a lot to be desired. There are areas where network congestion make Virgin virtually unusable, and backhaul in generally never seems to be kept up with demand. I’m sure there are some fantastic areas where Virgin is great, but it’s a bit of a gamble and the service is poor if you happen to have any problems.

(Dave) #32

That’s exactly my experience with Virgin. Back when the network in my area was Blueyonder/Telewest, cable broadband got so congested that if you turned your modem off thinking that it might help if you reconnected you often couldn’t get reconnected at all let alone get your congested slow connection back.

After complaining many times an engineer admitted to me that in my local headend they didn’t have enough connections for all customers to be online at the same time, and that is why if you rebooted your modem at peak times there was a chance you wouldn’t even get reconnected.

I moved to DSL for a few years, and in the meantime Virgin did a big upgrade in my area. Now I get the maximum speed specified for the product at peak and off-peak times. So yes, it can be very variable from one area to another I suspect.

(Andre Borie) #33

they didn’t have enough connections for all customers to be online at the same time

And this is where you needed to cancel the direct debit and when they complain you tell them that your bank account doesn’t have enough capacity for all customers to be online at the same time.


Agree with this. There’s a lot more network sharing going on and it slows down at peak times - with phone line based providers and FTTP I have never been slowed down, maybe they have more bandwidth or they just manage it better.

(Simmy) #35

As I’m moving home I’m checking all of the premises internet speed .
The one I’m looking at has a green box right outside yet the max speed according to BT is 40mb? How does that work ? I currently get 75mb at my current apartment and the green box is down the road

(Andre Borie) #36

Check and see what those guys can offer:

They know what they’re doing so their availability checker will tell you the correct numbers. It could be that you used the consumer-grade BT checker (instead of the wholesale one) and it just happens to tell you if you’re eligible for a lower plan that you selected, thus the limit of 40 Mbps.

I currently get 75mb at my current apartment and the green box is down the road

If the numbers are indeed correct then this could mean the property isn’t connected to that green box - it was added later on for new builds but existing ones still connect to a farther one.

Still keep in mind that technically having the “green box” nearby doesn’t guarantee good speeds either; the cable can still be damaged or rotten or go near high-voltage lines and pick up interference (this should never be the case, but then again I’ve seen a lot of things that shouldn’t be so nothing surprises me anymore), or the wiring in the property can be bad too - however none of this would reflect on the availability checker; it’s one of the “surprises” you get as a perk when installing DSL; a “new customer” gift from BT if you will. So even a “perfect” availability check doesn’t guarantee anything really.

( #37


The 20 meg limit is artificial. You 100% can get that speed.

Just use a proper isp like @PhilB