ADSL over coax (AKA I don't know anything about ADSL)

Its probably fair to say that *any* broadband technology needs a modem at each end, almost by definition.

(whether you would argue an optical fibre is broadband or not is another matter!)

Kind of like when (some) electricians do TV systems...

I had to extend a coax cable from where it was originally intended to where SWMBO wanted it. Then ultimately she realise that where the original socket was was indeed a better place, but by that time the radio tuner which shares the same cable (VHF and TV are multiplexed down the same cable from a distribution amp) had grown roots and was to stay where it was.

I am afraid I simply 'tapped off' the cable in a short spur to the TV..

It all still works with no ill effects.

Thanks for all the replies.

So ADSL is a technology developed to cope with the installed telephone lines, not a technology developed independently and then shoe-horned onto the existing lines? This makes much more sense to me now!

The one thing that annoys me about cable is the asymmetry of upload speed compared to download. I have a 60 meg DL, and 3 meg UL. I do enough uploading for this to be a bit of a pain in the arse!

ADSL seems to have MUCH better upload speeds. As I understand it, it is due to the bandwidth allocation of the cable system (DOCSYS?) and the 'traditional' bandwidth requirements of earlier consumer internet times.

I wonder if we'll ever get a Google fibre style company in the UK?

In article , David Paste scribeth thus

About right..

Well does it really matter for the great majority of users ., the name ADSL Asymmetric digital subscriber line implies that. Most everyone will download faster than upload and unless your running a server what's the real problem?, with anything I upload I just start it and let it get on with it.

DOCSIS

AIUI it is improving or will be when they change systems whenever that will be..

It could be some of the higher speed fibre connections use more than one laser frequency (aka carrier), but then you are probably talking silly data rates like a few Tbps... B-)

GPON uses two down a single fibre but in opposite directions.

Of course the vast majority saying that they have "fibre broadband" haven't they have VDSL with the local head end fed by fibre. I reckon all this crappy FTTC will come home to roost in ten years or so. When streaming multiple channels of HDTV at sensible bit rates (10 Mbps or more) becomes the norm, rather than the barely better than SD 2.5 Mbps or so that is used at present.

I think he means a company that installs FTTP. I doubt there will ever be a national one that covers everywhere. FTTC sort of works OK in densly populated areas. Move out into rural ones and the costs of digging 2 miles to connect a customer aren't economic for a commercial company.

There are a number number of community systems installed or very soon to be. Fibre GarDen in Garsdale/Dentdale springs to mind.

Fibre TTC doesn't have to be underground.

Well that's better than any ADSL setup...

The A of ADSL is the key! Typically most links will top out at about

VDSL (i.e. FTTC) will do a much better uplink at over 8Mb/s

There is also SDSL (symmetric) available in some places (usually at much higher cost) for those that need the outbound data rate.

Who knows... IIUC they have bought up loads of unlit fibre for future use.

I've recently been upgrading a network of private* ADSL1 connections, some to ADSL2+M, some to EFM, some to FTTC, others to "proper" fibre, depending on what's available at reasonable prices in various parts of the sticks.

The FTTC ones have tended to be exceptionally close to the cabinet (as in 5 yards outside the building) and have easily achieved 79Mbps down and 19Mbps up speeds.

• i.e. they don't go to an ISP.

What options are available for areas that don't have local cabinets, and the BT exchange can do ADSL max at best?

Most of the FTTC installs I have seen have done 70 or better downstream (sync speed, if not actual throughput)

essentially nothing. Satellite maybe or a private wifi link to something better

cab get that at sub 400 meters usually I think.

Maybe this is what I was thinking of. A relation has BT Infinity, installed last summer or thereabouts, and I was amazed by the upload speed. I presume this will be VDSL (I did not know that VDSL was different to ADSL).

Interesting!

If you're lucky, EFM, ok it's out of most "home" budgets as it bonds four PSTN lines but it gets 10-15Mbps symmetric, rather than whatever ADSL1 can manage.

Yup that sounds likely.

VDSL is a relative of ADSL, but optimised for this particular application, makes use of more sophisticated filtering and has much more stringent length limits.

Interesting - that is one I had not investigated before. Prices are not cheap (seems like £170/month is not uncommon for 10Mb symmetrical), but compared with a couple of business class ADSL connections and bundled phone lines its not a huge jump.

I heard an ISP comment the other day that they, BT, were delaying the roll out of Fibre to some industrial estates because why give them fibre at 30 odd quid a month when you can supply leased lines and EFM for a lot more moolah.....

that is one way to spin it. Another might be that they need symmetric performance so staff can use VPNS for home, or upload big data to the corporate (hosted) web site and ADSL isn't the best option. So why invest in it when what the dues actually need is different?

FTTC is only a stopgap anyway. In the end we need full symmetric 100Mbps or better. if ethernet over (two) twisted pairs is the next best thing one wonders whey its not being pushed harder.

Ethernet over twisted pair only goes 100m - and it needs to be a high-quality twisted pair (at least cat 5) not phone wire. If you're going to install fibre to within 100m of the premises, and replace the drop wire, then you might as well just take the fibre all the way. That's available now, Openreach will happily provide 10M or 100M symmetrical Ethernet - but you might not like the price!

Mike