The joys of xDSL

[Ignitionnet]

A reason why twisted-pair based xDSL services can be annoying.

Here're the stats from my modem when it was first installed, only connection on the cabinet:

Max: Upstream rate = 29421 Kbps, Downstream rate = 98020 Kbps
Path: 0, Upstream rate = 19999 Kbps, Downstream rate = 79987 Kbps

So in theory I could max out at 98Mb/s downstream, 29.4Mb/s upstream if the rate limits were removed.

Here're the stats now.

Max: Upstream rate = 21782 Kbps, Downstream rate = 66332 Kbps
Path: 0, Upstream rate = 19999 Kbps, Downstream rate = 65655 Kbps

Lost 20% from my downstream speed, 32% from the maximum attainable rate.

Bleh.

[cnewton2k]

Crosstalk caused as other people have had their lines turned on, the same this has happened with mine!!

When BT enable vectoring Thag should help sort the problem out.

[Ignitionnet]

Very aware, should be noted vectoring is still in trials and will require new hardware installation.

Whether it will see light of day I don't know.

[craigj2k12]

Originally Posted by Ignitionnet

Whether it will see light of day I don't know.

Last I heard it was being rolled out to enable a possible 110Mb/s or 120Mb/s service, merely rumours however

[qasdfdsaq]

Originally Posted by Ignitionnet

A reason why twisted-pair based xDSL services can be annoying.

Here're the stats from my modem when it was first installed, only connection on the cabinet:

Funny enough, its only ever this bad in an area with no VM service. Similarly in Aberdeen we have no VM cable and FTTC has seen an attainable rate drop of around 45% since installation (admittedly ours was literally one of the first lines connected on this cab)

[Ignitionnet]

Originally Posted by craigj2k12

Last I heard it was being rolled out to enable a possible 110Mb/s or 120Mb/s service, merely rumours however

Roll out if it happens will be for enabling more people to hit maximum speeds initially.

No plans for higher speeds on the current profiles, beyond rumours of a ~100Mb service. 110Mb or 120Mb will be achievable by hardly anyone, even with vectoring.

[qasdfdsaq]

Alcatel Lucent seem to be of the opinion vectoring will enable 110-120Mbps to be achievable up to around 300 metres or so, and ThinkBroadband says that's about one third of all lines, which isn't all that terrible, that's potentially 5 million people or almost the entirety of VM's broadband customer base. And that's without taking into account any possible increase or rebalancing of spectrum.

And the last Samknows report showed 100% of customers on 38Mb and 73% of customers on 76Mb were already in the highest group of line speeds for their class of service anyway. Personally every property I've lived at has had attainable FTTC rates of 110Mb or more.

[Ignitionnet]

Originally Posted by qasdfdsaq

Alcatel Lucent seem to be of the opinion vectoring will enable 110-120Mbps to be achievable up to around 300 metres or so, and ThinkBroadband says that's about one third of all lines, which isn't all that terrible, that's potentially 5 million people or almost the entirety of VM's broadband customer base. And that's without taking into account any possible increase or rebalancing of spectrum.

And the last Samknows report showed 100% of customers on 38Mb and 73% of customers on 76Mb were already in the highest group of line speeds for their class of service anyway. Personally every property I've lived at has had attainable FTTC rates of 110Mb or more.

Vectoring requires hardware replacements. Openreach haven't even started trialing vectoring with their ECI hardware, and have trialed FPGA-based and now ASIC-based vectoring on Huawei.

In the case of nodes like this another challenge is presented - multiple DSLAMs require node-based vectoring, as system-based doesn't cut it anymore.

You are pretty fortunate to have lived in areas with low FTTC takeup and been <100m from the DSLAM.

100% of FTTC subscribers on 38Mb services do not receive 38Mb, 73% do not receive 76Mb, what is this 'highest range'?

http://blog.thinkbroadband.com/2013/...band-services/

The average customer has a d-side length of either 450m or 550m, depending whether running on mean or median with median the most representative for obvious reasons, it's what 50% of the customer base are at, or further. At that range 76Mb isn't going to happen unless the line is perfect with zero cross-talk and perhaps even extra-thick copper. At ~400m, as the only connection on the cabinet, with a brand new e-side that had been completely rebuilt by an Openreach boost team 3 months before to try and fix a fault my maximum sync was 98.02Mb. Very few people will have d-sides that good.

On the first day of new connections that dropped 10%.

EDIT:

FTTC connections were less affected by peak-time contention than cable connections. The peak-time download speed on ‘up to’ 38Mbit/s FTTC connections was 32.5Mbit/s, 94% of the average maximum speed and 99% of the 24 hour average, while the peak-time download speed on ‘up to’ 76Mbit/s FTTC connections was 64.0Mbit/s, 96% of the average maximum speed and 99% of the 24 hour average.

http://stakeholders.ofcom.org.uk/mar...peeds-nov2013/

This will, if anything, drop as more rural areas come online on FTTC via BDUK. That average was from a panel of 147 urban FTTC lines and 17 rural ones.

[qasdfdsaq]

Originally Posted by Ignitionnet

You are pretty fortunate to have lived in areas with low FTTC takeup and been <100m from the DSLAM.

Actually both FTTC areas where I've lived have had pretty high takeup, and my line length was 140m in the first case and 80m in the second. The first area had massively oversubcribed VM services, and the second has no VM at all. While admittedly attainable rates at the first were just over 110Mb without crosstalk and 140Mb at the latter, both have lost about 25Mb due to crosstalk but given the point of vectoring is to restore near-crosstalk-free performance, both would presumably achieve 110-120 with vectoring.

Nonetheless, every property I looked at potentially moving to within the city was at most 200m from a cabinet, though that's not to say the line length won't be higher, but I recall reading somewhere that most urban D-sides were <300m.

100% of FTTC subscribers on 38Mb services do not receive 38Mb, 73% do not receive 76Mb, what is this 'highest range'?

The "highest range" I speak of is the highest bin Ofcom published results for that had any customers in it at all, presumably because it is the limit of the technology or the service.

http://blog.thinkbroadband.com/2013/...band-services/

The average customer has a d-side length of either 450m or 550m, depending whether running on mean or median with median the most representative for obvious reasons, it's what 50% of the customer base are at, or further. At that range 76Mb isn't going to happen unless the line is perfect with zero cross-talk and perhaps even extra-thick copper. At ~400m, as the only connection on the cabinet, with a brand new e-side that had been completely rebuilt by an Openreach boost team 3 months before to try and fix a fault my maximum sync was 98.02Mb. Very few people will have d-sides that good.

But we're talking potential speeds with vectoring if it were to be deployed, which most vendors state are in the range of 90-95% of zero-crosstalk speeds.

http://www.increasebroadbandspeed.co...ainst-distance

Notwithstanding any potential change to profile 30a in future, most urban customers would be seeing their speed limited by the service cap, not the line, if vectoring becomes available.

http://www.thinkbroadband.com/guide/...broadband.html

Gives a distribution of line lengths - 30% are 300m or shorter, 45% are 400m or shorter, 60% are 500m or shorter. 450m as a national median is about right. But then again rural areas with current speeds of <2Mb aren't going to be the ones shouting for a 120Mb service, they'd be happy if they could get 20. It's the high-end customers already accustomed to 80Mbps FTTC or VM FTTN that will be wanting it.

[Ignitionnet]

Hmm.

First an issue with those Ofcom graphs. If no-one can get 35Mb on the 38Mb service, VDSL rate 40000, confused how anyone, let alone almost everyone, is getting >70Mb on the 76, VDSL rate 79999kb?

Check figure 2.9 from that report, it contradicts those graphs by mentioning that there are customers on 38Mb FTTC receiving >35Mb.

Clearly some adjustments done to the data in places.

I also note the sample size of the 76Mbit FTTC packages in the graph you screenshot is 34. Those results appear problematic due to small and unrepresentative sample and are somewhat reduced by weighted graphs and 95% confidence adjustment.

Pleased your city has dense cabinet deployment. A number don't - the situation in London for example can be quite different and it doesn't take going far outside of the centre of cities to see distances from PCPs change. The centre of cities are more densely populated so obviously distances will drop. Leave the urban centres and go to their suburbs and distances soon rise.

Profile 30a doesn't mean a thing for those who are distance restricted on 17a and isn't intended for FTTC deployment for exactly that reason. It is an FTTB/S technology.

What can be achieved on vectoring is irrelevant until BT have pulled the trigger and actually announced a plan to JFDI. It's no more relevant than what VM's HFC network can do if caps are removed.

Thanks for reminding me of something with that link to the TBB guide though.

Current roll-out plans are predominantly FTTC and BT expect FTTH/P to make up around 17% of the completed fibre deployment. In 2013 the FTTP on Demand option should launch, which will allow small businesses and home owners to pay perhaps £500 to £1500 to get FTTP installed to their home if they live in an area with FTTC.

Ya. Try 0.5% without gap funding for FTTH/P, and FTTP on demand costing closer to 3 times that top end figure.

My quote, including VAT but not including any excess construction charges, not that there would be any, is £6,150, followed by a 36 month contract at £270/month.

FTTC can do more, if pairs are bonded, phantom pairs deployed, vectoring used, and indeed fibre pushed deeper into remote nodes.

BT have tested vectoring on one of their 2 vendors and shown precisely zero public interest in any of the rest, primarily because it costs BTCoins to deploy such things.

FTTP to a 1,000 premises housing estate potentially comes it at around the 1/6th of a BTCoin mark.

*BTCoin = £6 million, the approximate cost per footie game shown on BT Sport.

[qasdfdsaq]

Originally Posted by Ignitionnet

Hmm.

First an issue with those Ofcom graphs. If no-one can get 35Mb on the 38Mb service, VDSL rate 40000, confused how anyone, let alone almost everyone, is getting >70Mb on the 76, VDSL rate 79999kb?

Check figure 2.9 from that report, it contradicts those graphs by mentioning that there are customers on 38Mb FTTC receiving >35Mb.

Clearly some adjustments done to the data in places.

Evidently so. But unfortunately they don't release the raw data so it's hard to say what's being jiggled where. Nonetheless those charts show most people are getting near-maximum speeds as it is, although averages (affected by many factors beside line quality) are lower.

Profile 30a doesn't mean a thing for those who are distance restricted on 17a and isn't intended for FTTC deployment for exactly that reason. It is an FTTB/S technology.

True, it doesn't help those distance restricted - but those aren't going to get 100Mbps+ with vectoring either.

What can be achieved on vectoring is irrelevant until BT have pulled the trigger and actually announced a plan to JFDI. It's no more relevant than what VM's HFC network can do if caps are removed.

Well given the discussion was about the release of >100Mbps packages accompanied by vectoring (which makes sense since the former requires the latter) then I think it's totally relevant. If they do release 110/120Mbps then they're not going to do it without vectoring so non-vectoring speeds aren't going to be the ones achieved on said service.

Ya. Try 0.5% without gap funding for FTTH/P, and FTTP on demand costing closer to 3 times that top end figure.

Yes, that also reminds me of this rather older article:
http://www.techweekeurope.co.uk/news...bre-lte-101776

Now you're quite vocal about your objection to BT's current er, investment strategies, however I do wonder what you think about the comparison with Germany. After all, Germany started deploying VDSL several years before the UK yet we've already overtaken them in coverage and are offering comparable service for similar money (50/10 service is €40 on a 24m contract there). The investment, per home, by BT is only slightly lower than that done by DT (assuming those figures haven't changed drastically) - 66% of 25.7 million households for £2.5B here, 65% of 40.1 million households for £4.8B there, and we're getting there 2 years earlier and achieving a 60% faster headline speed. The last figure I could find for Germany put their FTTP coverage at a paltry 2.6% as well.

Perhaps we're getting a bit spoilt in Britain. Despite Openreach's "bargain basement" spending as you call it we're already well ahead of all other major European economies for NGA broadband speed, availability, price, and takeup. We have the most superfast broadband, the cheapest superfast broadband, the most widely available superfast broadband and the fastest superfast broadband [of the big 5 EU economies] - and many of those are true for our standard broadband and mobile broadband too. How much more do we really need?

[Ignitionnet]

Originally Posted by qasdfdsaq

Well given the discussion was about the release of >100Mbps packages accompanied by vectoring (which makes sense since the former requires the latter) then I think it's totally relevant. If they do release 110/120Mbps then they're not going to do it without vectoring so non-vectoring speeds aren't going to be the ones achieved on said service.

Given BT haven't announced any plans to go above the current speeds I'm not sure what discussion you're referring to. Quite the opposite actually, they're on record as saying vectoring, at least initially, is not seen as an opportunity to increase headline speeds.

Originally Posted by qasdfdsaq

Now you're quite vocal about your objection to BT's current er, investment strategies, however I do wonder what you think about the comparison with Germany. After all, Germany started deploying VDSL several years before the UK yet we've already overtaken them in coverage and are offering comparable service for similar money (50/10 service is €40 on a 24m contract there). The investment, per home, by BT is only slightly lower than that done by DT (assuming those figures haven't changed drastically) - 66% of 25.7 million households for £2.5B here, 65% of 40.1 million households for £4.8B there, and we're getting there 2 years earlier and achieving a 60% faster headline speed. The last figure I could find for Germany put their FTTP coverage at a paltry 2.6% as well.

Perhaps we're getting a bit spoilt in Britain. Despite Openreach's "bargain basement" spending as you call it we're already well ahead of all other major European economies for NGA broadband speed, availability, price, and takeup. We have the most superfast broadband, the cheapest superfast broadband, the most widely available superfast broadband and the fastest superfast broadband [of the big 5 EU economies] - and many of those are true for our standard broadband and mobile broadband too. How much more do we really need?

I couldn't care less about our comparison with Germany, owing to the fact that I'm in the UK, not Germany, and have no more interest in comparing our services to Germany's than I do comparing the private parts of my anatomy with someone else's

If we're talking about that article you might get a kick out of ThinkBroadband's most recent fact sheet.

Compare it to their first forecast less than 18 months earlier.

We can play games by comparing ourselves with countries that are far more sparsely populated, hence have far higher costs of deploying NGA, doesn't change that we could and should be much better.

A far more accurate comparison would be if we compared ourselves to Switzerland or the Netherlands. 85% of our population live in England; England is more densely populated than anything in Europe apart from Malta. 98% of the Netherlands has access to SFBB, there's more FTTP in one city than in the whole of the UK.

Clearly other companies agree given competition beginning to crawl out of the woodwork and show a face in some cities despite their cost of deployment being sky high compared with BT's.

Strange - you're constantly spending money on IT, seem to have more hardware at home than you support at work and have a NAS larger than some SME's but are fine with broadband way slower than many comparable urban areas outside of the UK.

Would have thought symmetrical gigabit would be of huge interest to you.

[qasdfdsaq]

Originally Posted by Ignitionnet

Given BT haven't announced any plans to go above the current speeds I'm not sure what discussion you're referring to. Quite the opposite actually, they're on record as saying vectoring, at least initially, is not seen as an opportunity to increase headline speeds.

The one I was replying to:

Originally Posted by craigj2k12

Last I heard it was being rolled out to enable a possible 110Mb/s or 120Mb/s service, merely rumours however

Originally Posted by Ignitionnet

Roll out if it happens will be for enabling more people to hit maximum speeds initially.

No plans for higher speeds on the current profiles, beyond rumours of a ~100Mb service. 110Mb or 120Mb will be achievable by hardly anyone, even with vectoring.

Nobody said they announced anything, it's all rumour at the moment anyway.

I couldn't care less about our comparison with Germany, owing to the fact that I'm in the UK, not Germany, and have no more interest in comparing our services to Germany's than I do comparing the private parts of my anatomy with someone else's

We can play games by comparing ourselves with countries that are far more sparsely populated, hence have far higher costs of deploying NGA, doesn't change that we could and should be much better.

A far more accurate comparison would be if we compared ourselves to Switzerland or the Netherlands. 85% of our population live in England; England is more densely populated than anything in Europe apart from Malta. 98% of the Netherlands has access to SFBB, there's more FTTP in one city than in the whole of the UK.

Well I could also say I couldn't care less about England, I'm in Scotland, not England but then the anti-nationalists would get me

Now the comparison countries used by Ofcom are Germany, France, Italy and Spain, all countries with similar population density to the UK as a whole (not England on it's own). The UK's overall population density is barely higher than Germany or Italy. But if you want to make arbitrary divisions within a "country of countries" I haven't seen separate figures for England vs. Scotland vs. Wales vs. NI so I can't really comment. Similarly I've seen no figures for FTTx availability vs. population density in separate countries, since that's what you'd really need to compare if you want to get super pedantic. After all nobody's expecting the top of the Swiss Alps to get FTTP any more than the Peak District, and there's parts of the Netherlands with zero broadband availability whatsoever (granted, there's nobody actually living there). That said, both Netherlands and Switzerland are far smaller than England or the UK (both less than 1/3rd the size of England alone) so that's hardly a fair comparison either. Switzerland, also being non-EU, has considerably different economics too.

Then again, looking here (again slightly old data):
http://point-topic.com/press-and-eve...age-in-europe/
The Netherlands, despite being the best connected country in Europe still only has 1% more FTTP coverage than the EU average (13% vs. 12%). Oddly enough the UK's LTE coverage has kept pace with that of the Netherlands for coverage and speed as well.

Strange - you're constantly spending money on IT, seem to have more hardware at home than you support at work and have a NAS larger than some SME's but are fine with broadband way slower than many comparable urban areas outside of the UK.

Would have thought symmetrical gigabit would be of huge interest to you.

Sure, I'd take symmetric gigabit if I could get it, I'd happily also take BT FTTPoD once it arrives. Yet being in the far reaches of Scotland I'm glad to be getting 80Mbps whereas friends of mine in "comparable urban areas outside the UK" are stuck with 1/10th the speed or less. Indeed, of my four flatmates, the one from Switzerland only gets 6Mbps while at home, the one from Germany has 2Mbps at home. I think the gal from Estonia is the only one who gets broadband of even the same magnitude available but even then it's only 10-20Mbps.

And then, even I personally, can't think of any real justification for symmetric gigabit. Most of my big-file downloads either come from Steam or my own dedicated server which only has a 100Mbps link, and most Steam games already complete within 10 minutes on 80Mb. If I was desperate for symmetric gigabit I could install a PtP wireless link on my roof and steal it from work, but I just don't see any need. As for streaming HD from my home NAS even that doesn't really need more than the 20Mbps upload I already have, given that's sufficient for near-perfect quality full HD and I can't reliably get more than 20Mbps while out and about anyway (nor can any other country - the UK has among the fastest average LTE speeds in the world)

Oddly enough though, all the largest EU economies have considerably lower FTTP penetration than Europe as a whole, or several exemplar countries like Holland. While the politics and economics of smaller countries will always be different, chances are if you look closely enough you'll find areas of England with the same FTTP availability as parts of the Netherlands. Extend your stats for the Netherlands outwards to include a land area the size of England though and the picture won't be nearly so rosy.

(Oh and I don't have anywhere close to as much hardware at home as I support at work, for one, just the current underspend in this year's budget alone is three times than my annual salary. Then again, since it's my job to find something to spend that on, maybe I should try wrangling 'Installing a dedicated, symmetric 10Gbps fibre line from the office to my home to enable more efficient remote working' as a business expense)

[Ignitionnet]

Originally Posted by qasdfdsaq

Oddly enough though, all the largest EU economies have considerably lower FTTP penetration than Europe as a whole, or several exemplar countries like Holland. While the politics and economics of smaller countries will always be different, chances are if you look closely enough you'll find areas of England with the same FTTP availability as parts of the Netherlands. Extend your stats for the Netherlands outwards to include a land area the size of England though and the picture won't be nearly so rosy.

Okay, let's deal purely with the urban areas.

Prior to the taxpayer getting involved in our urban areas SFBB passed ~85% of premises, with ~70-75% able to get speeds >24Mb.

Some exchanges received exactly nothing until the Superconnected Cities scheme came about, then suddenly FTTC appeared and the hands were open for the FTTPoD vouchers.

There is only one area of England with any significant FTTP, unsurprisingly it was co-funded by taxpayers.

Some staff at Openreach have been telling housing developers that FTTP is still in trials so they've continued to request copper for new builds. Building new estates with copper is nuts.

FTTPoD, I looked into it. Sadly an install cost of £6,150 along with a £270pm 3 year contact made me balk somewhat.

[Pierre]

Not that I know much about this, but it seems that technological advances will keep the good old twisted pair going for some time.

http://www.opticalconnectionsnews.co...telephone-wire