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Standard User jaybee2017
(newbie) Mon 24-Apr-17 11:15:37
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How to make good a brain-dead FTTC service?


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In short, we have recently upgraded from an ADSL service from our rural exchange over a cable distance of around 3 miles (2.5 - 3.5Mb/s down & 825kb/s up) to FTTC from the village's fibre cabinet. However the inscrutable network planners in OR decided to put that fibre cabinet around halfway between the exchange and our village, and tin the middle of nowhere. (The daft thing is that according to OFCOM our cabinet delivers "Superfast" to at most half a dozen scattered farms and rural properties.)

The result is that the line run from our location in the village and the cabinet is 1.9km but is as good as can be expected. Downstream syncs reliably at 16 - 17Mb/s and is a welcome improvement over the old ADSL service. However upstream only uses the U0 band and syncs at around 1Mb/s. This is no real improvement over ADSL and uploads and even download-intensive activities rapidly saturate the upstream channel.

Now the initial joy at 15Mb/s downloads has worn off, the upload log-jam is becoming a pain. So I'm looking for options to improve matters. From what I know, it looks unlikely that there is a technical fix with the FTTC cabinet in its present remote location. (If there is, please tell me!) We are the lucky ones another third of the village is more marginal than we are or beyond the reach of VDSL2 altogether.

So what are the options for OR to make good the poor service they are offering our village? Move the cabinet? A secondary cabinet located actually within the village? Next question how to find out what OR have in the pipeline with remedial measures and if the (likely) answer is nothing, how to get things moving to improve matters?
Administrator MrSaffron
(staff) Mon 24-Apr-17 11:24:05
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Re: How to make good a brain-dead FTTC service?


[re: jaybee2017] [link to this post]
 
Where does Ofcom say you are superfast? At 1.9km no-one should be under any idea that you are going to get superfast.

What do we say at https://labs.thinkbroadband.com/local/postcode-search

As for the decision, a lot depends on the postcode and which project, and density of premises in the area as to whether further work may take place to make you properly superfast. Given a postcode can usually give some feedback - sometimes it is just that we've seen other areas like this in a county see more work done, or that there are some plans underway, or nothing we know of. A lot hinges on what a county has as its superfast target.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User baby_frogmella
(fountain of knowledge) Mon 24-Apr-17 11:40:29
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Re: How to make good a brain-dead FTTC service?


[re: jaybee2017] [link to this post]
 
In reply to a post by jaybee2017:
So what are the options for OR to make good the poor service they are offering our village?

A secondary cabinet located actually within the village?


Yes. If other residents feel the same then club together with them to self-fund a second (in-fill) FTTC cabinet so that its located much closer to you.
https://www.homeandwork.openreach.co.uk/fibre-broadb...

°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°
TalkTalk Business 80/20..(soon to be FluidOne FTTP 330/30)
Netgear R9000 X10 running OpenWRT
My Broadband Quality Monitor
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Standard User David_W
(knowledge is power) Mon 24-Apr-17 11:51:32
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Re: How to make good a brain-dead FTTC service?


[re: jaybee2017] [link to this post]
 
In reply to a post by jaybee2017:
However the inscrutable network planners in OR decided to put that fibre cabinet around halfway between the exchange and our village, and tin the middle of nowhere. (The daft thing is that according to OFCOM our cabinet delivers "Superfast" to at most half a dozen scattered farms and rural properties.)
Though I don't know the history of your particular cabinet, it is very unlikely that Openreach deliberately chose a sub-optimal location for it. The cabinet will either have been sited at an existing PCP, or the network rearrangement needed to site the cabinet at a new PCP will have taken the topology of the existing cables into account. Network rearrangement is an expensive business and extensive rearrangement can soon eat up the available budget.

If there is no solution that makes meaningful use of the existing metallic pair assets, it is probably better for the planners to opt for FTTP; there comes a point where the work is so close to providing an entirely new network that it is best to start again with 'full fibre'. Even though you are in a rural area, a decision must have been made that the more modest benefits of a cheaper and quicker to deploy FTTC solution is the most cost effective approach overall for your location.


You are right to say that there is no technical solution to improve performance hugely on FTTC; only a deeper fibre solution (which is likely to be a long way away from being provided in a remote location such as yours) or radio based solution is going to offer significant improvement. It is also of note that whilst upstream speed matters to you, the primary criterion by which 'success' in broadband improvements are judged is downstream speed.

If you have only recently moved to VDSL2, you might eventually get some benefit from G.INP and a lower downstream signal to noise ratio margin, which might push your downstream speed up by a few Mbit/s. Even with those measures, you might still finish up a little short of the downstream speed required by a probable future broadband universal service obligation (if that is set at 20 Mbit/s - nothing is clear at the moment). It is possible that VDSL2 vectoring will offer you a small speed uplift, though crosstalk might only have a small effect on a cabinet such as yours.



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Administrator MrSaffron
(staff) Mon 24-Apr-17 12:14:34
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Re: How to make good a brain-dead FTTC service?


[re: MrSaffron] [link to this post]
 
Just integrated the Ofcom 2016 postcode level data into the search page, so you can see what we say and Ofcom say at the same time.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User WWWombat
(knowledge is power) Mon 24-Apr-17 12:29:07
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Re: How to make good a brain-dead FTTC service?


[re: jaybee2017] [link to this post]
 
In reply to a post by jaybee2017:
The daft thing is that according to OFCOM our cabinet delivers "Superfast" to at most half a dozen scattered farms and rural properties.


Homes that didn't get superfast speeds (ie 25Mbps+) will not have counted towards any subsidy from BDUK or the local council. Unless you were one of the last cabinets to get upgraded in the county, it seems likely that more premises were counted as "upgraded" than you think.

What exchange and cabinet number? People can then help with other estimates.

In reply to a post by jaybee2017:
So what are the options for OR to make good the poor service they are offering our village? Move the cabinet? A secondary cabinet located actually within the village?


An infill cabinet in the village will help speeds there, and will need subsidising.

Those premises not over the superfast threshold are still eligible for BDUK support from your local council project. Contacting them would be the logical first step, to discover whether there are enough properties for your area to stand a chance of this.

Failing that, persuading BT to include the cabinet in LR-VDSL trials might help.

Failing that, BT do run a community fibre scheme that allows community groups to contribute to an upgrade.

Failing that, a DIY wireless link to one of the properties that can get decent speeds.

In reply to a post by jaybee2017:
However upstream only uses the U0 band and syncs at around 1Mb/s.

From what I know, it looks unlikely that there is a technical fix with the FTTC cabinet in its present remote location. (If there is, please tell me!)


Here's one out of left field...

This is indeed a problem for longer lines. The upstream seems to drop away faster than downstream at longer ranges, beyond 1.5km or so. But the reasoning is complicated... (*)

There is a mechanism employed by the FTTC cabinets known as "upstream power backoff", UPBO. Its job is to reduce power on nearby modems, so that longer-range modems suffer less crosstalk, and get a better upstream speed.

However, the settings for this mechanism appear to be tunable by the operator, and can give different results to people at different distances. I cannot explain exactly how tuning works, but the upshot is that modems within (say) 200m get slower than expected upstream speeds, while those between (say) 200m and 900m get better, and then those beyond 900m get worse again. Instead of a 900m threshold, an operator could tune for a 600m threshold instead. Or a 1.2km threshold instead.

I have seen nothing (in, for example, the ANFP) where BT give details about their chosen setup for UPBO, and absolutely nothing that shows they can tune this setting for different cabinets. It suggests BT may have a single configuration common to all urban and rural cabinets.

If your first hypothesis is correct - that very few premises are within 1km, and many are beyond 1.2km - then my guess is that your upstream speeds could be collectively suffering in order to bring benefit to a set of lines (below 1km) that just don't exist in your case.

There is a chance that your upstream could behave differently if BT reconfigured UPBO. But I've never, ever, heard of this suggested or pursued anywhere at all. No ISP nor engineer will understand it. And there is no chance it would happen if there is a reasonable number of premises getting superfast speeds.



(*) - This paper describes UPBO.
http://www.4gbb.eu/images/4GBB_Publications/pub_2009...

The 6 graphs on page 3 show the result of tuning UPBO for different reference lengths (with "blue squares") vs the speed without UPBO at all ("black line").

It is obvious that whatever gain is made in the intermediate distances, it is paid for with relatively low speeds beyond the reference distance.

Edited by WWWombat (Mon 24-Apr-17 12:33:39)

Standard User WWWombat
(knowledge is power) Mon 24-Apr-17 12:48:58
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Re: How to make good a brain-dead FTTC service?


[re: WWWombat] [link to this post]
 
In reply to a post by WWWombat:
But I've never, ever, heard of this suggested or pursued anywhere at all. No ISP nor engineer will understand it.


Thinking about this aspect more, I suspect the best place where this issue could be pursued is in the NICC forum, where the ANFP is specified.

I note, for example, that one of their documents (ND1518, on sharing DLM data between operators) mentions the idea of dynamic UPBO.
http://www.niccstandards.org.uk/publications/reports...

I'm not sure how the general public can ask questions there, though.
Administrator MrSaffron
(staff) Mon 24-Apr-17 13:05:09
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Re: How to make good a brain-dead FTTC service?


[re: WWWombat] [link to this post]
 
Is that aspect not already covered possibly in the three power masks used? Short/Medium/Long with respect to avoiding undue crosstalk for ADSL2+ services.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User AndyHCZ
(experienced) Mon 24-Apr-17 13:32:57
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Re: How to make good a brain-dead FTTC service?


[re: jaybee2017] [link to this post]
 
Openreach recover the costs of a fibre cabinet quite quickly and the money is in the line rental for fibre services (between £82.80 and £119.40 ex VAT per annum, per user). It would make zero commercial sense for Openreach to install a cabinet in the middle of nowhere, where people cannot get superfast speeds.
Administrator MrSaffron
(staff) Mon 24-Apr-17 13:40:32
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Re: How to make good a brain-dead FTTC service?


[re: AndyHCZ] [link to this post]
 
Given a postcode very easy for me (and some others I suspect) to give an idea of what the situation looks like.

Some counties are running secondary speed target of 15 Mbps, so it may be location was not great for superfast but ticked that box nicely.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User jaybee2017
(newbie) Mon 24-Apr-17 13:59:33
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Re: How to make good a brain-dead FTTC service?


[re: MrSaffron] [link to this post]
 
Where does Ofcom say you are superfast? At 1.9km no-one should be under any idea that you are going to get superfast.

What do we say at https://labs.thinkbroadband.com/local/postcode-search


Sorry if I mislead here. Had no illusions about what to expect as the various online check services tended to be cautious, and would have been happy with 8-10Mb/s down. Instead and thanks to variable SNR & GINP are - in fact - getting in excess of 16Mb/s down. What I had not fully appreciated was how big a handicap a 1Mb/s upload channel would prove.

My point was that although improving matters somewhat for our at least a part of our village, the cabinet as positioned delivered "Superfast" to only a handful of properties (ref. https://checker.ofcom.org.uk/broadband-coverage for postcode EX16 9QD - the cabinet WWOAKF-2 is located at the fork in the road labelled "Stoodleighmoor").
Standard User jaybee2017
(newbie) Mon 24-Apr-17 14:07:34
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Re: How to make good a brain-dead FTTC service?


[re: David_W] [link to this post]
 
Though I don't know the history of your particular cabinet, it is very unlikely that Openreach deliberately chose a sub-optimal location for it. The cabinet will either have been sited at an existing PCP, or the network rearrangement needed to site the cabinet at a new PCP will have taken the topology of the existing cables into account. Network rearrangement is an expensive business and extensive rearrangement can soon eat up the available budget.


David_W - I think you are right about reason for the cabinet positioning. Moving it closer to our village would have necessitated extra cabling to "back haul" connections to a significant number of strung-out properties that - ironically - are too far off even now to consider using FTTC services.

A decision that was optimal for the OR accountants, not optimal for it's customers?
Administrator MrSaffron
(staff) Mon 24-Apr-17 14:11:04
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Re: How to make good a brain-dead FTTC service?


[re: jaybee2017] [link to this post]
 
Street view is not up to date, but you mean it is at this junction?

https://www.google.co.uk/maps/@50.9675726,-3.5415837...

Our guess was 150m out to the North West, and look ups will update to reflect this new position tonight.

If correct location then it is one of the most poorly located cabinets to date, but as its part of the CDS project, it is possible BT may have not wanted to do it, but local politics overrode them (e.g. got that nearby farm to get superfast), or if BT had got phase II contract they would have added an infill cabinet nearer to Kissing Gate Cross.

One contentious aspect of the CDS contract was the fate of those under 2 Mbps, so it may be that the cabinet location ticked that box sufficiently in the short term, and subsequent projects will fix that, but with no BT involvement in the next phase its talk to council and see what their plans are in terms of getting more people to superfast.

The BT involvement in Devon is not over, but unless the Openreach checker is talking of more work it is unlikely you will see anything more from BT.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User jaybee2017
(newbie) Mon 24-Apr-17 14:13:55
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Re: How to make good a brain-dead FTTC service?


[re: WWWombat] [link to this post]
 
There is a mechanism employed by the FTTC cabinets known as "upstream power backoff", UPBO. Its job is to reduce power on nearby modems, so that longer-range modems suffer less crosstalk, and get a better upstream speed.

However, the settings for this mechanism appear to be tunable by the operator, and can give different results to people at different distances. I cannot explain exactly how tuning works, but the upshot is that modems within (say) 200m get slower than expected upstream speeds, while those between (say) 200m and 900m get better, and then those beyond 900m get worse again. Instead of a 900m threshold, an operator could tune for a 600m threshold instead. Or a 1.2km threshold instead.

I have seen nothing (in, for example, the ANFP) where BT give details about their chosen setup for UPBO, and absolutely nothing that shows they can tune this setting for different cabinets. It suggests BT may have a single configuration common to all urban and rural cabinets.


WWWombat - thanks for that information. I'm a retired telecomms person (broadcast TV rather than telephone stuff) so will dig deeper using that information. (Sad to say I enjoy watching the modem stats as it juggles bit allocations to maintain data rates in the evening with the increase in MF radio station noise and the 2dB loss of SNR when our mystery interference source (sewage puping station?) comes on for a couple of hours.)
Standard User jaybee2017
(newbie) Mon 24-Apr-17 14:32:00
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Re: How to make good a brain-dead FTTC service?


[re: MrSaffron] [link to this post]
 
Street view is not up to date, but you mean it is at this junction?

https://www.google.co.uk/maps/@50.9675726,-3.5415837...

Our guess was 150m out to the North West, and look ups will update to reflect this new position tonight.


That's the spot - the wild flowers no longer grow so high thanks to two green cabinets and the OR mens' big boots. smile

If correct location then it is one of the most poorly located cabinets to date, but as its part of the CDS project, it is possible BT may have not wanted to do it, but local politics overrode them (e.g. got that nearby farm to get superfast), or if BT had got phase II contract they would have added an infill cabinet nearer to Kissing Gate Cross.


Kissing Gate would be an ideal location as it is fairly central to our rather linear village. At the moment the cable run goes to one end of the village (Quoit-at Cross) and then runs up through the village pretty well from one end to the other. Some of the properties forming the contiguous part of the village must be over 2.5km from the cabinets, as the cable runs.
Standard User Fastman2
(experienced) Mon 24-Apr-17 14:52:07
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Re: How to make good a brain-dead FTTC service?


[re: jaybee2017] [link to this post]
 
actually you would not have been able to backhaul those cables as that would have increased the line length and therefore worsened that ADSL -- that would not be allowed under the conditions of Licence that Openreach operates as you cannot worsen the ADSL service to force subscribers to but an FTTC service that's not equivalent
Standard User WWWombat
(knowledge is power) Mon 24-Apr-17 15:35:46
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Re: How to make good a brain-dead FTTC service?


[re: MrSaffron] [link to this post]
 
In reply to a post by MrSaffron:
Is that aspect not already covered possibly in the three power masks used? Short/Medium/Long with respect to avoiding undue crosstalk for ADSL2+ services.


Are you talking about the downstream power masks for VDSL2? The one where the ANFP shows 6 different masks (CAL=0, 10, 20, ... 50)?

If so, there are actually many more masks, for CAL=0dB through to CAL=52dB in steps of 2dB, varying by the distance of the cabinet from the exchange. 27 masks, in the lower portion of D1.

But the important bit is those are for downstream frequencies, not upstream. UPBO works across U1 and U2 instead, and varies by distance between CPE and cabinet.
Administrator MrSaffron
(staff) Mon 24-Apr-17 15:41:31
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Re: How to make good a brain-dead FTTC service?


[re: WWWombat] [link to this post]
 
Ta - not had time to read all the real techie docs for ages now

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User jaybee2017
(newbie) Mon 24-Apr-17 16:06:42
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Re: How to make good a brain-dead FTTC service?


[re: Fastman2] [link to this post]
 
actually you would not have been able to backhaul those cables as that would have increased the line length and therefore worsened that ADSL -- that would not be allowed under the conditions of Licence that Openreach operates as you cannot worsen the ADSL service to force subscribers to but an FTTC service that's not equivalent

An interesting point that. Would there have been an obligation to connect the very long lines (with no hope of a VDSL2 service from that point) via the FTTC cabinet? If not the long lines could be left "as is", no back-haul needed, and the cabinet could have been better placed.
Administrator MrSaffron
(staff) Mon 24-Apr-17 16:12:48
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Re: How to make good a brain-dead FTTC service?


[re: jaybee2017] [link to this post]
 
Anything is possible given unlimited resources, but doing what you suggest would add to the costs.

If BT had the phase II cabinet I'd predict an infill cabinet in the future, but they don't for Devon so its down to the priorities of the council and what they direct the new contract holders to do (i.e. experience from elsewhere in the UK does not apply)

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User WWWombat
(knowledge is power) Mon 24-Apr-17 16:40:16
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Re: How to make good a brain-dead FTTC service?


[re: MrSaffron] [link to this post]
 
BT does, however, have the work to do on re-investment of the clawback. But the planning won't start until Gigaclear's plans become clear in the next few months.
Administrator MrSaffron
(staff) Mon 24-Apr-17 17:51:23
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Re: How to make good a brain-dead FTTC service?


[re: WWWombat] [link to this post]
 
Only if the clawback is reused with BT, there are options to sit on it and get it paid back after the 7 year contract period is up.

The clawback would not be available for using with Gigaclear if its generated by BT takeup from phase 1, but can foresee a council finding a way of spending the money from elsewhere temporarily knowing it will eventually come back to them.

CDS given the angst and plain anger that seems to exist at times (may not really be the case but the impression one gets from what can see is that) means almost anything that is not BT will be preferred by the council.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User WWWombat
(knowledge is power) Tue 25-Apr-17 03:24:56
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Re: How to make good a brain-dead FTTC service?


[re: MrSaffron] [link to this post]
 
The CDS report at the most recent Devon CC meeting was that they'd already agreed to accept BT's offer for the early clawback.
Standard User Gadget
(committed) Tue 25-Apr-17 07:53:49
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Re: How to make good a brain-dead FTTC service?


[re: jaybee2017] [link to this post]
 
One thing to remember is that the fibre cabinet must be located within a short distance (50m if I recall) of the "normal" copper cabinet, so if there was a cabinet halfway between your village and the exchange in the first place that is where the fibre twin must be located - not that it helps your current FTTC speed but would explain why the FTTC cab is where it is.
Standard User lee111s
(fountain of knowledge) Tue 25-Apr-17 09:00:31
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Re: How to make good a brain-dead FTTC service?


[re: Gadget] [link to this post]
 
Usually 50, 100m max in extreme circumstances, but it requires sign off from someone high up in the project team.
Standard User jaybee2017
(newbie) Tue 25-Apr-17 10:51:27
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Re: How to make good a brain-dead FTTC service?


[re: Gadget] [link to this post]
 
One thing to remember is that the fibre cabinet must be located within a short distance (50m if I recall) of the "normal" copper cabinet, so if there was a cabinet halfway between your village and the exchange in the first place that is where the fibre twin must be located - not that it helps your current FTTC speed but would explain why the FTTC cab is where it is.


No, no cabinet between us and the exchange prior to the preparatory works for the FTTC. The FTTC box and "street cabinet" are new erections within a metre or two of each other at the location identified by MrSaffron earlier. I'll try to get a newer picture up on Google next time I'm going past.

The whole installation was a very drawn-out affair, partly due to the difficult route between the cabinet site and the exchange. Not obvious from the map is the valley in between is heavily wooded, very steep sided and around 500ft deep. This made for a number of difficulties with the FTTC works (e.g. seriously blocked ducts prevented pulling the FO cable) and meant that lots of the lines fan out from that valley crossing point to scattered farms on that side of the chasm, rather than fanning out from exchange as would be the case with flatter terrain.
Standard User jaybee2017
(newbie) Tue 25-Apr-17 14:00:33
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Re: How to make good a brain-dead FTTC service?


[re: MrSaffron] [link to this post]
 
Street view is not up to date, but you mean it is at this junction?

https://www.google.co.uk/maps/@50.9675726,-3.5415837...

This what it looks like now:
https://www.dropbox.com/s/vorjxlntpm7k0fb/IMG_201704...
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