Post by: Bowdon on November 22, 2018, 02:28:01 PM
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Openreach (BT) has today announced that they will conduct a “large scale” UK trial of Seamless Rate Adaption (SRA) technology on Fibre-to-the-Cabinet (FTTC / VDSL2) based superfast broadband ISP lines (40-80Mbps), which could improve service stability by varying the speed more effectively.
The technical way of explaining SRA is to say that it can be used to “reconfigure the total data rate by modifying the framing parameters and the bits and fine gains parameters.” If the noise condition (interference) improves then SRA can be used to gradually increase the data rate again, potentially taking it all the way back up to what you had before a nasty bit of sudden noise impacted the line.
SRA is technically nothing new to Openreach’s hybrid fibre network and it’s a standard part of the latest G.fast standard. Prior to that the operator has also previously tested it alongside the problematic VDSL2 Vectoring technology (2014 to 2015) and they recently tried to incorporate it as part of their Long Reach VDSL tests, which were shelved.
Earlier this year the operator decided that it might be better to try implementing SRA on its own and so they setup a small Proof of Concept (PoC) trial with 200 lines via Huawei based street cabinets. The service was applied gradually (line-by-line) and Dynamic Line Management (DLM) was also disabled. This ran for several months and after that Openreach began reviewing its impact, which brings us back to today.
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Openreach Statement
This briefing is to inform all CPs that following the successful proof of concept earlier this year we will be trialling Seamless Rate Adaption (SRA) on a larger volume of lines
We’ve published a briefing for CPs relating to SRA, which will vary the speed of a line as noise margin changes reducing the propensity to retrain, whereas today on NGA1, if the noise margin drops beyond a certain threshold, the line will retrain. Openreach will be running a large-scale trial to prove the benefits of this change.
Post by: dee.jay on November 22, 2018, 02:56:11 PM
Post by: ktz392837 on November 22, 2018, 03:20:40 PM
Post by: daveesh1 on November 22, 2018, 04:44:59 PM
Post by: niemand on November 22, 2018, 04:54:12 PM
Post by: Chrysalis on November 22, 2018, 05:10:13 PM
If it works out tho dont be surprised if its another hauwei only rollout.
The ECI situation is annoying, but I will say what I always say, its not as annoying as if there was no VDSL at all, aka been stuck on ADSL. The ECI cabinet's were the difference with some area's been viable for a VDSL rollout or not.
Post by: ejs on November 22, 2018, 06:46:11 PM
Post by: ktz392837 on November 22, 2018, 10:22:17 PM
I don't see how the headline is misleading. Nothing in there about deploying SRA to every cabinet.I guess it depends on what your view of large scale is - to me it is not excluding 30% of the ”country”.
It makes it sound like OR are doing everyone a favour but in actuality 30% will NEVER get the benefit as it is impossible due to the cabinet used.
Post by: ktz392837 on November 22, 2018, 10:42:26 PM
The ECI situation is annoying, but I will say what I always say, its not as annoying as if there was no VDSL at all, aka been stuck on ADSL. The ECI cabinet's were the difference with some area's been viable for a VDSL rollout or not.. Nope I disagree - nothing to do with costs - BDUK used Huawei cabinets, they were all working in my area before my ECI cabinet I wish BDUK did my cabinet rather than BT - I would still have FTTC and guessing a 30% better connection due to Ginp and 3db.
If ECI are cheaper why aren't BT using them now? Even better why were BDUK not using them if the public was funding them!
Not had a moan about the ECI cabinets recently - I'll shut up now
Post by: niemand on November 23, 2018, 12:32:56 AM
I guess it depends on what your view of large scale is - to me it is not excluding 30% of the ”country”.
I'm afraid deploying to about 65% of the country, or if you prefer about 18 million premises, strikes me as large scale.
Virgin Media's network coverage of 52-55% of the country must be tiny for you.
Post by: adslmax on November 23, 2018, 02:08:01 AM
Disable DLM? Very interesting.
But it running trial only. Once it become rolled out then I am sure Openreach will turn back on DLM.
Post by: Chrysalis on November 23, 2018, 07:01:34 AM
. Nope I disagree - nothing to do with costs - BDUK used Huawei cabinets, they were all working in my area before my ECI cabinet I wish BDUK did my cabinet rather than BT - I would still have FTTC and guessing a 30% better connection due to Ginp and 3db.
If ECI are cheaper why aren't BT using them now? Even better why were BDUK not using them if the public was funding them!
Not had a moan about the ECI cabinets recently - I'll shut up now
Openreach were paid handsomely for bduk, and alot of bduk areas were done after they decided to switch back to hauwei. Plus bduk had some requirements which are not applicable on the commercial rollout.
If you think adsl beats eci vdsl then I dont know what to say.
Its not realistic to think all eci cabinets would just be replaced with hauwei whilst they still work.
Post by: kitz on November 24, 2018, 10:24:13 AM
I didn't know VDSL2 Vectoring was "problematic".
Me neither.
Post by: kitz on November 24, 2018, 10:25:50 AM
Few people seem to realise that at the time Openreach were in the planning and ordering stage for the cabs... there weren't any MSANs that could do system based vectoring. At that time any vectoring was done at line card level (which the M41s can supposedly do btw).
Although the theory of system based vectoring had been around for a while, no manufacturer had produced any units for sale to the Telcos. The ECI V41's were the first MSANs to become available in the world able to perform system based vectoring... and unfortunately this probably overlapped with the period in which Openreach was already underway with the rollout of FTTC.
Bad timing and since when have BT/Openreach ever been the first to roll out new technology en masse?
Post by: kitz on November 24, 2018, 10:45:00 AM
If ECI are cheaper why aren't BT using them now? Even better why were BDUK not using them if the public was funding them!
Benefit of hindsight? BDUK was rolled out several years after the main FTTC rollout. I may be wrong but afaik its only the BDUK cabs that perform vectoring.
Since original rollout Huawei has developed a system based vectoring module that could be slotted into the larger Huwaei cabs.
What was one of ECI cabs major selling points (small footprint) became a major disadvantage because there was no room on the M41's back plane to insert a separate module for vectoring.
As to G.INP I've still no idea what the problem is because Openreach aren't publicly saying but all the rumours seem to say its something to do with modem incompatibility.
Being on an ECI cab myself I'm not too chuffed about no G.INP (which worked fine here during the brief period it was enabled). My line would happily work at 3dB, but that ain't happening. No prospect of vectoring which could give me back the >40Mbps overheads I've lost due to cross-talk... and now the unlikelihood of SRA... and on a line just to long to ever be able to benefit from g.fast. There's no VM here.
Yeah it's a bummer, but at the end of the day I try console myself with the fact that FTTC has been here now for ~6yrs and once upon a time I was able to get the full 80/20 with a faster connection than most at a time when the vast majority of people were still on adsl.
Post by: tiffy on November 24, 2018, 11:04:31 AM
Post by: kitz on November 24, 2018, 11:27:11 AM
They started roll-out in March 2014 which allowed them to claim they were one of the first telco's in the world to deploy (system based) vectoring. They got beat the previous year by some south american country who used the ECI V41's.
https://fibrerollout.ie/eir-commences-vectoring-roll-out-boosts-fibre-broadband-speeds-to-100mbs/
Post by: Chrysalis on November 24, 2018, 11:49:15 AM
Plus some other people have mentioned it as well such as john, andy and others.
I think with g.inp openreach dug their grave on that one, by allowing people to run whatever modem they wanted and then for whatever reason not kicking the incompatible modems off the network, I expect the reason that didnt happen is probably because openreach and the CP's couldnt decide between them who would fund replacement modems to the customers who were cutoff.
It does seem ECI have indeed rolled out g.inp overseas on M41's, so this is not a global problem.
Post by: tiffy on November 24, 2018, 12:02:48 PM
Thanks for the information & link ref Irish FTTC system, Font of knowledge as always.
Eircom appear to have exclusively adopted Huawei hardware which I suppose was a big factor in their decision to implement vectoring across their estate, noted that even Donegal, usually called the forgotten county in Ireland, physically in the north but politically in the south, was full upgraded, must have been a big cash injection from somewhere, pity BT had not followed the same philosophy.
Post by: kitz on November 24, 2018, 12:04:08 PM
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I am pretty sure its modem related,
Yup agreed - they have strongly hinted this is the case on more than one occasion. They won't name the modem's though. The annoying thing is that for those of us using the BCM modems and custom f/w ECI modems it worked fine. :(
I know there were a couple of Draytek modems which had problems with g.inp and they (Draytek) even offered those affected a £100 discount off purchasing a newer model.
Post by: kitz on November 24, 2018, 12:34:11 PM
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pity BT had not followed the same philosophy.
Agreed. But on the flip side it would further divide the country yet again if they installed the modules into all their MA5603s.
Those Huawei vectoring units weren't available until 2014. At which point in time almost half of Openreach's cabs were ECIs as most of the cabs installed during the period 2012-2013 were ECI's. It wasn't until 2014 that Openreach started favouring Huawei again. I'm not sure about the MA5616s - at first they were also incompatible but from memory I think ejs found something saying that they too could now be upgraded.
I've no idea of what the lead time between Openreach deciding they were going to need 'x' cabs, placing the order, installation and then to live date is. Someone like Carl may have a better idea... but for those cabs installed in 2012, I would not be surprised if it would be the previous year when they decided they were going to use ECI's. There will also be manufacturing time to be taken into account as although a lot of the DSLAMs are modularised, no manufacturer is likely to have circa 8k DSLAMs just lying around waiting to be shipped out as soon as a Telco places the order.
I really think as far as vectoring goes it was bad timing. Openreach wanted to get on and roll out FTTC and selected what at the time was considered one of the best manufacturers. Other countries such as Germany and France had been using ECI dslams/msans for years and they did have a good reputation back then for cutting edge technology. Deutsche Telekom in particular heavily invested in the M41's, but have later swapped out with V41's. Openreach seem hesitant to do this. If they were going to do so, then it would have been better to do it a couple of years ago. Now they are more concerned about (g.fast and) fttp.
Post by: Weaver on November 24, 2018, 12:50:52 PM
Post by: ejs on November 24, 2018, 12:52:35 PM
The publicly available Openreach R4000 EIP documents list a "NGA1 512pt DSLAM Upgrade". Lets all assume that will be some of the older large Huawei cabinets being replaced with brand new 512-port models, while ECI CABINETS GET NOTHING.
Post by: j0hn on November 24, 2018, 03:00:11 PM
8 x 64?
Post by: niemand on November 24, 2018, 04:20:40 PM
Upgrading to 512 lines would need an entirely new chassis. The 5600T could handle 1024 lines but as far as I know isn't for cabinet mounting.
Post by: burakkucat on November 24, 2018, 05:04:09 PM
It wasn't until 2014 that Openreach started favouring Huawei again. I'm not sure about the MA5616s - at first they were also incompatible but from memory I think ejs found something saying that they too could now be upgraded.
The MA5616s require a separate, add-on, back-plane for the vectoring engine.
Post by: j0hn on November 24, 2018, 05:21:30 PM
The publicly available Openreach R4000 EIP documents list a "NGA1 512pt DSLAM Upgrade". Lets all assume that will be some of the older large Huawei cabinets being replaced with brand new 512-port models, while ECI CABINETS GET NOTHING.
512 doesn't divide by 6.
That's why I queried 8 x 64.
Or maybe 4 x 96 ports and 2 x 64 ports.
Post by: niemand on November 24, 2018, 10:15:50 PM
http://support.huawei.com/enterprise/en/doc/EDOC1000060621?section=j061&topicName=vdsl2-service-board
Post by: Bowdon on November 25, 2018, 01:33:26 PM
Post by: ejs on November 25, 2018, 01:53:13 PM
I think vectoring requires fairly high bandwidth connections between the line cards and vectoring engine to get the data to the vectoring engine, which I think tends to be done by plugging all the cards into a system that was designed to do that.
If you have two DSLAMs, then you'd also need to coordinate the vectoring between the two.
Post by: j0hn on November 25, 2018, 07:26:45 PM
I noticed in the thread that people say ECI cabinets can do system based vectoring but because of space can't fit the vectoring card in.
I don't think anyone said the ECI M41 can do system level vectoring.
The issue is it can't.
Line card level vectoring is terribly inefficient, especially how the network is arranged.
Sticking 2 together wouldn't help.
Post by: niemand on November 25, 2018, 08:33:27 PM
Post by: kitz on November 25, 2018, 11:40:17 PM
In this type of situation you need to use node level vectoring so that the 2 dslam vector units can communicate with each other and perform the correct noise cancellation for interconnected devices :(
Node level vectoring is even newer technology than system level.
As others have said the problem with the ECI's isn't so much the green box but space on the backplane. Whilst not entirely true, the following may aid understanding. Imagine you have a PC which you use for a lot of graphic rendering. The onboard GPU is not able to handle the additional processing so you have to purchase a dedicated graphics card which you slot into the motherboard.
The vectoring module is a separate card like a graphics card with its own circuit board and processing designed to handle noise cancellation.
The backplane is sort of like a motherboard into which you plug in various modules. On a PC this may be things like an ethernet card, sound card, graphics card. On a dslam the modules will be things like line cards, controller units etc.
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The MA5616s require a separate, add-on, back-plane for the vectoring engine.From memory it is almost an internal rebuild as the existing power board and line cards don't support it either. Whilst it is possible, when it comes to finances I wouldn't think it was that practical or viable. It could well be nearing the cost of swapping out M41s with V41's by the time you add in labour. At least the VTU-C64 line cards in some of the ECI's are vectoring ready.
Post by: kitz on November 25, 2018, 11:46:17 PM
I wonder where that would leave an area with an ECI cab and Huawei cab on the same PCP.... even if it was a V41 rather than M41 in the ECIs.
Post by: burakkucat on November 25, 2018, 11:51:37 PM
The MA5616s require a separate, add-on, back-plane for the vectoring engine.
From memory it is almost an internal rebuild as the existing power board and line cards don't support it either. Whilst it is possible, when it comes to finances I wouldn't think it was that practical or viable. It could well be nearing the cost of swapping out M41s with V41's by the time you add in labour. At least the VTU-C64 line cards in some of the ECI's are vectoring ready.
I'm not sure how my statement about the Huawei MA5616s fits in with your comments about the ECI M41s other than, perhaps, to lead onto the fact that to attempt similar with the ECI kit would be a big financial no. I agree that for ECI system based vectoring the M41s would need to be replaced with V41s. And that will not happen.
Post by: burakkucat on November 25, 2018, 11:53:26 PM
PS just had another thought talking about node level vectoring.
I wonder where that would leave an area with an ECI cab and Huawei cab on the same PCP.... even if it was a V41 rather than M41 in the ECIs.
That is an interesting question. I guess it depends upon what actually controls node level vectoring.
Post by: kitz on November 26, 2018, 12:02:49 AM
Seemed to make sense to me... because so much inside the MA5616's would need replacing. :(
Therefore the cost of upgrading would likely almost be on a par with cost swapping out the M41s with V41's.
That's what I meant I said "when it came to finances I doubt it would be practical or viable" [for Openreach] to do so.
Post by: burakkucat on November 26, 2018, 12:19:26 AM
But there is a separate Huawei card-cage and backplane assembly, specifically for installation adjacent to a basic MA5616, to hold the vectoring engine . . . thus allowing a MA5616 to perform system level vectoring, just like the MA5603T.
The cost would be prohibitive and, agreed, it is another "no".
Post by: ejs on November 26, 2018, 05:57:07 PM
Post by: kitz on November 26, 2018, 11:22:35 PM
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swapping out some DSLAMs, unless there's some other way to get even more ports into the existing ones
TBH I don't think viability of the MA5616's is much more than of the M41's when it comes to upgrades. * But at least the Huaweis have g.inp and thus 3dB. However it's looking like most of the latest technology could be confined to the MA5603's
There's quite a bit more to making them vectoring enabled than just adding the cage. For starters the existing Central Control Unit Board would need upgrading from a CCUB to a CCUE (more specifically a H831CCUE) to be able to support daughter cards. (to attach a vectoring module to).
The backplane doesn't appear to be able to support this either and _would_ need upgrading from a H831MABA -> H831MABB. You'd also need to swap out the power board with one with higher wattage to be able to add the daughter card (200W -> 400W). There's about only the chassis, fan tray and service board that wouldn't need an upgrade. :( I'm even doubtful about those if they were to have vectoring as the line cards would also without need replacing so not sure how that would affect the system board. Finally the real bummer.. because of heat dissipation if you add a vectoring module, then the MA5616's are restricted to just 96 lines (compared to the current max of 128) which could in itself cause headaches for Openreach unless they housed it in a larger S200 **.
Hopefully SRA won't be as drastic as vectoring when it comes to the MA5616's. But it shows that the smaller Huawei cabs are not without their problems either.
TBH it would probably work out cheaper for Openreach to upgrade the M41's to V41's than it would be to fully upgrade the MA5616's. Yeah you can add a vectoring module in a cage.. but when the rest of the boards also would need upgrading to support the daughter board, but the time you paid someone to rebuild the MA5616's in the field then it probably works out as cheap to just buy a new [fully complete] dslam. Which is the point I was trying to make when it came to cost for Openreach. If OR arent willing to swap out the ECI's then I strongly doubt they will practically rebuild the 5616's by replacing most of the boards in field. I don't think I was getting my point across too well about just how much needs replacing in the 5616's before you can start adding daughter boards.
It only appears to be the MA5603's which are easily upgradable.. which is probably why they are the units which OR is installing most of these days.
*Yes they are upgradable, but if would require swapping out practically everything else in the MSAN
** At which point M41 -> V41 swapout is certainly easier than rebuilding the 5616's.
Post by: ejs on November 27, 2018, 04:30:47 PM
It sounds like Openreach are planning to have 512 port FTTC DSLAMs, so presumably that will involve replacing some DSLAMs.
Post by: niemand on November 29, 2018, 01:10:53 AM
Unless they have some latest and greatest kit that isn't yet public stashed somewhere I'm not sure what they can do.
The smaller Huawei can have an HD upgrade too by the way, letting it reach 256 line capacity.
Post by: niemand on November 29, 2018, 01:21:15 AM
Will spread the word if I can find out.
Post by: j0hn on December 04, 2018, 08:25:58 PM
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In addition, we are working closely with our vendors Huawei and Nokia to develop quicker alternatives to building new fibre cabinets – which can traditionally take up to nine months to complete. We are about to launch technical trials for a fibre cabinet side-pod and new fibre cabinet equipment capable of supporting double the current capacity. Following successful trials we are aiming to start deploying this kit in the next financial year.
https://www.thinkbroadband.com/news/8252-the-scale-of-the-problem-of-openreach-cabinets-at-capacity
The SRA discussion has gone quite off-topic.
Post by: michty_me on January 29, 2019, 10:17:38 AM
Also, What implications would there be if it was active but with SRA off on the modem (Zyxel)?
I recall when setting up the Zyxel, I was advised to leave SRA off. If I were to switch it on, Would and it was not activated on my line, Would there be adverse effects?
Post by: j0hn on January 29, 2019, 01:52:26 PM
On the topic of SRA, Are there any tell tale signs on stats that it is active on your line?
Instead of SNRM going up and down and the sync remaining static, SRA will do the opposite.
Your sync speed changes frequently without the line resyncing.
If you have it disabled then I would assume it would simply not be used.
Enabling it won't do anything until it's enabled on the DSLAM.
Post by: michty_me on January 29, 2019, 02:19:16 PM
Post by: burakkucat on January 29, 2019, 06:53:07 PM
Post by: michty_me on January 29, 2019, 08:26:11 PM
Have any members noticed it on their line for FTTC?
Post by: burakkucat on January 29, 2019, 10:16:40 PM
Have any members noticed it on their line for FTTC?
I don't think so. At least I have not read any report of such.
Post by: krypton on January 30, 2019, 05:57:01 PM
Have any members noticed it on their line for FTTC?
Are you asking in general or only concerning openreach lines?
Post by: michty_me on January 30, 2019, 07:59:37 PM
Are you asking in general or only concerning openreach lines?
Just openreach lines was what my query was with.
Post by: burakkucat on January 31, 2019, 12:09:46 AM
Just openreach lines . . .
And that's how I interpreted your query.