Kitz Forum
Announcements => Site Announcements => Topic started by: kitz on August 19, 2015, 09:39:25 PM
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As I'm sure most of you are already aware, BT Openreach is currently rolling out G.INP/Retransmission across its network.
Ian Lawrence who is their Chief Engineer and Director of Network Strategy & Engineering has kindly agreed to answer some of the more common questions about Openreach's implementation of Retransmission and progress to date posed my members of our community.
Those questions and Ian's answers are now available on this page: Openreach's implementation of G.INP / Retransmission (http://www.kitz.co.uk/adsl/ginp-retransmission.htm)
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Thank you muchly. ;D
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Thank you for asking and for documenting the questions & answers. :)
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Interesting but a pity he was so 'non-comittal' on the vectoring question. :(
In a nutshell 'What you have got' is what you have got !
Upstream G.INP will work if DLM thinks it is needed. (Only on non-ECI kit)
End of ;D
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Ah so when I had G.INP on the upstream it was "normal".
Now when will I get it back :(
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You will get it back in a few days ..... if DLM thinks you need it.
The difficult part is DLM deciding you need it.
Also a 'few days' is not an SI defined unit of measurement, so your guess is as good as mine what it means ;D
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Thats a lot of info in a few questions.
It's good to be able to hear from the horses mouth, as they say :)
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That's the best hard information we have on the subject, and it will hopefully scotch some of the wild rumours and speculation.
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Good news that some g.inp will be available to us ECI cabinet users, even if it is only downstream. My line currently has 12Mb of RS overhead downstream, so I can't wait!
Thanks Kitz
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Some when G inp is available on ECI Cabinet if modem is compatible in both directions will we get it in both directions
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It says
To clarify, the ECI Infrastructure supports retransmission in the downstream direction only.
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It says To clarify, the ECI Infrastructure supports retransmission in the downstream direction only.
My understanding is that someone using an ECI B-FOCuS /r modem with a service that is supplied from a Huawei equipped cabinet would be able to benefit from G.Inp in both directions (if deemed necessary by the DLM) by making use of the OpenWrt firmware image (http://forum.kitz.co.uk/index.php/topic,15918.0.html) that has been provided by jsamuel (http://forum.kitz.co.uk/index.php?action=profile;u=8531).
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To clarify the clarification: (My understanding of)
ECI Cab to Anything will support DS G.INP if the modem supports it. No support for US G.INP.
Huawei Cab to Anything will support DS G.INP if the Modem supports it. Excluding ECI & Others* US G.INP is enabled only if DLM thinks it is needed.
*There is a list of known Modems that do not support G.INP in one form or another on kitz. Caveats due to custom s/w etc are also noted on kitz.
Searching kitz for latest news/updates is recommended. ;D
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I'm glad you sorted that out ::)
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To clarify the clarification: (My understanding of)
ECI Cab to Anything will support DS G.INP if the modem supports it. No support for US G.INP.
Huawei Cab to Anything will support DS G.INP if the Modem supports it. Excluding ECI & Others* US G.INP is enabled only if DLM thinks it is needed.
That is my interpretation too.
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I'm glad you sorted that out ::)
Thank you :D
As there was still questions being raised I thought someone needed to state it as briefly as possible.
I am helpful like that ! ;D :D ::)
I also do a good line in the 'blindingly obvious' as well. :D ;)
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Thats great Kitz and very happy that all questions were answered it can't have been easy for you, yet the ECI re-transmission answer looks ambiguous but i would like to see the 1st ECI cabinet user get G.INP enabled this September :fingers:
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You have indeed gone to the very top there, Kitz. Great result.
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To clarify the clarification: (My understanding of)
ECI Cab to Anything will support DS G.INP if the modem supports it. No support for US G.INP.
Huawei Cab to Anything will support DS G.INP if the Modem supports it. Excluding ECI & Others* US G.INP is enabled only if DLM thinks it is needed.
That is my interpretation too.
firstly thanks for sharing the info, but his answer re g.inp doesn't make sense when G.inp MK1 g.inp was enabled on the us was enabled as well as ds , it imo is only due to the fact that the ECI hardware doesn't support it , they have change it to ds only, if you understand what i mean?
The community where correct with quite a lot of things really, but nice to have it confirmed or at least some of it confirmed, TBH some of his answers were a bit vague bordering on being incorrect possibly, not trying to start an argument , just pointing out how it read to me
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Read it again mate.
Huawei cabinet users can get (if DLM warrants) G.INP upstream OR downstream.
ECI cabinet users can get (if DLM warrants) G.INP downstream ONLY.
Thats it.
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firstly thanks for sharing the info, but his answer re g.inp doesn't make sense when G.inp MK1 g.inp was enabled on the us was enabled as well as ds , it imo is only due to the fact that the ECI hardware doesn't support it , they have change it to ds only, if you understand what i mean?
IMHO they were possibly caught out with so many ECI modems actually in use with the Huawei cabs and the speed loss experienced by those users. If all Huawei cabs had Huawei modems attached then there wouldn't have been a problem*.
If they never anticipated using upstream ReTX on the ECI cabs, then it wouldn't have mattered so much that the ECI modems doesn't support it.
But the problem is that there are god-knows how many ECI modems out there attached to Huaweis.
I know for a fact that in July 2013 that the Quinn guy who did my own install only had ECI modems on his van and was dishing out ECI's regardless of which cab. I specifically asked for a Huawei, but he couldnt provide one because he didnt have any... nor did he have much of the right equipment at all when it came to that.. not even correct Openreach NTE's, which led to my bodged install on using an LJU2 and me having to place a call to my ISP to get a proper OR engineer to come back and sort out his mess of an install. Basically all he had were ECI modems and a pile of SSFPs. :'(
*The issue with the HomeHub5A is another matter and IMHO thats up to BTretail to push their suppliers to update the f/w. The HH5A should have sufficient hardware resources to be able to cope with upstream retransmission. TP-Link have successfully been able to do so with the TD-W9980.
burakkucat raises a very interesting point about jsamuel (http://forum.kitz.co.uk/index.php?action=profile;u=8531)'s recent work into getting the ECI modems to work with upstream g.inp which has so far been successful (http://forum.kitz.co.uk/index.php/topic,15918.0.html). The question is, if a member of our community can get f/w working so that the ECI's can perform upstream ReTX then why arent Openreach doing this?
The community where correct with quite a lot of things really, but nice to have it confirmed or at least some of it confirmed,
It is. I felt it needed to be done, because there was so many rumours and BS floating around on other forums.. the whole thing became one big confusing mess full of myths :(
.. and on that note if Im wrong in my assumptions in the first couple of para's then the relevant people are free to poke me with a sharp pointed stick.
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burakkucat raises a very interesting point about jsamuel (http://forum.kitz.co.uk/index.php?action=profile;u=8531)'s recent work into getting the ECI modems to work with upstream g.inp which has so far been successful (http://forum.kitz.co.uk/index.php/topic,15918.0.html). The question is, if a member of our community can get f/w working so that the ECI's can perform upstream ReTX then why arent Openreach doing this?
Wouldn't the firmware have to come from ECI ?
I suspect that they would ask for a reasonable fee to do the work.
BT Openreach accepted the original firmware as it was/is, so there is a problem arguing about whose fault it is!
It would be quicker to go the custom route but un-supportable for BT Openreach :(
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Wouldn't the firmware have to come from ECI ?
Yes it would.
My line of thinking was that if they were still purchasing these units then they should have enough clout to getting ECI to work on this with Lantiq. - In the same way the Lantiq worked with TP-link to get the TD-W9980's sorted.
But as you say.. obviously much easier fix for them to adjust the Huawei DLM params... especially if they already had this planned for the ECI cabs anyway.
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We must remember that come next January (2016) Openreach will stop supplying modems for new VDSL2 installations. It will then be up to the CP/ISP to provide a satisfactory CPE.
From the following January (2017) Openreach will cease supporting the modems that they have previously installed.
Just thinking out loud . . . I wonder if there is a Kitizen who would be willing to install the OpenWrt software image (http://forum.kitz.co.uk/index.php/topic,15918.0.html) onto an ECI B-FOCuS /r modem and send that modem to Kitz, our leader, for testing? :-\
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We must remember that come next January (2016) Openreach will stop supplying modems for new VDSL2 installations. It will then be up to the CP/ISP to provide a satisfactory CPE.
From the following January (2017) Openreach will cease supporting the modems that they have previously installed.
It all makes sense now.
BT Openreach are not going to spent any money on this problem as by their timescales it is not worth the outlay.
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Read it again mate.
Huawei cabinet users can get (if DLM warrants) G.INP upstream OR downstream.
ECI cabinet users can get (if DLM warrants) G.INP downstream ONLY.
Thats it.
I have done and i still see an error in what he has said, So far no G.inp enabled circuit on MDWS has had this applied , And as said the MK1 G.inp enabled it on both US & DS , His answer imo was some what contradictory , perhaps he didn't really know ,he gave that impression also, chief engineer or not
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We must remember that come next January (2016) Openreach will stop supplying modems for new VDSL2 installations. It will then be up to the CP/ISP to provide a satisfactory CPE.
From the following January (2017) Openreach will cease supporting the modems that they have previously installed.
It all makes sense now.
BT Openreach are not going to spent any money on this problem as by their timescales it is not worth the outlay.
It wouldn't come as any surprise at all to me , if that is the real reason for this, which it probablly is ,imo you are bang on the money
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Read it again mate.
Huawei cabinet users can get (if DLM warrants) G.INP upstream OR downstream.
ECI cabinet users can get (if DLM warrants) G.INP downstream ONLY.
Thats it.
I have done and i still see an error in what he has said, So far no G.inp enabled circuit on MDWS has had this applied , And as said the MK1 G.inp enabled it on both US & DS , His answer imo was some what contradictory , perhaps he didn't really know ,he gave that impression also, chief engineer or not
There is at least 1 user in the PlusNet Community Forum (11110_110) reporting a return of US G.INP on his connection (his stats also confirm it is active for both DS & US):-
https://community.plus.net/forum/index.php?topic=136287.msg1259737#msg1259737
EDIT:-
A couple of MDWS users' stats are now reporting G.INP on DS & US & one of them (condi) is reportedly connected to an ECI cabinet
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Somebody heard my frustration as G.INP is back on my line :D
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EDIT:-
A couple of MDWS users' stats are now reporting G.INP on DS & US & one of them (condi) is reportedly connected to an ECI cabinet
That can be wrong sometimes as has been noted before. It uses the BPT data mainly looking at whether Tone 32 is there or not (it isn't on an ECI cab) plus elsewhere as a double check as there is no other data available to MDWS for the info. In this case, he has no tones at all until 33 and others missing as well so it's likely it is wrong. His BPT Graph show black bars which is an indication of not matching the bandplan for the stated cab.
The only way round this would be to upload some additional definitive data but that raises more problems although I think I can see a way round it in the back of my mind.
Visually the high end tones do look like a Huawei for condi.
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Sadly i feel underwhelmed, as the answers given are very vague and there is little there that we didnt already know :(
But I appreciate that you took the time to get answers on ECI even tho he was resistant to giving you an answer.
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That's very helpful, kitz - thanks for making this information available :)
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Thanks Kitz very interesting. I wonder if BT implements vectoring just on Huwais whether they can claim any higher speeds in adverts? Assuming 2:1 mix if only 66% support vectoring will BT meet requirements for a mimum level to increase from the current 80/20 limit?
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I think BT might just roll out vectoring on the BDUK cabinets as a way to cover more properties...
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Great to see the questions answered, thanks for posting that Kitz, that said a little disappointed that he seemed to avoid giving any detail for the ECI side of things, pretty much said what we already know.
It all looks great for Huawei users and i'm glad for them, ECI however for both G.INP and Vectoring it doesn't look good at all :'(
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I wonder if BT implements vectoring just on Huwais whether they can claim any higher speeds in adverts? Assuming 2:1 mix if only 66% support vectoring will BT meet requirements for a mimum level to increase from the current 80/20 limit?
I'm not sure. If they did advertise it with the newer headline rate then, I think it would make those (1/3rd?) of users on ECI's a tad unhappy.
There's no hard and fast rule about how much speed can be regained by the use of vectoring, but having lost 30Mbps off my headline rate and the average between users of this forum seems to be around the 20Mbps mark, then there are a lot of us impatient for the implementation of vectoring.
Its a tricky situation because if they aren't able to use vectoring on the ECI's, but rolled out to the Huaweis then it could make a two-tier situation across the UK. Im on an ECI myself and although I would be green with envy if I couldn't get it, I don't feel that should be made an excuse as to why progress should stop for the Huawei's.. especially with some long BDUK lines it could make a difference between getting a decent speed or not.
But then again its the shorter lines which lose the most from crosstalk and where vectoring can make massive difference. For longer lines the potential increases arent as much. There's a graph here (https://techzine.alcatel-lucent.com/boosting-vdsl2-bit-rates-vectoring) produced by Alcatel. I've no doubt BT have also got some figures somewhere from the trials that they've performed on their own plant and network.
It would be good if BT were a bit more open about their plans for vectoring because there is so much myth and rumour about this particular topic. I certainly dont feel that its a dead duck as far as BT are concerned especially because we know it could help in a lot of BDUK areas.
But the debate on Vectoring and Crosstalk is cause for a whole separate topic :)
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Somebody heard my frustration as G.INP is back on my line :D
That's excellent your DS errored seconds are non-existent and a bloody good sync rate to boot, just keep the manual re-syncs to a minium and you won't see that terrible old interleaving wtih errored correction again :)
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Whilst it's good to know all the Huawei cabs are done, and the ECI cabs will get done once the test equipment has been fixed, it kind of begs the question "what next"?
He was non committal re vectoring, and that appears to be a Huawei only thing.
Obviously G.FAST is next on the horizon, but that will only (probably) go to commercial areas and it's unlikely there'll be BDUK funding for that.
Given the rollout is still behind in terms of > 24Mbps coverage, and assuming G.INP could potentially be on all cabinets "soon", is there any real prospect that the target SNRM could be lowered to 3dB (or something else)?
6dB seems quite conservative...
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It would be interesting to see what the average SNR "swing" on FTTC lines is.
Looking at MDWS, most lines hardly change at all, so it would seem that 3dB may be justified.
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Having come to this through pm, I forgot to post something about it.
I think that experience has told us how g.INP has worked, and Ian's answers are really just confirmation. In the end, I find myself mostly wondering what else kitz managed to talk about ;)
Having said that, rereading the answers has left me with an interesting realisation...
The second point has two quotes that suggest a DLM reset now results in a different line profile:
- "Initially, low interleaving is enabled by default on all retransmission lines"
- "If a line is reset then it will initially move back to interleaved downstream and fast mode upstream." Followed by "Retransmission will be applied again after a few days."
That sounds like the new profile, post-dlm-reset, is to have "low interleaving" without retransmission.
I wonder if it means the kind of "low interleaving" we have seen alongside retransmission, with a configured delay of 0 that comes out to be 0.2ms. Or the old-style of "low interleaving" with delay set to 8ms.
Is anyone seeing either case in practice?
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When I had DLM reset on my line, the line went back to fast path for 12 hours or so before DLM switched on very high interleaving on the downstream (somewhere around 1000) and upstream (somewhere around 100).
It took a week or two for DLM to enable G.INP.
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Hmmm. DLM intervention in less than 12 hours after a reset is definitely far from the norm. Or the old norm anyway ... so perhaps things have changed.
When interleaving was round 1000, do you have any idea what the "INP" and "delay" values were?
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We must remember <snip>.
Just thinking out loud . . . I wonder if there is a Kitizen who would be willing to install the OpenWrt software image (http://forum.kitz.co.uk/index.php/topic,15918.0.html) onto an ECI B-FOCuS /r modem and send that modem to Kitz, our leader, for testing? :-\
b*kat has anybody offered this up yet or has it been 'overtaken by events'?? I have one, V-2Fub/r Rev. B fresh from being replaced by a VMG8924 :)
Rgds.
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b*kat has anybody offered this up yet or has it been 'overtaken by events'?? I have one, V-2Fub/r Rev. B fresh from being replaced by a VMG8924 :)
As of yet, I am not aware of Kitz being offered an ECI B-FOCuS V-2Fub/r, flashed with the OpenWRT firmware, for testing on her circuit (which originates from an ECI equipped cabinet).
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Thanks for the update, b*cat. I'm happy to offer mine as a loan for her to test as she needs to. I'll have a check through the guides for doing the OpenWrt flash and then I can send it on to here via whatever means is best for her.
Rgds,
Chris
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Does anyone have the faintest idea how G.INP fairs on a Aluminium line sadly during my Engineer visit today it turns out my line is Aluminium and not copper hence the issues i was having in the thread i posted in the FTTC FTTH issues section of the forums, looking around online i see no mention of how G.INP or Vectoring ect fair on such a line i'm not surprised given that Broadband isn't fit to run on it but hey that doesn't stop Openreach allowing ADSL / fibre to run on it knowing full well it can't handle it.
I'm just wondering if i'm likely to see a far more negative outcome if and when my ECI cab becomes enabled because of the Aluminium line it was bad enough to learn I would never get any of my previous speed back without fearing now it could be worse should G.INP come around.
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As I "see it" you should not experience any degradation of the VDSL2 based service when G.Inp is enabled. I would expect you to see an improvement but not quite as good as that for someone whose circuit is made up entirely of copper conductors.
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Thanks for the reply Burakkucat sounds promising although i guess i wont really know the answer until G.INP gets enabled when ever that happens. :fingers:
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Just as Burakkucat says, you will see a very worthwhile improvement when G.INP and vectoring become available, despite the aluminium.
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Thanks for the update, b*cat. I'm happy to offer mine as a loan for her to test as she needs to. I'll have a check through the guides for doing the OpenWrt flash and then I can send it on to here via whatever means is best for her.
Rgds,
Chris
Thank you for the kind offer.
I have an ECI modem here, unfortunately though I dont do soldering or any of the UART things that is needed to get OpenWrt f/w on to the modem.