Kitz Forum
Broadband Related => FTTC and FTTP Issues => Topic started by: ccarmock on February 26, 2019, 11:50:43 AM
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Originally I had Plusnet's up to 40 Mb/s FTTC service. Which was adequate since my line is estimated to achieve a max of 41 Mb/s anyway, but I still elected to got for their 80 Mb/s service since at the time they offered a paltry 2 Mb/s upload. That has changed now I know.
Anyway they did make some changes but seemed to move me to a 40/10 service in error but I didn't notice as the upload speed increaed to between 7 & 8 Mb/s and down remained much the same.
Anyway they have spotted their error which affects multiple customers and will refund the incorrectly billed amounts and have now moved me to the 80/20 service.
This has caused a DLM reset and performance now is worse than it was previously as I was on Fastpath both up & down with G.INP active.
Now I have ended up on Interleave down, Fastpath up with no G.INP and a growing number FECS - 185,000 in 8 hours.
The service has been table for over 220 hours according to my Draytek 2860, until yesterday when a power cut reset it. So based on these counters it's about 1 ES per hour
It seems like G.INP isn't coming back any time soon.
Following other treads here some people have suggested using Draytek's option to modify target SNR margin - will that likely help?
I am syncing between 5-6 Mb/s lower now after this change which in theory might have got an extra 1-2 Mb/s! Progress this isn't!
Details from the Draytek:-
DrayTek> vdsl status
---------------------- ATU-R Info (hw: annex A, f/w: annex A/B/C) -----------
Running Mode : 17A State : SHOWTIME
DS Actual Rate : 33562000 bps US Actual Rate : 8063000 bps
DS Attainable Rate : 40829960 bps US Attainable Rate : 8063000 bps
DS Path Mode : Interleave US Path Mode : Fast
DS Interleave Depth : 489 US Interleave Depth : 1
NE Current Attenuation : 26 dB Cur SNR Margin : 6 dB
DS actual PSD : 5. 7 dB US actual PSD : 11. 6 dB
NE CRC Count : 76 FE CRC Count : 81431
NE ES Count : 23 FE ES Count : 66006
Xdsl Reset Times : 0 Xdsl Link Times : 2
ITU Version[0] : 00000000 ITU Version[1] : 00000000
VDSL Firmware Version : 05-07-06-0D-01-07 [with Vectoring support]
Power Management Mode : DSL_G997_PMS_L0
Test Mode : DISABLE
-------------------------------- ATU-C Info ---------------------------------
Far Current Attenuation : 29 dB Far SNR Margin : 5 dB
CO ITU Version[0] : b5004244 CO ITU Version[1] : 434da48c
DSLAM CHIPSET VENDOR : < BDCM >
DrayTek>
Trellis ON ON
Bitswap ON ON
ReTx 0 0
SNR Margin 6dB 5dB
Attenuation 26dB 29dB
CRC 76 81435
FECS 15078145 47243
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I would advise you not to alter the SNR margin or to cap the line.
g.inp will eventually come back on the line itself and your speed will improve when it does.
Don't worry about FEC errors - they are actually 'good' in that they reflect errors avoided rather than having to be retransmitted.
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Thanks for that. I assume a growing number of FEC errors will not prevent DLM from switching from Interleave to Fastpath with G.INP?
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It will make no difference..
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G.INP may take a little while to return, but it should eventually return. You could increase the SNRM offset for your downstream (e.g. vdsl snr 30 would increase it by 3.0 dB, making it 9 dB instead of 6 dB), given you're on a DrayTek device, so that your connection appears even more stable to 'DLM' but I imagine for now just be patient and hope DLM takes positive steps without you trying to encourage it. As I'm on an ECI DSLAM I do the SNRM offset anyway, as I'd rather keep fastpath at a slower sync rate instead of traditional interleaving at a slower sync rate and higher latency. Fortunately I'll be getting FTTP very soon so I won't have this problem anymore.
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I am guessing the key reason to change SNR is to improve stability - the good thing is the line is very stable - before the powercut it has clocked up well over 200 hours of stability, and is still stable since. So it sounds like just wait. What prompted my question is last time there was a line change it went from Fastpath no G.INP to Fastpath G.INP and stayed that way.
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Just to give an update on this eventually DLM did intervene and switch me to Fastpath - great - but it also increased the target SNRM to 9dB which has kept the speed pretty much where it was before. See below. Hopefully the next steps DLM will take will be to reduce that back to 6dB which is where it was before Plusnet carried out the reset.
DrayTek> vdsl status
---------------------- ATU-R Info (hw: annex A, f/w: annex A/B/C) -----------
Running Mode : 17A State : SHOWTIME
DS Actual Rate : 32721000 bps US Actual Rate : 7660000 bps
DS Attainable Rate : 32649568 bps US Attainable Rate : 7660000 bps
DS Path Mode : Fast US Path Mode : Fast
DS Interleave Depth : 1 US Interleave Depth : 1
NE Current Attenuation : 26 dB Cur SNR Margin : 9 dB
DS actual PSD : 5. 9 dB US actual PSD : 11. 5 dB
NE CRC Count : 0 FE CRC Count : 87588
NE ES Count : 0 FE ES Count : 70711
Xdsl Reset Times : 0 Xdsl Link Times : 3
ITU Version[0] : 00000000 ITU Version[1] : 00000000
VDSL Firmware Version : 05-07-06-0D-01-07 [with Vectoring support]
Power Management Mode : DSL_G997_PMS_L0
Test Mode : DISABLE
-------------------------------- ATU-C Info ---------------------------------
Far Current Attenuation : 29 dB Far SNR Margin : 5 dB
CO ITU Version[0] : b5004244 CO ITU Version[1] : 434da48c
DSLAM CHIPSET VENDOR : < BDCM >
DrayTek> vdsl status more
---------------------- ATU-R Info (hw: annex A, f/w: annex A/B/C) -----------
Near End Far End Note
Trellis : 1 1
Bitswap : 1 1
ReTxEnable : 0 1
VirtualNoise : 0 0
20BitSupport : 0 0
LatencyPath : 0 0
LOS : 0 0
LOF : 0 0
LPR : 0 0
LOM : 0 0
SosSuccess : 0 0
NCD : 0 0
LCD : 0 0
FECS : 0 47243 (seconds)
ES : 0 70711 (seconds)
SES : 0 36 (seconds)
LOSS : 0 0 (seconds)
UAS : 28 72385 (seconds)
HECError : 0 0
CRC : 0 87588
INP : 0 225 (symbols)
INTLVDelay : 0 17 (1/100 ms)
NFEC : 240 32
RFEC : 0 16
LSYMB : 1929 16
INTLVBLOCK : 120 32
AELEM : 0 ----
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Perhaps I am missing something, but it seems there is no need to be provisioned on the 80/20 service because it looks you can't benefit from it. Save yourself some dosh and downgrade to 40/10.
Anyway, what does the DSLchecker (https://www.dslchecker.bt.com/) say for your VDSL estimates?
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You are right and I am now provisioned on 40/10 Originally I was on 80/20 purely to get an improved upload speed when Plusnet were stuck in the dark days on 10/2. It took Talktalk to change so they can follow, rather than lead the way.
So yes 40/10 now. Just hope the SNRM moves back to 6 dB and I can get closer to 40
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I do remember such dark days. Some applications would fully saturate the 2 Mbps upstream when trying to download, which made it frustrating to use sometimes for anything else.
Good luck on your journey to 6 dB!