Kitz Forum
Broadband Related => FTTC and FTTP Issues => Topic started by: seajayshome on June 11, 2023, 03:28:44 PM
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So, long story short, I was with Sky with stable FTTC connection for many years. Speed Download was 24MBps+ and Upload 3.8MBps+ -the SNR was 3dB, but was very stable at that - would go for months.
I recently changed to talktalk, and their modem was horrible... :D Problems encountered meant I needed to change router, and got myself a Draytek Vigor 2766.
The problem I have now is the sync speed is significantly lower - AND significantly lower than my old Sky router still connects at (on the talktalk line).
My Vigor 2766 is connecting at 18MBps and upload 2.8MBps - which is a lot slower than I'm used to - I'm not sure how much of this may be because the exchange is back in it's "training" mode, and that may have been exacerbated by lots of reboots and switching of routers recently trying to resolve things... however, these are my current stats below.
Does anyone see anything that jumps out as odd - and is there any way to get back to the type of speeds I had with the sky router?
---------------------- ATU-R Info (hw: annex A, f/w: annex A/B/C) -----------
Running Mode : 17A State : SHOWTIME
DS Actual Rate : 18108000 bps US Actual Rate : 2824000 bps
DS Attainable Rate : 20495370 bps US Attainable Rate : 2826000 bps
DS Path Mode : Fast US Path Mode : Fast
DS Interleave Depth : 4 US Interleave Depth : 1
NE Current Attenuation : 28 dB Cur SNR Margin : 6 dB
DS actual PSD : 9. 1 dB US actual PSD : 7. 3 dB
NE CRC Count : 7823 FE CRC Count : 314
NE ES Count : 0 FE ES Count : 0
Xdsl Reset Times : 0 Xdsl Link Times : 2
ITU Version[0] : 00000000 ITU Version[1] : 00000000
VDSL Firmware Version : 12-3-2-3-0-5 [with Vectoring support]
Power Management Mode : DSL_G997_PMS_L0
Test Mode : DISABLE
nBandPlan : 0
-------------------------------- ATU-C Info ---------------------------------
Far Current Attenuation : 0 dB Far SNR Margin : 6 dB
CO ITU Version[0] : b5004244 CO ITU Version[1] : 434dc190
DSLAM CHIPSET VENDOR : < BDCM >
---------------------- ATU-R Info (hw: annex A, f/w: annex A/B/C) -----------
Near End Far End Note
Trellis : 0 1
Bitswap : 0 0
ReTxEnable : 1 1
VirtualNoise : 1626203824 1626203824
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 : 3097471 816 (seconds)
ES : 0 0 (seconds)
SES : 0 0 (seconds)
LOSS : 0 0 (seconds)
UAS : 0 0 (seconds)
HECError : 0 0
CRC : 7823 314
INP : 0 260 (symbols)
INTLVDelay : 100 0 (1/100 ms)
NFEC : 88 236
RFEC : 8 8
LSYMB : 788 5056
INTLVBLOCK : 88 236
AELEM : 0 ----
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Yes, the speed difference is due to being 6dB SNRm now, its just a case of waiting and hoping DLM switches it back.
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Thank you - I did wonder if that might be the case... I was slightly worried that the "attainable rate" listed there was only saying 20 - but is that "attainable" at that particular SNR...?
Somewhat fortunately I am going away to a conference this week, so I will not be tempted to try other stuff to "fix" things, and is probably doing more harm than good with more router resets :blush:, I will attempt not to touch it and hope that retraining occurs over the next few weeks... ;D
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Thank you - I did wonder if that might be the case... I was slightly worried that the "attainable rate" listed there was only saying 20 - but is that "attainable" at that particular SNR...?
It's exactly that. The attainable increases as the SNRM target decreases.
Talktalk could be using a different DLM policy from Sky that makes it less likely for a line to go down to 3dB.
It might just be that the DLM is taking it's time though.
With the Draytek you can force a 3dB target, overriding the DLM.
Alternatively you could force a higher SNRM, trucking the DLM in to thinking the line is more stable than it is, making it lower the SNRM.
Personally I would increase the SNRM, temporarily lowering your sync further. Within a few days the DLM usually lowers the SNRM , but not always.
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Thanks - it decided to resync last night - but it has actually increased the SNRM itself... and therefore has lowered the speed even further :( - it's now below my minimum speed guarantee (20Mbps)
---------------------- ATU-R Info (hw: annex A, f/w: annex A/B/C) -----------
Running Mode : 17A State : SHOWTIME
DS Actual Rate : 18440000 bps US Actual Rate : 2844000 bps
DS Attainable Rate : 19487142 bps US Attainable Rate : 2844000 bps
DS Path Mode : Fast US Path Mode : Fast
DS Interleave Depth : 8 US Interleave Depth : 1
NE Current Attenuation : 28 dB Cur SNR Margin : 7 dB
DS actual PSD : 9. 4 dB US actual PSD : 7. 3 dB
NE CRC Count : 15065 FE CRC Count : 468
NE ES Count : 0 FE ES Count : 0
Xdsl Reset Times : 0 Xdsl Link Times : 3
ITU Version[0] : 00000000 ITU Version[1] : 00000000
VDSL Firmware Version : 12-3-2-3-0-5 [with Vectoring support]
Power Management Mode : DSL_G997_PMS_L0
Test Mode : DISABLE
nBandPlan : 0
-------------------------------- ATU-C Info ---------------------------------
Far Current Attenuation : 0 dB Far SNR Margin : 6 dB
CO ITU Version[0] : b5004244 CO ITU Version[1] : 434dc190
DSLAM CHIPSET VENDOR : < BDCM >
I'm away now for a few days so I'll see what it's like when I come back on Friday. :-\
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Which modem firmware are you running?
https://www.draytek.co.uk/support/downloads/vigor-2766
Are you using BT Recommended?
There are three firmware variants available for download.
Download Filename Firmware Filename Modem Code
VDSL ADSL
v2766_4421_BT.zip v2766_4421BT_1232305.all 1232305 12321014
v2766_4421_MDM0.zip v2766_4421_1232302.all 1232302 12321030
v2766_4421_MDM1.zip v2766_4421_12611012.all 12611012 12601015
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Yes, it's the 4.4.2.1 BT firmware.
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So back home after a few days, and the modem/DLM has reset a few times while I've been away - and now the speed is so much worse... Down to 14Mbsp! :(
I don't understand why the Draytek does not seem to be coping - the talktalk/sky one did not seem to be doing this. I tried using the "vdsl snr -20" to force it top reconnect at a lower SNRM, however it just wouldn't sync at all when I did that (amber light just kept flashing and it never reconnected - had to reboot router). Should I contact talktalk, or draytek?
---------------------- ATU-R Info (hw: annex A, f/w: annex A/B/C) -----------
Running Mode : 17A State : SHOWTIME
DS Actual Rate : 14283000 bps US Actual Rate : 2776000 bps
DS Attainable Rate : 17166376 bps US Attainable Rate : 2772000 bps
DS Path Mode : Fast US Path Mode : Fast
DS Interleave Depth : 4 US Interleave Depth : 1
NE Current Attenuation : 29 dB Cur SNR Margin : 8 dB
DS actual PSD : 8. 5 dB US actual PSD : 7. 3 dB
NE CRC Count : 19081 FE CRC Count : 1337
NE ES Count : 0 FE ES Count : 0
Xdsl Reset Times : 0 Xdsl Link Times : 5
ITU Version[0] : 00000000 ITU Version[1] : 00000000
VDSL Firmware Version : 12-3-2-3-0-5 [with Vectoring support]
Power Management Mode : DSL_G997_PMS_L0
Test Mode : DISABLE
nBandPlan : 0
-------------------------------- ATU-C Info ---------------------------------
Far Current Attenuation : 0 dB Far SNR Margin : 6 dB
CO ITU Version[0] : b5004244 CO ITU Version[1] : 434dc190
DSLAM CHIPSET VENDOR : < BDCM >
---------------------- ATU-R Info (hw: annex A, f/w: annex A/B/C) -----------
Near End Far End Note
Trellis : 0 1
Bitswap : 0 0
ReTxEnable : 1 1
VirtualNoise : 1626203824 1626203824
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 : 4109657 3317 (seconds)
ES : 0 0 (seconds)
SES : 0 0 (seconds)
LOSS : 0 0 (seconds)
UAS : 0 0 (seconds)
HECError : 0 0
CRC : 19081 1337
INP : 0 250 (symbols)
INTLVDelay : 100 100 (1/100 ms)
NFEC : 88 236
RFEC : 8 8
LSYMB : 775 4029
INTLVBLOCK : 88 236
AELEM : 0 ----
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Are you able to put the Talktalk router back on the line for a while to see if the issue goes away as it's sounding like the Draytek is either faulty or unfortunately just isn't a good one for your line?
Out of interest which Talktalk router is it that you have?
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I could put either the talktalk one back (or my very old sky router). The talktalk is a Sagemcom FAST 5364. The sky one is an SR102.
The problem with the talktalk one is that I'm no longer able to cast from my Plex media server to my Chromecast devices as the router has some form of DNS rebind protection for which you can't put exceptions and plex/Chromecast need that to work properly (this was after quite a lot of research and forums trying to work out what was happening)
The sky one also worked fine (it was always very stable. I may put that back. Problem is you are locked to sky's DNS servers as there is no option to change them.
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So I put the Sky router back in and it immediately synced 4MBps faster than the Draytek could... that's without it sitting letting DLM do it's thing, which I expect would get me back to the 3dB SNRM and 25MBps-ish.
I didn't change anything else - just the router - unplugged the RJ11 out of the back of the Draytek and put it in the Sky box.
Broadband Link Downstream Upstream
Connection Speed (Kbps) 21272 2898
Line Attenuation (dB) DS1:24.1 DS2:73.9 DS3:0.0 US0:10.1 US1:59.6 US2:0.0
Noise Margin (dB) DS1:6.8 DS2:6.7 DS3:0.0 US0:6.4 US1:6.4 US2:0.0
Do I have a faulty draytek router?
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Do I have a faulty draytek router?
Possibly, or as I mentioned before it may be that the Draytek and your line just can't get on together.
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Yeah - someone over on the draytek forum has said that the Draytek are known to have issues with the broadcom chipsets in the cabinets - especially over longer line distances (I think we're about a kilometre from our cabinet...) - the draytek routers are based on Lantiq? Wish I had know there were such problems before... ::)
So my next question is, what would be a better router, based on a broadcom chipset then? I don't need wifi, as I have a seperate mesh network, just something with a solid VDSL2 connection, and the ability to configure things like DNS servers etc.
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Draytek modems and routers with Lantiq chipsets are notorious for performing badly with Huawei Broadcom based cabinets.
There's plenty of threads on here complaining about them, here are a couple that I commented on based on my Draytek experience:
https://forum.kitz.co.uk/index.php/topic,24884.0.html (https://forum.kitz.co.uk/index.php/topic,24884.0.html)
https://forum.kitz.co.uk/index.php/topic,25646.0.html (https://forum.kitz.co.uk/index.php/topic,25646.0.html)
I'd recommend a Zyxel Broadcom based modem/router. I've had great experience with my two VMG1312-B10A modems, one of which you could use alongside your Vigor 2766 in router mode. If you're looking to ditch the Draytek completely then I've also had good experience with the Zyxel VMG3925-B10B
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Well, Draytek are not the only ones equipping their routers with Lantiq chipsets and the others can work fine. I'm connected to a Huawei cabinet, yet my Lantiq-based Fritzbox works the same, if not better, than a brand new Zyxel.
The issue of matching chipsets has been discussed before and yet there's still no evidence of one of them doing better than the other; it's all purely subjective, as it depends on an individual's line.
There's also an issue of security with Zyxel's firmware not being updated for a while, while my Fritzbox got an update the other week. Draytek get their updates pretty regularly, though how they can handle a noisy(ier) line is another matter.
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There's also an issue of security with Zyxel's firmware not being updated for a while...
A fair point but I'd say the risks are small, especially so when operating in bridge mode.