SNR improved after VDSL modem change


Ian

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I've just swapped out my old Xyzel modem for a newer model and it looks like I've got a much improved SNR. My line rate was closer to 15.5Mbps before and it's already jumped to 18.00... It looks like there is quite a bit more room for improvement if my SNR is 13dB.

Any thoughts on how long it can take for the line to adjust to the new modem and potential speed improvements? I'm with Plusnet and I've asked if it would be useful for a line reset, given how it looks like it's hitting a banding threshold at the moment.

Code:
VDSL Port Details       Upstream         Downstream
               Line Rate:      5.324 Mbps       17.999 Mbps
    Actual Net Data Rate:      5.296 Mbps       18.000 Mbps
          Trellis Coding:         ON                ON
              SNR Margin:        6.2 dB           13.0 dB
            Actual Delay:          0 ms              0 ms
          Transmit Power:        7.1 dBm           8.9 dBm
           Receive Power:      -10.2 dBm         -17.6 dBm
              Actual INP:        0.0 symbols      54.0 symbols
       Total Attenuation:        0.0 dB          27.2 dB
Attainable Net Data Rate:      5.296 Mbps       25.907 Mbps
 
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EvanDavis

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No idea what SNR and all that is but got a nw router when I renewed my TalkTalk and internet seems to be flying now. WiFi is much faster than it was before.
 

V_R

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Ask Plusnet for a DLM reset, it looks like your line is banded to 18,000Mbps.
 

Ian

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Ask Plusnet for a DLM reset, it looks like your line is banded to 18,000Mbps.
Ta, did that yesterday morning as it happens and they said it was indeed banded. Do you know how long it normally takes to lift the banding (do I need to force a resync, I haven't tried as don't want to confuse DLM)?
 

V_R

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I'm not sure tbh. But from what I've read it should be pretty quick, a week maybe?

DLM should do it for you, I'd leave it a while and see if it moves. :)
 

Ian

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Got a DLM reset in the works, as it went a bit bonkers and plusnets internal profile set me to 5.4mbps. Now back up to 17.65mbps, but hoping a DLM reset will get me back to 26mbps :D .
 
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Were Plusnet accommodating when you asked for a DLM reset? I would like to try the same but not sure if I can face being on the phone for hours....
 

Ian

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Were Plusnet accommodating when you asked for a DLM reset? I would like to try the same but not sure if I can face being on the phone for hours....
Yep, they did a DLM reset, but only as my possible sync speed was showing so much higher. It's taken me a while to get there, as there was a possible line fault and some odd Plusnet side issues - but I'm now syncing at 27mbps.

I posted on their forum to get a response, as took me ages on phone too.

Are you also facing problems?
 

Ian

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Made some further improvements, including switching to a Draytek 130 modem and I'm now syncing at almost 32mbps!!! A crazy increase on my 15.5Mbps :D. That's faster than the line max estimate, so very pleased indeed!
 

V_R

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Nice! Out of interest, have you ever used one of the Huawei HG612's?
 

Ian

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I've been so close to getting one so many times, but they're getting up to 10 years old now, so I used a mixture of different modems - the Draytek 130 beats both the Zyxel broadcom based modems I've used, which I didn't expect.
 
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Ian

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Now syncing at almost 33mbps, this is a crazy speed increase compared to what I was used to. Very happy :D. It means I can wait only 2 hours for MS Flight Sim 2020 to patch every day, rather than 4 hours :lol: .

My SNR is now 5db, so if the line remains stable then I'm hoping I might end up on a 3db profile. Do you have any idea how much of a speed increase this may give if so @V_R (you seem to know a lot more about this than I do!).

Code:
---------------------- ATU-R Info (hw: annex A, f/w: annex A/B/C) -----------
   Running Mode            :      17A       State                : SHOWTIME
   DS Actual Rate          : 32959000 bps   US Actual Rate       :  5319000 bps
   DS Attainable Rate      : 32179640 bps   US Attainable Rate   :  5300000 bps
   DS Path Mode            :        Fast    US Path Mode         :        Fast
   DS Interleave Depth     :        1       US Interleave Depth  :        1
   NE Current Attenuation  :       29 dB    Cur SNR Margin       :        3  dB
   DS actual PSD           :     7. 0 dB    US actual PSD        :    10. 8  dB
   NE CRC Count            :       33       FE CRC Count         :     1804
   NE ES Count             :        3       FE  ES Count         :     1653
   Xdsl Reset Times        :        0       Xdsl Link  Times     :        1
   ITU Version[0]          : fe004452       ITU Version[1]       : 41590000
   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 :       32 dB    Far SNR Margin       :        5  dB
   CO ITU Version[0]       : b5004244       CO ITU Version[1]    : 434dc190
   DSLAM CHIPSET VENDOR    : < BDCM >
 

V_R

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I've been so close to getting one so many times, but they're getting up to 10 years old now, so I used a mixture of different modems - the Draytek 130 beats both the Zyxel broadcom based modems I've used, which I didn't expect.
Ah fair play. I've often thought about replacing mine but its been 100% rock solid stable since I've had it, and its unlocked so I can see all sorts of info regarding the line. If I ever get G.Fast of FTTP though it will be retired though.

My SNR is now 5db, so if the line remains stable then I'm hoping I might end up on a 3db profile. Do you have any idea how much of a speed increase this may give if so @V_R (you seem to know a lot more about this than I do!).

Ha! I don't know about that.
To be honest I'm not sure, DLM is a strange beast it seems to take as much time as it likes to do what is needed sometimes.

An example: one of our neighbours (I think) here has done something/got something to cause a lot more crosstalk recently, my attainable dropped a lot, I'm just under max sync, at 79436 (upstream attainable is still 30000!), but my SNR is at 6.5dB, if DLM would drop it to 6 or 6.1 I'd be back at the full 79999. Been like it for ages, tried a few random reboots, even leaving it for half an hour before turning it back on so DLM doesn't see it as a resync, still nothing. :rolleyes:

Its not a big deal I know, but it just goes to show how one little thing can have such a dramatic effect on line noise!
 
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Ian

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Ah fair play. I've often thought about replacing mine but its been 100% rock solid stable since I've had it, and its unlocked so I can see all sorts of info regarding the line. If I ever get G.Fast of FTTP though it will be retired though.

If it works, no need to replace it :D, especially at those speeds!

Been like it for ages, tried a few random reboots, even leaving it for half an hour before turning it back on so DLM doesn't see it as a resync, still nothing.

Yeah DLM is weird, it looks like it works well most of the time, but I was stuck on a much slower profile for a long time for little reason until a DLM reset was performed.
 

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