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[Brian Coat]

1) I just connected the Zyxel router (I did not reboot it, I just connected the DSL lead.
I did this just for for monitoring purposes but I noticed that the d/s speed has gone up - a lot.

After months at 2MBPS and 2 days at 10-12, I now see IP profile of 15.39 MBPS and a download rate of nearly 14MBPS.

The upstream rate is stubbornly slow. I wonder if there are any ways you can address this? (I have no idea whether you can boost a modem's output signal, for example, or indeed if it would help.).
     
From BT wholesale ....

Download speed achieved during the test was - 13.84 Mbps
IP Profile for your line is - 15.39 Mbps

Upload speed achieved during the test was - 0.43Mbps
Upstream Rate IP profile on your line is - 2 Mbps
----------------------------------------------------------------------------------------------------------------------

2) I've looked at the modem but I have not tweaked the target SNR - the modem says the margin is about 6, which seems right.

I wonder why it is faster d/s on the Zyxel??  I'm not complaining but I'm not sure why. Maybe it has good signal conditioning circuitry or a nice/cabinet-compatible chipset, ...?  Or maybe it won't last.

If anything, u/s is a smidgen slower on the Zyxel but that's like saying it lost a photo finish in snail race.

Here are the figures from the Zyxel modem ....

    VDSL Training Status:   Showtime
                    Mode:   VDSL2 Annex B
            VDSL Profile:   Profile 17a
            Traffic Type:   PTM Mode
             Link Uptime:   0 day: 0 hour: 13 minutes
============================================================================
       VDSL Port Details       Upstream         Downstream
               Line Rate:      0.493 Mbps       15.947 Mbps
    Actual Net Data Rate:      0.474 Mbps       15.901 Mbps
          Trellis Coding:         ON                ON
              SNR Margin:        6.6 dB            6.2 dB
            Actual Delay:          8 ms              8 ms
          Transmit Power:        4.8 dBm          11.6 dBm
           Receive Power:       -5.0 dBm         -20.1 dBm
              Actual INP:        2.5 symbols       3.0 symbols
       Total Attenuation:        9.8 dB           31.7 dB
Attainable Net Data Rate:      0.476 Mbps       18.408 Mbps
============================================================================
      VDSL Band Status    U0      U1      U2      U3      D1      D2      D3
  Line Attenuation(dB):  9.8    68.5    66.8     N/A    31.7    90.3    102.3   
Signal Attenuation(dB):  9.8     N/A     N/A     N/A    31.7     N/A     N/A   
        SNR Margin(dB):  6.6     N/A     N/A     N/A     6.2     N/A     N/A   
   Transmit Power(dBm):  4.8     N/A     N/A     N/A    11.6     N/A     N/A   
============================================================================

            VDSL Counters

           Downstream        Upstream
Since Link time = 13 min 51 sec
FEC:      31168      77
CRC:      3      0
ES:      2      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Latest 15 minutes time = 11 min 28 sec
FEC:      24158      59
CRC:      3      0
ES:      2      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Previous 15 minutes time = 15 min 0 sec
FEC:      7010      18
CRC:      0      0
ES:      0      0
SES:      0      0
UAS:      756      756
LOS:      0      0
LOF:      0      0
LOM:      0      0
Latest 1 day time = 18 hours 56 min 28 sec
FEC:      31168      77
CRC:      3      0
ES:      2      0
SES:      0      0
UAS:      67355      67355
LOS:      0      0
LOF:      0      0
LOM:      0      0
Previous 1 day time = 24 hours 0 sec
FEC:      0      0
CRC:      0      0
ES:      0      0
SES:      0      0
UAS:      86401      86401
LOS:      0      0
LOF:      0      0
LOM:      0      0
Total time = 1 days 18 hours 56 min 28 sec
FEC:      35482      77
CRC:      694      4
ES:      13      3
SES:      10      0
UAS:      531824      531824
LOS:      10      0
LOF:      9      0
LOM:      0      0
============================================================================
3) I downloaded DSLstats and it is logging away.

How long to let it run before posting some data to the forum??


Thanks for any advise you can offer on (3)

[kitz]

The speed differences between the 2 routers could just be a time of day thing, especially if the difference isnt that much between them.  The router will always try to sync with a target SNRm of 6dB.
The line hasnt been up long enough yet to be able to tell anything much from your SNRm.  Your FECs seem to be racking up nicely though :/
Id suggest posting some DSLstats SNRm graphs this evening. Some time after 6-8pm will usually be when you start to see any swings, but just keep an eye open for any before.

Your upstream speed concerns me as it seems quite poor, but I suspect theres a reason for this, which would be seen by looking at the bitloading graph in DSLstats.

It looks like your line is only capable of using tones up to around 859.   In which case its not leaving many tones for your upstream bitload, normally after tone 880 this will be allocated to your upstream speed.  The fact that your U1 attenuation is at 68.5dB, means the signal isnt strong enough to be able to load any more upstream bits.

I still find it very strange that U1 has more attenuation than U2 - thats just not right somehow. 
Although I can say without doubt, that is what is keeping your upstream speed so low.... I dont know what could be causing it. :/

-----
As to tweaking upwards you will be guinea pig..  like I said Ive known people to try tweak down on FTTC in an attempt to get more speed,  Ive not heard of anyone wanting to tweak up. 
Tweaking down hasnt worked for anyone who has tried it as the BToR DLM still sticks to the target 6dB which is their minimum (unlike adsl2+ which is 3dB).    The fact that SNRm tweaking down has been unsuccessful on FTTC could be due to the fact that 6dB is as low as they will allow.. or it could be that it just isnt going to work at all.

[Bald_Eagle1]

As to tweaking upwards you will be guinea pig..  like I said Ive known people to try tweak down on FTTC in an attempt to get more speed,  Ive not heard of anyone wanting to tweak up. 
Tweaking down hasnt worked for anyone who has tried it as the BToR DLM still sticks to the target 6dB which is their minimum (unlike adsl2+ which is 3dB).    The fact that SNRm tweaking down has been unsuccessful on FTTC could be due to the fact that 6dB is as low as they will allow.. or it could be that it just isnt going to work at all.

Just to confirm, I attempted to tweak downward again early this morning, thinking/hoping the firmware/DSLAM band plan updates MIGHT have changed something that might allow it.

As always, the attempt caused a resync, but was unfortunately just as unsuccessful as previous attempts 

[Ixel]

As to tweaking upwards you will be guinea pig..  like I said Ive known people to try tweak down on FTTC in an attempt to get more speed,  Ive not heard of anyone wanting to tweak up. 
Tweaking down hasnt worked for anyone who has tried it as the BToR DLM still sticks to the target 6dB which is their minimum (unlike adsl2+ which is 3dB).    The fact that SNRm tweaking down has been unsuccessful on FTTC could be due to the fact that 6dB is as low as they will allow.. or it could be that it just isnt going to work at all.

Just to confirm, I attempted to tweak downward again early this morning, thinking/hoping the firmware/DSLAM band plan updates MIGHT have changed something that might allow it.

As always, the attempt caused a resync, but was unfortunately just as unsuccessful as previous attempts 

The only success I've had is banding the downstream and upstream rates on the Fritz!Box I had, tweaking SNR and INP values didn't seem to work. I'm guessing the DSLAM restricts changes to those parameters.

[Brian Coat]

Re: "How long to let it run before posting some data to the forum?"

I was asking the wrong question ... I should have been asking myself, "How long will it log before one of the kids turns off PC/changes network/other"

Mean Time to Kid-struction of the logging session is currently running at about 3 hours.

The d/s SNR margin seems to cycle between 8dB (daytime) and 5dB (evening).

That all seems pretty normal and stable to me, so I won't be doing any tweaking just yet.

The U1 attenuation seems poor and inconcistent with U0 and U2, as Kitz says.

Anyone have ideas on how to interrogate what is happening there?

Thanks for any insight you can provide.

[kitz]

Im not sure what could be causing it Im afraid :/   Just that something isnt quite right.  Perhaps someone else may have a suggestion.

The problem being that unless you can get bit loading in the US1 band, then you arent going to be able to get much more than 500kbps on your upstream 

[Brian Coat]

I have some stats now.
Not  sure how to arrange in a single png file so it will take 3 posts ... sorry.

[Brian Coat]

2nd lot

[attachment deleted by admin]

[Brian Coat]

3rd set of png's

[burakkucat]

A significant number of CRCs occurred at around 0742 hours, so much so that the modem dropped the VDSL2 connection and then resynchronised.

Something is decidedly odd with your connection . . . but I currently have no idea as to what might be the cause. 

[kitz]

hmmm   h-log is normal

QLN kind of sits with the SNR, both are a tad messy 
I don't see any specific tone(s) being targeted.  A long line such as yours would be expected to show some uneveness, particularly at the highest frequencies, but tones 150 to 350 seem a bit spikey compared to 400+.  Tones in the region of 100 seem a bit low too.

The 7.30ish drop is a bit interesting, it looked like things were on the up, then 'poof' the line went.   Is there anything on a timer or anything that could have been switched on at that time? 
Things get worse again at 5pm - tea time.

>> but I currently have no idea as to what might be the cause.

Ive no idea either atm..   I think it may be a good idea to keep monitoring and see if we can see any daily pattern emerging.
Theres obviously some sort of noise going on,  low level REIN/EMI?

[Brian Coat]

Morning,

Another set of logs.

D/S SNR gets ropey at night then improves dramatically at about 6 am each day.

Typical BTW test result is 14.5 Down 0.45 UP, IP Profile 14.9/2

[burakkucat]

I had to check back to see which class of connection your graphs relate . . . and see VDSL2. 

I would really like to see the SNRM graph for an entire 24 hour period. It does appear that your line suffers from a significant amount of RFI during the hours of darkness. 

[Brian Coat]

There is  one full 24 hr snr margin graph above.

Attempts to get another full one have been scuppered by the PC being turned off (see comments above re Kid-struction).

Thanks.

[burakkucat]

There is  one full 24 hr snr margin graph above.

Ah, yes. That is the graph showing a resynchronisation event, due to an excessive number of CRC errors being logged, at about 0742 hours.

Still puzzled.