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[LaurieR]

Does anyone have slower FTTC upstream than me?

Max:   Upstream rate = 708 Kbps, Downstream rate = 25236 Kbps
Bearer:   0, Upstream rate = 742 Kbps, Downstream rate = 25814 Kbps
Bearer:   1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Link Power State:   L0
Mode:         VDSL2 Annex B
VDSL2 Profile:      Profile 17a
TPS-TC:         PTM Mode(0x0)
Trellis:      U:ON /D:ON
Line Status:      No Defect
Training Status:   Showtime
      Down      Up
SNR (dB):    6.3       5.2

(I'm "kempshott" on mydslwebstats)

[simmotech]

Plusnet have now reset their WP Profile and I now get 59.2 DL (previous highest was 52.4) 
So overall I lost 6 on the UL and gained 6 on the DL.

Last question....

Below are my pbStats. U1 shows a 'low' TX power (I think) and I was wondering if there a tweak on the modem I could try to increase that?

     VDSL Port Details        Upstream        Downstream
Attainable Net Data Rate:       14715 kbps          62784 kbps
Actual Aggregate Tx Power:          7.1 dBm           13.6 dBm
====================================================================================
  VDSL Band Status   U0   U1   U2   U3   U4   D1   D2   D3
  Line Attenuation(dB):   3.9   22.3   34.4   N/A   N/A   11.7   28.2   43.9
Signal Attenuation(dB):   3.9   21.3   33.3   N/A   N/A   15.2   28.0   43.8
        SNR Margin(dB):   6.2   6.1   6.1   N/A   N/A   6.4   6.4   6.3
         TX Power(dBm):   -2.0   -20.9   6.4   N/A   N/A   10.8   7.8   7.1
#

[roseway]

No, you can't tweak the transmitted power levels. These are controlled by a power spectrum mask (PSD) which is applied to try to minimise interference with other systems.

[WWWombat]

More than that, upstream power goes through a back off process, to allow distant modems a fair chance. Essentially, this stops nearby modems from shouting over the distant ones, and causing crosstalk.

For similar reasons, nearby modems attempt to put higher bit-loading in the higher frequencies than the lower ones. This allows lower power, lower crosstalk, and attempts to give a fairer chance to distant modems to use the lower spectrum.

This kind of equitable use of spectrum is another kind of dynamic line management, except it takes into account multiple lines. I wonder if a DLM-like process has been at work here, and dropped your power (and therefore SNRM and sync speed) as a consequence?

[WWWombat]

Incidentally, my current pbstats, on a 100m line, look like this:

Code: [Select]

Max:    Upstream rate = 32774 Kbps, Downstream rate = 106553 Kbps
Bearer: 0, Upstream rate = 19999 Kbps, Downstream rate = 79999 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps

                  VDSL Port Details               Upstream                Downstream
Attainable Net Data Rate:           32774 kbps             106553 kbps
Actual Aggregate Tx Power:         -   7.3 dBm               13.1 dBm
====================================================================================
  VDSL Band Status U0 U1 U2 U3 U4 D1 D2 D3
  Line Attenuation(dB): 1.9 8.7 11.5 N/A N/A 4.7 10.9 17.4
Signal Attenuation(dB): 1.9 7.8 10.3 N/A N/A 6.3 10.8 17.4
        SNR Margin(dB): 15.3 15.2 15.2 N/A N/A 12.5 12.4 12.5
         TX Power(dBm): -21.6 -35.1 -7.6 N/A N/A 9.7 8.0 6.9
The upstream TX power is an awful lot lower. Bit loading levels are 3x higher in U2 than in U1 (at 6-7 bits vs 2-3 bits)

I looked back at an old line that was just under 400m, which looked like this:

Code: [Select]

Max: Upstream rate = 22994 Kbps, Downstream rate = 79732 Kbps
Bearer: 0, Upstream rate = 19999 Kbps, Downstream rate = 79509 Kbps

  VDSL Port Details   Upstream   Downstream
Attainable Net Data Rate:     22994 kbps     79732 kbps
Actual Aggregate Tx Power:        7.1 dBm      13.0 dBm
====================================================================================
  VDSL Band Status U0 U1 U2 U3 U4 D1 D2 D3
  Line Attenuation(dB): 4.4 22.6 34.0   N/A   N/A 11.7 28.4 43.5
Signal Attenuation(dB): 4.4 21.3 32.6   N/A   N/A 16.4 28.2 43.4
SNR Margin(dB): 7.3 7.3 7.3   N/A   N/A 6.3 6.3 6.3
TX Power(dBm): -1.6 -20.6 6.4   N/A   N/A 9.6 7.8 7.0

Isn't it amazing how alike the attenuation values are compared to your line? Yet very different speeds.

The difference would have to be explained by the intrinsic noise level the line encountered. I've attached the QLN graph that the old line was working within.

[simmotech]

So with the new Huawai modem plus download G.INP plus the removal of the old PlusNet capped profile, I have now gained 12Mbs on the download. 
And both download and upload seemed to have crept up a bit by themselves over the last week (63.6 -> 64.6; 14.5 -> 14.8)
Thanks for all your help in this thread and putting up with my daft questions.

Code: [Select]

DSLAM/MSAN type:        BDCM:0xa41b / v0xa41b
Modem/router firmware:  AnnexA version - A2pv6C038m.d24j
DSL mode:                VDSL2 Profile 17a
Status:                  Showtime
Uptime:                  4 days 21 hours 35 min 45 sec
Resyncs:                0 (since 01 Sep 2015 07:51:14)

Downstream Upstream
Line attenuation (dB):  16.8 0.0
Signal attenuation (dB): Not available on VDSL2
Connection speed (kbps): 64681 14799
SNR margin (dB):        5.9 6.0
Power (dBm):            13.6 7.0
Interleave depth:        8 1
INP:                    48.00 0
G.INP:                  Enabled
I'm still a bit confused about how connection/sync speed is calculated (just for the upload which I believe is on FastPath now because of the DLM reset).
Is it the case that when the modem is powered on it does a bit of 'tooing and froing' and works out the best speed at that point in time?

If so, does the lack of G.INP and/or interleaving or other error correction currently on the upload side mean that if or when they get switched on by the DLM (I have a 566 ES per day on the upload due to CRCs) that the upload could go back to what it was because during the 'tooing and froing' the errors were reduced producing a more stable line?

[simmotech]

For several weeks, my SNR Margins have been around 5.7 and everything has been stable.

At 1:30am today, the DSLstats chart showed a resync occurred (u/l went to 0 but d/l went to 6.1 briefly). I now have SNR Margins for d/l at 4.8 and u/l at 1.2

My download speed is the same but upload has shot back up to where it was when I started this ticket! A speedtest shows 17.3Mbps where I was getting 12.1 prior to the resync.

Max:   Upstream rate = 22568 Kbps, Downstream rate = 67096 Kbps
Bearer:   0, Upstream rate = 19999 Kbps, Downstream rate = 67908 Kbps
Bearer:   1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps

How long do you think I have before the low SNRMargins causes another resync?
(I'd actually be happy to leave it like this)

Also, SpeedTest to Leicester always shows a 1ms ping whereas all other destinations are ~13ms. Is a 1ms ping really possible?