Kitz Forum

Broadband Related => FTTC and FTTP Issues => Topic started by: HitmanAlex on August 24, 2021, 11:49:09 AM

Title: FTTC - Interleaved again!
Post by: HitmanAlex on August 24, 2021, 11:49:09 AM
Hi All,

I was wondering if anyone could let me know if these graphs are showing any reason to why I have been interleaved?

I've had many Openreach engineers out and the last one performed a ton of tests and one which was in red and required a visit to the ECI Cab and then to the exchange to change out some cables I believe.

ISP: Sky FTTC Super Fast

Max Speed - 52Mb/s download / 17.5Mb/s upload

Router: Zyxel (VMG8924-B10A) - This router was a preferred choice for ECI Cab's

Custom Firmware: johnson custom firmware (running v2 dsl which also supports retransmission)

MTU 1500 (believe this is also due to baby jumbo frames)

CAB: ECI - No Retransmission / G.inp

(https://i.imgur.com/TwXxDWg.png)

(https://i.imgur.com/jr76jsY.png)

(https://i.imgur.com/qgjtMma.png)

(https://i.imgur.com/PQBHPrl.png)

(https://i.imgur.com/Wkm6M9p.png)

(https://i.imgur.com/YsNTItg.png)

(https://i.imgur.com/DUuiJXH.png)

(https://i.imgur.com/teTXMI8.png)

               
====================================================================================
    VDSL Training Status:   Showtime
                    Mode:   VDSL2 Annex B
            VDSL Profile:   Profile 17a
                G.Vector:   Disable
            Traffic Type:   PTM Mode
             Link Uptime:   1 day: 2 hours: 18 minutes
====================================================================================
       VDSL Port Details       Upstream         Downstream
               Line Rate:     17.518 Mbps       49.959 Mbps
    Actual Net Data Rate:     17.495 Mbps       49.869 Mbps
          Trellis Coding:         ON                ON
              SNR Margin:        6.0 dB            6.1 dB
            Actual Delay:          0 ms              8 ms
          Transmit Power:        6.8 dBm           6.9 dBm
           Receive Power:       -7.0 dBm          -8.9 dBm
              Actual INP:        0.0 symbols       3.0 symbols
       Total Attenuation:        0.0 dB          20.3 dB
Attainable Net Data Rate:     17.570 Mbps       58.511 Mbps
====================================================================================
  VDSL Band Status        U0      U1      U2      U3      U4      D1      D2      D3
  Line Attenuation(dB):    2.7    27.9    43.5     N/A     N/A    14.9    35.6    55.9   
Signal Attenuation(dB):    2.6    27.7    43.4     N/A     N/A    19.5    35.4    55.9   
        SNR Margin(dB):    6.4    6.1    6.0     N/A     N/A    6.1    6.0    6.1   
         TX Power(dBm):   -4.5   -14.7    6.5     N/A     N/A    10.5    7.2    7.4   
====================================================================================

            VDSL Counters

           Downstream        Upstream
Since Link time = 18 min 41 sec
FEC:      84590      19
CRC:      36      0
ES:      12      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Latest 15 minutes time = 4 min 13 sec
FEC:      0      0
CRC:      0      0
ES:      0      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:      6521      0
CRC:      8      0
ES:      2      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Latest 1 day time = 2 hours 19 min 13 sec
FEC:      23674      0
CRC:      24      0
ES:      7      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Previous 1 day time = 24 hours 0 sec
FEC:      60916      19
CRC:      12      0
ES:      5      0
SES:      0      0
UAS:      30      30
LOS:      0      0
LOF:      0      0
LOM:      0      0
Total time = 1 days 2 hours 19 min 13 sec
FEC:      84590      19
CRC:      36      0
ES:      12      0
SES:      0      0
UAS:      30      30
LOS:      0      0
LOF:      0      0
LOM:      0      0
====================================================================================

Thank you for all your input :)

Updated: I've also attached vmgGraph's data, The night before I did a download of 27GB's. 23/08/2021.

https://drive.google.com/file/d/12t11y9rVx4EiGrffVZUtx-3P09g4CA-u/view?usp=sharing
Title: Re: FTTC - Interleaved again!
Post by: burakkucat on August 24, 2021, 03:22:27 PM
Welcome to the kitz forum.  :)

I was wondering if anyone could let me know if these graphs are showing any reason to why I have been interleaved?


I cannot see any obvious reason for the circuit to be operating in interleaved mode. What convinces you that it is operating as such?
Title: Re: FTTC - Interleaved again!
Post by: j0hn on August 24, 2021, 03:49:03 PM
I cannot see any obvious reason for the circuit to be operating in interleaved mode. What convinces you that it is operating as such?

Quote
Actual Delay:          0 ms              8 ms
Actual INP:        0.0 symbols       3.0 symbols

As for why it's interleaved, no idea.
Title: Re: FTTC - Interleaved again!
Post by: Ixel on August 24, 2021, 04:07:27 PM
I'm equally puzzled as to why it has become interleaved. I can't see any clear indications as to the cause from the data you've shared. Perhaps your line has had a DLM reset or has been taken off of the G.INP trial? My only guesses.
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on August 24, 2021, 05:49:21 PM
I'm equally puzzled as to why it has become interleaved. I can't see any clear indications as to the cause from the data you've shared. Perhaps your line has had a DLM reset or has been taken off of the G.INP trial? My only guesses.

Was never apart of the trial:(, I even asked Sky to put me on the list but it seems only plusnet has interaction with its users for this about (10 or so people got it).

Welcome to the kitz forum.  :)

I cannot see any obvious reason for the circuit to be operating in interleaved mode. What convinces you that it is operating as such?

As J0hn has rightfully pointed out 8ms delay increase.

I'm am no expert in this area and i've learned it all from kitz forums and internet, however for me the graphs don't make much sense to me i don't know what's good or what's bad unless i've seen it before :S.
Title: Re: FTTC - Interleaved again!
Post by: Alex Atkin UK on August 24, 2021, 11:14:13 PM
You'd likely need to see the stats/graphs BEFORE it was interleaved, to get some idea of what might have triggered it.
Title: Re: FTTC - Interleaved again!
Post by: Chrysalis on August 25, 2021, 12:11:22 AM
Alex beat me to it.

What "probably" happened is a burst of errors in the day leading up to the DLM action.

If we can see the 24-48h period before you became interleaved, we will probably find the reason.
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on August 25, 2021, 10:13:03 AM
You'd likely need to see the stats/graphs BEFORE it was interleaved, to get some idea of what might have triggered it.

Alex beat me to it.

What "probably" happened is a burst of errors in the day leading up to the DLM action.

If we can see the 24-48h period before you became interleaved, we will probably find the reason.

Thank you both for your input! I can say that after looking at the graphs in the morning i could see a huge amount of CRC errors that night. I'm afraid due to not saving the data and rebooting the router I don't have that data to provide but it was by no means a large amount of errors.

I assume now  it will be several days / weeks before potentially i come out of interleaving again, I seriously cannot be bothered anymore with getting OR engineers out through Sky as majority of them do not care (well the ones i had don't) I even have to tell them to reset if i've been hard capped because they would prefer you to wait several years for DLM to reset and retune/retrain.

Apparently Fibre is being worked on in my area as per Openreach website, however the message below is pretty much "Yeah but when" along with expected to be completed by 2026.

(https://i.imgur.com/Bxlptig.png)

I don't see much activity on one.network site for Telephone works, However about a month ago there was the big open reach vans and it looked like they was planning deployment.
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on August 25, 2021, 10:17:17 AM
Today's Main Stats Snippet

(https://i.imgur.com/rVqDpoD.png)
Title: Re: FTTC - Interleaved again!
Post by: Chrysalis on August 26, 2021, 05:36:12 AM
Its just a waiting game might be a few days, might be a few weeks, and engineers may put you down as no fault if the line is performing within spec.   So not advisable to book one just for been interleaved.

A few people have had success of a quicker recovery by capping the line rate.
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on August 26, 2021, 10:11:26 AM
Its just a waiting game might be a few days, might be a few weeks, and engineers may put you down as no fault if the line is performing within spec.   So not advisable to book one just for been interleaved.

A few people have had success of a quicker recovery by capping the line rate.

Thanks for the reply Chrysalis,

Given the below I should be well in the green to not be kept on interleaved?

(https://i.imgur.com/kHBeosP.png)
Title: Re: FTTC - Interleaved again!
Post by: j0hn on August 26, 2021, 11:13:46 AM
Being "in the green" isn't usually enough to have Interleaving removed.

On the "Speed" DLM profile anything under 288 ES per 24 hours is meant to be ILQ green.
However I've never seen Interleaving removed on a line with roughly 100 ES per day.

In my experience a line needs to be much nearer single digit ES per day for Interleaving to be removed.

As Chrysalis mentions above, capping the downstream sync rate can lower the ES numbers which can speed up Interleaving being removed.
On some lines a cap is necessary as without it the line will be stuck interleaved.

At your current ES rate (around 15 ES per 24 hours) I would expect the line to return to fastpath.
How long it takes depends on the lines history.
It's usually 2, 4, 8 or 11 days.
If you're still interleaved after 11 days then you will need to cap the sync rate.
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on August 29, 2021, 01:35:08 PM
Thanks for that info j0hn :)

This is some odd stuff i've seen here and there note that i am on a ECI Cab with no g.inp.

So i should be getting 6db snr margin for both Upload and Download however upload is going as low as 4.9?

(https://i.imgur.com/wzNBaHv.png)

(https://i.imgur.com/whBsFj2.png)
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on August 29, 2021, 05:20:25 PM
               
====================================================================================
    VDSL Training Status:   Showtime
                    Mode:   VDSL2 Annex B
            VDSL Profile:   Profile 17a
                G.Vector:   Disable
            Traffic Type:   PTM Mode
             Link Uptime:   5 days: 5 hours: 3 minutes
====================================================================================
       VDSL Port Details       Upstream         Downstream
               Line Rate:     17.697 Mbps       49.985 Mbps
    Actual Net Data Rate:     17.674 Mbps       49.895 Mbps
          Trellis Coding:         ON                ON
              SNR Margin:        4.9 dB            6.0 dB
            Actual Delay:          0 ms              8 ms
          Transmit Power:        6.8 dBm           6.9 dBm
           Receive Power:       -7.2 dBm          -8.8 dBm
              Actual INP:        0.0 symbols       3.0 symbols
       Total Attenuation:        0.0 dB          20.3 dB
Attainable Net Data Rate:     16.373 Mbps       58.564 Mbps
====================================================================================
  VDSL Band Status        U0      U1      U2      U3      U4      D1      D2      D3
  Line Attenuation(dB):    2.7    27.9    43.5     N/A     N/A    14.9    35.6    55.9   
Signal Attenuation(dB):    2.6    27.8    43.4     N/A     N/A    19.4    35.3    55.9   
        SNR Margin(dB):    5.4    5.0    4.9     N/A     N/A    5.9    6.0    6.1   
         TX Power(dBm):   -4.7   -14.7    6.5     N/A     N/A    10.5    7.2    7.4   
====================================================================================
Title: Re: FTTC - Interleaved again!
Post by: g3uiss on August 29, 2021, 05:32:40 PM
The SNRM will always fluctuate. On ECI the median SNRM is 6.3. My goes down to 4 on occasions. By definition itís not fixed
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on August 31, 2021, 10:39:52 AM
The SNRM will always fluctuate. On ECI the median SNRM is 6.3. My goes down to 4 on occasions. By definition itís not fixed

All I can say is it hate FTTC!

Todays stats - Seem to be way below the max ES Count p/day?

(https://i.imgur.com/Pcutdvf.png)
Title: Re: FTTC - Interleaved again!
Post by: j0hn on August 31, 2021, 10:52:05 AM
Seem to be way below the max ES Count p/day?

Based on what?

As mentioned above the ILQ green figures on kitz wiki pages are no longer accurate.
You need to be considerably below the figures quoted there.

It is possible that you will have to cap your downstream sync rate to lower the ES/FEC numbers enough for Interleaving to drop.

If it's still interleaved after 8 days then a cap of 40Mb for a few days should work.
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on August 31, 2021, 12:34:53 PM
Based on what?

As mentioned above the ILQ green figures on kitz wiki pages are no longer accurate.
You need to be considerably below the figures quoted there.

It is possible that you will have to cap your downstream sync rate to lower the ES/FEC numbers enough for Interleaving to drop.

If it's still interleaved after 8 days then a cap of 40Mb for a few days should work.

Hi j0hn,

Do you know how to cap based on router?
Title: Re: FTTC - Interleaved again!
Post by: j0hn on August 31, 2021, 02:17:26 PM
It will be either...

Code: [Select]
xdslcmd configure --maxDataRate 40000 20000 100000

Or

Code: [Select]
xdslctl configure --maxDataRate 40000 20000 100000

I can't remember if the zyxel uses xdslcmd or xdslctl.

That will set a cap of 40 down / 20 up / 100 combined (up and down).
Effectively it's a cap of 40Mb on the downstream only.

That's usually enough to shake sticky Interleaving. My line would never drop Interleaving without a cap despite being well below the assumed ES limits and that was years ago. The thresholds appear to be even stricter now than they did then.
Title: Re: FTTC - Interleaved again!
Post by: tiffy on August 31, 2021, 04:21:16 PM
Quote
I can't remember if the zyxel uses xdslcmd or xdslctl.

For my ZyXEL VMG1312-B10A it's:
adsl configure --maxDataRate ***** **** 100000
DS desired rate followed by US desired rate (or max.) in Kbps as j0hn has said.

In my case entered from command line after logging into modem via Telnet, Win 10 OS.
I believe application of a modem cap instigates a re-synch, have never tried.
The cap won't survive a modem re-boot, if still required will have to be re-applied.
Title: Re: FTTC - Interleaved again!
Post by: g3uiss on August 31, 2021, 04:39:13 PM
It does definitely cause a resync and as @tiffy remarks it will not survive a reboot.

After applying you need to forget it for a week or so.
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on September 03, 2021, 10:07:14 AM
Morning All,

So interleaving has now gone! However I fear it will be back shortly ES at 90! for 8 hours..

(https://i.imgur.com/7bKiDOm.png)

Should I see if interleaving get's reapplied and if so put downstream limits via router?
Title: Re: FTTC - Interleaved again!
Post by: tiffy on September 03, 2021, 10:27:36 AM
Just to clarify, did you actually apply a DS modem speed clamp or was interleaving removed by normal DLM action without clamping?
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on September 03, 2021, 10:35:35 AM
Just to clarify, did you actually apply a DS modem speed clamp or was interleaving removed by normal DLM action without clamping?

Hi tiffy,

No modem speed clamp was put on, interleaving was removed by normal DLM action without clamping :).
Title: Re: FTTC - Interleaved again!
Post by: g3uiss on September 03, 2021, 01:09:02 PM
90 in 8 hrs should be fine if your on a speed profile
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on September 03, 2021, 09:34:08 PM
90 in 8 hrs should be fine if your on a speed profile


Hi g3uiss, think its more then that

(https://i.imgur.com/EH0tlum.png)
Title: Re: FTTC - Interleaved again!
Post by: g3uiss on September 03, 2021, 09:51:52 PM
Thatís CRC nor ES ?
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on September 03, 2021, 11:02:40 PM
Thatís CRC nor ES ?

Well ES has risen from 90 from original screenshot to looking around 300 or so a day.
Title: Re: FTTC - Interleaved again!
Post by: g3uiss on September 04, 2021, 07:51:01 AM
I wouldnít be concerned at 300 the original limit was 2880 that @kitz published although itís considered to be less now before DLM acts on speed profile. But its well over that. I have around 500/day on both lines that remain on fast path.
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on September 05, 2021, 03:48:26 AM
I wouldnít be concerned at 300 the original limit was 2880 that @kitz published although itís considered to be less now before DLM acts on speed profile. But its well over that. I have around 500/day on both lines that remain on fast path.

ECI Cab as well then?

Latest stats below

(https://i.imgur.com/kNhtSfX.png)
Title: Re: FTTC - Interleaved again!
Post by: g3uiss on September 05, 2021, 09:17:58 AM
Yes ECI. CRC normally higher than ES you show CRC. On my circuit 24hrs. CRC 561 ES 129.
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on September 05, 2021, 04:10:55 PM
Yes ECI. CRC normally higher than ES you show CRC. On my circuit 24hrs. CRC 561 ES 129.

I believe DSLAM will react to it in 7 days or less if its too high?

(https://i.imgur.com/J0VhDd1.png)
Title: Re: FTTC - Interleaved again!
Post by: g3uiss on September 05, 2021, 04:39:27 PM
No thatís not right. The DSLAM isnít the issue itís the DLM and it acts in 24hrs but NOT on those figures! And you keep quoting CRC Not ES.

And in any event you canít stop it !

Read here.
https://kitz.co.uk/adsl/DLM_system.htm

But the 2880 ES fig is lower now but we donít know by how much.
Title: Re: FTTC - Interleaved again!
Post by: j0hn on September 06, 2021, 03:10:08 PM
And you keep quoting CRC Not ES.

Every image he's posted has both CRC & ES.
If viewing on a smaller screen you need to scroll to the right of the images to see the ES figures.

I believe DSLAM will react to it in 7 days or less if its too high?

The DLM will apply Interleaving within 24 hours of breaking the ES threshold.

We have no idea what the limits are now but to my eye you have nothing to worry about at the moment.
Title: Re: FTTC - Interleaved again!
Post by: g3uiss on September 06, 2021, 05:42:03 PM
Oh thanks @j0hn and the ES seem quite ok to me also to retain fastpath
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on September 07, 2021, 03:28:11 AM
Sorry if it's not as visible, here's txt at this current time  :).

Not change to interleaving so far so it might be within the okay, i normally see it go wrong with 3 or 4 days of a reset but this was done by itself no engineer needed to bring it back off interleaving.


Sync
52541 Kbps

17954 Kbps

Attainable
52541 Kbps

17980 Kbps

SNR
5.8 dB

6.0 dB

Attenuation
20.2 dB

0.0 dB

CRC
3647

3

ES
1477

2

SES
0

0

FEC
0

1191
Title: Re: FTTC - Interleaved again!
Post by: g3uiss on September 09, 2021, 11:03:21 PM
I donít think there is anything to concern you !
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on November 03, 2021, 04:56:58 PM
Well I was not interleaved for a long time, now for a few days i'm back on the god awful 8ms increase.

7 Days shows I had a LOF's and LOS.

xdslctl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason:   1
Last initialization procedure status:   0
Max:   Upstream rate = 17900 Kbps, Downstream rate = 59469 Kbps
Bearer:   0, Upstream rate = 17764 Kbps, Downstream rate = 50282 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):    5.9       6.0
Attn(dB):    20.2       0.0
Pwr(dBm):    6.9       6.8

         VDSL2 framing
         Bearer 0
MSGc:      18      14
B:      51      238
M:      1      1
T:      64      16
R:      12      16
S:      0.0329      0.4283
L:      15560      4763
D:      985      1
I:      64      255
N:      64      255

         Counters
         Bearer 0
OHF:      139438805      1411142
OHFErr:      192      0
RS:      1336475805      821508
RSCorr:      564189      616
RSUnCorr:   6988      0

         Bearer 0
HEC:      1312      0
OCD:      0      0
LCD:      0      0
Total Cells:   2735774617      0
Data Cells:   3621606102      0
Drop Cells:   0
Bit Errors:   0      0

ES:      1863      0
SES:      192      0
UAS:      480      469
AS:      294881

         Bearer 0
INP:      3.00      0.00
INPRein:   0.00      0.00
delay:      8      0
PER:      2.11      6.87
OR:      90.81      23.25
AgR:      50373.22   17787.09

Bitswap:   30564/30583      1461/1468

Total time = 7 days 4 hours 27 min 2 sec
FEC:      564189      616
CRC:      192      0
ES:      1863      0
SES:      192      0
UAS:      480      469
LOS:      1      0
LOF:      6      0
LOM:      0      0
Title: Re: FTTC - Interleaved again!
Post by: g3uiss on November 03, 2021, 04:59:29 PM
Those errors are the result of the resync. Given your speed how is the interleave affecting your use of the circuit I wonder ?
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on November 07, 2021, 09:41:20 PM
Hi g3uiss,

The line can run on no interleave something just keeps triggering it. Last time they had to go to the exchange and cabinet as they noticed a feedback or something like this?
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on November 19, 2021, 06:43:47 PM
Hi Guys,

Can anyone make out the below? Interleaving normally shows increased bandwidth capacity but of course this is just a false display due to interleaving being applied at 8ms.

However today it's now changed from standard 6 SNR to 7.5 SNR and a higher attainable again?

Normally increased SNR results lower bandwidth so i don't understand how it's gone from 59Mbps to now 64Mbps?

====================================================================================
    VDSL Training Status:   Showtime
                    Mode:   VDSL2 Annex B
            VDSL Profile:   Profile 17a
                G.Vector:   Disable
            Traffic Type:   PTM Mode
             Link Uptime:   8 days: 18 hours: 1 minute
====================================================================================
       VDSL Port Details       Upstream         Downstream
               Line Rate:     17.951 Mbps       50.010 Mbps
    Actual Net Data Rate:     17.928 Mbps       49.920 Mbps
          Trellis Coding:         ON                ON
              SNR Margin:        6.7 dB            7.6 dB
            Actual Delay:          0 ms              8 ms
          Transmit Power:        6.8 dBm           6.9 dBm
           Receive Power:       -6.9 dBm          -8.6 dBm
              Actual INP:        0.0 symbols       3.0 symbols
       Total Attenuation:        0.0 dB          20.1 dB
Attainable Net Data Rate:     19.063 Mbps       64.499 Mbps
====================================================================================
  VDSL Band Status        U0      U1      U2      U3      U4      D1      D2      D3
  Line Attenuation(dB):    2.6    27.3    42.2     N/A     N/A    14.7    34.8    54.2   
Signal Attenuation(dB):    2.5    27.1    42.1     N/A     N/A    19.2    34.5    54.2   
        SNR Margin(dB):    6.5    6.7    6.7     N/A     N/A    7.6    7.6    7.6   
         TX Power(dBm):   -4.5   -15.3    6.4     N/A     N/A    10.5    7.2    7.4   
====================================================================================

            VDSL Counters

           Downstream        Upstream
Since Link time = 1 min 51 sec
FEC:      1417105      755
CRC:      530      4
ES:      146      4
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Latest 15 minutes time = 2 min 22 sec
FEC:      0      0
CRC:      0      0
ES:      0      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:      7695      0
CRC:      0      0
ES:      0      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Latest 1 day time = 18 hours 2 min 22 sec
FEC:      88595      9
CRC:      31      0
ES:      9      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Previous 1 day time = 24 hours 0 sec
FEC:      90366      14
CRC:      13      1
ES:      5      1
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Total time = 1 days 18 hours 2 min 22 sec
FEC:      1417105      755
CRC:      530      4
ES:      146      4
SES:      0      0
UAS:      30      30
LOS:      0      0
LOF:      0      0
LOM:      0      0
====================================================================================
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on November 19, 2021, 06:46:12 PM
To add to this i've just noticed INP showing enabled?

Actual INP:        0.0 symbols       3.0 symbols

This is new considering the cabinet is ECI and not many if any have ECI enabled due to issues.
Title: Re: FTTC - Interleaved again!
Post by: j0hn on November 19, 2021, 07:00:56 PM
INP is always enabled with Interleaving on Openreach VDSL2. It's usually 3 or 3.5 with 8ms delay.

It's G.INP that has issues with ECI cabinets.

If your attainable has increased and the SNRM has gone up then it's likely a crosstalker has gone offline. That looks like the impact of an individual line.
A neighbour on the cabinet has turned their modem off, gone on holiday or cancelled their broadband.

If you resync it will be slightly higher sync and the SNRM will return to normal.
However if the crosstalker comes back your SNRM would drop a similar amount.
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on November 20, 2021, 10:42:50 AM
Hi John,

Thank you for the response i think i might be getting mixed up with SNR and SNRM.

I know that Openreach are working on the back bone infrastructure for Fibre roll out in my area as it states on their site that its coming to my area (FTTP). I assume as per any other backbone network provider that they pull the fibre through the backbone infrastructure e.g. main roads ducts etc before they start hitting the residential areas.

Based on the stats you see, do you think it qualifies the reason to why i have been interleaved? It was flawless for over a month after open reach engineer did several tests and needed to go back to the exchange and cabinet to swap out some cables due to feedback on the line think it was Ohms or something?

Title: Re: FTTC - Interleaved again!
Post by: burakkucat on November 20, 2021, 04:02:37 PM
It was flawless for over a month after open reach engineer did several tests and needed to go back to the exchange and cabinet to swap out some cables due to feedback on the line think it was Ohms or something?

I suspect it would have been the AC balance of the pair.
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on November 20, 2021, 07:51:03 PM
I suspect it would have been the AC balance of the pair.

Yeah which seemed to have stopped interleaving, Line was stable etc. I can only assume that its gone to fault again or maybe something new?
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on November 27, 2021, 03:07:58 PM
So i have changed my MTU from 1500 (SKY FTTC) to 1492.

I am now no longer interleaved not sure if this was just luck?

 VDSL Port Details       Upstream         Downstream
               Line Rate:     19.090 Mbps       52.466 Mbps
    Actual Net Data Rate:     19.066 Mbps       52.381 Mbps
          Trellis Coding:         ON                ON
              SNR Margin:        6.2 dB            7.8 dB
            Actual Delay:          0 ms              0 ms
          Transmit Power:        6.8 dBm           6.9 dBm
           Receive Power:       -6.9 dBm          -8.4 dBm
              Actual INP:        0.0 symbols       0.0 symbols
       Total Attenuation:        0.0 dB          20.0 dB
Attainable Net Data Rate:     19.403 Mbps       57.804 Mbps


Interestingly Attainable is higher even without interleave? Also my SNR Margin is 7.8 when normally 6.

Anyone have an idea? I know there was mention of a crosstalker potentially no longer being in play here?
Title: Re: FTTC - Interleaved again!
Post by: j0hn on November 27, 2021, 04:45:46 PM
So i have changed my MTU from 1500 (SKY FTTC) to 1492.

Definitely unrelated.

Also 1500 was the correct MTU for Sky
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on November 27, 2021, 06:06:41 PM
Hi John,

Should i change the MTU back to 1500? Or should i avoid a resync?

Strange numbers showing considering i thought higher SNR mean's lower Downstream sync rate?
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on November 27, 2021, 06:13:09 PM
MTU back to 1500 and resync

   VDSL Port Details       Upstream         Downstream
               Line Rate:     19.213 Mbps       58.140 Mbps
    Actual Net Data Rate:     19.189 Mbps       58.046 Mbps
          Trellis Coding:         ON                ON
              SNR Margin:        6.0 dB            6.2 dB
            Actual Delay:          0 ms              0 ms
          Transmit Power:        6.8 dBm           6.9 dBm
           Receive Power:       -7.0 dBm          -8.2 dBm
              Actual INP:        0.0 symbols       0.0 symbols
       Total Attenuation:        0.0 dB          20.0 dB
Attainable Net Data Rate:     19.186 Mbps       58.074 Mbps

Oddly tho i am unable to utilize past 50Mbps on either fast.com or speedtest.net.

Title: Re: FTTC - Interleaved again!
Post by: g3uiss on November 27, 2021, 06:14:34 PM
Earlier in the thread the SNRM was explained. Itís not quite as you state, the slightly higher SNRM, is likely the line synced at a lower figure than the max hence the SNRM Is VERY slightly higher. I would really leave it alone unless itís stopping you using the service.
Title: Re: FTTC - Interleaved again!
Post by: g3uiss on November 27, 2021, 06:15:36 PM
Definitely leave it now, thatís as good as itís going to get ,
Title: Re: FTTC - Interleaved again!
Post by: Chrysalis on November 27, 2021, 06:21:17 PM
Note if you separate the router from the modem, changing PPP parameters(such as MTU) doesnt cause a resync, and wont even on "some" modems used as a router.
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on November 27, 2021, 07:42:32 PM
Earlier in the thread the SNRM was explained. Itís not quite as you state, the slightly higher SNRM, is likely the line synced at a lower figure than the max hence the SNRM Is VERY slightly higher. I would really leave it alone unless itís stopping you using the service.

Thanks g3uiss i'll leave as is now as per my latest post. Hopefully it stays stable.

Note if you separate the router from the modem, changing PPP parameters(such as MTU) doesnt cause a resync, and wont even on "some" modems used as a router.

Yeah I noticed this and did a xdslctl connection --down and then --up to resync.

Interleaving is now gone however I'm surprised i cannot reach the 58Mbps? It's as if its wrongly providing 58Mbps hiding the true value.

Title: Re: FTTC - Interleaved again!
Post by: Chrysalis on November 27, 2021, 07:53:18 PM
Thanks g3uiss i'll leave as is now as per my latest post. Hopefully it stays stable.

Yeah I noticed this and did a xdslctl connection --down and then --up to resync.

Interleaving is now gone however I'm surprised i cannot reach the 58Mbps? It's as if its wrongly providing 58Mbps hiding the true value.



Ok I worded it wrong, you dont need to resync to apply new MTU settings, so if you manually did it, no need to do it again if you adjust the MTU.
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on November 30, 2021, 08:19:33 PM
Hi Guys,

Thoughts? It seems likely i will be put back onto interleaving?

(https://i.imgur.com/OuDZjY3.png)
Title: Re: FTTC - Interleaved again!
Post by: j0hn on November 30, 2021, 08:29:29 PM
It's certainly possible.

You could try capping the sync speed a little. It lowers the number of ES a line gets. The lower you cap it, the lower the ES.

A good balance would be capping the line roughly at the speed the line syncs at when interleaved.
That maintains the low latency with the same sync speed you would get when interleaved.

Capping my line was the only way to maintain fastpath.

See this thread for more info (https://forum.kitz.co.uk/index.php/topic,16427.0.html)
Title: Re: FTTC - Interleaved again!
Post by: neil on December 01, 2021, 03:12:36 AM
I suspect it would have been the AC balance of the pair.

what is that?
Title: Re: FTTC - Interleaved again!
Post by: tubaman on December 01, 2021, 08:44:32 AM
If you do get interleaved again does an 8ms delay really make that much of a difference to how you use the connection as I'm not sure I'd even notice it?
 :)
Title: Re: FTTC - Interleaved again!
Post by: g3uiss on December 01, 2021, 12:26:26 PM
I made the comment about the interleave delay earlier in the post. It rarely causes any issues, as it actually fixes them !
Title: Re: FTTC - Interleaved again!
Post by: Alex Atkin UK on December 07, 2021, 12:18:06 PM
If you do get interleaved again does an 8ms delay really make that much of a difference to how you use the connection as I'm not sure I'd even notice it?
 :)

I used to be really picky about it myself, now I'm balancing between 14ms on Zen and 46ms on Lebara which seems to have pages loading the fastest I've ever seen.  Jitter is about 8ms on Lebara too.
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on December 14, 2021, 02:43:56 PM
I used to be really picky about it myself, now I'm balancing between 14ms on Zen and 46ms on Lebara which seems to have pages loading the fastest I've ever seen.  Jitter is about 8ms on Lebara too.

I know it seems silly for 8ms's but when I've had it for so long and that some games I play are heavily placed around good ping. So the closer to 0 the better, I'm pretty sure FTTP would even further reduce this latency?

Does anyone know at (guessing) what the latency would look like e.g. pinging bbc.co.uk = 8ms would FTTP put that at like 3/4ms?

On another note, my interleaving has been off so far fingers cross along with an increase of 6-8Mb download and 1-2mb upload. (Link Uptime 16 days, 20 hours, 38 minutes, 46 seconds)

(https://i.imgur.com/XazCTnB.png)


Title: Re: FTTC - Interleaved again!
Post by: j0hn on December 14, 2021, 03:31:31 PM
Openreach FTTP is around 2ms lower latency compared to Openreach FTTC.

That's based on an FTTC line with no added latency (fastpath or Retx/G.INP enabled) and using the same ISP, backhaul and routing.
Title: Re: FTTC - Interleaved again!
Post by: Alex Atkin UK on December 14, 2021, 06:58:38 PM
Yeah I'm pretty sure the lowest latency over FTTP is 6ms and is entirely dependent on how close to London you are thanks to how the backhaul gets routed.

Although saying that I got 8ms to Plusnet from Sheffield which seemed really low considering the above.
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on December 16, 2021, 11:30:22 AM
Hi all,

thank you for the information.

Looks like my luck ran out :D

Interleaving is back on lost 3 or so Mb download speed :(.

(https://i.imgur.com/yj33tHM.png)
Title: Re: FTTC - Interleaved again!
Post by: Reformed on December 16, 2021, 12:00:14 PM
Yeah I'm pretty sure the lowest latency over FTTP is 6ms and is entirely dependent on how close to London you are thanks to how the backhaul gets routed.

Goes under 2 if on the right ISP and in London or surroundings. Round trip to OLT via GPON is 1.1-1.5 ms, mostly around 1.3.
Title: Re: FTTC - Interleaved again!
Post by: Alex Atkin UK on December 16, 2021, 01:23:11 PM
Goes under 2 if on the right ISP and in London or surroundings. Round trip to OLT via GPON is 1.1-1.5 ms, mostly around 1.3.

That would explain how I got as low as 8ms on Plusnet FTTC and possibly why 6ms being the lowest I've seen mentioned on FTTP as that's probably the average for most of England and Wales.

We can't complain, my friend in Texas gets 60ms minimum to most places as that's how much it takes to reach most PoP in the US as they tend to be further north.  If I recall correctly I get around 60ms to New York but it doubles to Texas as there's no faster route.  We joke about Texas broadband using horseback or carrier pigeon.
Title: Re: FTTC - Interleaved again!
Post by: j0hn on December 16, 2021, 02:39:06 PM
Goes under 2 if on the right ISP and in London or surroundings. Round trip to OLT via GPON is 1.1-1.5 ms, mostly around 1.3.

This ^^

Most BT Wholesale FTTP in and around London is sub 2ms to London based servers.
Equivalent FTTC is in the 4-5ms region.

In a previous thread CarlT was monitoring his latency between home and the Nokia 7750 in the exchange and was getting between 1.1ms -1.3ms, averaging 1.2ms.

Looks like my luck ran out :D

Interleaving is back on lost 3 or so Mb download speed :(.

I mentioned this earlier in the thread but not sure if you read it...

Did you try capping the sync speed to keep Interleaving off?

It can be very effective at lowering the ES numbers enough to keep a line on fastpath.

More info in the sticky at the top of this forum section.

Speed Capping and ES Rates on a Moderately Noisy Line (https://forum.kitz.co.uk/index.php/topic,16427.0.html)

It very much looks like your line is unable to maintain fastpath with full sync. That's a number of times in a short time period it has gone back to Interleaving.

If you cap the sync speed at the rate the line syncs at when interleaved you may find that's sufficient to keep ES low enough to stay on fastpath.
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on December 17, 2021, 06:35:09 PM
This ^^

Most BT Wholesale FTTP in and around London is sub 2ms to London based servers.
Equivalent FTTC is in the 4-5ms region.

In a previous thread CarlT was monitoring his latency between home and the Nokia 7750 in the exchange and was getting between 1.1ms -1.3ms, averaging 1.2ms.

I mentioned this earlier in the thread but not sure if you read it...

Did you try capping the sync speed to keep Interleaving off?

It can be very effective at lowering the ES numbers enough to keep a line on fastpath.

More info in the sticky at the top of this forum section.

Speed Capping and ES Rates on a Moderately Noisy Line (https://forum.kitz.co.uk/index.php/topic,16427.0.html)

It very much looks like your line is unable to maintain fastpath with full sync. That's a number of times in a short time period it has gone back to Interleaving.

If you cap the sync speed at the rate the line syncs at when interleaved you may find that's sufficient to keep ES low enough to stay on fastpath.

Hi J0hn,

Apologies i did see this but didn't want to mess about with it as it was running okay, I did this before on a vigor (i know Broadcom chipset is better for ECI) adjusting the SNR. It never hit the same speeds but when i capped using SNR it went worse.

Hopefully in a next few weeks i might be ordering 1Gbps FTTP. Just waiting on some info before i proceed with limiting speeds. If i can get FTTP then waiting for 7 days etc for interleaving to be removed would be pointless if i can get FTTP shortly after :).
Title: Re: FTTC - Interleaved again!
Post by: j0hn on December 18, 2021, 01:39:19 AM
Absolutely. A connection without the DLM is better than having to limit the connection to avoid the DLM.
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on December 20, 2021, 07:38:13 PM
Absolutely. A connection without the DLM is better than having to limit the connection to avoid the DLM.

I think the DLM has just had enough of me anyway :D

(https://i.imgur.com/ZQ8m8TI.png)

(https://i.imgur.com/vHlCHem.png)


This doesn't make any sense :S
Title: Re: FTTC - Interleaved again!
Post by: g3uiss on December 20, 2021, 09:41:43 PM
Well FTTP will be the answer! Have you got that sorted?
Title: Re: FTTC - Interleaved again!
Post by: HitmanAlex on December 20, 2021, 11:36:55 PM
Well FTTP will be the answer! Have you got that sorted?

Hi g3uiss,

I got the leaflet through the post from litfibre.com, according to ispreview it's set to start offering services as early as January. Considering I got the Leaflet and at the top of my road they was putting in duct's i hope that means good results.

The rep at litfibre.com confirmed that they are working within my precise postcode within the next 2 weeks. Just waiting for them to send me an email so i can order straight away :), going for that 1Gbps Up/Down.

Does the graphs make any sense why they are being so random while i'm still on FTTC would be nice if there is some explanation to these wacky results :D
Title: Re: FTTC - Interleaved again!
Post by: g3uiss on December 21, 2021, 09:41:25 AM
The fluctuation is normal accentuated by the scale of the graph.