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[j0hn]

When your switch ISP you change from fastpath to Interleaved.
The stats show your line is Interleaved.

The way OpenReach deploy Interleaving on FTTC it takes roughly 10% off your sync.

In my opinion the difference in speed is almost certainly the DLM changes to Interleaving. With fastpath you would be back near 67Mb.


The line and port used are identical between ISP's.
The ISP had zero control over the DLM.

Plusnet in my experience will pass a no fault found charge on to you the customer if/when OpenReach do not find a fault.
I'd recommend cancelling the engineer visit.

There are ways to try force the DLM to remove Interleaving by temporarily capping your sync speed.
Lines often hold Interleaving off after taking this manual approach.
The powerline adapters can increase FEC errors which I believe are used in determining if Interleaving should be removed.
You may wish to try a few days/a week without them connected to see if the Interleaving is removed.

[bobfrombirmingham]

When your switch ISP you change from fastpath to Interleaved.
The stats show your line is Interleaved.

The way OpenReach deploy Interleaving on FTTC it takes roughly 10% off your sync.

In my opinion the difference in speed is almost certainly the DLM changes to Interleaving. With fastpath you would be back near 67Mb.

There are ways to try force the DLM to remove Interleaving by temporarily capping your sync speed.
Lines often hold Interleaving off after taking this manual approach.
The powerline adapters can increase FEC errors which I believe are used in determining if Interleaving should be removed.
You may wish to try a few days/a week without them connected to see if the Interleaving is removed.

Just been changed to a new port and following stats - obviously these will change as DLM kicks in...

Slightly better sync.

I've unplugged one of the two Powerline adapters.

What's the simplest way to temporarily cap speed?


Status: Showtime
Retrain Reason:   1
Last initialization procedure status:   0
Max:   Upstream rate = 25330 Kbps, Downstream rate = 63076 Kbps
Bearer:   0, Upstream rate = 20000 Kbps, Downstream rate = 63077 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       9.6
Attn(dB):    14.9       0.0
Pwr(dBm):    6.0       6.1
         VDSL2 framing
         Bearer 0
MSGc:      18      150
B:      239      236
M:      1      1
T:      21      5
R:      0      16
S:      0.1211      0.3771
L:      15856      5410
D:      1      1
I:      240      255
N:      240      255
         Counters
         Bearer 0
OHF:      1105705      345657
OHFErr:      1949      0
RS:      0      981773
RSCorr:      0      0
RSUnCorr:   0      0

         Bearer 0
HEC:      222      0
OCD:      0      0
LCD:      0      0
Total Cells:   256635607      0
Data Cells:   388678      0
Drop Cells:   0
Bit Errors:   0      0

ES:      961      5
SES:      23      2
UAS:      3035      3015
AS:      2118

         Bearer 0
INP:      0.00      0.00
INPRein:   0.00      0.00
delay:      0      0
PER:      1.91      6.15
OR:      100.28      202.87
AgR:      63177.21   20203.27

Bitswap:   1054/1054      0/0

Total time = 1 days 22 hours 7 min 16 sec
FEC:      0      0
CRC:      1949      0
ES:      961      5
SES:      23      2
UAS:      3035      3015
LOS:      2      0
LOF:      18      0
LOM:      0      0
Latest 15 minutes time = 7 min 16 sec
FEC:      0      0
CRC:      574      0
ES:      207      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:      0      0
CRC:      828      0
ES:      364      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Latest 1 day time = 22 hours 7 min 16 sec
FEC:      0      0
CRC:      1949      0
ES:      952      0
SES:      20      0
UAS:      3009      2989
LOS:      2      0
LOF:      18      0
LOM:      0      0
Previous 1 day time = 24 hours 0 sec
FEC:      0      0
CRC:      0      0
ES:      6      5
SES:      3      2
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Since Link time = 35 min 17 sec
FEC:      0      0
CRC:      1949      0
ES:      931      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
#

[g3uiss]

See this post

https://forum.kitz.co.uk/index.php/topic,16427.0.html

[j0hn]

You don't need to cap your speed.

The "new port" might look faster but you're actually on fastpath now.
The DLM has nothing to give.

I'm not convinced your port was changed.
The DLM should start interleaved on a port swap.

The improvement in sync looks to be the DLM changing from interleaved to fastpath.

Did the sync change at the exact time the engineer was working on the line or could it have improved before he/she arrived?

If the port was indeed changed, there's no improvement from before. It's simply caused the DLM to start on fastpath, which isn't what we normally see.

[bobfrombirmingham]

Thanks.

I will see what happens to the line and then try this if necessary.

I watched the engineer at the cabinet - we had a socially distanced chat - and she did request a new port and swap over the connection.  It took about 30mins to get the port allocated.  When it then re-synced the new speed was as above.

My current interleave depth is 1 /1 (Interleave Depth = 1 means that data is being transmitted over the interleaved path but data packets are not being interleaved. ie the equivalent of Fast Path.)

This suggests I'm on equivalent of Fastpath.

Pings to bbc.co.uk are 7ms.

I will keep an eye on it - but error rate seems to be climbing.

She did mention that my area has a lot of Aluminium cable and does cause issues.  She also rubbished the Cross talk theory.

DSLAM type / SW version:   IFTN:0xb206 (178.6) / v0xb206
Modem/router firmware:     AnnexA version - A2pv6C038m.d24j
DSL mode:                  VDSL2 Profile 17a
Status:                    Showtime
Uptime:                     1 hour 40 min 48 sec
Resyncs:                   0 (since 10 Mar 2021 11:53:41)
         
            Downstream   Upstream
Line attenuation (dB):     14.9      0.0
Signal attenuation (dB):   Not monitored      
Connection speed (kbps):   63077      20000
SNR margin (dB):           6.3      9.5
Power (dBm):               6.0      6.1
Interleave depth:          1      1
INP:                       0      0
G.INP:                     Not enabled      Not enabled
Vectoring status:          5 (VECT_UNCONFIGURED)      

RSCorr/RS (%):             N/A      0.0000
RSUnCorr/RS (%):           N/A      0.0000
ES/hour:                   742      0

[j0hn]

I will keep an eye on it - but error rate seems to be climbing.

Indeed.
You will definitely be put back on interleaved in the next day or 2.
ES are way above the allowed limit.

[bobfrombirmingham]

I removed the plugged in Powerline adapters ethernet cable from the Power line adapter as although I had unplugged the other adapter I had a feeling it would still be trying to send data... and lo and behold, my errors have dropped rapidly...

Latest 15 minutes time = 4 min 16 sec
FEC:      0      0
CRC:      2      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:      0      0
CRC:      3      0
ES:      3      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0

[j0hn]

A staggering drop.

Hopefully enough to keep fastpath, but it's possible the damage was done.

If the line does go interleaved it should return to fastpath if the powerline adapters are kept off.

[bobfrombirmingham]

Yeah - it was definitely the PowerLine adapters.

Is there anything I can do - if I unplug modem for 30minutes perhaps then reconnect will it make any difference?  Probably not because I assume the DSLAM is keeping the total errors and won't reset the counter either way.

Also - are there any PowerLine adapters that don't cause interference - I can't run Ethernet from router to lounge without ripping up floors and I'm not really wanting to do this if I can avoid avoid it!

My current adapters are TP-LINK AV2000.  I doubt it... but I thought I'd ask!

[bobfrombirmingham]

Latest 15 minutes time = 46 sec
FEC:      0      0
CRC:      1      0
ES:      1      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:      0      0
CRC:      0      0
ES:      0      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0

[j0hn]

The previous known ES limits were either 1440 per 24 hours or 2880 per 24 hours, depending on which DLM profile the ISP used.

These limits appear to be lower than they were and are now unknown.

Resyncing and keeping the line offline is only likely to make things worse.
It's worked out on the average ES per seconds uptime.
You want longer uptime while the errors are lower to average out the period of high ES.

I think you'll be alright and should retain fastpath. You may have caught it early enough.

Powerline adapters cause no issues for some lines.
It depends how close the incoming OpenReach line runs in relation to the electrical wiring of the property.

I used to get higher errors using powerlines until i moved the power socket and wiring next to my master socket.

Some powerline adapters also advertise a VDSL interference feature where they won't use the same frequencies as your FTTC but I found it made little difference.

If latency and retaining fastpath is essential to you then you may just have to ditch the homeplugs.