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[eduncle]

Hi there,

I have a Billion 8800NL r1 paired with an ASUS RT-AC86U and workmen recently cut our line so after a couple of days of no broadband followed by a repair and DLM reset by the kind man from Openreach, the line came back up at roughly 60mb/18mb with interleaving on.

That was Thursday and the profile stayed the same until this morning at 3am when it resynced itself at 71mb/18mb

My problem is although my sync is now back roughly where it used to be, my actual maximum download speed is still only around 60mb (measured from the router so not affected by other network devices etc).

Could anyone suggest a likely cause for this and how I could improve it?

Thanks

Code: [Select]

> adsl info --stats
adsl: ADSL driver and PHY status
Status: Showtime
Last Retrain Reason:    1
Last initialization procedure status:   0
Max:    Upstream rate = 18305 Kbps, Downstream rate = 70904 Kbps
Bearer: 0, Upstream rate = 18305 Kbps, Downstream rate = 70944 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):        6.4             6.1
Attn(dB):        17.4            0.0
Pwr(dBm):        13.4            6.9

                        VDSL2 framing
                        Bearer 0
MSGc:           -6              22
B:              243             239
M:              1               1
T:              0               64
R:              10              14
S:              0.1095          0.4172
L:              18554           4871
D:              8               1
I:              254             127
N:              254             254
Q:              8               0
V:              0               0
RxQueue:                56              0
TxQueue:                14              0
G.INP Framing:          18              0
G.INP lookback:         14              0
RRC bits:               0               24
                        Bearer 1
MSGc:           154             -6
B:              0               0
M:              2               0
T:              2               0
R:              16              0
S:              6.4000          0.0000
L:              40              0
D:              3               0
I:              32              0
N:              32              0
Q:              0               0
V:              0               0
RxQueue:                0               0
TxQueue:                0               0
G.INP Framing:          0               0
G.INP lookback:         0               0
RRC bits:               0               0

                        Counters
                        Bearer 0
OHF:            0               2222798
OHFErr:         185             1
RS:             1149692000              2404491
RSCorr:         1123            334
RSUnCorr:       0               0
                        Bearer 1
OHF:            1967439         0
OHFErr:         195             0
RS:             19673774                0
RSCorr:         11              0
RSUnCorr:       1923            0

                        Retransmit Counters
rtx_tx:         20293309                0
rtx_c:          28              0
rtx_uc:         14436           0

                        G.INP Counters
LEFTRS:         6               0
minEFTR:        70943           0
errFreeBits:    34189954                0

                        Bearer 0
HEC:            0               0
OCD:            0               0
LCD:            0               0
Total Cells:    16083849                0
Data Cells:     334083575               0
Drop Cells:     0
Bit Errors:     0               0

                        Bearer 1
HEC:            0               0
OCD:            0               0
LCD:            0               0
Total Cells:    0               0
Data Cells:     0               0
Drop Cells:     0
Bit Errors:     0               0

ES:             17              10
SES:            15              0
UAS:            70              59
AS:             31608

                        Bearer 0
INP:            48.00           0.00
INPRein:        0.00            0.00
delay:          0               0
PER:            0.00            6.70
OR:             0.01            33.42
AgR:            71016.70        18338.44

                        Bearer 1
INP:            4.50            0.00
INPRein:        4.50            0.00
delay:          3               0
PER:            16.06           0.01
OR:             79.68           0.01
AgR:            79.68   0.01

Bitswap:        19/19           542/542

Total time = 1 days 23 hours 6 min 8 sec
FEC:            27556           387
CRC:            6310            11
ES:             17              10
SES:            15              0
UAS:            70              59
LOS:            1               0
LOF:            7               0
LOM:            1               0
Latest 15 minutes time = 6 min 8 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:            13              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 = 23 hours 6 min 8 sec
FEC:            10003           359
CRC:            6310            6
ES:             17              5
SES:            15              0
UAS:            40              29
LOS:            1               0
LOF:            7               0
LOM:            1               0
Previous 1 day time = 24 hours 0 sec
FEC:            17553           28
CRC:            0               5
ES:             0               5
SES:            0               0
UAS:            30              30
LOS:            0               0
LOF:            0               0
LOM:            0               0
Since Link time = 8 hours 46 min 47 sec
FEC:            1123            334
CRC:            185             1
ES:             6               1
SES:            4               0
UAS:            0               0
LOS:            0               0
LOF:            0               0
LOM:            1               0


[Aos6aXie]

Your ISP is only made aware of changes in sync speed during a new PPP transaction. If your modem resyncs quickly and the PPP session doesn't timeout the ISP is unaware that anything has changed and they continue rate limiting your connection at the old speed.

Restart your router or manually restart your PPP session and the ISP hardware should automatically adjust to the new sync speed.

[eduncle]

Thanks for the suggestion. I tried this but it didn’t improve things. Resync was at similar speeds but still with a max throughput around 12mb lower than sync speed.

I then swapped out the Bipac 8800nl for a Draytek Vigor 130 which bumped download to 64mb on a 68mb sync so much better.

Doesn’t explain why the 8800NL was giving such a poor throughput though, especially as the cab reports BDCM chipset which I thought preferred the 8800 chipset to that of the Vigor.

Obviously reluctant to tinker too much as I don’t want to trigger DLM. I disconnected for 30mins each time I swapped modem etc but still nervous in case that’s not sufficient.

[burakkucat]

Ah, I think is see it.

. . . a repair and DLM reset by the kind man from Openreach, the line came back up at roughly 60mb/18mb with interleaving on.

A DLM system reset.

Doesn’t explain why the 8800NL was giving such a poor throughput though, especially as the cab reports BDCM chipset . . .

A cabinet equipped with Huawei electronics.

Code: [Select]

> adsl info --stats
. . .
Training Status:        Showtime
                Down            Up
SNR (dB):        6.4             6.1
 . . .


Now back to a target SNRM of 6 dB. I suspect pre-DLM reset, the circuit was running with a target SNRM of 3 dB. Hence the difference now seen.

Give it some time with the Billion device connected as the modem and, if the circuit shows itself to be stable, the target SNRM will be lowered in 1 dB steps.

[eduncle]

Ah makes sense, and the Draytek I’ve substituted may have an SNR -20 offset set which would explain the greater throughput despite the similar sync speed?

Just to confirm, am I safe to pull the link down to swap modems provided I wait 30 mins before powering back on or am I risking negative DLM reactions?

Thanks for all the help, really appreciated.

[burakkucat]

Earlier I forgot to type: "Welcome to the kitz forum." 

Why not power off and disconnect the Draytek modem, once you have finished using it for today. Leave the circuit inactive overnight and reconnect the Billion device tomorrow morning. All should then be good.

[eduncle]

Thanks    It's a great resource and I've learned a lot about DSL from browsing threads here.

Just an update on my (minor) issue..
I disconnected for a second time for about an hour following my previous comment and after that, the speed increased to 69mb as suggested by Aos6aXie.
 
It's now a few days later and my SNRM has indeed gradually dropped in 1db increments every 48 hours but again my actual throughput hasn't changed so I'm guessing Aos6aXie's comment is exactly right - the ISP is rate limiting it rather than the connection being the issue and hasn't noticed the change in my sync rate.

Here's whats happened this week.

21/1 - SNRM at 6.4 - Upstream rate = 18305 Kbps, Downstream rate = 70904 Kbps - Speedtest shows 65mb peak
Power off router manually for 1 hour during day as per Aos6aXie's suggestion - Speedtest shows 69mb peak
22/2 2am(ish) - Connection reset by DSLAM - SNRM changed to 5.4 - Upstream rate = 18857 Kbps, Downstream rate = 73953 Kbps - Speedtest shows 69.02mb peak
24/2 2am(ish) - Connection reset by DSLAM - SNRM changed to 4.4 - Upstream rate = 18790 Kbps, Downstream rate = 76351 Kbps - Speedtest shows 69.02mb peak
26/2 2am(ish) - Connection reset by DSLAM - SNRM changed to 3.4 - Upstream rate = 18990 Kbps, Downstream rate = 79997 Kbps - Speedtest shows 69.02mb peak

So a couple of questions if you don't mind!

Should I just power-off for another hour or two so Sky's kit works out that my rate can be increased?
Will that harm my improved SNRM or cause any other issues while line is still in 10 day training window?

Thanks again for the help!

[Alex Atkin UK]

The 10 day training window is pretty much a myth these days, they say that just so people give it a chance to adjust as it actually never stops training, its just you will see the most changes generally in the first few days or so.

Turned it off for an hour shouldn't hurt, but I'm not sure if it will do anything productive either.