Insight into VDSL stats

Hello,
I've been having some slower-than-hoped line speeds recently. It looks like interleaving has been applied on the line and is the cause, but I wanted to post the modem stats here to see if I could get any more insight on how to read these properly to help debugging issues in the future.

Thanks.

Stats from Draytek Vigor 130, connection reset a little while before posting.

> vdsl status
---------------------- ATU-R Info (hw: annex A, f/w: annex A/B/C) -----------
Running Mode : 17A State : SHOWTIME
DS Actual Rate : 34999000 bps US Actual Rate : 11999000 bps
DS Attainable Rate : 54200248 bps US Attainable Rate : 15545250 bps
DS Path Mode : Interleave US Path Mode : Interleave
DS Interleave Depth : 1647 US Interleave Depth : 189
NE Current Attenuation : 19 dB Cur SNR Margin : 8 dB
DS actual PSD : 5. 8 dB US actual PSD : 5. 9 dB
NE CRC Count : 0 FE CRC Count : 64481
NE ES Count : 0 FE ES Count : 52239
Xdsl Reset Times : 0 Xdsl Link Times : 2
ITU Version[0] : b5004946 ITU Version[1] : 544e0000
VDSL Firmware Version : 05-07-06-0D-01-07 [with Vectoring support]
Power Management Mode : DSL_G997_PMS_L0
Test Mode : DISABLE
-------------------------------- ATU-C Info ---------------------------------
Far Current Attenuation : 23 dB Far SNR Margin : 6 dB
CO ITU Version[0] : b5004946 CO ITU Version[1] : 544eb206
DSLAM CHIPSET VENDOR : < IFTN >

> vdsl status more
---------------------- ATU-R Info (hw: annex A, f/w: annex A/B/C) -----------
Near End Far End Note
Trellis : 1 1
Bitswap : 0 1
ReTxEnable : 0 0
VirtualNoise : 0 0
20BitSupport : 0 0
LatencyPath : 0 0
LOS : 0 0
LOF : 0 0
LPR : 0 0
LOM : 0 0
SosSuccess : 0 0
NCD : 0 0
LCD : 0 0
FECS : 90921 432147256 (seconds)
ES : 0 52239 (seconds)
SES : 0 7 (seconds)
LOSS : 0 511 (seconds)
UAS : 33 1350016 (seconds)
HECError : 0 0
CRC : 0 64481
RsCorrection : 0 0
INP : 10 40 (symbols)
InterleaveDelay : 600 1300 (1/100 ms)
NFEC : 65 52
RFEC : 16 16
LSYMB : 4078 12777
INTLVBLOCK : 65 52
AELEM : 0 ----

Not just interleaving, but by the look of it also "banding".

DS Actual Rate : 34999000 bps US Actual Rate : 11999000 bps
DS Attainable Rate : 54200248 bps US Attainable Rate : 15545250 bps

Figures ending on 999000 with much higher attainable are the clue.

Lots of noise are generally what causes that.

Ah right, thank you. Is this something that will be automatically removed by leaving the line connected for a couple of weeks? Or if its noise, is that indictive of an actual fault?

Depends whether it is recurring high noise or a couple of heavy bursts more than once. Next time you post the stats don't restart the modem first .

Hmm it's been a couple of weeks now... still looks like the downstream and upstream are being banded or limited in some way

> vdsl status
---------------------- ATU-R Info (hw: annex A, f/w: annex A/B/C) -----------
Running Mode : 17A State : SHOWTIME
DS Actual Rate : 35000000 bps US Actual Rate : 12000000 bps
DS Attainable Rate : 55261992 bps US Attainable Rate : 17744493 bps
DS Path Mode : Interleave US Path Mode : Fast
DS Interleave Depth : 722 US Interleave Depth : 1
NE Current Attenuation : 19 dB Cur SNR Margin : 9 dB
DS actual PSD : 6. 0 dB US actual PSD : 6. 2 dB
NE CRC Count : 26 FE CRC Count : 64488
NE ES Count : 7 FE ES Count : 52245
Xdsl Reset Times : 0 Xdsl Link Times : 4
ITU Version[0] : b5004946 ITU Version[1] : 544e0000
VDSL Firmware Version : 05-07-06-0D-01-07 [with Vectoring support]
Power Management Mode : DSL_G997_PMS_L0
Test Mode : DISABLE
-------------------------------- ATU-C Info ---------------------------------
Far Current Attenuation : 23 dB Far SNR Margin : 9 dB
CO ITU Version[0] : b5004946 CO ITU Version[1] : 544eb206
DSLAM CHIPSET VENDOR : < IFTN >

---------------------- ATU-R Info (hw: annex A, f/w: annex A/B/C) -----------
Near End Far End Note
Trellis : 1 1
Bitswap : 1 1
ReTxEnable : 0 0
VirtualNoise : 0 0
20BitSupport : 0 0
LatencyPath : 0 0
LOS : 4 0
LOF : 0 0
LPR : 0 0
LOM : 0 0
SosSuccess : 0 0
NCD : 0 0
LCD : 0 0
FECS : 11483929 432230608 (seconds)
ES : 7 52245 (seconds)
SES : 0 7 (seconds)
LOSS : 0 511 (seconds)
UAS : 34 1350093 (seconds)
HECError : 0 0
CRC : 26 64488
RsCorrection : 0 0
INP : 0 15 (symbols)
InterleaveDelay : 0 800 (1/100 ms)
NFEC : 255 63
RFEC : 16 16
LSYMB : 3268 11825
INTLVBLOCK : 255 63
AELEM : 0 ----