Kitz Forum

Broadband Related => FTTC and FTTP Issues => Topic started by: frh187 on August 16, 2020, 01:42:41 PM

Title: FTTC connection slowdown - help with stats
Post by: frh187 on August 16, 2020, 01:42:41 PM
Over the past several days my TalkTalk FTTC connection as been achieving only around half its usual sync speed. I typically get a steady 22Mbps, however speed tests are now showing 11Mbps with sync speed from my modem stats page showing approx 13Mbps.

My usual setup is an Openreach HG612 modem attached to an Apple Time Capsule router. My master socket was upgraded a couple of years ago with an NTE5 filtered faceplate. TalkTalk's official support had recommended connecting my TalkTalk-supplied HG633 router to the test socket behind the NTE5 faceplate for 48 hours in the hope that DLM would increase the sync speed. I did as they suggested for just over 24 hours without any improvement in sync speed but then realised that removing the faceplate from the master socket resulted in my internal telephone extension wiring being disconnected - not an acceptable situation as I live in a rural area with no mobile phone coverage. I therefore replaced the faceplate, and have ended up going back to the Openreach modem/Apple router, as the connection via the TalkTalk router felt generally 'slower', though measured speed seemed similar.

I have posted my connection stats obtained by Telnet to my unlocked HG612 below. Can anyone with experience of interpreting these shed any light? Many thanks.

Quote
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason:   0
Last initialization procedure status:   0
Max:   Upstream rate = 1165 Kbps, Downstream rate = 22404 Kbps
Bearer:   0, Upstream rate = 1165 Kbps, Downstream rate = 13096 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):    13.6       5.9
Attn(dB):    29.7       0.0
Pwr(dBm):    10.2       10.5
         VDSL2 framing
         Bearer 0
MSGc:      -6      26
B:      32      31
M:      1      1
T:      0      53
R:      6      0
S:      0.0791      0.8591
L:      3944      298
D:      8      1
I:      39      32
N:      39      32
Q:      8      0
V:      2      0
RxQueue:      112      0
TxQueue:      28      0
G.INP Framing:      18      0
G.INP lookback:      28      0
RRC bits:      0      24
         Bearer 1
MSGc:      90      -6
B:      0      0
M:      2      0
T:      2      0
R:      16      0
S:      10.6667      0.0000
L:      24      0
D:      1      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      1141002
OHFErr:      81      58
RS:      3188908360      2736910
RSCorr:      66027      0
RSUnCorr:   0      0
         Bearer 1
OHF:      3941727      0
OHFErr:      1      0
RS:      23649993      0
RSCorr:      518      0
RSUnCorr:   1      0

         Retransmit Counters
rtx_tx:      8753369      0
rtx_c:      16150      0
rtx_uc:      3487      0

         G.INP Counters
LEFTRS:      17      0
minEFTR:   13096      0
errFreeBits:   12598728      0

         Bearer 0
HEC:      0      0
OCD:      0      0
LCD:      0      0
Total Cells:   1594344049      0
Data Cells:   121936303      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:      37      52
SES:      0      0
UAS:      25      25
AS:      63316

         Bearer 0
INP:      52.00      0.00
INPRein:   1.00      0.00
delay:      0      0
PER:      0.00      11.42
OR:      0.01      22.40
AgR:      13296.98   1187.36

         Bearer 1
INP:      2.50      0.00
INPRein:   2.50      0.00
delay:      0      0
PER:      16.06      0.01
OR:      47.81      0.01
AgR:      47.81   0.01

Bitswap:   35263/35263      1/1

Total time = 17 hours 35 min 41 sec
FEC:      66027      0
CRC:      81      58
ES:      37      52
SES:      0      0
UAS:      25      25
LOS:      0      0
LOF:      0      0
LOM:      0      0
Latest 15 minutes time = 5 min 41 sec
FEC:      331      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:      902      0
CRC:      2      0
ES:      1      0
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Latest 1 day time = 17 hours 35 min 41 sec
FEC:      66027      0
CRC:      81      58
ES:      37      52
SES:      0      0
UAS:      25      25
LOS:      0      0
LOF:      0      0
LOM:      0      0
Previous 1 day time = 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
Since Link time = 17 hours 35 min 15 sec
FEC:      66027      0
CRC:      81      58
ES:      37      52
SES:      0      0
UAS:      0      0
LOS:      0      0
LOF:      0      0
LOM:      0      0
Title: Re: FTTC connection slowdown - help with stats
Post by: Weaver on August 16, 2020, 02:49:07 PM
A very warm welcome to the forum!  ;D

The thing that stands out is the very high downstream SNRM of 13.6dB - should be either 6dB or if you are really lucky, 3dB. Downstream 20% of the data sent is Reed-Solomon error correction information (https://kitz.co.uk/adsl/error_correction.htm#RS) and the modem is needing to adopt powerful techniques to cope with a very noisy line. Some noise burst has really upset BT’s DLM (https://kitz.co.uk/adsl/DLM.htm). It should hopefully recover, but might take a while.