As i have an identical ds attenuation to the OP, any idea why the max attainable speed on my FTTC connection is ~ 86000 kbps instead of 120000 kbps?

And why are some connections like mine and OPs only able to sync at 79987kbps instead of 80000kbps? Perhaps its a bug inside unlocked HG612 fw?
Cheers

# xdslcmd info --stats
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Last initialization procedure status: 0
Max: Upstream rate = 31929 Kbps, Downstream rate = 86216 Kbps
Bearer: 0, Upstream rate = 19999 Kbps, Downstream rate = 79987 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): 7.9 15.0
Attn(dB): 12.7 0.0
Pwr(dBm): 12.8 0.8
VDSL2 framing
Bearer 0
MSGc: 18 26
B: 239 237
M: 1 1
T: 23 42
R: 0 16
S: 0.0955 0.3781
L: 20104 5374
D: 1 1
I: 240 127
N: 240 254
Counters
Bearer 0
OHF: 166100253 1580245
OHFErr: 741 87
RS: 0 2453335
RSCorr: 0 713
RSUnCorr: 0 0

Bearer 0
HEC: 1304 0
OCD: 34 0
LCD: 34 0
Total Cells: 3582122852 0
Data Cells: 1332108251 0
Drop Cells: 0
Bit Errors: 0 0

ES: 485 69
SES: 0 0
UAS: 29 29
AS: 274709

Bearer 0
INP: 0.00 0.00
INPRein: 0.00 0.00
delay: 0 0
PER: 1.65 3.98
OR: 116.09 64.22
AgR: 80103.09 20063.54

Bitswap: 133775/133775 2485/2485

Total time = 1 days 4 hours 18 min 58 sec
FEC: 0 713
CRC: 741 87
ES: 485 69
SES: 0 0
UAS: 29 29
LOS: 0 0
LOF: 0 0
LOM: 0 0
Latest 15 minutes time = 3 min 58 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: 0 0
CRC: 3 0
ES: 2 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Latest 1 day time = 4 hours 18 min 58 sec
FEC: 0 31
CRC: 35 1
ES: 20 1
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Previous 1 day time = 24 hours 0 sec
FEC: 0 211
CRC: 186 33
ES: 115 19
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Since Link time = 3 days 4 hours 18 min 27 sec
FEC: 0 713
CRC: 741 87
ES: 485 69
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
#
ATP>




Last initialization procedure status: 0
Max: Upstream rate = 31941 Kbps, Downstream rate = 86216 Kbps
Bearer: 0, Upstream rate = 19999 Kbps, Downstream rate = 79987 Kbps

Discovery Phase (Initial) Band Plan
US: (7,32) (871,1205) (1972,2782)
DS: (33,859) (1216,1961) (2793,3970)
Medley Phase (Final) Band Plan
US: (7,32) (871,1205) (1972,2782)
DS: (33,859) (1216,1961) (2793,3970)
VDSL Port Details Upstream Downstream
Attainable Net Data Rate: 31941 kbps 86216 kbps
Actual Aggregate Tx Power: 0.8 dBm 12.8 dBm
====================================================================================
VDSL Band Status U0 U1 U2
U3 U4 D1 D2 D3
Line Attenuation(dB): 3.1 14.4 21.0 N/A N/A 8.0 17.4
26.4
Signal Attenuation(dB): 3.1 13.6 20.6 N/A N/A 9.1 17.3
26.4
SNR Margin(dB): 14.6 14.6 15.2 N/A N/A 7.9
7.9 7.9
TX Power(dBm): -13.5 -29.2 0.7 N/A N/A 9.0
7.8 7.0
#
ATP>

FTTC is capped at 76 down and 20 up at max
if distance is less that 500 metres would suggest in excess of 40m/bps at a network level

Yes i'm fully aware that FTTC is capped at 80/20 but out of curiousity i want to know why the max attainable rate on my line is 86 meg yet the OP has 120 meg despite both of us having a ds attenuation of 12-13 db.

Perhaps he's on a different profile?

We're both on fastpath mate

There are 3 DLM profiles and fastpath isn't one of them.

3 DLM profiles are Standard, Speed & Stable. There is no fastpath on FTTC.

Most likely one of

1. Cross talk levels are different
2. Different power mask, i.e. not all cabinets put out same level of signal, three power levels to avoid cross talk killing ADSL2+
3. Presence of a noise source not enough to impact connection speed, but max attainable

I did recently get a new line about 4 years ago, I say the Line Length is at least 250 metres.

Your SNR/SNRM is lower, indicating a 'noisier' connection which will impact attainable rates & for those unable to achieve the full whack due to distance, actual sync speeds.


'Noise' can be from many varied sources.
My connection has seen increased 'noise' due to crosstalk over an 18 month period as more users have been connected.

As I am 1100m or so from the cabinet, my sync speeds have gradually deteriorated from around 30 Mbps DS to currently around 19 Mbps.

It was around 22 Mbps until yesterday - assumption is someone else was connected recently as My SNRM has been running as low as 5 dB for a while.

This morning's resync restored the 6dB margin, but that has reduced actual sync speed accordingly.

Edited by deleted (Tue 20-May-14 08:31:44)