low snr and speed

dhalijet — Sat, 09 Feb 2013 21:11:45 GMT

hello

i have noticed that i have a very low snr (around 3db) and a 2270 kbps connection with a 57db attenuation.

others nearby (therr is only one green box where i am serving 300 premises), are getting a solid 3.8Mbps at 6db.

i only have the router connected directly to the test socket less than a meter away. there are no extensions connected too.

ive done a quiet line test and had no issue. the bt helpdesk ran a line test and found no problem.

ive tried the bt hub, draytek and now a billion 7800n router and not had much difference.

here are my line stats

> adsl info --stats

adsl: ADSL driver and PHY status

Status: Showtime

Retrain Reason: 8000

Max: Upstream rate = 736 Kbps, Downstream rate = 5496 Kbps

Path: 0, Upstream rate = 444 Kbps, Downstream rate = 2270 Kbps

Link Power State: L0

Mode: ADSL2

TPS-TC: ATM Mode

Trellis: U:ON /D:ON

Line Status: No Defect

Training Status: Showtime

Down Up

SNR (dB): 2.6 14.5

Attn(dB): 57.5 33.7

Pwr(dBm): 0.0 13.1

ADSL2 framing

MSGc: 89 10

B: 6 63

M: 1 1

T: 7 1

R: 6 0

S: 0.0966 4.5309

L: 1076 113

😧 320 1

Counters

SF: 1016558 901436

SFErr: 215 29

RS: 676011486 0

RSCorr: 1944195 0

RSUnCorr: 5038 0

HEC: 143 12

OCD: 4 0

LCD: 0 0

Total Cells: 87462431 17102659

Data Cells: 26410217 1910997

Drop Cells: 0

Bit Errors: 0 1287

ES: 89 15

SES: 1 0

UAS: 90 90

AS: 16335

INP: 7.13 0.00

PER: 16.06 18.12

delay: 7.73 1.13

OR: 47.29 7.06

Bitswap: 79 74

Total time = 4 hours 34 min 54 sec

FEC: 1944195 0

CRC: 215 29

ES: 89 15

SES: 1 0

UAS: 90 90

LOS: 0 0

LOF: 0 0

Latest 15 minutes time = 4 min 54 sec

FEC: 6296 0

CRC: 0 0

ES: 0 0

SES: 0 0

UAS: 0 0

LOS: 0 0

LOF: 0 0

Previous 15 minutes time = 15 min 0 sec

FEC: 19764 0

CRC: 0 0

ES: 0 0

SES: 0 0

UAS: 0 0

LOS: 0 0

LOF: 0 0

Latest 1 day time = 4 hours 34 min 54 sec

FEC: 1944195 0

CRC: 215 29

ES: 89 15

SES: 1 0

UAS: 90 90

LOS: 0 0

LOF: 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

Since Link time = 4 hours 32 min 15 sec

FEC: 1944195 0

CRC: 215 29

ES: 89 15

SES: 1 0

UAS: 0 0

LOS: 0 0

LOF: 0 0

i've check on the wholesale checker and see the following for my number, which makes me think i am basically locked at 2Mbps. the router stats show that i am on adsl 2.any suggestipns as to how i move the issue forward to get a bit more ?

thanks

Available ProductsDownstream Line Rate(Mbps)Upstream Line Rate(Mbps)Downstream Range(Mbps)Availability Date

Featured Products
WBC ADSL 2+	Up to 6	--	4 to 8	Available
ADSL Max	Up to 5	--	3.5 to 7.5	Available
WBC Fixed Rate	2	--	--	Available
Fixed Rate	2	--	--	Available

Re: low snr and speed

adrianc — Sun, 10 Feb 2013 11:32:35 GMT

A couple of suggestions:

1. Double-check all your internal wiring, low SNR margin often points towards issues in the premises.

2. If the router allows it, change the mode from ADSL2+ to G.DMT. I have a long line issue (~4km) as well as aluminium cabling between here and the cabinet, so I was never going to see the benefits of ADSL2+. Changing to G.DMT has made increased the SNR from around 5db to 15db. It hasn't increased the sync speed by much (2072kbps to 3584kbps), but it is rock stable now as opposed to having lots of HEC/FEC errors.

HTH,

Adrian

Re: low snr and speed

dhalijet — Mon, 11 Feb 2013 06:10:46 GMT

Adrian

Well, number 2 definitely helped. I selected only G.DMT and my downstream SNR has risen to 13.6 from 3. I just need to get the BT business folks to look at why I can't synch at a lower SNR, so maybe I can climb up a couple of notches in terms of profile.

Great work and thanks.

Fingers crossed I can move forward now.

Jet

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