line stats

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ghostbuster

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are these line stats good? SNR and Attenuation?
de: ADSL_G.dmt
Type: ATM
Status: Up

Downstream Upstream
Line Coding(Trellis): On On
SNR Margin (dB): 418 130
Attenuation (dB): 210 125
Output Power (dBm): 49 51
Attainable Rate (Kbps): 11296 1036
Rate (Kbps): 2048 512
D (interleaver depth): 1 1
Delay (msec): 0.13 0.25

HEC Errors: 0 0
OCD Errors: 0 0
LCD Errors: 0 0

Total ES: 0 0
 
ghostbuster said:
are these line stats good? SNR and Attenuation?
de: ADSL_G.dmt
Type: ATM
Status: Up

Downstream Upstream
Line Coding(Trellis): On On
SNR Margin (dB): 418 130
Attenuation (dB): 210 125
Output Power (dBm): 49 51
Attainable Rate (Kbps): 11296 1036
Rate (Kbps): 2048 512
D (interleaver depth): 1 1
Delay (msec): 0.13 0.25

HEC Errors: 0 0
OCD Errors: 0 0
LCD Errors: 0 0

Total ES: 0 0
Click to expand...
Very good, yes.
SNR (I'm guessing that's a D-Link router, you divide that number by 10) of 41.8 is well above the recommended, and attenuation of 21.0 is also well below the limit.
See http://mybroadband.co.za/vb/showthread.php/186156-Understanding-SNR-and-Attenuation-Rates for more details.
 
ADSL

Mode: ADSL_G.dmt
Type: ATM
Status: Up

Downstream Upstream
Line Coding(Trellis): On On
SNR Margin (dB): 183 140
Attenuation (dB): 65 40
Output Power (dBm): 20 39
Attainable Rate (Kbps): 10560 1080
Rate (Kbps): 4096 512
D (interleaver depth): 1 1
Delay (msec): 0.13 0.25

HEC Errors: 0 0
OCD Errors: 0 0
LCD Errors: 0 0

Total ES: 0 0

Does that SNR look right? A higher SNR is better aint it?
 
Gboss said:
ADSL

Mode: ADSL_G.dmt
Type: ATM
Status: Up

Downstream Upstream
Line Coding(Trellis): On On
SNR Margin (dB): 183 140
Attenuation (dB): 65 40
Output Power (dBm): 20 39
Attainable Rate (Kbps): 10560 1080
Rate (Kbps): 4096 512
D (interleaver depth): 1 1
Delay (msec): 0.13 0.25

HEC Errors: 0 0
OCD Errors: 0 0
LCD Errors: 0 0

Total ES: 0 0

Does that SNR look right? A higher SNR is better aint it?
Click to expand...
Higher is better, but 18.3 isn't too bad. It's not fantastic, but it's not too bad either :P
Attenuation looks very good though. Weirdly good - for such a low SNR, you'd expect a higher attenuation. Or the other way round.
 
aktor said:
Higher is better, but 18.3 isn't too bad. It's not fantastic, but it's not too bad either :P
Attenuation looks very good though. Weirdly good - for such a low SNR, you'd expect a higher attenuation. Or the other way round.
Click to expand...

My thoughts exactly, with an attentuation of 6.5db I was expecting an SNR in the region of around 25-35.
They say attentuation below 20db and SNR above 29db is outstanding. My att is very low almost like the exchange is in my backyard LOL
Could it be because my exchange is still ADSL_G.dmt and not ADSL2+?

AFTER THOUGHT: The higher your line speed the lower your SNR drops, could be my SNR is low because my line speed is 4MB. At 2MB line speed I should expect my SNR to increase. 4MB is close to the theoritical max speed you can obtain on a gmt exchange. If I had to try go up to 6 or 8MB my SNR will drop further, anything below 10db will mean sync issues and intermittent disconnects. Dammit!!!
 
Last edited:
Gboss said:
My thoughts exactly, with an attentuation of 6.5db I was expecting an SNR in the region of around 25-35.
They say attentuation below 20db and SNR above 29db is outstanding. My att is very low almost like the exchange is in my backyard LOL
Could it be because my exchange is still ADSL_G.dmt and not ADSL2+?

AFTER THOUGHT: The higher your line speed the lower your SNR drops, could be my SNR is low because my line speed is 4MB. At 2MB line speed I should expect my SNR to increase. 4MB is close to the theoritical max speed you can obtain on a gmt exchange. If I had to try go up to 6 or 8MB my SNR will drop further, anything below 10db will mean sync issues and intermittent disconnects. Dammit!!!
Click to expand...
Yup, that could definitely be it.
 
Gboss said:
My thoughts exactly, with an attentuation of 6.5db I was expecting an SNR in the region of around 25-35.
They say attentuation below 20db and SNR above 29db is outstanding. My att is very low almost like the exchange is in my backyard LOL
Could it be because my exchange is still ADSL_G.dmt and not ADSL2+?

AFTER THOUGHT: The higher your line speed the lower your SNR drops, could be my SNR is low because my line speed is 4MB. At 2MB line speed I should expect my SNR to increase. 4MB is close to the theoritical max speed you can obtain on a gmt exchange. If I had to try go up to 6 or 8MB my SNR will drop further, anything below 10db will mean sync issues and intermittent disconnects. Dammit!!!
Click to expand...

So with what you said, it doesnt seem I will get any faster speed than 2Mb. I know my attenuation is 53.0dB & SNR 12.5dB on 2Mb at home, I thought I might have a (slight) chance because at work attenuation is 60dB & SNR 11.30dB, sync at 3Mb, but after reading what you said it does make sense that the SNR will decrease on higher speed. SNR will probably drop below 10dB, even if I can (somehow) sync at more than 2Mb, its not going to be stable. Btw what is the SNR level that could be described as 'frequent disconnects'?
 
CVRChameleon said:
So with what you said, it doesnt seem I will get any faster speed than 2Mb. I know my attenuation is 53.0dB & SNR 12.5dB on 2Mb at home, I thought I might have a (slight) chance because at work attenuation is 60dB & SNR 11.30dB, sync at 3Mb, but after reading what you said it does make sense that the SNR will decrease on higher speed. SNR will probably drop below 10dB, even if I can (somehow) sync at more than 2Mb, its not going to be stable. Btw what is the SNR level that could be described as 'frequent disconnects'?
Click to expand...

I'm no cabling expert but a high attentuation normally indicates signal degradation and if its high then generally you are staying quite a distance from your exchange. I'm not sure why SNR decreases as line speed increases maybe an expert from here can shed some light on that for me. I guess thats why if you having a problem syncing at 10MB they keep dropping your line speed till your SNR is high enough for you to get a stable connection,
As a rule of thumb I use ATT low and SNR high = Faster max line speed

Below is a table I found which shows the ATT and SNR and which values predict a good line.

ATT
20dB and below is outstanding
20dB-30dB is excellent
30dB-40dB is very good
40dB-50dB is good
50dB-60dB is poor and may experience connectivity issues
60dB or above is bad and will experience connectivity issues

SNR
6dB or below is bad and will experience no synch or intermittent synch problems
7dB-10dB is fair but does not leave much room for variances in conditions
11dB-20dB is good with no synch problems
20dB-28dB is excellent
29dB or above is outstanding

Dont know how your work is sustaining 3MB with such poor line stats.
 
Gboss said:
I'm no cabling expert but a high attentuation normally indicates signal degradation and if its high then generally you are staying quite a distance from your exchange. I'm not sure why SNR decreases as line speed increases maybe an expert from here can shed some light on that for me. I guess thats why if you having a problem syncing at 10MB they keep dropping your line speed till your SNR is high enough for you to get a stable connection,
As a rule of thumb I use ATT low and SNR high = Faster max line speed

Below is a table I found which shows the ATT and SNR and which values predict a good line.

ATT
20dB and below is outstanding
20dB-30dB is excellent
30dB-40dB is very good
40dB-50dB is good
50dB-60dB is poor and may experience connectivity issues
60dB or above is bad and will experience connectivity issues

SNR
6dB or below is bad and will experience no synch or intermittent synch problems
7dB-10dB is fair but does not leave much room for variances in conditions
11dB-20dB is good with no synch problems
20dB-28dB is excellent
29dB or above is outstanding

Dont know how your work is sustaining 3MB with such poor line stats.
Click to expand...

Thank you for the reference :). So, as I thought Im already near the least possible 'good' connection range in SNR. Regarding my work sustaining 3Mb, I'm also surprised if I look at your list. So essentially, I should prepare to downgrade my 2Mb to 1Mb.

Btw the internet at work is baaaaaaaaaad today :( Wonder if its something to do with the upgrades of Telkom...
 
CVRChameleon said:
Thank you for the reference :). So, as I thought Im already near the least possible 'good' connection range in SNR. Regarding my work sustaining 3Mb, I'm also surprised if I look at your list. So essentially, I should prepare to downgrade my 2Mb to 1Mb.

Btw the internet at work is baaaaaaaaaad today :( Wonder if its something to do with the upgrades of Telkom...
Click to expand...

Lets hope with the exchange upgrades comes better line stats for you. Or you can buy a new house clposer to the exchange.
I would start looking for a house, its alot quicker and easier than waiting for Telkom to fix their infrastructure :p

I'm guessing the problems you been having with your Ti account speed has alot more to do with you poor line stats than anything else.
 
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