ADSL /VDSL help

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Hi

Been a while since I worked with DSL , but looking at upgrading a line
Line is 100% stable and has been for more than 3 years (Backup line)

Speedtest : Mybroadband on a speed capped account 10Mbps
Ping: 24ms
Download: 9.93Mbps
Upload: 0.61Mbps

Ping 24ms a concern ?

Line attenuation 6.5 downstream 5 upstream
Signal attenuation / Noise Margin 19.4 downstream 8.5 upstream

What can i realistically expect from this line in terms of VDSL ?
My needs are for higher upload speed , download is of secondary importance
20 Mbps down and 5 + Mbps up would be fantastic
 
Attenuation looks pretty good. Your line is probably interleaved if you're getting 24ms to local servers, try the closest one to you on speedtest and see if you ping lower. @AfriNatic this should be a fine attenuation for a 20/5 pure VDSL line?
 
Anagram said:
Hi

Been a while since I worked with DSL , but looking at upgrading a line
Line is 100% stable and has been for more than 3 years (Backup line)

Speedtest : Mybroadband on a speed capped account 10Mbps
Ping: 24ms
Download: 9.93Mbps
Upload: 0.61Mbps

Ping 24ms a concern ?

Line attenuation 6.5 downstream 5 upstream
Signal attenuation / Noise Margin 19.4 downstream 8.5 upstream

What can i realistically expect from this line in terms of VDSL ?
My needs are for higher upload speed , download is of secondary importance
20 Mbps down and 5 + Mbps up would be fantastic
Click to expand...

You have a line fault if you have those attenuation values being so good but the SNR relatively low. With those Attenuation value 40Mbps is feasible however the noise on the line needs to be addressed first.
 
Last edited:
AfriNatic said:
You have a line fault if you have those attenuation values and the SNR is so low. With those Attenuation value 40Mbps is feasible however the noise on the line needs to be addressed first.
Click to expand...

I think you are mistaken, Line attenuation, lower is better and SNR, higher is better.

For SNR, 6 is the lowest to sync, so 19 isnt great but not terrible.
 
Rickster said:
I think you are mistaken, Line attenuation, lower is better and SNR, higher is better.

For SNR, 6 is the lowest to sync, so 19 isnt great but not terrible.
Click to expand...

No I haven't. At 6.5 and 5dB attenuation when the line syncs at 12.5Mbps it's low figures for SNR. Should 25dB+ on the SNR at that sync rate. By the looks of the speedtest upload is not syncing at the max of 1.25Mbps if the upload speed maxes out at 0.61 which suggest a lower than 1Mbps upload rate and seeing the distance it's a problem.

I have a line with 44dB Attenuation but still syncs as 10Mbps and 1.25Mbps upload and still has 10dB on SNR for a comparison.
 
AfriNatic said:
No I haven't. At 6.5 and 5dB attenuation when the line syncs at 12.5Mbps it's low figures for SNR. Should 25dB+ on the SNR at that sync rate. By the looks of the speedtest upload is not syncing at the max of 1.25Mbps if the upload speed maxes out at 0.61 which suggest a lower than 1Mbps upload rate and seeing the distance it's a problem.

I have a line with 44dB Attenuation but still syncs as 10Mbps and 1.25Mbps upload and still has 10dB on SNR for a comparison.
Click to expand...
But his SNR is 19, not 6.5


Signal attenuation / Noise Margin 19.4 downstream 8.5 upstream
 
Thanks for the replies

Ping on speedtest.net to Rocketnet and Afrihost Johannesburg is 27 ms

iirc the reason this line was a backup was that after numerous fault reports this was the best achieved and fatigue to continue trying took over

What happened to the sticky explaining SNR and attenuation in the forum ,? It always was extremely helpfull

Probably moving the line to an ISP and see if that way I can get the faults resolved
 
:thumbsup:

Understanding SNR and Attenuation Rates

Signal-to-noise ratio Signal-to-noise ratio (often abbreviated SNR or S/N) is an electrical engineering measurement defined as the ratio of a signal power to the noise power corrupting the signal. In less technical terms, signal-to-noise ratio compares the level of a desired signal (such as...
mybroadband.co.za mybroadband.co.za
 
AfriNatic said:
No I haven't. At 6.5 and 5dB attenuation when the line syncs at 12.5Mbps it's low figures for SNR. Should 25dB+ on the SNR at that sync rate. By the looks of the speedtest upload is not syncing at the max of 1.25Mbps if the upload speed maxes out at 0.61 which suggest a lower than 1Mbps upload rate and seeing the distance it's a problem.

I have a line with 44dB Attenuation but still syncs as 10Mbps and 1.25Mbps upload and still has 10dB on SNR for a comparison.
Click to expand...
I have seen some posts mentioning that once using an actual VDSL router, and switching modulation to VDSL, the line stats changed completely for the better. Maybe the router itself could be the problem? AFAIK with ADSL connections there is some sort of default target SNR of around 6db? I know this can be meddled with through telnet and such, and have done so myself. The only weird thing I notice is the 5 on the upstream when there is a 6.5 on the downstream.
 
ghostbunny said:
I have seen some posts mentioning that once using an actual VDSL router, and switching modulation to VDSL, the line stats changed completely for the better. Maybe the router itself could be the problem? AFAIK with ADSL connections there is some sort of default target SNR of around 6db? I know this can be meddled with through telnet and such, and have done so myself. The only weird thing I notice is the 5 on the upstream when there is a 6.5 on the downstream.
Click to expand...

Once you start reaching the max speed of ADSL2+ which is ~24Mbps the SNR drops quite a bit even under good line conditions. Once you switch over to VDSL2 mode those stats improve significantly.

There is a limit though. After about 2km from the exchange there is no difference in line stats when comparing ADSL2+ and VDSL2.
 
AfriNatic said:
Once you start reaching the max speed of ADSL2+ which is ~24Mbps the SNR drops quite a bit even under good line conditions. Once you switch over to VDSL2 mode those stats improve significantly.

There is a limit though. After about 2km from the exchange there is no difference in line stats when comparing ADSL2+ and VDSL2.
Click to expand...
I can vouch for this.
I am hurting on my 20 meg VDSL line over nearly 2 km of tired old copper. SNR of just 9. Unlike many others, I'm not really looking forward to the line speed doubling, the SNR halving, and the signal dropping out. :(
 
AfriNatic said:
Once you start reaching the max speed of ADSL2+ which is ~24Mbps the SNR drops quite a bit even under good line conditions. Once you switch over to VDSL2 mode those stats improve significantly.

There is a limit though. After about 2km from the exchange there is no difference in line stats when comparing ADSL2+ and VDSL2.
Click to expand...
I actually made a bit of a mistake there, I was reading the line attenuation stats which are actually really good.
I mean 6.5 downstream attenuation would imply you're near like 500m away from the exchange?
 
(would imply you're near like 500m away from the exchange?)

Apparently yes , Tech says its a "mini exchange" though , less than 1 km

Just DSL from Axxess on a new installation using guest account "Telkom" gave test results of 40/10 to multiple test servers Telkom Mybroadband and speedtest.net

Opted for a new install rather than trying to "fix" the old line , just waiting for the jack to be pulled to correct location and then will be able to test SNR and attenuation
 
ghostbunny said:
I actually made a bit of a mistake there, I was reading the line attenuation stats which are actually really good.
I mean 6.5 downstream attenuation would imply you're near like 500m away from the exchange?
Click to expand...

Yes very very close hence I'm concerned about the SNR although not totally bad still a bit concerning that the line is only at 10Mbps and so close to the exchange.

VDSL2 mode should sort it out otherwise there is noise on the line that is causing the numbers to be a but lower than expected.
 
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