How do you improve SNR Margin?

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recre8

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I'm currently on 10mbps. My line stats show that the attenuation is acceptable, but the SNR Margin is terrible. My upstream SNR Margin sometimes drops below 6.5dB and I have on occasion had disconnects. The problem is that my RedAfrica account doesn't allow concurrent connections, and sometimes, the disconnect and reconnect are so quick after each other that WebAfrica doesn't realize that the line actually dropped, and then sends back an "Authentication Fail" which in turn causes the router to stop attempting to reconnect, meaning I have no internet until I get back home and turn the router off and on again.

My line stats on a Billion 7300GRA:
Code: 
Operational Mode 	ADSL2+
Upstream	        963 kbps
Downstream	10015 kbps
SNR Margin (Upstream)	6.4 db
SNR Margin (Downstream)	10.9 db
Line Attenuation (Upstream)	31.8 db
Line Attenuation (Downstream)	29.0 db

Is my SNR that bad? Can it be improved somehow?
 
How do you improve SNR Margin?
Click to expand...
You don't.

Or an alternative answer if you prefer:

Move closer to DSLAM (reliable results)... or buy an expensive router (unreliable results).
 
recre8 said:
I'm currently on 10mbps. My line stats show that the attenuation is acceptable, but the SNR Margin is terrible. My upstream SNR Margin sometimes drops below 6.5dB and I have on occasion had disconnects. The problem is that my RedAfrica account doesn't allow concurrent connections, and sometimes, the disconnect and reconnect are so quick after each other that WebAfrica doesn't realize that the line actually dropped, and then sends back an "Authentication Fail" which in turn causes the router to stop attempting to reconnect, meaning I have no internet until I get back home and turn the router off and on again.

My line stats on a Billion 7300GRA:
Code: 
Operational Mode 	ADSL2+
Upstream	        963 kbps
Downstream	10015 kbps
SNR Margin (Upstream)	6.4 db
SNR Margin (Downstream)	10.9 db
Line Attenuation (Upstream)	31.8 db
Line Attenuation (Downstream)	29.0 db

Is my SNR that bad? Can it be improved somehow?
Click to expand...

Have you tried another router, since sometimes it improves the stats and even new pots filters
 
ichigo said:
Have you tried another router, since sometimes it improves the stats and even new pots filters
Click to expand...

Haven't tried another router. The only other router I have is another Billion router, but will try and borrow one from work. I don't have a POTS filter on the line, because there is nothing connected to the line other than the router. Do you still need a filter if there are no analogue devices connected?
 
recre8 said:
Haven't tried another router. The only other router I have is another Billion router, but will try and borrow one from work. I don't have a POTS filter on the line, because there is nothing connected to the line other than the router. Do you still need a filter if there are no analogue devices connected?
Click to expand...

You shouldn't need one if you have nothing else including alarms connected to the line

If the work one is a different make/model it would be great to see the stats it says on it

I found my Telkom billion 400g router and Telkom Netgear one was giving bad SNR readings, but after changing to TP-Link 8690N and Netgear N300 I get like 2-3 times better SNR than I use to plus a smoother line.
 
Last edited:
ichigo said:
You shouldn't need one if you have nothing else including alarms connected to the line

If the work one is a different make/model it would be great to see the stats it says on it

I found my Telkom billion 400g router and Telkom Netgear one was giving bad SNR readings, but after changing to TP-Link 8690N and Netgear N300 I get like 2-3 times better SNR than I use to plus a smoother line.
Click to expand...

Yep, just the router connected to the line. Found a very old D-Link router here at work. Going to test it out later. Will report back.
 
Your upstream attenuation does not look right.It should be around 50% of your downstream attenuation
Either something wrong with your line or router
 
I replaced the entire section of telephone line between where it comes into the house (from the thick black telkom cable that comes into my garage) all the way up to and including the little box with the RJ11 socket. Stats are still exactly the same.
 
Last edited:
ajules said:
Your upstream attenuation does not look right.It should be around 50% of your downstream attenuation
Either something wrong with your line or router
Click to expand...

+1, You look like you need a port recreate. give telkom a call and advise them to recreate your port.
 
Keegan said:
+1, You look like you need a port recreate. give telkom a call and advise them to recreate your port.
Click to expand...

Is "port recreate" something different than "port reset"? I can reset the port on WebAfrica, but it doesn't make a difference.
 
recre8 said:
Is "port recreate" something different than "port reset"? I can reset the port on WebAfrica, but it doesn't make a difference.
Click to expand...

Yeah it is,
Normally your router needs to be switched off while doing the recreate/reset. best bet will be to give Telkom a call.... Gooo ooonn they not that bad :P
 
Keegan said:
Yeah it is,
Normally your router needs to be switched off while doing the recreate/reset. best bet will be to give Telkom a call.... Gooo ooonn they not that bad :P
Click to expand...

Will definitely try that. Do I need to phone WebAfrica (my DSL rental is through them) or Telkom? i.e. Is it a general phone line fault, or DSL specific.
 
recre8 said:
Will definitely try that. Do I need to phone WebAfrica (my DSL rental is through them) or Telkom? i.e. Is it a general phone line fault, or DSL specific.
Click to expand...

Hmm you got me there, I'm not sure how it works with WA, (the line is on your name or WA)
Probably should ask WA first before contacting Telkom. You can log it as a normal line/internet fault, the Telkom rep does it while you on the line.
 
Keegan said:
Hmm you got me there, I'm not sure how it works with WA, (the line is on your name or WA)
Probably should ask WA first before contacting Telkom. You can log it as a normal line/internet fault, the Telkom rep does it while you on the line.
Click to expand...

OK I phoned Telkom and they recreated the port. Stats are still pretty much the same. I'm also going to try and switch off the electric fence later and see if that makes any difference. That and trying a D-link and Netgear DSL routers. Will report back.
 
recre8 said:
OK I phoned Telkom and they recreated the port. Stats are still pretty much the same. I'm also going to try and switch off the electric fence later and see if that makes any difference. That and trying a D-link and Netgear DSL routers. Will report back.
Click to expand...

Cool, Can you PM your adsl number, I can do a line interrogation.
 
recre8 said:
I'm currently on 10mbps. My line stats show that the attenuation is acceptable, but the SNR Margin is terrible. My upstream SNR Margin sometimes drops below 6.5dB and I have on occasion had disconnects. The problem is that my RedAfrica account doesn't allow concurrent connections, and sometimes, the disconnect and reconnect are so quick after each other that WebAfrica doesn't realize that the line actually dropped, and then sends back an "Authentication Fail" which in turn causes the router to stop attempting to reconnect, meaning I have no internet until I get back home and turn the router off and on again.

My line stats on a Billion 7300GRA:
Code: 
Operational Mode 	ADSL2+
Upstream	        963 kbps
Downstream	10015 kbps
SNR Margin (Upstream)	6.4 db
SNR Margin (Downstream)	10.9 db
Line Attenuation (Upstream)	31.8 db
Line Attenuation (Downstream)	29.0 db

Is my SNR that bad? Can it be improved somehow?
Click to expand...
As mentioned try other routers, but I think the inevitable is, you need to downgrade your line from 10mbit to 8mbit, which may most probably keep your SNR just just high enough to not drop. Your attenuation is just just more than mine, and my SNR is a bit higher than yours.

Worst case scenario, drop your line speed between 4-6mbit and your SNR will be high enough.

The only other thing that will up your SNR, is Telkom installing a DSLAM closer to your house, take a guess what the probability of that is.
 
Hi,

Found where your exchange should be,
http://www.broadbandstats.co.za/exchange/WBTG04

are you far from there?

Below is your line interrogation, Doesn't look very pretty... could be your electric fence or distance from exchange.
If you are close to the exchange and turning off your electric fence does not change the SNR then you should log a fault with Telkom: slow/intermittent connectivity.

line inter.jpg
 
Keegan said:
Hi,

Found where your exchange should be,
http://www.broadbandstats.co.za/exchange/WBTG04

are you far from there?

Below is your line interrogation, Doesn't look very pretty... could be your electric fence or distance from exchange.
If you are close to the exchange and turning off your electric fence does not change the SNR then you should log a fault with Telkom: slow/intermittent connectivity.

View attachment 33054
Click to expand...

I'm on the same exchange - and I'm not having any issues. My SNR is in the same range - 6.5 to 6.6dB, line is synching at 10Mbps.

Might be worth actually getting a Telkom techie out to check your line and look for possible faults.
 
Note that the higher your throughput the more it chows your SNR margin. If you downgrade from the 10mb profile to the 8mb one your SNR stats will definitely improve.

In any case, I had *** SNR at my last house and, in order of effectiveness, I did the following:
(1) Had telkom replace the pole cabling for my street (there were existing problems related to the trees)
(2) Replaced all internal wiring after the dropwire with cat5 ethernet (original cabling was around 40 years old)
(3) Had telkom replace the dropwire from the phone pole to my house. (this had sections of exposed wiring and was badly worn)

Got from +12dB to +24dB after all of the above was done. (so an extra 12dB)
 
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