Very unstable line

K

Kayoss

Expert Member
Joined
Feb 26, 2007
Messages
1,079
Reaction score
267
Seem to be having a problem with my adsl line. Every night, for the past 5 days, my line becomes very unstable. I mean so unstable that it can't be used. My SNR margin drops to about 4 (normally around 12) and my line syncs at about 600kbps (normally over 3000kbps). My line wont stay connected for more than a few minutes and even when it is, i can bearly even load a website.

On monday i phoned telkom and asked them to change my profile from 4mb to 10mb (thinking that way i would be able to at least sync at 4mbs and get the speed i pay for).. turns out that i get a lower speed when on a 10mb profile than when im set to 4mb. So anyway, i asked them to change my profile back to 4mb and then logged a fault due to the slow speed on 10mb.

That night, around 8/9pm it started dropping and only came back around midnight.. Same thing every night since then. No problems in the day however..

Any advice on what to do would be great.

Thanks

btw, i have been trying for a few hours now to post this.
 
Telkom are probably busy with network upgrades in your area. But there can also be something wrong at the exchange.
Phone 0800 375 375 and ask them to reset your ADSL port on the exchange. Ask them to also check for any problems on your line and for congestion at the exchange.

Good luck :)
 
ZeRo_CoOl said:
Telkom are probably busy with network upgrades in your area. But there can also be something wrong at the exchange.
Phone 0800 375 375 and ask them to reset your ADSL port on the exchange. Ask them to also check for any problems on your line and for congestion at the exchange.

Good luck :)
Click to expand...
? Are you guessing random solutions for him? None of these are relevant, but thanks for offering help anyway -- it seems his problem is being caused by attennuation/noise margin fluctuations which are causing line instability

Kayoss, the reason your line is so unstable is because of your distance from the exchange, or just simply the quality of the copper phone line FROM your house to the exchange. It could also be caused by other conditions inside your home... Noise seems to be the main concern.
First, try the following:
- Unplug everything connected to that phone line (including POTS filters), except the ADSL modem.
- Make sure the ADSL modem is connected to the closest phone socket to your demarcation point (where the phone line enters your home from outside).
- Try get a filter that has an ADSL port/socket as well. These filter out all frequencies which aren't used for ADSL, and therefore helps a bit with noise problems.
- Try another phone cable to link your modem to the wall socket... also, if you have any electrical experience you may want to check out that socket and rewire it yourself.. just be careful, ringing voltage can give a nasty tingle

If none of that reveals anything useful, then you need to try get Telkom out to check out the quality of the line and maybe see if fixing some corroded joints or replacing straight cable with twisted pair from the nearest pole to your house might help with the noise problem. Also, try another ADSL modem such as the D-Link DSL-2500U, the Netgear DG834(/DG834G) with DGTeam firmware, or the Siemens 762SX which works really well for me. Until then, your best bet is to call Telkom and ask them to put you on a 3Mbps or even 2Mbps profile, to help with stability.
 
Last edited:
fragtion said:
you need to try get Telkom out to check out the quality of the line and maybe see if fixing some corroded joints might help with the noise problem.
Click to expand...
This is my bet. Seems to be a intermittent cable fault most likely due to a dry joint. Ask Telkom to send a technician to check the condition of your cable from your house to the MDF.
 
fragtion said:
? Are you guessing random solutions for him? None of these are relevant, but thanks for offering help anyway -- it seems his problem is being caused by attennuation/noise margin fluctuations which are causing line instability

Kayoss, the reason your line is so unstable is because of your distance from the exchange, or just simply the quality of the copper phone line FROM your house to the exchange. It could also be caused by other conditions inside your home... Noise seems to be the main concern.
First, try the following:
- Unplug everything connected to that phone line (including POTS filters), except the ADSL modem.
- Make sure the ADSL modem is connected to the closest phone socket to your demarcation point (where the phone line enters your home from outside).
- Try get a filter that has an ADSL port/socket as well. These filter out all frequencies which aren't used for ADSL, and therefore helps a bit with noise problems.
- Try another phone cable to link your modem to the wall socket... also, if you have any electrical experience you may want to check out that socket and rewire it yourself.. just be careful, ringing voltage can give a nasty tingle

If none of that reveals anything useful, then you need to try get Telkom out to check out the quality of the line and maybe see if fixing some corroded joints or replacing straight cable with twisted pair from the nearest pole to your house might help with the noise problem. Also, try another ADSL modem such as the D-Link DSL-2500U, the Netgear DG834(/DG834G) with DGTeam firmware, or the Siemens 762SX which works really well for me. Until then, your best bet is to call Telkom and ask them to put you on a 3Mbps or even 2Mbps profile, to help with stability.
Click to expand...

Well at the end of the day it all comes down to the fact that he will need to contact Telkom to investigate. He also stated that he does not experience any problems during the day, only at night which might indicate problems at the exchange. If their was noise on the line then he would have experienced the problem during the day as well, so your answer is not really relevant in this case.
 
Thanks for the suggestions guys. After logging a fault last monday, telkom phoned me today to tell me that they've assigned someone to my fault.

btw, i do hear noise on my phone line even tho i do have filters on but, this happens 24/7 and my line is perfect in the day. My line attenuation sits at about 48 (down), even when i have the problems.
I'm 2.5km from the exchange. And i've had adsl for years now and have never had this problem before..

Will let you know what happens
 
Just an update..
i phoned Telkom today, still without internet at night, and they told me that the fault had been closed. They did not notify me of this. Telkom also claim that this is an mweb problem and not a telkom problem! They say that it's because im on mweb's uncapped account.

I can't begin to tell you how annoyed i am.
 
Well over a month later and this problem still hasn't been resovled. No internet for a few hours every night, apart from today, where i had no internet the whole day, and now have it at night (and it's very slow)..

I escalated the fault and telkom sent a technician to my house. He had never heard of SNR margins and line attenuation before.. He then asked if i would be available the next day and i said yes, he did not get back to me and instead, he closed the fault as 'resolved'.

I have opened another fault but i'm not holding thumbs. I guess my only option is to get wireless net?

I'm not sure how to upload an image but i took a few screenshots when i was having the problem.

...........................Down........Up
SNR Margin:..........3.5...........12
Line Attenuation:...50.5..........27
Data Rate:............960..........511

My SNR margin sits at around 13(down) when working properly and my Data Rate(down) is normally over 3000. Again, this problem started at the same time that Telkom upgraded my exchange to support 10mb.

Any advice would be great.
Thanks.
 
Kayoss said:
Again, this problem started at the same time that Telkom upgraded my exchange to support 10mb.
Any advice would be great.
Click to expand...
If it happened when they switched over to 10Mbps, then it could be that your modem syncs okay on G.DMT (ITU G.992.1) but not on ADSL2+ (ITU G.992.5). What modem do you have? Go into your modem advanced adsl settings, and look for the setting. It's probably set to "Automatic" or "Multimode", change it to G.DMT. If your line conditions improve, you can try go back... I hope this helps!
 
With a Line Attenuation like that you will not be able to get 4Mbps unless you have an awesome ADSL modem.
My guess would be that with your current router that you will not even be able to get a stable 1Mbps connection. Unfortunately if you didn't know what your line attenuation was previously, I can't say whether Telkom would be able to "fix" it.

If you downgrade to 384kbps you shouldn't have any issues though.

Edit:
I would really try and do like Fragtion suggested and see if you can set the modulation to G.Dmt and not ADSL2+

Could you perhaps tell us what modem you have? Please don't tell me Netgear...
 
Im also having a very similar problem with my line it stable during day but when i try online gaming it just drop like crazy , i am using a netgear dgn2000 router with custom firmware, telkom put my line down to a 3mb but i dont see a noticeable change in stability
ADSL Link Downstream Upstream
Connection Speed 3072 kbps 512 kbps
Line Attenuation 34.0 db 19.0 db
Noise Margin 14.4 db 12.0 db
are these values good enough for a 4mb line and how can i find out how far away i am from the exchange?(noob question)
 
Flip123 said:
Im also having a very similar problem with my line it stable during day but when i try online gaming it just drop like crazy , i am using a netgear dgn2000 router with custom firmware, telkom put my line down to a 3mb but i dont see a noticeable change in stability
ADSL Link Downstream Upstream
Connection Speed 3072 kbps 512 kbps
Line Attenuation 34.0 db 19.0 db
Noise Margin 14.4 db 12.0 db
are these values good enough for a 4mb line and how can i find out how far away i am from the exchange?(noob question)
Click to expand...
Doesn't seem to be anything wrong with your line - you SHOULD be on 4Mbps assuming your noise margins stay stable (at least above 5-10dB). Seems like you've got an exchange problem, which is Telkom's baby...

I have similar stats, but check my line rate:
Downstream rate: 10012 kbps
Upstream rate: 1023 kbps

Line mode: ADSL2+
Maximum line rate: 10688 kbps (downstream) / 1176 kbps (upstream)
Noise margin: 6 dB (downstream) / 9.2 dB (upstream)
Line attenuation: 35.9 dB (downstream) / 19.8 dB (upstream)
Output power: 16.9 dBm (downstream) / 12.4 dBm (upstream)
Click to expand...
This is with a de-branded (latest firmware) Telkom Siemens SX762. Line attenuation fluctuates between 35-37dB, I had ~10-16dB DS noise margin on 4Mbps, which was reduced to ~4-7dB on 10Mb, but even when noise margin is 5dB, my line stays stable 950-1020KB/s (8-9)Mbps with this modem, although sometimes it just drops badly to like 100K and needs a reboot which normally sorts it out...
With my Netgear DG384 & 384T, and VOX modem I get like 400-700kb/s, which shows that the Siemens is superior for this sort of line. I've ordered a D-Link 2500U to try too because it's well priced and I've heard good stuff about it. If anyone has any suggestions for a modem that gets good rates under bad conditions, and latency comparable with the SX762 (which is excellent) that would be sweet =D

So with your attenuation, 4Mbps shouldn't be a problem.

It's interesting to see how rarely (despite really low noise margins) I lose sync now - in fact I don't think my line has dropped once since the switch to ADSL2+. I even tried unplugging the line from the modem for like 2 seconds and plugging it back in, which would normally have caused a guaranteed re-sync, but not the case with this modem/DSLAM/ADSL2+ combo. At the office, the modem even dynamically adjusts the MAX Attainable Rate and Rate according to the condition of the line automatically/without requiring a re-sync, but it seems the DSLAM for my home line doesn't have that feature(enabled?) =(
 
Last edited:
fragtion said:
Doesn't seem to be anything wrong with your line - you SHOULD be on 4Mbps assuming your noise margins stay stable (at least above 5-10dB). Seems like you've got an exchange problem, which is Telkom's baby...
Click to expand...

i have logged 3 faults in the past 4 months hoping that they would do something but Telkom just blames my isp (mweb) for the line problems so what do i do? should i take an aggressive approach and start swearing at them over the phone or just give up
 
Have you tried another ISP account? Try a Telkom account. When it seems to cut out for mweb, use the telkom guest account:
Username: guest1@telkomadsl
Password: guest1
Then see how your speeds are to: ftp://ftp-test.telkomadsl.co.za/
If it's bad with that too, then u can tell Telkom that its not the ISP because using a Telkom account you get the same problem
 
@fragtion, thats correct, my modulation switched over from G.DMT to ADSL2+ however changing this on my modem doesn't help. It's currently set to automatic and i see that sometimes it connects on G.DMT and sometimes on ADSL2+. I have tried to force it to G.DMT when im having the connectivity issues but it doesnt help.

@Pada, My line attenuation is usually in the high 40's and i've been able to have a stable 2.5-3mb for some time now. I've had 4mb ever since it came out and only for the last month have i had issues..

I uses a billion modem (not sure of the model number) and i also have a planet modem. My line doesn't work on both.

Thanks again for the suggestions
 
Just to revive an old thread.. 7 months later and I still don't have internet at night and now during the day on weekends. Everytime I log a fault with telkom, a few days later its closed without change.. They don't care.
somehow, my snr margins have been in the -ve's lately?!? I don't know how that's even possible.
Amazing how "upgrading" my exchange to support 10mb/s has ended up in a major downgrade.
 
Sorry, its no internet at night on weekdays and then no internet during the day on weekends.
Posting this on my blackberry
 
i had a problem about a year ago with my telkom line. They also kept closing the tickets.
Open a new one as soon as the old ticket is closed. Keep doing it.
I discovered by doing that my complaint was handed over to a quality dept coz i complain too many times in 2 months.

A gent came to my place. Inspected all my equipment, pots filters etc.... & less than a week later my line was fixed.
 
You must log in or register to reply here.
Back
Top
Sign up to the MyBroadband newsletter
X