Help diagnose weird connection issue

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21stcn

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Hi there,

I have for the past 24 hours had a problem with my 2MB adsl connection. I've logged a fault with telkom but while I wait for that nightmare to unravel I wonder if any one might have any idea what is happening here.

So basically my normally reliable 2MB uncapped is averaging about 8KB/s down (up is fine). It spikes and goes dead but for the most part is unusable. I will list the test I've done below but will just jump into the weird symptoms. I don't think it is congestion as my ping is fine (20ms).

So the dl speed averages at a few KB, BUT if I open all of my favourites in new tabs in any browser, the connection jumps to 200KB/s until all of those tabs are loaded. So it seems to only use the full connection with multiple connections. If it is a single tab, it is dead slow, and I couldn't even download a 800Kb file (network adapter drivers) because it went at 800 bytes per seconds for 10 minutes before failing, or stream.

The other weird thing is that when I ping or do a speed test, the tests themselves last about 2 minutes. In other words, if I ping google.com, while it reports low latency (30ms), the time between each result is about 20 seconds. Same with the speed test, it takes 2 minutes but seems to average the ACTUAL TIME IT WAS downloading and not the dead time in between. So the speed test might report 0.8MB/s while the test takes 2 minutes. I've never seen this before. Is this indicative of any issue?

Tracert also reports packet loss. Everything was fine for 3 months until suddenly. I also checked that is not throttling from my ISP. I have a good rating and they are not throttling at present. Further, neither webafrica nor telkom can detect any issues on their end.

Other tests I have done:
-Used telkom guest (webafrica ISP) = same problem (speed test 2 minutes)
-Tested in safe mode with networking and killed all network processes = same problem
-Tired different router without wireless to rule out the router and devices hogging wireless = same problem
-Turned off firewalls and antiviruses
- Asked telkom for port reset

Essentially I have a few seconds of activity and then nothing, so download speed graphs are just a bunch of spaced out spikes.

SNR and attenuation seem fine as far as I can tell. Although Attenuation is reported as 100dB I believe this is at a factor of 100 as the other router reports 1.

Any one know what the problem might be? Does it sound like a line issue?

Thanks

usage.jpg
tracert.jpg
speedtest.jpg
ping.jpg
snr.jpg
 
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Can you run a test with another router?

Edit : sorry fail at reading :o , you've done this already

With all the tests you have done i would imagine the issue is on telkoms side.
 
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There could be a number of issues. First check that your line is syncing at 2mbps. You might have bought the 2mbps product, but for some reason your downstream sync rate could have been dropped to 512kbps. The problem could also be anywhere between the Telkom exchange and your router/modem/PC. It could be the wiring in your house or external wiring to the Telkom pole and onwards towards the exchange, or even within the exchange. It could be the modem/router, filter, or even your PC.

Check my blog post for some guidelines to help you narrow it down: How to diagnose ADSL line, speed & stability problems

And do provide us with further feedback. I will try to assist if I can.
 
Thanks Saajid for the reply and the useful info on your site.

here is an update:

A telkom techie called me from the exchange yesterday and said everything was testing fine. At the time, my internet was fully functional so I had no option but to resolve the fault (and it was an awkward conversation: "No, I swear it wasn't working, but it is now"). I also secretly hoped it was in fact somehow resolved. It is not.

Today at 10:00 my internet went from perfect to useless. I am now averaging 6KB/s. Once again it is spiking. So I have 15 minutes of nothing and then 2 seconds of full speed and then nothing again.

I wonder if the time of day indicates anything? Literally nothing changed from fully functional to almost dead. It just happened in an instant and will probably last a few hours or the whole day which isn't great for a web designer.

If this is some rare line thing, the DILEMMA is how to get telkom to do a call out WHEN the line is ****ed? If I reopen the fault, the same thing will occur. They will test at the exchange at some random time and report it working. Worse, if the problem is between my flat and the exchange, I will have to take a leap of faith and get them to come over. When they come over, chances are the problem won't be 'active' and I'll just get lumped with an 'unnecessary callout fee' and no help.

That is why I need MBB to solve this, as it has helped me do in the past. I want to be thorough in my testing and would appreciate help if this particular problem rings a bell for anyone.

Once again, the symptoms:
- Speed is fine most of the time
- Sporadically becomes absolutely useless, working at speeds of less than 10KB/s for a random period of time. During this time there are a few short spikes of activity lasting a few seconds at most.
- Resolves itself eventually
- Ping seems fine though huge delays between ping results (see top post)
- Router swapped, filter removed, processes killed, ports recreated, no ISP throttle, SNR and Atten fine, anti virus run, firewall/antivirus deactivated

Right now internet unusable. Right now I need it badly for my goddamn income stream.

Maybe I should just turn the line over to Webafrica... would this result in a better chance of someone actually LISTENING to what I am saying and investigating, as opposed to "This problem isn't obvious, pay us"?
 
I have seen some threads here on MyBB where people posted very similar problems, i.e. where the line drops in intervals, or at particular times of the day, but Telkom closes the fault as resolved because at the time they check it, their is no problem.

Unfortunately I don't have a link to any of these threads, but there might be useful information in their that could assist. You could do a search of the forums for the following keywords:
- line sync issues
- adsl dropping
- adsl unstable

Then read through the first post of each of these threads, to find the one that is most similar to your problem, and then read the whole thread.
 
Check the following threads:
- http://mybroadband.co.za/vb/showthread.php/476572-ADSL-Keeps-desyncing
- http://mybroadband.co.za/vb/showthr...ems-Both-ADSLs-can-t-sync-up-at-the-same-time
- mybroadband.co.za/vb/showthread.php/480920-ADSL-line-issue-telkom-exchange-related

You should also check the following:
- if your modem is to ADSL2+, try changing it to G.DMT (or vice versa)
- you need to determine if your line is losing sync (i.e. getting disconnected from the exchange, and then re-syncing), or your line sync is stable, but you're losing connectivity. You can get this info from Telkom. They should be able to tell you over the phone when you last disconnects and reconnects happened. I think you can login to the Telkom Online Tracker as well, and it will give you this info as well.
 
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Saajid and Keegan, thanks for your advice.

It seems to be ok for now, but I will definitely follow more of the steps and PM if it resumes.

I don't know if this makes any sense, but this is what SEEMS to have made a difference: I was trying to do this step "if your modem is to ADSL2+, try changing it to G.DMT (or vice versa)" but my d-link has select boxes for mode and ADSL2+ and G.Dmt along with a lot of other modes were ALL selected.

I switched to ADSL2+ only but had zero action, then back to G.Dmt and after a reset, it has been smooth since. Maybe it is just a coincidence and the problem will appear again down the line, but it somehow seems to have made a difference. This doesn't explain the same problem with the other router, I don't think.

If it starts again I will find out definitively if it losing sync or losing connectivity. Thanks again for your very useful advice.
 
21stcn said:
Saajid and Keegan, thanks for your advice.

It seems to be ok for now, but I will definitely follow more of the steps and PM if it resumes.
Click to expand...

No problem. Please keep us updated, whether your line has become stable, or if you experience more problems. I have a feeling that is the change you made, setting it to ADSL2+ only, that made the difference.

You might want to make these same changes on the other router as well, and test. But give it a few days. After a while, I would also try to update the firmware on the modem. More likely than not, it is an incompatibility between the exchange and the modems that is causing problems. They're not communicating properly all the time, or so it seems.
 
Hi There,
Glad the problem seems to have now gone away. Saajid's suggestion of checking and updating the firmwsare of the modem is a good idea that all too often we all forget to do.

Regards

Tim
 
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