Weird Line Sync Problems

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Mean_Monster

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Hi all,

I had some problem with my adsl at home (384kbps line). I asked Telkom to investigate as I was getting frequent line drops on my line at night, which messes around when playing games online. The line would come back automatically after 10 - 20 minutes, without no user intervention just swearing.

Telkom then said that they have swapped out a DSLAM port in the exchange. Now a totally new problem has arisen. Sometimes my line will sync at 12000+ kbps with 800+ upstrean and other times it will connect at 381kbps and 123 upstream. This is also the only time it will work as seeing I am only suppose to be on a 384kbps connection.

Telkom have now claimed that this is due to a faulty router. I never used to have sync problems before. Any ideas? Router is a Netgear 834GT.
 
Updated. I have now tried 3 different modems on this line.

Netgear DG834GT
Netgear DG834v3
Telkom Mega 100WR

All of them sync at 381/123. Even on Telkom's side that is the sync they pickup so the routers are not reporting it wrongly. However when Telkom tech used 2 USB Billion modems both worked and synched @ 384/128, even used more that 1 notebook as 2 techs came out to my house.

Now you may say that I have 3 faulty routers. This would be incorrect as I tested them all at the office and they all work 100% their and sync at 384/128 on the line in our IT Workshop.

I am really getting nowhere with this problem and hope that somewhere out their someone else has experienced the same problem or know what the problem could possibly be as Telkom just says sorry your problem.

Trust me if I do get to the bottom of this I will reply to this post so others don't go thru the same problem as me without answers.

I have also since updated firmware on the routers to try and see whether it is not possibly that the newer DSLAM port communicate with the router in a different manner and therefore the sync issue. The line now seems to stay up longer but the speed seems to be noticeably slower.

Any assistance / advice will be greatly appreciated.
 
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unplug every normal house telephone , every fax , and every filter..

run your router 100% directly on the main line..

also report back figures like your line attenuation down and snr margins down(ds margin)
 
ADSL Link Downstream Upstream
Connection Speed 381 kbps 123 kbps
Line Attenuation 40.0 db 21.3 db
Noise Margin 29.3 db 29.4 db


Which from what I have read and understand is fairly okay.

I have done the uplug everything as well but this doesn't make a big difference except a 0.5 added to the line attenuation.
 
Have you tried changing the training mode of the router? I was also getting strange synch speeds on my router until I changed the modulation mode to ADSL G DMT.
 
Since I have done the following. I got a copy of the DGTEAM firmware for my router. Google it and you should be able to find it fairly easily. I updated my router to the latest version of this software. Be sure to grab a copy of the recovery tools that they talk about on that page just in case you "brick" the router. The upgrade works the same as any other firmware upgrade. The web gui also doesn't change that much just ads some extra features. One of the features it adds it the ability to change the ADSL Modulation. I changed mine to G.DMT and since then my sync has been corrected again to 384 and 128. However the disconnections are still debatable. I cannot get my ADSL to stay up for 200 days like @ the office, but it stays up for a couple of hours then drops.

As mentioned I know they swapped DSLAM ports and that is when the sync issue started. However, it would seem the setting I am setting is forcing this new port into a mode that it still is not 100% happy with therefore I get drops or maybe my line overnight became bad quality???

Anyone else experience this?
 
I have a friend who a few days ago also complained that he had problems with this line. ISP would say their stuff is working, and Telkom would say the line and exchange is fine.

Yet while he plays WoW he would get constant disconnects, high latency ect ect.

He tested 3 different netgear modems all same things. After reading this thead I asked him to check the settings, and he said he forced adsl2+ since forever on his modem. Obviously in the past this made no difference untill Telkom put in the adsl2+ equipment. He set his modem back to G.dmt after I asked him to, since then he said his line is much better.

My guess? Netgear modems do not like the new adsl2+ implementation.

ps. Billion modems seems to work almost always, bad lines new implementations whatever you throw at them. My parents lost the netgear I initially installed there, but luckily I left a Billion backup modem there before I moved down to CT. They happily using the Billion now with no problem either, but did complain they had problem with the netgear.
 
What is the normal db for downstream and upstream on a 384 kb line.....i have got this:

Downstream Upstream

SNR Margin :45.5 12.0 db
Line Attenuation :27.0 14.0 db

Data Rate:384 128 kbps
 
I have the Netgear DG834GT modem on a 4MB line. I was getting frequent line drops nearly everyday. My router would sync but I do not get an IP. The error message will say:"LCP down. LCP can't connect" (or something similar). After about 5 minutes it would reconnect properly.

I contacted Telkom and the technician came out and said my line is fine but he will put my line on a different DSLAM box at my exchange that is much newer that has been recently installed. He said they are moving all their 4MB customers there.

After that my line started syncing at 4095 and 507. I did not have a line drop for a few weeks but since last Thursday the line has been dropping constantly. Telkom did a reset on my port but that did not help.

I did a bit of reading and after reading Mean Monster's advice I used DMT (http://dmt.mhilfe.de/) which allows you to change your router to ADSL V.1 without flashing the firmware.

After using this my line immediately synced at 4096 and 512. My Downstream line attenuation came down from 39.5 to 37 and the SNR increased from 16 to 27. The SNR increase is very big and means that my line should theoretically be more stable.

The only downside is that you will have to use the tool each time the router is reset but if that makes my line more stable it is a small price I am willing to pay.

I will monitor the line and keep you guys updated regarding the stability.

BTW the DMT tool is a great device to check what your max speed can be on your line and it allows you to increase your SNR.
 
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Just simply buy a router that allows you to set the modulation mode manually. Not sure which ones do off the top of my head, but there will be a few out there.
 
Tinuva said:
My guess? Netgear modems do not like the new adsl2+ implementation.
Click to expand...

Tried that argument with Telkom apparently I am the only one :rolleyes:

bokka1. I just flashed it as I wasn't in the mood to do the reconfig all the time. I am not saying that is what you should do. I am just sharing my experience and what has worked for me so far. I must say the last 3 nights my line has been fairly stable.
 
I started experiencing the same issues end of last week. Also on 4MB. I would lose sync randomly during the day. I've now changed my modulation to G.dmt and will see how it goes. Before last week my line was stable as a rock for more than a year. The upgrading of all 4MB customers to ADSL2+ sounds like a good explanation since my modem was set to Multimode, it probably switched to ADSL2+ when my DSLAM was upgraded. I'm assuming it's been upgraded though since that's all that could explain the sudden sync problems... :)
 
I had a similar problem. Mine was real bad. Something like 1200 disconnects/line drops a month. It ended up being a faulty line which they replaced and now my internet only disconnects when I reset my router.
 
Well in this thread I think its not only the line that disc, its also that when it syncs it doesnt sync at the exact correct values of the line, which is the real problem.
 
So my problem was not resolved with changing the modulation to G.dmt
Again lost sync at around 09:00 this morning. Will try another router, if problem persist then I'll have to wait on Telkom/Axxess I guess...
 
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