ADSL Up and Down like a Yo-Yo

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Shirou

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I am so fedup with my ADSL line already, its up and down the whole time, the DSL line keeps dropping, i called telkom several times before there has been 5+ telkom guys solving it already they cant get to fix it.

Anyone else with this problems?
 
same thing here, started on sunday evening. after I unplugged my phone & pots filter it seemed better so I'm bringing a new set from work to see if the phone/filter may just be faulty.
 
jprheeder said:
same thing here, started on sunday evening. after I unplugged my phone & pots filter it seemed better so I'm bringing a new set from work to see if the phone/filter may just be faulty.
Click to expand...

I logged the fault with telkom again this morning my 7th time now.

What Telkom did:

1. Replaced underground cable.
2. Did a new ADSL installation.
3. Changed my port to another port on the exchange.
4. Replaced the micro filters.

What i did:

1. Bought a new Telkom line from the microfilter to the router.
2. Bought a new router.

Still it keeps dropping, And i had 4mb lastyear without a single DSL line drop, this year my 4mb just constantly drops from after Feb 2010, from that time i have been calling Telkom every month to sort it out.. i am now in October, they are still trying to solve it, the 7th Telkom guy will probally be here this week to have a look.
 
Maybe it is your ISP thats dropping your line? you using any 3rd party downloading methods? (ie: raping their network?)
 
Shirou, could you post your line statistics (sync rates, line attenuation and SNR margins) and specify which ADSL modem/router you have too.
 
What Pada said....
I'll wager if you drop to the 512 connection all your problems will be solved :)
 
Thats not gonne happen, i had 4mb stable before 100% no drops, why the disconnects now?
 
There are tonnes of reasons.
One of the most prominent on is more subscribers at higher speeds, causing interference.

Like my office started off with 4Mbps ADSL in March this year, and we gradually had to change the sync profile to lower rates until we reached 1Mbps last week.
Now we're simply using another ADSL modem and the 4Mbps connection is working OK, but we might have to downgrade to 3Mbps just to ensure that the line does not drop.
 
What i did now in the last 2days:

1. Stopped my downloads no one was downloading for a day, and it kept disconnecting the whole time.
2. Unplugged the tellephone, only the router was pluged in with its micro filter.

I have the Zyxel P-660HW-T1 v2

noise margin upstream: 7 db
output power downstream: 0 db
attenuation upstream: 24 db

noise margin downstream: 5 db
output power upstream: 12 db
attenuation downstream: 40 db
 
Shirou:
With those low noise margins you will have an ADSL that will go up & down rapidly! You need at least 6dB to establish an ADSL connection in the first place.
What I do find strange is that your line attenuation is reasonably high, but still low enough to be able to get like a stable 6Mbps ADSL connection.

I would suggest that you first try to remove ALL the telephone, alarms & fax machines from your telephone line and then connect the ADSL router directly on the telephone line (bypassing the micro filter).

If your noise margins are still below 12dB, then I would suggest that you borrow someone's D-Link or Marconi router. I have a Zyxel SDSL router and it sux, because I have to run it at 1.5Mbps.

Another alternative would be to drop your ADSL line's profile to 2Mbps down and also reduce the upload speed from like 512kbps to 384kbps or something like that, to ensure that both upstream and downstream noise margins are well above 10dB.
 
Pada said:
Shirou:
With those low noise margins you will have an ADSL that will go up & down rapidly! You need at least 6dB to establish an ADSL connection in the first place.
What I do find strange is that your line attenuation is reasonably high, but still low enough to be able to get like a stable 6Mbps ADSL connection.

I would suggest that you first try to remove ALL the telephone, alarms & fax machines from your telephone line and then connect the ADSL router directly on the telephone line (bypassing the micro filter).

If your noise margins are still below 12dB, then I would suggest that you borrow someone's D-Link or Marconi router. I have a Zyxel SDSL router and it sux, because I have to run it at 1.5Mbps.

Another alternative would be to drop your ADSL line's profile to 2Mbps down and also reduce the upload speed from like 512kbps to 384kbps or something like that, to ensure that both upstream and downstream noise margins are well above 10dB.
Click to expand...

Thanks i will try this tonite! So my noise margins needs to be atleast 12? and whats best for attenuation? the thing is i had a Marconi router before the Zyxel, same problem that was the reason to get the Zyxel.
 
Last edited:
You cannot change the line attenuation. Line attenuation is the loss measured on your line, which almost directly related to the distance of the cable.
 
Pada said:
You cannot change the line attenuation. Line attenuation is the loss measured on your line, which almost directly related to the distance of the cable.
Click to expand...

What is the best attenuation for downstream/upstream and the best margins for downstream/upstream

Because i have just checked the router at work, its also a Zyxel.

Upstream noise margins: 6dB
Attenuation Upstream: 8 dB


Downstream noise margins: 19 dB
Attenuation Downstream: 11 dB

And this lines here is stable like nothing before :) So your attenuation needs to be low, and noise margins needs to be high?
 
Shirou:
Yes, the line attenuation needs to be low and the SNR needs to be high.
A lower line attenuation, means that the signal loss on the cable is low, which will in effect result in a better SNR (noise) margin.
The downstream SNR margin would also drop at about 3dB per 1 Mbps increase. Like if you have an SNR of 20dB at 384kbps, then you'll have like 12dB at 3Mbps. The same goes for the upstream SNR, but its rate is different than 3dB/Mbps. Also note that this 3dB/Mbps rate is just a VERY rough estimate of mine!

It would be a good idea to read the following thread: Understanding SNR and Attenuation Rates.
 
Pada said:
Shirou:
Yes, the line attenuation needs to be low and the SNR needs to be high.
A lower line attenuation, means that the signal loss on the cable is low, which will in effect result in a better SNR (noise) margin.
The downstream SNR margin would also drop at about 3dB per 1 Mbps increase. Like if you have an SNR of 20dB at 384kbps, then you'll have like 12dB at 3Mbps. The same goes for the upstream SNR, but its rate is different than 3dB/Mbps. Also note that this 3dB/Mbps rate is just a VERY rough estimate of mine!


It would be a good idea to read the following thread: Understanding SNR and Attenuation Rates.
Click to expand...

Thanks Pada, this do help me alot.

Question now is, how can i increase my noise margins
 
Last edited:
I got telkom to downgrade my line to 6mb,

New Results:

noise margin upstream: 14 db
output power downstream: 0 db
attenuation upstream: 24 db

noise margin downstream: 17 db
output power upstream: 2 db
attenuation downstream: 40 db
 
Were you on 10Mbps? If you were, then my estimation of +3dB SNR/-1Mbps were correct :)
 
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