Continuous disconnects on all devices / upload snr magrin drop

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Danny94
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Joined: Tue Feb 06, 2018 3:23 am

Continuous disconnects on all devices / upload snr magrin drop

Post by Danny94 »

Hi,
we got ADSL2 over FTTC now, the cabinet is 2,2 km (wich should not be as bad) and the central is about 3,5km away.

But we have extremly problems, while gaming for example we got mini dcs (packet losses) for ~1-2 seconds almost every 1-2 minutes and longer dcs 10-15 seconds every 10+ minutes. I really dont know how this can happen with those stats.
I noticed that snr margin for upload drops from 6db to 3db and while a disconnect it rises to 6665db or something like that.

For now i read this guide:
https://www.speedguide.net/articles/tip ... r-snr-2074

We removed every splitter and filters and replaced the in house cable wich now is not longer then 3 meters anymore (no kinks).
The telephone cables outside get transported over mast and those cables all are not shielded with a aluminium foil. So we didnt used a shielded cable to.

So my question is does we propably need a band filter to filter mobile radio (wich probably can disturb into the cable) or does the modem already does this job?
What we can do to fix this problems ?
Its definitly not a fault of modem or devices. I tried a lot on different devices and modems, was connected via ethernet.

UP / DOWN
Speed: 800kbps /1550 kbps
Line attenuation: 18db / 35 db
Snr Margin: 5,5 db / 6db
Power transmitted: 10,4dbm / 10,6dbm

ERRORS (24 hours):
ES: 1482
SES: 440
FEC: 95884
CV: 378 (could anyone explain me please for what does it stand)
LPR: 0
UAS: 797
Failed initializations: 12

Btw i exactly know the used frequencys:
25 kHz - 138 kHz UPLOAD
138 kHz - 3.75 MHz DOWNLOAD
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Philip
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Location: Jacksonville, Florida

Post by Philip »

That particular article refers more to coax cables than pots, but you are on the right track if you want to clean up your signal. When your DSL modem disconnects, it may increase the SNR margin and reduce the speed to cope with the line conditions.. but ultimately it is dependent on the line feed from your ISP. I would talk to them and try to convince them to improve your line noise if possible. Not sure if some type of band filter on your end would do much.
Danny94
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Posts: 2
Joined: Tue Feb 06, 2018 3:23 am

Post by Danny94 »

Well thank you very much for you answer.
I have seen that the isp increase the noise automatically. Sometimes its on ~9db and sometimes on ~12db, i think before or after a dc. Maybe i should ask if they can fix it on 9db or 12db. With 12 db we ended up onliy with ~300kbps / ~8000kbps.

Ok as i understood at this point we can't do much more, the problem is just that we have this line conditions over 10 years and had a lot of tecnicans at home. Lets hope they get fixxed it this time.

But in your opinion the line is ok just the length cause this noise ?
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Philip
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Post by Philip »

That is SNR margin, i.e. when the noise on the line increases (due to faulty connections/lines, attenuation, environment, etc.), the modem syncs at a lower speed by increasing that "SNR margin" automatically. When the line is cleaner, it can be reduced. It is normal for the SNR to fluctuate, that safety "SNR margin" is just the difference between signal and noise, something the modem needs so it doesn't disconnect because of the variance in noise.

I hope this makes some sense. I can't be sure what causes the noise exactly, your ISP's techs may be able to inspect the line and do something about it eventually.
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