Deteriorating quality

[nooby]

I used to get a 4096 kbps sync rate on both my Netgear DGN2000 and my Linksys WAG354G
Then my line went dead one day, and called repairs...
The Telkom techie was at pains to explain that it is impossible to get a full 4Mb connect rate. I had to humbly concede my 2 years of experience to his superior knowledge on the matter, and he left me with a fluctuating 3300-3600.

Then a few months ago I suddenly got a hopeful 3600-3900 and I was happy!

Coincidentally, with implementation of the current bonus traffic allocation from TelkomInternet, My Netgear router syncs at about 2800Kbps on average
and my Linksys steadily reports this:
DSL Status: Up
DSL Modulation Mode: ADSL2+
Number of failed trainings: 1
ISP DSLAM Chipset ATUC Code & Brand: IFTN -- Infineon

DSP Datapump version: [7.04.03.00] Annex A
DSL Path Mode: FAST
Downstream Rate: 3102 Kbps
Upstream Rate: 503 Kbps
Downstream Margin: 8 db
Upstream Margin: 12 db
Downstream Line Attenuation: 55
Upstream Line Attenuation: 38
Downstream Transmit Power: 21
Upstream Transmit Power: 6
Downstream Max Attain Bitrate: 3120 Kbps
Upstream Max Attain Bitrate: 896000 Kbps

 

[twhitehead]

Downstream Margin: 8 db
Upstream Margin: 12 db
Downstream Line Attenuation: 55
Upstream Line Attenuation: 38
Downstream Transmit Power: 21
Upstream Transmit Power: 6
Downstream Max Attain Bitrate: 3120 Kbps
Upstream Max Attain Bitrate: 896000 Kbps

Its odd that the problem seems to be only in the downstream. Normally downstream margin db should be much higher than upstream margin db. I am no expert, but I would suspect some sort of interference on the line in the downstream frequency range.

 

[Pada]

You can try to change your modulation mode from ADSL2+ to G.Dmt.

Your problem is that your Line Attenuation is VERY high for a 4Mbps connection, making it almost impossible to sync reliably at 4Mbps.
I haven't really seen people synchronizing at 4096kbps with such a high line attenuation though.

I would suggest that you also try and connect your ADSL modem directly on the Telkom line - bypassing all filters - and removing all the other telephonic devices.
If your stats remain just as bad, then you can try phoning Telkom and ask what happened.

 

[nooby]

I never really took note of my attenuation while I was connecting on 4096.. But I think it was much less in the 30s...
ADSL2+ seems to give me the best rate now

G.Dmt syncs like below but tends to drop and retrain every few minutes.
Telkom accepts the fault and just clears it without doing anything and say it is at an acceptable delivery level and passes the quality standard..


Downstream Rate: 3072 Kbps
Upstream Rate: 512 Kbps
Downstream Margin: 6 db
Upstream Margin: 13 db
Downstream Line Attenuation: 56
Upstream Line Attenuation: 31
Downstream Transmit Power: 2
Upstream Transmit Power: 8
Downstream Max Attain Bitrate: 3072 Kbps
Upstream Max Attain Bitrate: 0 Kbps