ADSL2+ vs G.CMT

I've had consistent issues with my line for the last two years but considering an attenuation of 72(it nearly doubled when the issues started two years ago) that is expected.

Last week I asked my ISP(Afrihost) to drop the sync speed from 2 Mbps to 1 Mbps after a trial period on 2 Mbps and they mistakenly moved me over from ADSL2+ to G.DMT and I didn't have a single dropout. My attenuation dropped to about 65 and my snr went from 5-6(on ADSL2+) to 13.5 on G.DMT. Line didn't drop out once while I was on G.DMT. They have now switched me back to ADSL2+ and once again I am having sync issues.

Can anyone explain this to me since I do believe that ADSl2+ is meant to have a longer reach and therefore should be more stable at the same speed than G.DMT but this is not so for my line. I am on the REDY exchange in Brakpan and am about 4 KM from the exchange as the crow flies, about 6-7 KM of copper between me and the exchange.

Have you had Telkom out to investigate why your line quality dropped suddenly?

Also you can try forcing your modem to sync using G.DMT instead of ADSL2+

grim said:

Have you had Telkom out to investigate why your line quality dropped suddenly?

Also you can try forcing your modem to sync using G.DMT instead of ADSL2+

Click to expand...

Yes and I can just ask Afrihost to change it, for now it seems to be stable, don't fix it if it ain't broke...

I was on telkom when it was well I changed to afrihost after it went to hell because I got sick of dealing with telkom. Afrihost was able to get telkom to get my line to sync most of the time but telkom just says that they cannot find the problem on the line, they are now saying the copper is 20+ years old etc. which I do not believe since they tell us often that the lines are stolen and our phone will be dead untill they replace them(about once every 2 months and interestingly the quality drop started after just such an incident). I constantly get different reports from Telkom and Afrihost on such issues(afrihost says exchange is being upgraded Telkom says lines are stolen etc.)

If anyone may have any theory to propose to telkom about this I will also be more than happy to have them check it out but I am out of theories. If you need more information I can supply it.

You can't have a downstream line attenuation of 72dB and still have a working ADSL connection of 384kbps even.

G.DMT should work better with such high line attenuations, but ADSL2+ is better for higher speeds and lower line attenuations.
Just take note that the line attenuation will change when you change between ADSL2+ & G.DMT.

DSP Firmware Version DMT FwVer: 3.10.0.0_A, HwVer:TeF7_7.0
DMT Status Up
Operational Mode ADSL2+
Upstream 487 kbps
Downstream 1024 kbps
SNR Margin (Upstream) 5.5 db
SNR Margin (Downstream) 11.3 db
Line Attenuation (Upstream) 45.5 db
Line Attenuation (Downstream) 72.0 db

That would be the ADSL stats shown on my router and have confirmed these with Afrihost from their side. Billion 7300 router, netgear router shows a lower attenuation but not sure if it is just because it cannot show higher.

Would screenshot but not sure how to do that(there any guide for that here somewhere?)

Pada said:

...
G.DMT should work better with such high line attenuations, but ADSL2+ is better for higher speeds and lower line attenuations.
Just take note that the line attenuation will change when you change between ADSL2+ & G.DMT.

Click to expand...

That was what I was looking for though, thanks.

Most ADSL modems won't be able to show anything above like 62.5dB for the line attenuation.

The upstream ADSL line attenuation is usually about 1/2 of the downstream one.

Telkom should definitely fix it if it is above like 60dB, because that is basically unusable.

jpc0_za said:

I constantly get different reports from Telkom and Afrihost on such issues(afrihost says exchange is being upgraded Telkom says lines are stolen etc.)

Click to expand...

That's because the Telkom "workers" are mostly either clueless, making stuff up or downright lying. Of course they tell the AH guys they're on top of things and just having some probs during the upgrading process. And for you, the stupid useless customer, they have the wonderful tale of stolen lines, thus putting the general population at fault for their own shortcomings. You should really be ashamed of yourself for stealing all their wonderful and expensive copper and still demanding the best service.

Neither story is true I guess.