SNR and Line Attenuation on Sky

Hello

I recently switched my Broadband and calls to Sky. In fact today was my activation day. Looking at the stats of my new sky connection i can't but worry about some of the figures.

Both Upstream and Downstream attenuation went considerably up. (66.5 from 62 db downstream and a huge 40.1 from 31.5 db upstream)
Why is it reporting that my line is even longer from the exchange now? Has the route to my house changed? Is there anything i can do about that?

Also my Upstream SNR has more than doubled (16db from 6db). Upload speeds are very important to me, equally important to the download ones.

As i live quite far from the exchange my speeds are already slow and any change for the worse is very bad news to me.

Please click here to see some typical current and old line stats. They are all from the same line, same exchange.

Thank you in advance for your time and answers, i am waiting with anticipation for your advice/suggestions/experiences

Try it set to G.DMT and ADSL2 (G992.3). As it is your not comparing like for like and I suppect its the modulation type you are currently set to (ADSL2+/G992.5) that is the reason for the differences are you are seeing.

Edited by deleted (Tue 24-Jan-12 17:34:01)

The Down attn. goes up about 3 dB when you switch from ADSL to ADSL2+. So that explains that!

The Up NM is so high cuz the Up speed is so low. Hopefully it should increase.

But do try G,DMT & G.992.3 as Roberto suggests.

If you are within the first 10 days... Do nothing DLM is probably still running
That's so important

Otherwise mess around with things

DLM will try adsl 2 & adsl 2 + etc

Once the 10 days is over it should have put you onto the modulation that's best for your line

If you force anything during training it will mess things up

Agreed Sky's DLM is the one that starts low and increases slowly. They like to see you prove the stability before giving the speed.

The BT one tends to start high and leave it high unless there is instability.

The real attenuation in the up to 1.1Mhz band has not really changed, just the way the 7800N is reporting it by including the pretty much useless frequencies from 1.1Mhz up to 2.2Mhz that ADSL2+ try to use.

But on a long line like yours ADSL2+ brings nothing, any boost is from ADSL2 mode.

Post deleted by moskolio

Thank you all very much for your answers.

It is day 3 now and it seems that the modem reconnects roughly at 2am every night and figures change a bit.

Upstream SNR has dropped to 10 db now from 16 which is much better.

It seems to me that the modulation type changes as well but not certain about that.

One question that i have is should i leave the billion 7800n for the training period (which i am planning to use after that) or should i plug in the sagem that sky sent me?

Also what is the recommended MTU figure for Sky LLU ADSL2+ ? From what i read the best figure is 1500, mine is currenty set to 1492 should i change it?

Thanks

MTU what ever works best for you, personally leave at default 1500 as I travel with PC a lot.

If the billion is in place now, then just leave it be, let the Sky systems settle and then fiddle if you are the fiddling sort

I hope I dont have this problem when i switch over wed, on a 61db connection atm and get around 2.5-3mb! Would like to keep that, I know not to interfere with the router for the first 10day settlement period.

On a dg834gt just tweaked snr to 1% and now get :

ADSL Link Downstream Upstream
Connection Speed 3730 kbps 747 kbps
Line Attenuation 61.0 db 38.0 db
Noise Margin 3.4 db 6.0 db

http://www.speedtest.net/result/1737981504.png

Edited by deleted (Sun 29-Jan-12 14:07:17)