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6km line with 67db (6.3 Nosie Margin) SNR Tweak ?
Posted: Mon Sep 30, 2013 8:32 pm
by dread_uk
Hi
I'm currently using a Sky branded Sagem 2504
My line length is around 6km long I get 3meg down and about 70k up as seen in the following pic from the router.
Would tweaking my SNR give me much if any improvements in speed ?
To be honest I can't quite believe I'm getting the speeds I do at the moment.
The line is very stable, unless I batter it really hard, maxed out on torrents for a length of time, then I will get a drop.
Worth investing in a 7800n ?
Thanks for any help.
Re: 6km line with 67db (6.3 Nosie Margin) SNR Tweak ?
Posted: Tue Oct 01, 2013 1:06 pm
by tinytim
For your attenuation you're getting very good speeds - close on 2 x what would be generally estimated I think.
So personally I'd not attempt any tweaking , however , a Billion is a far better router than that Sagem of yours.
Also any gain I'd expect to be outweighed by a loss of stability, and as you say you do drop the line occasionally when hammering it.
Re: 6km line with 67db (6.3 Nosie Margin) SNR Tweak ?
Posted: Tue Oct 01, 2013 5:59 pm
by dread_uk
That's the answer I pretty much expected.
My line is a little odd, originally with BT they refused to give me any more then 512k
After moving to Sky, it settled down to 2mb
Then at some point I've no idea when it improved to 3mb
But the 67db has never changed, I think way back when it may of been 65db.
All very odd.
If I can pick up a second hand 7800n cheap I will give it a try otherwise I won't waste my time and effort for maybe another 512k if I'm lucky.
Re: 6km line with 67db (6.3 Nosie Margin) SNR Tweak ?
Posted: Sat Oct 19, 2013 11:17 am
by dread_uk
Well I managed to pick up a 7800n for £30 minus a PSU which I already had from another router.
I dropped the SNR to 3*
Can anyone explain
Max: Upstream rate = 752 Kbps, Downstream rate = 4534 Kbps
Path: 0, Upstream rate = 751 Kbps, Downstream rate = 3071 Kbps
Is the max literally that, the max and clearly the numbers under are what I'm currently getting..
I did a few long high speed downloads last night and it very stable not a single drop.
I'm on sky and looking on the sky user forums, I'm going to have to ask sky to re profile my line, I'm not sure if it's worth the risk tbh..
Status: Showtime
Retrain Reason: 0
Max: Upstream rate = 752 Kbps, Downstream rate = 4534 Kbps
Path: 0, Upstream rate = 751 Kbps, Downstream rate = 3071 Kbps
Link Power State: L0
Mode: ADSL2+
TPS-TC: ATM Mode
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 3.9 6.9
Attn(dB): 66.5 41.9
Pwr(dBm): 16.2 12.6
Re: 6km line with 67db (6.3 Nosie Margin) SNR Tweak ?
Posted: Sat Oct 19, 2013 11:33 am
by dread_uk
just out of interest as I have a long line I set the Mode to DMT, and defaulted the SNR
DMT Status No Defect
Operational Mode G.DMT
Upstream 692
Downstream 3045
SNR Margin(Upstream) 8.0
SNR Margin(Downstream) 10.1
Line Attenuation(Upstream) 31.5
Line Attenuation(Downstream) 63.5
Re: 6km line with 67db (6.3 Nosie Margin) SNR Tweak ?
Posted: Sat Oct 19, 2013 5:23 pm
by tinytim
On a very long line DMT is generally much better.
See what happens if you drop the SNR now.
Re: 6km line with 67db (6.3 Nosie Margin) SNR Tweak ?
Posted: Sat Oct 19, 2013 8:51 pm
by dread_uk
doesn't seem to make the slighest bit of differance if I try and tweak the SNR
but, Max is just under 4mb, is this in theory what I will get a connect at ?
Code: Select all
adsl: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Max: Upstream rate = 886 Kbps, Downstream rate = 3911 Kbps
Channel: INTR, Upstream rate = 693 Kbps, Downstream rate = 3046 Kbps
Link Power State: L0
Mode: G.DMT
TPS-TC: ATM Mode
Trellis: ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 9.4 8.0
Attn(dB): 63.5 31.5
Pwr(dBm): 17.9 12.3
Re: 6km line with 67db (6.3 Nosie Margin) SNR Tweak ?
Posted: Sun Oct 20, 2013 10:42 am
by tinytim
Sky run their network at max SNR of 7 , obviously I mean that's the lowest they'll drop it too. Also they don't seem to know much about g.DMT as they use ADSL2+ , so unless you're very lucky when you talk to them they won't understand about plain ADSL.
It does seem that 3mb is all you're going to get which , as I said before , is far better than you could typically expect.
If it's stable at that speed I'd be inclined to leave well alone.