Your help needed

[Rik]

We are often asked what speed someone might expect from their line. The answers we give are based upon experience, things we've read on the 'net etc. Different people will give different answers depending on situations they've encountered.

So, I thought it would be useful to collect some data on the subject, and see if we can generate a more reliable predictor, based on as many people's data as possible.

What I would like from you, please, is your d/s attenuation, sync speed and noise margin. If you have had the margin raised, it would be helpful if you could say so.

My figures are:

56db - 3264k - 9db (raised at my request).

Thanks.

[DorsetBoy]

 

Righto Rik, something I see people saying is that the downstream SNR should be 6db or there has been a problem,this is not so,the targert is decided by the exchange equipment during the training period,the target being 6-15 db with a defailt of 6db.

My line hs always been @ 9.5-10.5db.

Now there used to be a chart for workng out the figures but can I find it?

Never mind ourn friend Kitza has saved us all the trouble

Take a look at this.............  http://212.23.23.177/calc.htm and this ........

http://www.internode.on.net/images/copyright/internode-adsl2-distance.jpg

and this .... http://212.23.23.177/ADSL/default.aspx 

Stick in your stats and it's done for you

[Rik]

Those are Saffy's calculators, aren't they. Not surprisingly, they tell me that 3264 is what I can get from my line.

I thought it would be useful to collect some real data, instead of relying on the calculators, then see how that matches. Best of both worlds.

[DorsetBoy]

OK here  are my stats.........

Modulation:   G.992.1 Annex A

Bandwidth (Up/Down) [kbps/kbps]:   448 / 8,128

Data Transferred (Sent/Received) [KB/KB]:   0.00 / 2.00

Output Power (Up/Down) [dBm]:   11.5 / 19.5

Line Attenuation (Up/Down) [dB]:   13.5 / 25.0

SN Margin (Up/Down) [dB]:   21.0 / 10.0

The calculator gives..........

Current Line Sync (connection) speed in Kilo bits per second (Kbps) 8128

Downstream Line Attenuation (dB)25

Noise Margin, sometimes referred to as Signal to Noise Ratio (SNR)10

If you do not know how to obtain your line stats from your ADSL modem or router then visit Kitz's website which shows how to get these values for lots of kit.

 
We estimate that if using a rate adaptive up to 8Mbps service your maximum line speed will be:8128Kbps 

If you are on a Max product, that uses the IP Profile system (sometimes called BRAS Data Rate) if you maintain the above line speed for 3 days or more your IP Profile would be set to: 7.15Mbps

If your service provider uses ADSL2+ we estimate you may manage line speeds of:19097Kbps
With ADSL2+ the maximum IP throughput is likely to be around:16900Kbps

[Rik]

You're making me jealous again, Dorset, especially for the ADSL2+ figures, they barely differ for me.

[DorsetBoy]

You're making me jealous again, Dorset, especially for the ADSL2+ figures, they barely differ for me.

There are 2 bungalows for sale just up the road and there lines are shorter than mine

[Ray]

Here are mine Rik: -

ADSL Link                 Downstream     Upstream
Connection Speed    7616 kbps       448 kbps
Line Attenuation       29 db                9 db
Noise Margin                 10 db                14 db

My IP profile is 6500kbps

[Rik]

Thanks, Ray.

[Inactive]

No idea how to get the figures from the router that I am using, a Zyxel P-660 OHW, sorry.

It was a doddle on my old BT Voyager, however the Zyxel far outperforms the BT. one.

[Lance]

My line hs always been @ 9.5-10.5db.

The reason for this, DB, is because it doesn't need to fall to 6db in order to get increased sync. You already have the maximum sync!

[Rik]

No idea how to get the figures from the router that I am using, a Zyxel P-660 OHW, sorry.

http://192.168.1.1

> Diagnostic
> DSL Line

Up and downstream SNR Margins available

Default username = admin
Password = 1234

According to Kitz. You can get the sync speed from a BT test, if the modem isn't reporting it.

[Inactive]

OK found that it reads;

Noise Margin up  22db
Output Power downstream 12db
Attenuation upstream  5db

Noise Margin Down 17db
Output Power upstream 15db
Attenuation Downstream 9db


None of that means anything to me.. 

[DorsetBoy]

OK found that it reads;

Noise Margin up  22db
Output Power downstream 12db
Attenuation upstream  5db

Noise Margin Down 17db
Output Power upstream 15db
Attenuation Downstream 9db


None of that means anything to me.. 

That means you are @700 metres from the exchange.....what synch speed do you have?
It's on the first page of the Zyxell interface.

[MoHux]

Router DLink DSL-524T.

ADSL Status
 
ADSL status shows the ADSL physical layer status.
 
ADSL Firmware Version: 6.00.01.00 - 6.00.01.00 - 6.00.04.00 Annex A - 01.07.2b - 0.54 
ADSL Software Version: V3.00B01T02.UK-A.20060621
Line State Connected
Modulation ADSL_G.dmt
Annex Mode Annex A 
Max Tx Power -38 dBm/Hz
 
Item           Downstream Upstream Unit
SNR Margin        8               24 dB
Line Attenuation 20             14 dB
Data Rate         7616          448 kbps

My Data Rate always used to be 8128 (540mtrs fm Xchnge) until Easter.  Then it dropped several times when I was doing clean installs of XP and Vista, and Interleaving was put on.  Been at above level for some time now, I can't get it to go back to 8128.

[Rik]

You would need to get interleaving turned off to get the higher sync speed, Mo.

[B52]

Modem Status
Connection Status  Connected
Us Rate (Kbps) 448
Ds Rate (Kbps) 4640
US Margin 24
DS Margin 15
Modulation MMODE
LOS Errors 0
DS Line Attenuation 51
US Line Attenuation 57
Path Mode Interleaved

 
DSL Statistics
Near End F4 Loop Back Count  0
Near End F5 Loop Back Count 0


Edimax Wireless

[MoHux]

You would need to get interleaving turned off to get the higher sync speed, Mo.

Yes, that's what I thought Rik.  My router doesn't record if interleaving is on actually, but my pings went from 15/18 av' to the stock intlvng level 20/26, and have stayed there.
Since easter I have been sperimentin with RWins/MTUs, and trying to get the best out of both O/Ss generally.  Plus getting drivers/updates, all requiring re-boots.
I have delayed asking for interleaving to be turned off until I stopped buttering about!! 

 

[Rik]

Nothing you do at the software level, Mo, should affect your line, ie anything you do in XP will only affect the computer. Unless you disconnect or re-boot the router, you shouldn't be seeing any loss of sync.

[Rik]

DS Margin 15

It looks like your line has had some noise problems and the target noise margin has been set to 15db as a result. If your line is now stable, it might be worth asking for that to be reduced again.

[Inactive]

That means you are @700 metres from the exchange.....what synch speed do you have?
It's on the first page of the Zyxell interface.

Read, it should be on the first page, it isn't.

Less than 700 metres as the crow flies, about 100 yards, same road 7 bungalows away .

[Rik]

Given your noise margin and attenuation, I'd take a bet it's 8128. Why do I feel deprived. 

[RobMc]

Well ok here goes....

Upstream Rate (Kbps) 448
Downstream Rate (Kbps) 8128
US Margin 21
DS Margin 7
Modulation MMODE
LOS Errors 0
DS Line Attenuation 47
US Line Attenuation 51
Path Mode Interleaved

Using a Dlink DSL-G604T and I'm approx 0.63 miles from the exchange as the crow flies.

Rob.

[Inactive]

Given your noise margin and attenuation, I'd take a bet it's 8128. Why do I feel deprived. 

It was on my old BT Router Rik, so I guess it still is.

Sorry.. 

[Rik]

It's OK, think what I have to look forward to if we ever get around to moving! 

[Inactive]

It's OK, think what I have to look forward to if we ever get around to moving! 

True, I never looked at it in that light..