Which dsl modem for poor line

trompele

Hi,
Currently using BT 1mbit with OfficeConnect ADSL Wireless 11g (3com).
Stats as follow:
Operation Data Upstream Downstream
Noise Margin 20 dB 10 dB
Attenuation 63 dB 60 dB

According to BT consultants i might not get full speed if I upgraded my broadband to 2mbit package. Here is the question:
Is it possible that when I get better (propably dearer) ADSL modem i'll get better stats and then chance for 2/3 mbit package ?
I was thinking about ie:
http://www.komplett.ie/k/ki.aspx?sku=337363

Thanks for any kind of advice

Sponge Bob

http://www.kitz.co.uk/adsl/lowSNR.htm

Spear

trompele wrote: »

Hi,
Currently using BT 1mbit with OfficeConnect ADSL Wireless 11g (3com).
Stats as follow:
Operation Data Upstream Downstream
Noise Margin 20 dB 10 dB
Attenuation 63 dB 60 dB

According to BT consultants i might not get full speed if I upgraded my broadband to 2mbit package. Here is the question:
Is it possible that when I get better (propably dearer) ADSL modem i'll get better stats and then chance for 2/3 mbit package ?
I was thinking about ie:
http://www.komplett.ie/k/ki.aspx?sku=337363

Thanks for any kind of advice

Your line is just terrible. The ADSL standard sets a max attenuation of 63.5 dB, and you're at 60 on the downstream. Do you know how far you are from your exchange?

Simi

http://www2.farina1.com/adsl/

Upon inputting your data, I noted you won't be able to get much higher than 1mb from that line.

Do the usual connect to the main phone point, disconnect everything from the phone line except the router etc & reset your modem & see if your stats change.

watty

Scroll down here:
http://wiki.openwrt.org/CompleteTableOfHardware
and
http://en.wikipedia.org/wiki/TI-AR7
Avoid any DSL modem with Infineon / Texas AR7.
Unfortunately it won't say on the box. You'll have to check each model.
This is why: http://www.theregister.co.uk/2007/10/22/zen_ar7_infineon_bt_fault/

trompele

Hi, Thanks for all replies.
I made some test today and here are the results
(All tests were done twice (router restart - test, another restart - test))


Morning (same config - 3com)
Operation Data Upstream Downstream
Noise Margin 20 dB 13 dB
Attenuation 63 dB 61 dB

Phone disconnected
Noise Margin 20 dB 13 dB
Attenuation 63 dB 61 dB

Directly to socket
Noise Margin 20 dB 12 dB
Attenuation 63 dB 61 dB

Netopia Old - no wifi
SNR Margin: 19 dB 16 dB
Line Attenuation: 31 dB 61 dB

Netopia Old (dark blue) with wi fi
SN Margin 10 dB 15 dB
Line Attenuation 31 dB 62 dB

New Netopia (silver) (without DSL filter)
SN Margin 19 dB 13 dB
Line Attenuation 31 dB 60 dB

New Netopia (silver) (with DSL filter)
SN Margin 20 dB 13 dB
Line Attenuation 31 dB 59 dB




So conclusions:
1. Old Netopia routers (dark blue) have slightly better parameters in SNR and twice better Attenuation on upstream than rest.
2. No difference between direct socket connection or with extended cable.
3. Small difference with or without DSL filter (one parameter changed - see new netopia)
Looks like changing routers and position of my modem does not make a difference for downstream at all. Im going to order one of thompson modems and then i'll post results ( http://www.broadbandbuyer.co.uk/Shop/ShopDetail.asp?ProductID=6798 ).
Also ill get NTE5 compatibile DSL faceplate. Will see how it goes.
Looks that im lucky that i have internet at all.

Sponge Bob

Your stats would indicate a perfect line @ 4 miles from the exchange or so .

Old Netopias were good units, yes!

NTE5 is for the UK but some modems are recommended for their ability on bad lines in that Kitz link .

watty

It's important to realise the attenuation doesn't change. The real SNR isn't changing. Mostly the accuracy of measurement, though inherently very good and very poor modems might have a difference in effective BER, thus SNR. None of these specs really measure how well the units work. You'd need to measure lost packets, jitter, speed etc to a fixed point (such as your gateway or 1st hop ISP router) on your own ISP's network.