ADSL2+ slower than ADSL2 :S

Soldato
Joined
26 May 2009
Posts
22,174
OK here's the situation, last week after 9 years of good service our Netgear router went senile and so in a pinch I had to replace it with the 2wire "business hub" BT gave us when we moved to them in 2008. in 2010 BT upgraded the local exchange and moved everyone from their "up to 8mb" service to a shiny new "up to 20mb" service.

The old netgear router being a pre ADSL2+ design stayed with its connection speed of 6-7mb when this change came in. But when I changed to the BT router last week the speed went up to 10-11mb which I thought was great until I started to notice odd behaviour, sometimes the internet would just stall, you would click on a site and the browser would spends ages and ages loading it before it finally appeared.

Then on Friday the BT router died (lasted less than 7 days) completely, piece of junk, ** No mentioning of competitors ** and bought a new netgear router which was configured just like the original however it too has this stalling issue (although it connects at 11-12mb). Its really annoying waiting for ages for websites to load like 56k and what's worse is its breaking downloads.

Any ideas :S
 
Just stalling, but I managed to fix it by manually setting the router to ADSL2 mode instead of letting it auto set itself in ADSL2+ mode, only running at 8.8Mb/s now so lost 3Mb/s but its working properly.

I wouldn't have thought it would be a training phase as its nearly two years since they moved us to the ADSL2+ connection, its just our router was only ADSL compliant so we never got an increase then.
 
It sounds like the Routers are pushing the ADSL SNR (Signal to Noise Ratio) too hard.
Some lines are actually worse with ADSL2+, as odd as it sounds.

My advice would be to find out if you can set the SNR to 6Db or 9Db on the new router, this margin of stability should be sufficient to stop the disconnects
 
This is what I get under ADSL2:

Connection Speed: 8887 Kbps down / 976 Kbps up
Line Attenuation: 33.1 dB down / 18.8 dB up
Noise Margin: 2.8 dB down / 6.1 dB up

Ill set it back to ADSL2+ later and see what it says then.
 
How is your filter and wiring set up including any extensions for phones etc?
 
Looks like your downward target SNR has been set to 3dB. So as commented above, you probably want to try and negotiate a 6dB target SNR. 3dB does give you much leeway if your line is even slightly noisy and ADSL2+ is more susceptible to noise than ADSL max.

As always. Best connection for your modem, is direct into your BT master socket via a filtered faceplate (if only because it gets rid of those pesky ADSL filters).

With those ATTN figures, I would expect you to be able to sync at around 12Mbps download (if not higher), with the full 1Mbps upload speed.

PS. Is interleaving on, or off? (IE. is it logging FEC errors).
 
Looks like your downward target SNR has been set to 3dB. So as commented above, you probably want to try and negotiate a 6dB target SNR. 3dB does give you much leeway if your line is even slightly noisy and ADSL2+ is more susceptible to noise than ADSL max.

Right ill try and manually set it to 6dB then and set the connection back to ADSL2+


As always. Best connection for your modem, is direct into your BT master socket via a filtered faceplate (if only because it gets rid of those pesky ADSL filters).

Thats how I have it set up at the moment with the router and a fax machine plugged into the filtered socket.


With those ATTN figures, I would expect you to be able to sync at around 12Mbps download (if not higher), with the full 1Mbps upload speed.

Cool


PS. Is interleaving on, or off? (IE. is it logging FEC errors).

Ill look up what that means :P
 
When I set it to auto mode and let it choose ADSL2+ I get:

Connection Speed: 12247 Kbps down / 960 Kbps up
Line Attenuation: 32.9 dB down / 18.8 dB up
Noise Margin: 3.1 dB down / 6.2 dB up

Ill try setting the dB down to 6 like people said and see how that works out :)
 
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