[LINK] RFI: ADLS2+ Performance
rene
rene.ln at libertus.net
Thu Jul 5 17:06:42 AEST 2012
On Thu, 5 Jul 2012 15:43:55 +1000, Roger Clarke wrote:
[...]
> That's after 'Jerome', presumably in Manila, "increased the signal-to-
> noise ratio [on the DSLAM] at the exchange".
>
> Can anyone explain, or point to an explanation of, what that really
> means?
In short, it's highly likely that your copper phone line has become noisy
in recent times with the result that the modem can't "hear" the DSLAM, so
the ADSL connection drops out.
Increasing the SNR margin on the DSLAM (or on the modem if one has a model
that has such a setting - not many do) can overcome the noise problem but
at the expense of sync and download speed, i.e. the connection can become
stable, but speeds will be slower.
A detailed explanation, in pretty much layman's language, is here:
http://www.kitz.co.uk/adsl/lowSNR.htm
I had the same problem some months ago, and I ended up downloading
RouterStats.exe
http://www.vwlowen.co.uk/internet/files.htm
so that I could monitor and record the SNR fluctuations - such fluctuations
in effect show how much noise is on the line at any given time. However, on
a quick glance at the page, it looks like it's not available for Mac. There
may, I suppose, be some other program that runs on Macs that does the same
thing.
NB: Some ISPs provide a variety of ADSL2 "profiles" that customers can
set/change by logging into the ISP's web site, each profile with a
different SNR margin. However, if the ISP doesn't provide such an option
and noise problems start occurring, then the only option is to try to get
customer support techs to change it.
Also, fwiw, there's a very good ADSL troubleshooting / tips page here:
http://www.internode.on.net/support/guides/internet_access/broadband_adsl/o
ptimising_adsl2_//
Irene
More information about the Link
mailing list