<html><head>
<meta content="text/html; charset=UTF-8" http-equiv="Content-Type">
</head><body bgcolor="#FFFFFF" text="#000000">That's... not strictly
true.<br>
<br>
SNR indicates the noise margin, but doesn't necessarily dictate if line
is "good" or not. What're you really interested in are CRC errors, or
Errored Seconds (ES). I've seen lines that have been able to run with a
solid SNR of 3dB with minimal CRCs and a resync once a month.<br>
<br>
It's also worth noting that if you're on Open 2 (20/1) on Telstra
Wholesale, your default target SNR *is* 6dB, so assuming an SNR that low
means the line is fubar is a bit of a red herring.<br>
<br>
Different profiles on different ISPs/DSLAMS will often set a target SNR
when they're initially syncing. From memory you can use the following
profiles on some ISPs to hit an SNR target:<br>
<br>
- Telstra Wholesale Default - 6dB<br>
- Telstra Wholesale "Stability Profile" 15dB<br>
- iiNet Thrillseeker - 7dB<br>
- iiNet Standard - 9dB<br>
- iiNet Controlled - 15dB<br>
<br>
To recap, a low SNR doesn't mean you're having issues, but having a high
one helps prevent them.<br>
<br>
-Shane<br>
<br>
<br>
<a class="moz-txt-link-abbreviated" href="mailto:adamn@eyemedia.com.au">adamn@eyemedia.com.au</a> wrote:
<blockquote
cite="mid:OF18D0CD72.FB52DBF4-ONCA257D63.002C1A8F-CA257D63.002C32BE@eyemedia.com.au"
type="cite"><font face="sans-serif" size="2">This was one I stumbled on
the web sometime
back, I can't find the back reference for it :\<br>
<br>
</font><font size="3"><b>SNR is Signal to Noise Ratio</b> (aka Noise
Margin
or Signal to Noise Margin)<br>
Relative strength of the DSL signal to Noise ratio. 6dB is the lowest dB
manufactures specify for modem to be able to synch. In some instances
interleaving
can help raise the noise margin to an acceptable level. The higher the
number the better for this measurement.</font>
<p><font size="3">6dB or below is bad and will experience no synch or
intermittent
synch problems<br>
7dB-10dB is fair but does not leave much room for variances in
conditions<br>
11dB-20dB is good with no synch problems<br>
20dB-28dB is excellent<br>
29dB or above is outstanding</font>
</p>
<p><font size="3"><b>Loop Att. is Line Attenuation</b><br>
Measure of how much the signal has degraded between the DSLAM and the
modem.
Maximum signal loss recommendation is usually about 60dB. The lower the
dB the better for this measurement.<br>
20dB and below is outstanding<br>
20dB-30dB is excellent<br>
30dB-40dB is very good<br>
40dB-50dB is good<br>
50dB-60dB is poor and may experience connectivity issues<br>
60dB or above is bad and will experience connectivity issues</font>
</p>
<p><font size="3"><b>Output Power</b><br>
How much power modem (upstream) or DSLAM (downstream) is using. Maximum
recommended is about 15dB. The lower the power the better for this
measurement.</font><font face="sans-serif" size="2"><br>
<br>
Cheers,<br>
Adam<br>
</font>
<br>
<br>
<br><font color="#5f5f5f" face="sans-serif" size="1">From:
</font><font face="sans-serif" size="1">Travis
<a class="moz-txt-link-rfc2396E" href="mailto:mallik@internode.on.net"><mallik@internode.on.net></a></font>
<br><font color="#5f5f5f" face="sans-serif" size="1">To:
</font><font face="sans-serif" size="1">Jason Reid
<a class="moz-txt-link-rfc2396E" href="mailto:jasereid@gmail.com"><jasereid@gmail.com></a>,
</font>
<br><font color="#5f5f5f" face="sans-serif" size="1">Cc:
</font><font face="sans-serif" size="1"><a class="moz-txt-link-rfc2396E" href="mailto:AusNOG@lists.ausnog.net">"AusNOG@lists.ausnog.net"</a>
<a class="moz-txt-link-rfc2396E" href="mailto:AusNOG@lists.ausnog.net"><AusNOG@lists.ausnog.net></a></font>
<br><font color="#5f5f5f" face="sans-serif" size="1">Date:
</font><font face="sans-serif" size="1">30/09/2014 05:47 PM</font>
<br><font color="#5f5f5f" face="sans-serif" size="1">Subject:
</font><font face="sans-serif" size="1">Re: [AusNOG]
DSL Line Stats</font>
<br><font color="#5f5f5f" face="sans-serif" size="1">Sent by:
</font><font face="sans-serif" size="1">"AusNOG"
<a class="moz-txt-link-rfc2396E" href="mailto:ausnog-bounces@lists.ausnog.net"><ausnog-bounces@lists.ausnog.net></a></font>
<br>
</p>
<hr noshade="noshade">
<br>
<br>
<br>
<font size="3">I always thought this was a pretty good explaination:<br>
</font><font color="blue" size="3"><u><br>
</u></font><a moz-do-not-send="true"
href="http://www.kitz.co.uk/adsl/linestats.htm"><font color="blue"
size="3"><u>http://www.kitz.co.uk/adsl/linestats.htm</u></font></a><font
size="3">
</font>
<br>
<br>
<font size="3">On 25 September 2014 17:12, Jason Reid <</font><a
moz-do-not-send="true" href="mailto:jasereid@gmail.com" target="_blank"><font
color="blue" size="3"><u>jasereid@gmail.com</u></font></a><font
size="3">>
wrote:</font>
<br>
<font size="3">I'd also be interested in this.</font>
<br>
<br>
<font size="3">Regards</font>
<br>
<font size="3">Jason Reid</font>
<br>
<font size="3"><br>
<br>
On Thursday, 25 September 2014, Jacob Kino <</font><a
moz-do-not-send="true" href="mailto:jacob@interconnekt.com.au"
target="_blank"><font color="blue" size="3"><u>jacob@interconnekt.com.au</u></font></a><font
size="3">>
wrote:</font>
<br>
<font size="3">Hi All,</font>
<p><font size="3"> </font>
</p>
<p><font size="3">Someone in our team has asked for a good document to
explain
DSL line stats, primarily in the context of interpreting wholesale DSL
line stats reports.</font>
</p>
<p><font size="3"> </font>
</p>
<p><font size="3">I had a look at our carrier’s product definition
document
but it doesn’t seem to speak much about layer 1, wondering if anyone had
a good reference they could point to, ideally that has some real world
reference values in an Australian context.</font>
</p>
<p><font size="3"> </font>
</p>
<p><font size="3">Cheers,</font>
</p>
<p><font size="3"> </font>
</p>
<p><font size="3">Jacob</font>
</p>
<p><font size="3"> </font>
</p>
<p><font size="3"><b>Jacob Kino</b></font><font size="1"><br>
<br>
<br>
<br>
Suite 5, 25-27 Izett St<br>
Prahran, VIC, 3181<br>
Hi <b><br>
e-mail </b><a class="moz-txt-link-abbreviated" href="mailto:jacob@interconnekt.com.au">jacob@interconnekt.com.au</a>
<b><br>
phone</b> 1300 852 842<b><br>
fax </b> 03 9011 6298<b><br>
www </b> </font><a moz-do-not-send="true"
href="http://www.interconnekt.com.au/" target="_blank"><font
color="blue" size="1"><u>www.interconnekt.com.au</u></font></a><font
size="1">
</font>
</p>
<p><font size="3"> </font>
</p>
<p><font color="#8f8f8f" size="3"><br>
<br>
-- <br>
Jason Reid</font><font size="3"><br>
<br>
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