- Line noise margin variation?
- Posted by Gareth on January 3rd, 2005
My line noise margin varies between 25 and 14 (or lower).
Does this indicate a faulty line or is variation during the course of a
day - and a few minutes - part of normal line function?
Gareth.
- Posted by Sunil Sood on January 3rd, 2005
"Gareth" <hotmail.com@dgareth.spm> wrote in message
news:41d99943$0$48227$ed2619ec@ptn-nntp-reader02.plus.net
Its nothing to worry about.
Regards
Sunil
- Posted by Grant on January 4th, 2005
"Brian Morrison" scrapspam@fenrir.org.uk wrote in message
news
an.2005.01.04.09.18.19.530508@fenrir.org.uk
Jeez.
Highest I've ever seen here is 16dB. Right now, it's 9.5dB. Average is 11dB.
Had another 3 hour outage last night when it stayed below 3dB the whole
time.
*Really* must find a round tuit soon.
- Posted by Peter M on January 6th, 2005
On 4 Jan 2005 , in uk.telecom.broadband, "Grant" <news@mason.sh> wrote:
Must be a distance thing. Happily I am ~ 30 minutes walk to the exchange
so the figures I have are usually good (and I wish I had some note of the
figures before the BT guy changed the pair back to the exchange, sometime
in December, to be able to compare with the figures today)...
ADSL STATUS (My Plus.Net connection)
Showtime Firmware Version: 2.28b
ADSL Startup Attempts: 1
Elaspsed Time: 0 days 20 hours 7 minutes 35 seconds
SNR Margin 39.8 25.0 dB
Line Attenuation 34.1 21.0 dB
Errored Seconds 0 0
Loss of Signal 0 0
Loss of Frame 0 0
CRC Errors 0 0
Data Rate 576 288 kbps
Only 20 hours as I rebooted it after making some forwarding changes.
ADSL STATUS (My UKFSN connection, using Tiscali's network)
Showtime Firmware Version: 3.27
Startup Attempts: 1
Max Tx Power: -38 dBm/Hz
CO Vendor: ALCATEL_NETWORK
Elaspsed Time: 61 days 15 hours 46 minutes 28 seconds
SNR Margin 29.6 25.0 dB
Line Attenuation 34.1 21.0 dB
Errored Seconds 195 2
Loss of Signal 0 0
Loss of Frame 0 0
CRC Errors 391 2
Data Rate 2272 288 kbps
--------------------------------------------------------------------
For anyone interested, the later firmware for the Conexant / PTI /
DabsValue router (v3.27) has no diagnostic test display within the
browser UI, which is a bit of a shame, IMO. Peter M.
--
PlusNet <http://tinyurl.com/24ymz> - I recommend them and save some cash.
My other ISP : UK Free Software Network <http://www.ukfsn.org>
UKFSN passes all profits to Free Software projects in the UK.
- Posted by Phil Thompson on January 6th, 2005
On Thu, 06 Jan 2005 20:21:36 +0000, Brian Morrison
<scrapspam@fenrir.org.uk> wrote:
SNR + attenuation is often around 70, if you get 80 then the
interference level must be nice and low. Enjoy !
Phil
--
Splenda - the only sweetener made from chlorine :-)
- Posted by robert w hall on January 6th, 2005
In article <4u7rt0lpgt7vu1onn9j57avujtjkqgggfb@4ax.com>, Phil Thompson
<phil.thompson@spamcop.net> writes
So anyone at greater than 7.5km/75db is demonstrably stuffed???
(Hey Phil, I feel we're exchanging similar posts in two different
forums, the other being demon.service, at about the same time...)
Bob
--
robert w hall
- Posted by robert w hall on January 6th, 2005
In article <4u7rt0lpgt7vu1onn9j57avujtjkqgggfb@4ax.com>, Phil Thompson
<phil.thompson@spamcop.net> writes
This is a rather limited rule of thumb IMHO Phil.
(I thought it was quite useful until I tried applying it :-))
Looking at a few data for Berkeley and Falfield exchanges, the value for
the sum seems to vary between 75 and 90, and that's a pretty wide range
in SNR.
You _might_ expect there was a correlation of the form
atten + a. SNR = b
where a might be of order 2ish
that might be more serviceable.
--
robert w hall
- Posted by Phil Thompson on January 7th, 2005
On Thu, 6 Jan 2005 23:52:48 +0000, robert w hall
<bobh@n-cantrell.demon.co.uk> wrote:
that is huge, what is the 90 made up of - not 70 attenuation and 20
SNR I hope (envy !)
The "70" came from observing reports from people on longish lines. If
the attenuation exceeds 65 then the inteference level has to be pretty
low to get a decent SNR but this does happen reasonably often.
The time to worry is when you see 50 attenuation and 8 SNR on a 512k
line.
Phil
--
Splenda - the only sweetener made from chlorine :-)
- Posted by kraftee on January 7th, 2005
Phil Thompson wrote:
No the time to worry is when you see 0db line loss & -65db snr on the
line.....
Yes it still synched up, just, but was un-usable....
- Posted by Grant on January 7th, 2005
"kraftee" kraftee@spamoff& die.com wrote in message
news:41ded28e$0$44542$ed2619ec@ptn-nntp-reader02.plus.net
Coo. I'm currently dreaming of a 0dB loss.
Operation Data Downstream
Noise Margin -8.5 dB
Output Power 16 dBm
Attenuation -64 dB
Finally got round to complaining to Pipex today. Watch this space.
