A Broadband and ADSL forum. BroadbanterBanter

Welcome to BroadbanterBanter.

You are currently viewing as a guest which gives you limited access to view most discussions and other FREE features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload your own photos and access many other special features. Registration is fast, simple and absolutely free so please, join our community today.

Go Back   Home » BroadbanterBanter forum » Newsgroup Discussions » uk.telecom.broadband (UK broadband)
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

uk.telecom.broadband (UK broadband) (uk.telecom.broadband) Discussion of broadband services, technology and equipment as provided in the UK. Discussions of specific services based on ADSL, cable modems or other broadband technology are also on-topic. Advertising is not allowed.

Line Stats - uplink problem



 
 
Thread Tools Display Modes
  #1  
Old March 26th 13, 02:03 PM posted to uk.telecom.broadband
Martin Brown
external usenet poster
 
Posts: 343
Default Line Stats - uplink problem

I have previously posted about my broadband connection that misbehaved
dropping from a fastpath 5300kbps down to its present BRAS 2500 limit.
Interleaving is now firmly on. Sync speed is OK but BRAS stays low.

The downlink sync on a new modem is actually 3776 and pretty solid, but
the uplink is unreliable with error statistics to match. I don't
understand why the line attenuation is asymmetric for up 27 vs down 46.5

Information
Stream Type Actual Data Rate
Upstream 448 (Kbps.)
Downstream 3776 (Kbps.)

Defect/Failure Indication
Operation Data Upstream Downstream
Noise Margin 20.0 dB 14.6 dB
Line Attenuation 27.0 dB 46.5 dB

Indicator Name Near End Indicator Far End Indicator
Output Power 12.1 dBm 19.9 dBm
Interleaved Path FEC Correction 10524 32
Interleaved Path CRC Error 116 29
Loss of Signal Defect 0 0
Interleaved Path HEC Error 624 15
Error Seconds 93 0

Statistics
Received Cells 5513387
Transmitted Cells 795235

The previous modem used to drop the line several times a day. This one
holds the connection but reports error seconds. It is a default Orange
Brightbox modem that they gave me a while ago after I complained of
instability. Finally got around to trying it. The instability is gone
but the uplink error rates for FEC, CRC and HEC seem high to me.

Any idea what other tests or tricks I can try to get this improved?

Ideally I would like more download speed and would happily sacrifice
some upload speed to get it. Any suggestions for tweaks?

Thanks for any enlightenment!

--
Thanks,
Martin Brown
  #2  
Old March 26th 13, 03:04 PM posted to uk.telecom.broadband
The Natural Philosopher
external usenet poster
 
Posts: 2,728
Default Line Stats - uplink problem

On 26/03/13 14:03, Martin Brown wrote:
I have previously posted about my broadband connection that misbehaved
dropping from a fastpath 5300kbps down to its present BRAS 2500 limit.
Interleaving is now firmly on. Sync speed is OK but BRAS stays low.

that's very close to what my line used to support. Its better now, so I
may have something to say.

The downlink sync on a new modem is actually 3776 and pretty solid, but
the uplink is unreliable with error statistics to match.


eh? what staistics are those, and what is unrelaible? either you are
getting around 448 synch or you are not getting anything, at all, with
adls2.

I don't
understand why the line attenuation is asymmetric for up 27 vs down 46.5


simply because upstream tends to use the lower part of the spectruim
from around IIRC 40khz to around 100Khz whereas the downstream uses
100khz to maybe 2Mhz..naturally there is more attentuation at higher
frequencies,



Information
Stream Type Actual Data Rate
Upstream 448 (Kbps.)
Downstream 3776 (Kbps.)

Defect/Failure Indication
Operation Data Upstream Downstream
Noise Margin 20.0 dB 14.6 dB
Line Attenuation 27.0 dB 46.5 dB


apart from a higher synch speed and lower noise margin, than you I have
almost identical stats here. You should be able to get more synch. Id
guess in the high 4Ms or low 5Ms or even more with a spot on cable
...but..see later


Indicator Name Near End Indicator Far End Indicator
Output Power 12.1 dBm 19.9 dBm
Interleaved Path FEC Correction 10524 32
Interleaved Path CRC Error 116 29
Loss of Signal Defect 0 0
Interleaved Path HEC Error 624 15
Error Seconds 93 0

Statistics
Received Cells 5513387
Transmitted Cells 795235

The previous modem used to drop the line several times a day. This one
holds the connection but reports error seconds. It is a default Orange
Brightbox modem that they gave me a while ago after I complained of
instability. Finally got around to trying it. The instability is gone
but the uplink error rates for FEC, CRC and HEC seem high to me.


I think BT agrees with you and that's why they have whacked the noise
margin to probably 12.5dB I vary between 6dB and 9dB but it used to be
12,5dB too...


Any idea what other tests or tricks I can try to get this improved?

Ideally I would like more download speed and would happily sacrifice
some upload speed to get it. Any suggestions for tweaks?

Thanks for any enlightenment!


what that tells me is one thing and one thing alone. Your line to the
exchange is short enough to support maybe 6Mbps. 448k will always be
your load whatever. But its noisy as ****.

What you need to do is first of all disconnect everything (including
extension wiring) except the router from master socket, reboot the
router and compare error seconds for a day.

If that makes a huge difference, then sort out your internal phone
wiring. My mate had similar, and I told him 'that ain't right' and so he
pulled up some floorboards and sorted out his extensions and told me
'got 6mbps now'!.

If however that makes eff all difference...and that was the case for me
- you have a problem.

What you NEED is to get every single piece of copper between you and the
exchange checked out and the best one selected and every joint tested
and with a reflectometer and re-made.

Now that is of course about two man days of openreach engineer time, and
they may tell you to **** off.

I had aboy 5 years of 3000-3500 speeds that were fairly stable with
12.5dB margins and inteleaving. Then suddenly it started falling
dramatically. I phoned the ISP (IDNET) tried another router (cheapo
tplink, crap in everything BUT maintaining a fast spec on a long line)
disconnected everything, and eventually they agreed that my stats were
in fact showing a degradation that would need to be investigated. BUT if
the engineer fund nothing wrong 'and your specifications are within
normal standards' they would ding me 200 or something. I agreed.

So they first reported it as a voice fault. And engineer no 1 duly
turned up as filled up with sticky cakes, biscuits and fresh ground
coffee, and flattering opinions on the Irish rugby team - he certainly
was not from Birmingham. A dubliner expat as it turned out.

Filled with the milk of human kindness, Colombian coffee and a warm
glow, this honourable man set about remaking every single joint between
me and the main trunk using three different pairs on the post to trunk
links and trying out the other pair I had in my drop cable. "I cant do
the trunk stuff, that's broadband engineering, I am voice' Anyway he got
me another 2.5 db better attenuation.

At the end of that visit, speeds were up but the unreliability and
drop-outs remained. I emailed my ISP 'problem is still there' they
looked, ad it was so the they engaged a broadband engineer to come visit me.

He stick a reflectometer on the line, and sucked his teeth and said 'you
had an engineer for the voice in already I understand' 'yes' ;well hes
was pretty good. No joints showing much at all, but theres a cople down
in the trunk I want to test and off he went. Back later an 'well that's
a completely new pair on the trunk and remade joints at both ends' I
didn't get better attenuation, but the noise dropped a bit - a dB or so.

But still dropping out. And in fact I was fairly convinced by what the
ISP told me that there was a problem in the exchange itself. The noise
was on the upstream channel, and the signal is weakest at the exchange
on that. I had mentioned this to the second engineer but 'we aren't
allowed to work INSIDE the exchange: we deal with the wires only;'

I told IDNET that as far as I was concerned the problem though better
remained unresolved.

Then suddenly three days later, it cleared. I conated IDNET 'waht
happened' 'nothing we know about' well its been rock solid for 48 hours,
can you reset the BRAS and see where I end up' ' sure'

And there it was a massively unstable 7MBPS, well itst settled down to
around 6 and a gnats cock MBPS these days, but I can hold a 6db noise
margin.

I conjecture that the fault was escalated to someone who WAS allowed to
tinker with the DSLAM, and a joint remade or a card replaced.


The point of all this is that once you have eliminated stuff inside the
house, getting a better speed is very labour intensive, very expensive
and there exists the possibility that if you insist, the engineer can
still say 'its within spec: you pay 200 quid' and are no better off.

I was prompted into that course because I had a history of decent ish
speed that deteriorated rapidly. That was enough to get the attention.
Just. The fact that I came out with double the speed I originally had
was down mainly to one Dubliner, bless him,, who liked coffee, blarney
and rugby, going WAY beyond the call of duty to repay me with the best
possible copper circuit he knew how to make out if what he had. And I
love him for that.

he actual fault was fixed much later, but only after the crap process of
grinding through internal faults, local loop faults and trunk faults had
been done.

The process must have cost Openreach at least 1000 That's like 5 years
of my total broadband and phone rental charges.

All I wanted was stability. I ended up with speed and stability.

It took the best part of a month. Two engineer visits and half a dozen
email chats with the ISP. And lots of coffee an cakes.

So that is what you are facing.

What worries me in your case is the high noise margin and the history of
dropouts, That to me suggest a bad joint or a flaky DSLAM card
somewhere. You have eliminated the router, so next check internal
wiring and then settle down for a long tussle with your ISP.

At the worst you SHOULD be able to achieve stable 4500 BRAS in those
attenuation stats.

If your ISP ****es all over you, change to one that won't.





--
Ineptocracy

(in-ep-toc'-ra-cy) - a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

  #3  
Old March 26th 13, 03:49 PM posted to uk.telecom.broadband
Graham J
external usenet poster
 
Posts: 620
Default Line Stats - uplink problem

Martin Brown wrote:
I have previously posted about my broadband connection that misbehaved
dropping from a fastpath 5300kbps down to its present BRAS 2500 limit.
Interleaving is now firmly on. Sync speed is OK but BRAS stays low.

The downlink sync on a new modem is actually 3776 and pretty solid, but
the uplink is unreliable with error statistics to match. I don't
understand why the line attenuation is asymmetric for up 27 vs down 46.5

Information
Stream Type Actual Data Rate
Upstream 448 (Kbps.)
Downstream 3776 (Kbps.)

Defect/Failure Indication
Operation Data Upstream Downstream
Noise Margin 20.0 dB 14.6 dB
Line Attenuation 27.0 dB 46.5 dB

Indicator Name Near End Indicator Far End Indicator
Output Power 12.1 dBm 19.9 dBm
Interleaved Path FEC Correction 10524 32
Interleaved Path CRC Error 116 29
Loss of Signal Defect 0 0
Interleaved Path HEC Error 624 15
Error Seconds 93 0

Statistics
Received Cells 5513387
Transmitted Cells 795235

The previous modem used to drop the line several times a day. This one
holds the connection but reports error seconds. It is a default Orange
Brightbox modem that they gave me a while ago after I complained of
instability. Finally got around to trying it. The instability is gone
but the uplink error rates for FEC, CRC and HEC seem high to me.

Any idea what other tests or tricks I can try to get this improved?

Ideally I would like more download speed and would happily sacrifice
some upload speed to get it. Any suggestions for tweaks?

Thanks for any enlightenment!

The key parameter is the 14.6dB download noise margin.

The target SNR margin for most routers on typical lines and any "up to
8mbit/sec service" is 6dB. Your margin indicates that the router and
DSLAM between them have agreed to reduce the speed to accommodate the
noise on the line. Some people say you could get an extra magabit/sec
per 3dB improvement in SNR margin - so you might get an extra 4
mbits/sec - but I think it unlikely with 46.5dB loss.

Presumably you have a faceplate filter and isolated any/all extension
wiring? Tried several routers? Tried the "Quiet Line" test?

Monitor the error counters. Do they increase reqularly? Or do they
stay more or less constant then suddenly increase rapidly? If the
latter there may be impulse noise - tune an AM radio to an empty
frequency about 600hHz and listen to see if you can hear noise occurring
at the same time as the error counters increase? Then try to find out
where the noise is coming from, and fix it.

Who is your ISP? Is it in fact Orange?

Change to a professional ISP (A&A or Zen) then report any disconnections
(oher than those occuring during thunderstorms). People here will tell
you that their connections stay up for thouands of hours - myself, I've
never seen above about 150, but I and all my clients are in relatively
rural locations.

--
Graham J


 




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Line stats Cullen Skink uk.telecom.broadband (UK broadband) 19 March 6th 13 01:32 PM
Line Stats Paul uk.telecom.broadband (UK broadband) 7 October 3rd 07 12:18 AM
Comments on Line Stats Please TheScullster uk.telecom.broadband (UK broadband) 1 August 14th 07 12:44 AM
Line Stats? Simon Dean uk.telecom.broadband (UK broadband) 4 May 26th 06 10:01 AM
Line stats Fred uk.telecom.broadband (UK broadband) 1 November 4th 05 01:17 PM


All times are GMT +1. The time now is 05:58 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.Content Relevant URLs by vBSEO 2.4.0
Copyright 2004-2019 BroadbanterBanter.
The comments are property of their posters.