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.

Help sought in identifying loss-of-sync problem



 
 
Thread Tools Display Modes
  #1  
Old December 11th 06, 04:33 PM posted to uk.telecom.broadband
RMC
external usenet poster
 
Posts: 21
Default Help sought in identifying loss-of-sync problem

Hello

Please could someone take a look at these fault-finding steps I've taken, so
I can get a second opinion on where the fault lies? I am sure it is either
the BT line having degraded or something inside my house which I am trying
to identify via the following discourse:

1) My ADSL and telephone setup has remained unchanged and working fine for
many months - until yesterday when my router (3Com) sync light extinguished.
Rebooting the router didn't help - I would see the sync light come on and go
off a few times as the router tried to negotiate setting with the DSLAM, but
ultimately it gives up and I am left with an unsync'd router.

2) If I plug the router directly into the master socket (MS) with nothing
else connected, I get sync and it all works fine. (HTTP/POP3/SMTP/NNTP - all
working).

3) If I plug into the MS via an ADSL microfilter, I get sync and it all
works fine.

4) If I plug a metre of BT telephone cable into the "phone" port of the
microfilter and leave the router connected still via the microfilter
straight into the MS , I lose sync.

5) If I then terminate that 1m flying lead with a phone, I lose sync.

6) If I change the microfilter I get the same responses as 3-5 above

7) If I change the BT flying lead to a different one , I still lose sync.

8) The phone works fine when connected via the microfilter or direct to the
MS, irrespective of whether the router is connected or not.


Observations:
A) I only have a master socket which is maybe 2m from the BT riser into the
house. My phone and router then plugged into it, via a microfilter, and all
was well. There are no extension sockets.


My conclusion:
the microfilters are both OK as is the cabling inside the house, as is the
router. However, the external line to the property has become
damaged/waterlogged, such that the REN support capability of the line has
degraded. Loading the line with more than just the router causes the SNR on
the line to drop such that the router cannot negotiate its noise
environment.

What do I do next?
1) Try a different phone - mine is a DECT phone which although it has a REN
of 1, may have developed a fault such that its REN equivalence has
increased.
2) Get BT to test the line - the fault has been reported via my ISP
3)? Any suggestions anyone please?

My router is reporting the following operating conditions when it is synced
(clearly I can't get it to report when it is not synced - the router
diagnostics page just says "disconnected" and no specs are given for SNR
etc.):

Operation Data Upstream Downstream
Noise Margin 30 dB 9.5 dB
Output Power 10.5 dBm 20 dBm
Attenuation 20.5 dB 38 dB

Cheers for any pointers

RMC, England



























  #2  
Old December 11th 06, 04:50 PM posted to uk.telecom.broadband
RMC
external usenet poster
 
Posts: 21
Default Help sought in identifying loss-of-sync problem

My router is reporting the following operating conditions when it is
synced (clearly I can't get it to report when it is not synced - the
router diagnostics page just says "disconnected" and no specs are given
for SNR etc.):

Operation Data Upstream Downstream
Noise Margin 30 dB 9.5 dB
Output Power 10.5 dBm 20 dBm
Attenuation 20.5 dB 38 dB


I note that if I interrogate the router immediately after conecting a
phonelead or phonelead with telephone, I get the following figures in the
20-30s it takes before I lose connectivity:

Operation Data Upstream Downstream
Noise Margin 30 dB 5.5 dB
Output Power 10.5 dBm 20 dBm
Attenuation 20.5 dB 38 dB

and then

Operation Data Upstream Downstream
Noise Margin 29 dB -7.5 dB
Output Power 10.5 dBm 20 dBm
Attenuation 20.5 dB 37 dB

The downstream margin drops from 9.5 to 5.5 to -7.5 dB! Clearly some form of
line loading is in force - either due to my phone having developed a fault
or the line impedance altering due to the environment. looks like I need to
find another landline phone to test against.

Cheers

RMC, England







  #3  
Old December 11th 06, 07:45 PM posted to uk.telecom.broadband
Barry
external usenet poster
 
Posts: 9
Default Help sought in identifying loss-of-sync problem

My router is reporting the following operating conditions when it is
synced (clearly I can't get it to report when it is not synced - the
router diagnostics page just says "disconnected" and no specs are given
for SNR etc.):


If you have a 3COM modem get hold of a different power supply and try
it. I've been through five 3COM power supplies in the last 6 months.
They generally fail completely but I did have one that was creating a
lot of electrical noise giving all sorts of connection problems.

Good luck!

Regards
Barry
  #4  
Old December 11th 06, 09:56 PM posted to uk.telecom.broadband
kráftéé
external usenet poster
 
Posts: 1,765
Default Help sought in identifying loss-of-sync problem


"Barry" wrote in message
...
My router is reporting the following operating conditions when it
is synced (clearly I can't get it to report when it is not
synced - the router diagnostics page just says "disconnected" and
no specs are given for SNR etc.):


If you have a 3COM modem get hold of a different power supply and
try it. I've been through five 3COM power supplies in the last 6
months. They generally fail completely but I did have one that was
creating a lot of electrical noise giving all sorts of connection
problems.

Good luck!

Don't buy Belkin they can be even worse.

Get a small AM radio & tune it to around 612Khz & see if there is any
difference in signals heard with the power supply on & then off. You
may get a nasty surprise.

Only last week I found a Freeview set top box at one house & a plug
wart power supply for a USB hub in another, busy pushing out signals &
causing problems with the end users ADSL service.


  #5  
Old December 11th 06, 10:21 PM posted to uk.telecom.broadband
Zomaar
external usenet poster
 
Posts: 40
Default Help sought in identifying loss-of-sync problem


"RMC" wrote in message
...
Hello

Please could someone take a look at these fault-finding steps I've taken,
so I can get a second opinion on where the fault lies? I am sure it is
either the BT line having degraded or something inside my house which I am
trying to identify via the following discourse:

1) My ADSL and telephone setup has remained unchanged and working fine for
many months - until yesterday when my router (3Com) sync light
extinguished.


Did you hang up your Christmas decorations yesterday ?

There are known problems with some tree lights causing loss of synch...

HTH, Ali


  #6  
Old December 11th 06, 11:11 PM posted to uk.telecom.broadband
RMC
external usenet poster
 
Posts: 21
Default Help sought in identifying loss-of-sync problem

Barry, kráftéé and Zomaar

Please could someone take a look at these fault-finding steps ?


Thanks for your replies and encouragement. I will look into PSU issues in
case the original supply has started radiating noise - if I can find a
linear one that'll do as a proof-of-concept check. I'll get onto that. The
suggestion extraneous equipment being a source of interference is also a
good one - we don't have any Xmas lights up yet and our neighbours are
similarly miserable so far!

One thing I have since observed is that, even when I do get sync and a
working connection, the speed is down to something like 180kbps instead of
1800 kbps - I'm on a 2Mbps fixed rate DSL line (should be, anyway!)

Cheers

RMC, England


  #7  
Old December 12th 06, 01:07 AM posted to uk.telecom.broadband
kráftéé
external usenet poster
 
Posts: 1,765
Default Help sought in identifying loss-of-sync problem

RMC wrote:
Barry, kráftéé and Zomaar

Please could someone take a look at these fault-finding steps ?


Thanks for your replies and encouragement. I will look into PSU
issues in case the original supply has started radiating noise - if
I
can find a linear one that'll do as a proof-of-concept check. I'll
get onto that. The suggestion extraneous equipment being a
source
of interference is also a good one - we don't have any Xmas lights
up yet and our neighbours are similarly miserable so far!

One thing I have since observed is that, even when I do get sync and
a
working connection, the speed is down to something like 180kbps
instead of 1800 kbps - I'm on a 2Mbps fixed rate DSL line (should
be,
anyway!)
Cheers

RMC, England


Can you check for errors?


  #8  
Old December 12th 06, 05:26 PM posted to uk.telecom.broadband
RMC
external usenet poster
 
Posts: 21
Default Help sought in identifying loss-of-sync problem


Barry, kráftéé and Zomaar
Please could someone take a look at these fault-finding steps ?


Can you check for errors?


That's a good point - I didn't think of that. The error page says the
following (which I don't understand):

Indicator Name Near End Indicator
Far End Indicator
Fast Path FEC Correction 0
1
Interleaved Path FEC Correction 0
0
Fast Path CRC Error 14852
0
Interleaved Path CRC Error 0
0
Loss of Signal
---
Loss of Frame
---
Loss of Power
---
Fast Path HEC Error 1618
1618
Interleaved Path HEC Error 0
1



I don't know if that's good or bad. Can you comment on them for me please?

What I do know is that it is becoming increasingly difficult for me to gain
sync when the router is connected (nothig else connected) which suggests a
deteriorating line condition. My download rates are less than a tenth of
expected still and they may be slowing yet further (not enough test data to
mean anything yet).

Cheers

RMC, England


  #9  
Old December 12th 06, 05:34 PM posted to uk.telecom.broadband
kráftéé
external usenet poster
 
Posts: 1,765
Default Help sought in identifying loss-of-sync problem


"RMC" wrote in message
...

Barry, kráftéé and Zomaar
Please could someone take a look at these fault-finding steps ?


Can you check for errors?


That's a good point - I didn't think of that. The error page says
the following (which I don't understand):

Indicator Name Near End Indicator Far
End Indicator
Fast Path FEC Correction 0 1
Interleaved Path FEC Correction 0 0
Fast Path CRC Error 14852 0
Interleaved Path CRC Error 0 0
Loss of Signal ---
Loss of Frame ---
Loss of Power ---
Fast Path HEC Error 1618 1618
Interleaved Path HEC Error 0 1



I don't know if that's good or bad. Can you comment on them for me
please?

What I do know is that it is becoming increasingly difficult for me
to gain sync when the router is connected (nothig else connected)
which suggests a deteriorating line condition. My download rates
are less than a tenth of expected still and they may be slowing yet
further (not enough test data to mean anything yet).

Cheers


Time period????


  #10  
Old December 12th 06, 08:19 PM posted to uk.telecom.broadband
RMC
external usenet poster
 
Posts: 21
Default Help sought in identifying loss-of-sync problem

Can you check for errors?

That's a good point:


Fast Path CRC Error 14852 0
Fast Path HEC Error 1618 1618
Interleaved Path HEC Error 0 1


Time period????


These results were obtained once sync had occurred and the router had
negotiated a successful connection - something like 2 - 3 minutes I would
guess. The errors mounted up when I did a few refreshes over the next few
minutes, but then the sync failed again and this is the first time I've been
back online since my earlier post.

RMC, England


 




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
sync loss Gavin uk.telecom.broadband (UK broadband) 16 March 20th 06 11:26 PM
What is this "loss of sync", and do I have it? Hugo Nebula uk.telecom.broadband (UK broadband) 25 January 15th 06 05:48 PM
would these loop loss figures explain my disconnection/sync problems? jkn uk.telecom.broadband (UK broadband) 2 September 19th 05 10:23 PM
Help sought - problem configuring D-Link DSL-500 Jim Macleod uk.telecom.broadband (UK broadband) 8 September 19th 05 09:29 AM
sync loss Gavin uk.telecom.broadband (UK broadband) 5 February 20th 04 12:31 PM


All times are GMT +1. The time now is 10:39 PM.


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.