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Author Topic: BT2100 Router Errors and speed fuctuations  (Read 5400 times)

Kev

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BT2100 Router Errors and speed fuctuations
« on: November 11, 2006, 10:34:59 AM »

Hi All
New to this but after reading KITZ advice on ADSL I understand a lot more - thanks!

I've just upgraded my connection from 512 to 8Mbps with Virgin and after a long delay in getting my router to sync I've now managed to connect but my speed fluctuates enormously, see below, (connection is stable with no drop outs). When I checked my Broadband Status via the router I noted I'm getting a lot of Super Frames and RS Word error, see below - what does this mean and is there a way to correct them? I've changed my MTU to 1400 to match Virgin but still get these errors.

Running on Microsoft XP with Wireless BT2100 router

Any help welcomed!
Kev
___________________________________________________

Broadband Line Status
   
 Line Mode G.dmt   Line State Show Time 
 Latency Type Interleave   Line Up Time 00:00:16:37 
 Line Coding Trellis Off   Line Up Count 1 
   
 Statistics Downstream Upstream 
 Line Rate 5024 448 
 Noise Margin 8.9 dB  23.0 dB   
 Line Attenuation 29.5 dB  21.0 dB   
 Output Power 11.9 dBm  19.6 dBm   
 K (number of bytes in DMT frame) 158 15 
 R (number of check bytes in RS code word) 14 16 
 S (RS code word size in DMT frame) 1 8 
 D (interleaver depth) 16 2 
 Super Frames 38228  38226   
 Super Frame Errors 10  0   
 RS Words 2599472  324921   
 RS Correctable Errors 650936  0   
 RS Uncorrectable Errors 10  0   
 HEC Errors 7  0   
 OCD Errors 0  0   
 LCD Errors 0  0   
 ES Errors 0  0   
   _______________________________________________________

SPEED VARIATION LOG
9th Nov 2006 @ 6:20am
Downstream 2,594.0 Kbps ( = 2.5 Mbps )   
Upstream 372.0 Kbps ( = 0.4 Mbps )   

9th Nov 2006 @ 8:20pm
Downstream 131.2 Kbps ( = 0.1 Mbps )   
Upstream 269.0 Kbps ( = 0.3 Mbps )   

9th Nov 2006 @ 11.50pm
Downstream 1,536.3 Kbps ( = 1.5 Mbps )   
Upstream 371.4 Kbps ( = 0.4 Mbps )   

10th Nov 2006 @ 7:20am
Downstream 3,225.0 Kbps ( = 3.1 Mbps )   
Upstream 371.2 Kbps ( = 0.4 Mbps )   

10th Nov 2006 @ 5:20pm
Downstream 537.9 Kbps ( = 0.5 Mbps )   
Upstream 329.9 Kbps ( = 0.3 Mbps )   

10th Nov 2006 @ 6:20pm
Downstream 354.8 Kbps ( = 0.3 Mbps )   
Upstream 316.8 Kbps ( = 0.3 Mbps )   

10th Nov 2006 @ 7:20pm
Downstream 1,257.9 Kbps ( = 1.2 Mbps )   
Upstream 373.6 Kbps ( = 0.4 Mbps )   

 

 
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Kev

mr_chris

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Re: BT2100 Router Errors and speed fuctuations
« Reply #1 on: November 11, 2006, 11:50:22 AM »

Hi Kev welcome to the forum

I've just noticed you're connecting at ~ 5Mb with a reasonably low line attenuation - lower than mine, and I sync at 7.8Mb

Before we go down other routes of contention (which it might well be), I'd like you to try connecting your router into the BT master socket, unplugging all other phone extensions, if possible.

What would be even better is if you could plug the router directly into the test socket behind the master socket faceplate and see if that makes things any better.

If it does see a marked improvement, then the problem would lie with phone extensions in your house and/or your filter setup.

Try the test socket and get back to us and we'll take it from there :)
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Chris

Kev

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Re: BT2100 Router Errors and speed fuctuations
« Reply #2 on: November 11, 2006, 05:59:40 PM »

Hi Chris,

My router is plugged into a NTE5 adsl faceplate and I get similar results if I plug in directly into the master socket with a filter. All extensions in the house have neen disconnected so can't be an internal issue.
I did a check on my exchange status - EASTWOOD, and it states....

BT is reporting that some of the virtual paths at this exchange are not operating within BT Wholesale's planning guidance, although they are still operating within the product specification.

At busy times, your ADSL connection may operate at a reduced speed, although not all customers on your exchange may be affected. You should only contact support if there is no current ETA date set.

The ETA fix time is: 17 Nov 06


So maybe it'll get better after the 17th but I'm not holding my breath!

I'd still like to know what the errors mean though - see below;

Regards,
Kev

________________________________________________________________

Line Mode G.dmt   Line State Show Time 
 Latency Type Interleave   Line Up Time 00:07:53:38 
 Line Coding Trellis Off   Line Up Count 1 
   
 Statistics Downstream Upstream 
 Line Rate 5024 448 
 Noise Margin 8.4 dB  23.0 dB   
 Line Attenuation 29.5 dB  21.0 dB   
 Output Power 11.9 dBm  19.6 dBm   
 K (number of bytes in DMT frame) 158 15 
 R (number of check bytes in RS code word) 14 16 
 S (RS code word size in DMT frame) 1 8 
 D (interleaver depth) 16 2 
 Super Frames 1651430  1651428   
 Super Frame Errors 1646  1   
 RS Words 112297210  14037138   
 RS Correctable Errors 31604268  8   
 RS Uncorrectable Errors 1744  0   
 HEC Errors 917  0   
 OCD Errors 0  0   
 LCD Errors 0  0   
 ES Errors 0  0 
 ______________________________________________________________________
   



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Kev

kitz

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Re: BT2100 Router Errors and speed fuctuations
« Reply #3 on: November 11, 2006, 07:14:52 PM »

Theres different types of errors that you can get on your line.

I notice that your line is interleaved and therefore its quite usual when interleaving is applied to see an error correction count (far end correction), which means that interleaving is working as it should....  or more correctly... interleaving and error correction are both turned on at the same time.

I dont think many people actually understands too much about the different types of errors. - me certainly
CRC, HEC errors are something thats seen on both FAST and Interleaved lines.  Too many of those arent good because they can slow your speeds because data packets are having to be re-requested.

Without actually doing some research however I would guess that RS Correctable Errors 650936  are the FEC errors that have been corrected via Interleaving? -
If so then its nothing to be too concerned about and is just your line and interleaving and error correction are working as they should

Theres some more info on Interleaving here
http://www.kitz.co.uk/adsl/interleaving.htm


Like I say theres no quick and easy explanation of CRC/HEC errors in one place but the following links are the ones that  normally direct people too when they ask.

The CRC-based framing link probably has the best info to give basic understanding.

HEC http://en.wikipedia.org/wiki/Header_Error_Correction
FEC http://en.wikipedia.org/wiki/Forward_error_correction
CRC http://en.wikipedia.org/wiki/CRC-based_framing
« Last Edit: November 11, 2006, 07:56:36 PM by kitz »
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How to get your router line stats :: ADSL Exchange Checker

Kev

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Re: BT2100 Router Errors and speed fuctuations
« Reply #4 on: November 12, 2006, 12:16:00 PM »

Thanks for the info Kitz, very useful.

Guess I'll have to wait until the error in my exchange is fixed before I chase up BT/Virgin about my speed fluctuation  :no:

I'll let you know how it goes after the 17th Nov
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Kev
 

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