Your forum username:
Do you already have an account?
Forgot your password?
  • Log in or Sign up


    Welcome to Sky User - The Unofficial Support Forum for everything Sky! - Proudly helping over 65k members.


    Advertisement

    Page 7 of 7 FirstFirst ... 567
    Results 61 to 64 of 64

    Overwhelmed with CRC errors

    This is a discussion on Overwhelmed with CRC errors within the Technical discussion forums, part of the Broadband Technical Help category; James67 - have run your utility and am trying to work out what is happening on my line - below ...

    1. #61
      Connormp's Avatar
      Connormp is offline Sky User Member
      Exchange: 01926
      Broadband ISP: Mid
      Router:
      Sky TV:
      Join Date
      Oct 2007
      Location
      Kenilworth
      Posts
      7
      Thanks
      0
      Thanked 0 Times in 0 Posts

      Re: Overwhelmed with CRC errors

      James67 - have run your utility and am trying to work out what is happening on my line - below is the output from your monitor where it has a positive CRC together with the router log for the same period. I presume when it says LCP down in the router log, the router has resynched as these seem to correspond to a build up of CRC errors ? eg at 0945 when the error rate has reached 6% - NB the connection was fine all night with no CRC errors at all with a SNR of over 16.

      My question is - given that there was no activity in the house, does this suggest it is the BT line at fault rather than my internal wiring? NB I am still working on my wiring. On arriving home, my router had resynched at just over 1Mb...normally it appears to be capped at 4448kbps.

      It has just disconnected again with a CRC error rate of 3%....this is maddening....

      Any thoughts appreciated.

      Cheers


      Oct 29 09:04 localhost: Error rate is 0.10% (SF = 17819, CRC = 19)
      Oct 29 09:09 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 09:14 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 09:19 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 09:24 localhost: Error rate is 0.00% (SF = 17879, CRC = 0)
      Oct 29 09:29 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 09:34 localhost: Error rate is 1.17% (SF = 15877, CRC = 186)
      Oct 29 09:39 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 09:45 localhost: Error rate is 6.05% (SF = 16289, CRC = 986)
      Oct 29 09:50 localhost: Error rate is 0.84% (SF = 17820, CRC = 151)
      Oct 29 09:55 localhost: Error rate is 0.05% (SF = 17820, CRC = 10)
      Oct 29 10:00 localhost: Error rate is 0.05% (SF = 17820, CRC = 9)
      Oct 29 10:05 localhost: Error rate is 0.02% (SF = 17820, CRC = 4)
      Oct 29 10:10 localhost: Error rate is 0.01% (SF = 17878, CRC = 3)
      Oct 29 10:15 localhost: Error rate is 0.10% (SF = 17820, CRC = 18)
      Oct 29 10:20 localhost: Error rate is 0.05% (SF = 17820, CRC = 10)
      Oct 29 10:25 localhost: Error rate is 0.06% (SF = 17820, CRC = 11)
      Oct 29 10:30 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 10:35 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 10:40 localhost: Error rate is 0.00% (SF = 17879, CRC = 0)
      Oct 29 10:45 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 10:50 localhost: Error rate is 0.01% (SF = 17819, CRC = 3)
      Oct 29 10:55 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 11:00 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 11:05 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 11:10 localhost: Error rate is 0.00% (SF = 17879, CRC = 0)
      Oct 29 11:15 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 11:21 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 11:26 localhost: Error rate is 0.01% (SF = 17820, CRC = 2)
      Oct 29 11:31 localhost: Error rate is 0.03% (SF = 17820, CRC = 7)
      Oct 29 11:36 localhost: Error rate is 0.87% (SF = 17878, CRC = 156)
      Oct 29 11:41 localhost: Error rate is 0.53% (SF = 17820, CRC = 96)
      Oct 29 11:46 localhost: Error rate is 0.38% (SF = 17820, CRC = 69)
      Oct 29 11:51 localhost: Error rate is 0.28% (SF = 17820, CRC = 51)
      Oct 29 11:56 localhost: Error rate is 0.43% (SF = 17820, CRC = 78)
      Oct 29 12:01 localhost: Error rate is 0.43% (SF = 17879, CRC = 78)
      Oct 29 12:06 localhost: Error rate is 0.59% (SF = 17820, CRC = 106)
      Oct 29 12:11 localhost: Error rate is 0.87% (SF = 17820, CRC = 156)
      Oct 29 12:16 localhost: Error rate is 0.72% (SF = 17819, CRC = 129)
      Oct 29 12:21 localhost: Error rate is 1.13% (SF = 17820, CRC = 203)
      Oct 29 12:26 localhost: Error rate is 0.77% (SF = 17820, CRC = 138)
      Oct 29 12:31 localhost: Error rate is 0.43% (SF = 17879, CRC = 78)
      Oct 29 12:36 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 12:41 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 12:46 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 12:51 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 12:56 localhost: Error rate is 0.00% (SF = 17878, CRC = 0)
      Oct 29 13:02 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 13:07 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 13:12 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 13:17 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 13:22 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 13:27 localhost: Error rate is 0.00% (SF = 17879, CRC = 0)
      Oct 29 13:32 localhost: Error rate is 0.07% (SF = 17820, CRC = 13)
      Oct 29 13:37 localhost: Error rate is 0.00% (SF = 17819, CRC = 0)
      Oct 29 13:42 localhost: Error rate is 0.19% (SF = 17820, CRC = 35)
      Oct 29 13:47 localhost: Error rate is 2.68% (SF = 17820, CRC = 479)
      Oct 29 13:52 localhost: Error rate is 1.86% (SF = 17879, CRC = 333)
      Oct 29 13:57 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 14:02 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)
      Oct 29 14:07 localhost: Error rate is 0.95% (SF = 17820, CRC = 171)
      Oct 29 14:12 localhost: Error rate is 0.62% (SF = 17820, CRC = 112)
      Oct 29 14:17 localhost: Error rate is 0.00% (SF = 17878, CRC = 0)
      Oct 29 14:22 localhost: Error rate is 0.01% (SF = 17820, CRC = 3)
      Oct 29 14:27 localhost: Error rate is 0.00% (SF = 17820, CRC = 1)
      Oct 29 14:32 localhost: Error rate is 1.32% (SF = 15877, CRC = 210)
      Oct 29 14:38 localhost: Error rate is 1.02% (SF = 17879, CRC = 183)
      Oct 29 14:43 localhost: Error rate is 3.98% (SF = 14231, CRC = 567)
      Oct 29 14:48 localhost: Error rate is 0.00% (SF = 17406, CRC = 0)
      Oct 29 14:53 localhost: Error rate is 0.00% (SF = 17819, CRC = 0)
      Oct 29 14:58 localhost: Error rate is 0.00% (SF = 17879, CRC = 0)
      Oct 29 15:03 localhost: Error rate is 0.00% (SF = 17820, CRC = 0)


      Router log:

      Mon, 2007-10-29 09:32:08 - Initialize LCP.
      Mon, 2007-10-29 09:32:08 - LCP is allowed to come up.
      Mon, 2007-10-29 09:32:09 - CHAP authentication success
      Mon, 2007-10-29 09:43:08 - LCP down.
      Mon, 2007-10-29 09:43:15 - Initialize LCP.
      Mon, 2007-10-29 09:43:15 - LCP is allowed to come up.
      Mon, 2007-10-29 09:43:21 - CHAP authentication success
      Mon, 2007-10-29 14:31:20 - Initialize LCP.
      Mon, 2007-10-29 14:31:20 - LCP is allowed to come up.
      Mon, 2007-10-29 14:31:24 - CHAP authentication success
      Mon, 2007-10-29 14:39:40 - LCP down.
      Mon, 2007-10-29 14:39:46 - Initialize LCP.
      Mon, 2007-10-29 14:39:46 - LCP is allowed to come up.
      Mon, 2007-10-29 14:39:46 - CHAP authentication success
      Mon, 2007-10-29 14:43:39 - Initialize LCP.
      Mon, 2007-10-29 14:43:39 - LCP is allowed to come up.
      Mon, 2007-10-29 14:43:39 - CHAP authentication success


    2. Advertisement
    3. #62
      machasm's Avatar
      machasm is offline Sky User Member
      Exchange: Broadstone
      Broadband ISP: Connect
      Router:
      Sky TV:
      Join Date
      Oct 2007
      Posts
      63
      Thanks
      0
      Thanked 0 Times in 0 Posts

      Re: Overwhelmed with CRC errors

      What a marathon of a thread James67.
      I am impressed by your knowledge of ADSL technologies as well as your ability to follow a logical fault-finding path.
      One thing that I am puzzled by though is how could this be happening on several different modems?
      Surely they cannot all be suffering from badly written error correction algorithms?
      The different manufacturers would have surely developed their error correction programs in different ways or at least be at different stages of development such that at least someones bit swapping mechanism would work!
      I use a Billion 7402R2 router which uses the Argon 432 chipset and is steady as a rock.
      That doesn't mean much though since I am nowhere near the sync speeds that you are at and am on ADSL1 (connect).
      But might be worth checking with a better grade DSL modem perhaps?
      Mac.

    4. #63
      James67's Avatar
      James67 is offline Sky User Member
      Exchange:
      Broadband ISP: Other ISP
      Router: Non Sky Router
      Sky TV: Freesat
      Join Date
      Sep 2007
      Posts
      1,789
      Thanks
      0
      Thanked 2 Times in 2 Posts
      Blog Entries
      3

      Re: Overwhelmed with CRC errors

      Quote Originally Posted by Connormp View Post
      I presume when it says LCP down in the router log, the router has resynched as these seem to correspond to a build up of CRC errors ?
      If the stability script triggers a resync, it'll say so in the log. The equipment at the exchange end can also trigger resyncs if it detects errors in the upstream data (from the router to the exchange) and it can't get the router to bit swap the error-prone channels to error-free channels. Or it could be that you're getting very bad, but intermittent interference on your phone line.

    5. #64
      James67's Avatar
      James67 is offline Sky User Member
      Exchange:
      Broadband ISP: Other ISP
      Router: Non Sky Router
      Sky TV: Freesat
      Join Date
      Sep 2007
      Posts
      1,789
      Thanks
      0
      Thanked 2 Times in 2 Posts
      Blog Entries
      3

      Re: Overwhelmed with CRC errors

      Quote Originally Posted by machasm View Post
      Surely they cannot all be suffering from badly written error correction algorithms?
      The different manufacturers would have surely developed their error correction programs in different ways or at least be at different stages of development such that at least someones bit swapping mechanism would work!
      Well they would if they actually wrote substantial sections of their own code.

      Nowadays, routers will be running an embedded version of Linux with ADSL chipset driver code written by the chipset manufacturer. There'll be tweaks in the software here and there to cover small differences in the hardware - one router manufacturer might use an Atheros wireless card, another might use a TI card - but the software on one Broadcom-based router will be substatially similar to another. I noticed that a friend's Linksys router had exactly the same firmware version number as an off-the-shelf Netgear one. It turned out that they run the same release of Linux with the same version of ADSL driver code as each other.

      Often even the hardware will be substantially the same, as they are often based on a "reference design" from Broadcom.

     

     
    Page 7 of 7 FirstFirst ... 567

    LinkBacks (?)


    Tags for this Thread

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •  
    SkyUser - Copyright © 2006-2020. SatDish and NewsreadeR | SkyUser is in no way affiliated with Sky Broadband / BSkyB
    RIPA NOTICE: NO CONSENT IS GIVEN FOR INTERCEPTION OF PAGE TRANSMISSION