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Router error query

Discussion in 'Networks & Internet Connectivity' started by CurlyWhirly, 19 May 2006.

  1. CurlyWhirly

    Wise Guy

    Joined: 24 May 2003

    Posts: 1,429

    Location: UK

    I have been on Max DSL since 5th May and so I am out of my 10 day training period and since being on Max DSL I have noticed that the number of packet errors has shot up :eek:


    [​IMG]


    As my screenshot shows, in just over 13 hours I have amassed over 197,000 FEC errors and over 12,000 CRC errors.

    Are these errors normal for a rate adaptive line as when I was on a fixed 1 Mb connection, I don't remember seeing that many errors?

    Is it because my SN/R margin has been reduced from around 24 dB to around 6 dB which although it is just enough to keep my line stable, it apparently allows more errors in the data transmission?

    I do have interleaving enabled by the way.
    Talking of interleaving, can it correct more than one type of error or does it only work on FEC errors?

    Also in the error stats are the errors recorded whether they are fixed or not by the error correction feature in interleaving?

    p.s. I've also noticed that I have many more downstream errors compared to upstream errors and would this be because my upstream SN/R is a fair bit higher than my downstream reading which tends to hover around the 6 dB mark depending on the time of day although it tends to drop to around 3 dB in the evenings resulting in a dropped connection!
     
  2. CurlyWhirly

    Wise Guy

    Joined: 24 May 2003

    Posts: 1,429

    Location: UK

    Just to clear this up, for some reason having interleaving enabled leads to an increase in router errors but as it is normal and my connection is stable (apart from a daily disconnection due to a falling SN/R margin), I am not going to worry about it!
     
  3. tolien

    Caporegime

    Joined: 16 May 2003

    Posts: 25,368

    Location: ::1

    Interleaving doesn't give you increased errors, it gives you better error correction (which is what FEC "errors" is showing).
     
  4. CurlyWhirly

    Wise Guy

    Joined: 24 May 2003

    Posts: 1,429

    Location: UK

    That's what I was trying to say but worded it wrong :o

    Does that mean with interleaving off, the reason why the number of errors was lower was because the corrupt data packets were re-sent at the routers request as opposed to (most of) them being fixed by the error correction algorithms of the interleaving feature?
     
  5. tolien

    Caporegime

    Joined: 16 May 2003

    Posts: 25,368

    Location: ::1

    Yes. Frames that arrive corrupted (and can't be fixed, if interleaving's enabled) will appear at a higher level as packet loss.
     
  6. CurlyWhirly

    Wise Guy

    Joined: 24 May 2003

    Posts: 1,429

    Location: UK

    Just a final query if I could Tolien ;)

    Am I right in thinking that interleaving ONLY attempts to correct FEC errors or does it attempt CRC and HEC errors as well?

    I assume that Error Seconds (Local) aren't covered?
     
  7. tolien

    Caporegime

    Joined: 16 May 2003

    Posts: 25,368

    Location: ::1

    FECs aren't errors, as I've already said...

    Errored seconds are just counts of seconds when frames had errors (either CRC/HEC, or corrected by FEC).
     
  8. CurlyWhirly

    Wise Guy

    Joined: 24 May 2003

    Posts: 1,429

    Location: UK

    Thanks.

    I was under the impression that the high number of 'errors' displayed (since asking to have interleaving enabled) was bad but as they have probably been corrected by interleaving, I see what you mean by them not been errors as such.
     
  9. tolien

    Caporegime

    Joined: 16 May 2003

    Posts: 25,368

    Location: ::1

    It's less bad that they're getting fixed, but more bad in that ideally you'd have no errors to correct in the first place.