What causes ADSL "errors"?

A couple of questions..

On a ADSL line what would cause CRC and SDU Length errors (as reported
by the Alcatel USB modem software)?

Are they serious (or not) ?

And finally whats a reasonable/expected number that one should receive
in a given time period "without worrying"?

Regards
Sunil

"Sunil Sood" <(E-Mail Removed)> wrote in message
news:biuglp$celvd$(E-Mail Removed)...
> A couple of questions..
>
> On a ADSL line what would cause CRC and SDU Length errors (as reported
> by the Alcatel USB modem software)?
>
> Are they serious (or not) ?
>
> And finally whats a reasonable/expected number that one should receive
> in a given time period "without worrying"?
>
> Regards
> Sunil
>
>

Typically CRC Errors are caused by noise.

I'm on the extended rach trial, 60db attenuation, 21db SNR and I get about
3-4 recoverable CRC errors and hour on average (which is nothing).

Check your Attenuation and SNR.
Better quality filters also help reduced CRC errors (in my experience).

Jc.