[Asterisk-Users] Line Noise HELP!

[Rich Adamson]

> Excerpt of email from Digium support:
> 
> Digium does not support CAPI or BRI, either freely or commercially.
> 
> We can only provide support for you Digium TDM400P card.
> 
> Your zttest output is extemely low.  We are looking for nothing less
> than 99.98%.  If you are receiving 99.96% this will cause major
> problems.  Have a best output of 99.975% is really low.

For the record, I ran zttest against a new TDM04b Rev H board and it
consistently reported 99.975586%. There is no noise, crackling, etc.
So, not sure what "99.975% is really low" is based on.

> If you are running an IDE hard drive please verify that you are using
> DMA mode with a UDMA setting of no lower than 2 or higher than 3.  UDMA
> mode 2 is ATA33.  UDMA mode 3 is ATA44.  This can be done using hdparm.
>  We suggest using "hdparm -d 1 -X udma2 -c 3 /dev/[IDE Device]".  You
> can check the status using "hdparm /dev/[IDE Device]" and "hdparm -i
> /dev/[IDE Device]".  If you make modifications to your IDE hard drive
> settings they will only be kept until you reboot.  

Also, did the above, which had zero impact on the zttest results.

If I try to use spandsp-pre11 for fax reception, it results in far less 
then usable output (*.tiff), and supposedly that is due to missed 
frames, missed interrupts, or something like that with the TDM04b 
card.

Checked and double-checked share interrupts, and that isn't a problem.

This is on a cvs-head RHv9 box with 2.2ghz processor, and nothing else
running on the system.

So, best guess is that 99.975586% is impacting fax but not voice.