[Asterisk-Users] Will Echo problems EVER be solved, I'm scared

[Rich Adamson]

> On Fri, Aug 26, 2005 at 02:00:54PM -0600, Rich Adamson wrote:
> > Relative to the fxotune app, it would appear the app is specific
> > to the v2.4 kernels (/dev/zap*), which the v2.6 kernels don't use
> 
> It should with 2.4 and 2.6.  2.6 kernels with properly configured udev
> rules should create the /dev/zap/* entries dynamically.
> 
> > (but rather the udev equivalent). (When I had * running on a v2.4
> > kernel, the output from fxotune never deviated from all zero's. So
> > I'm assuming the default chipset values were already tweaked by the
> > chipset manufacturer to US telco lines. If that is true, then 
> > running fxotune in the US has very little value.)
> 
> Sometimes in the US you still deal with line impedance issues.  In fact,
> I was told by an engineer that worked for the company that designs the
> line interface part that the bulk of echo problems (with line interface 
> parts such as this) are related to AC impedance mismatches (which is one
> reason why I haven't done the digital hybrid tuning portion of fxotune
> still).  It should work the same regardless of which kernel (2.4 or 2.6)
> you are using.
> 
> If it doesn't, and you have udev setup correctly, something is fundamentally
> wrong in the setup.

Matt,

To bring closure (and for archive purposes), the changes that you submitted
to cvs-head around noon today (8/26/05) did correct the issue with
running fxotune on FC3 (v2.6 kernel). Since the values written to the
/etc/fxotune.conf file were identical (and the file datestamp matched
the individual runs of fxotune), I'll assume the error messages that I
seen yesterday were cosmetic and not real. 

As mentioned in my last private email, all four analog pstn lines attached
to my TDM04b have been tested with a professional transmission test set
and all four are in excellent condition. Fxotune did not generate any
noticable differences to my ear. I'm only mentioning that for those readers
that might expect something different to happen and don't notice any
changes/improvements on US pstn lines.

Rich