> > > Are these settings persistent across reboots? The README for > > fxotune seems to mention that you > > > need to do a "fxotune -s" in order to reload the card with the > > analyzed settings (rather than > > > take the 20 minutes it seems to take on my 6 lines). However, if > > fxotune.conf is all 0's, I > > sure > > > hope that the settings are persistent on the board! :) > > > > The results of fxotune is written to /etc/fxotune.conf; I don't believe > > they are read back in unless you build something into a bootup script. > > Correct. From the README: > > It will write a configuration file to /etc/fxotune.conf. You will > need to have your system run fxotune with the -s flag (`fxotune -s`) to set > the > module with the previously discovered values from fxotune.conf for it to take > affect, so essentially if each time you reboot the machine you need to run > `fxotune -s`. You might consider putting it in your startup scripts some time > after the module loads and before asterisk runs. > > However, my fxotune.conf contains only 0's for all 8 of each of 6 lines. I'm > wondering does that > mean that fxotune had no effect, or that whatever effect it does have is A) > Persistent within the > card between reboots and B) Not reflected by a fxotune.conf filled with 0's... >
When wctdm is loaded, the registers in the chipsets on the TDM card get initialized. That implies whatever was there is overwritten. The default register values have been preprogrammed into the driver for some time, and those defaults are those applicable to the US telephone lines. So, if you're using a TDM card in the US, the fxotune functions provided today don't really add any value to the operation of the card since those values are already programmed (eg, impedence). I'm assuming (but haven't bothered to look) that if the card is used in a non-US location, the loadzone parameter in /etc/zaptel.conf changes the impedence setting to what is appropriate for that country. If that is case, then the current value of running fxotune is apparently zero. About a year or so ago, I played around with changing the coefficients manually and did not find where those changes had any significant impact on audio quality (including echo). But, there has been many changes and improvements within zaptel and the canceller where maybe playing with the coefficients might now be noticed. The echo issue seems to always come back to the software canceller and how well it performs in various environments. Those that have attempted to optimize the canceller have indicated its previous operating range is rather limited when compared to dedicated cancellers. I only know enough about it to know that I don't have the knowledge or background to offer improvements, but I do understand the issues. Matt has been working on canceller improvements including the MG2 that he posted today. So, gut feeling (as of this moment anyway) is that fxotune is not the answer to echo. The changes being made involving the canceller have had very noticable improvements starting with the KB canceller. (Now off to play with MG2. :) Rich _______________________________________________ --Bandwidth and Colocation sponsored by Easynews.com -- Asterisk-Users mailing list [email protected] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
