Echo Issues

I am at a bit of a loss with our Asterisk/FreePBX system. The system has been up for about a a month now and everything seemed to be working great. The call quality was great and the system was running smoothly. On Wednesday, two days ago, I installed some updates on our linux machine and rebooted the system and since that time there has been a terrible echo on all of the phone calls. We have the Digium analog card with the echo cancellation module. I checked to see if it was still configured and it looked like it was. Everything seems to be the same but now we have this annoying echo issue. I tried poking around in FreePBX to see if there was anything i could configure in there, but I am at a loss. Any ideas? Thanks.

What card? What version of Asterisk? What version of FreePBX? What is your Kernel version? Which Distro?

Did you run FXOtune previously and wipe out your saved settings with the updates?

A mismatched hybrid would do all the things you are describing.

Using an echo canceler module without tuning the circuit is foolish. It asks the module to do far more than what is was designed to do.

I get this BS all the time, tech’s telling me “I have an echo canceler”. Doesn’t mean a thing. 90% of the time it is not needed on a properly tuned circuit. That is the reason that gain adjustments exists on the channel.

AsteriskTutorials had a video in which it was stated that proper gain would place the meter level of Dahdi_monitor at the midpoint for most of the conversation.

There is also another document I found which uses the milliwatt test number. http://www.mattgwatson.ca/2008/05/howto-tune-zaptel-dahdi-fxo-interfaces-on-asterisk-pbx/

Which method is closer to the “proper” way to tune?

What you have all said makes complete sense. I ran FXOtune but that didnt seem to do the trick. I honestly cant tell if the system is even using those settings. I am new to the whole asterisk world so the deeper workings tend to evade me. Which files do I need to edit in order to properly do rx and tx gain? Also, how do I ensure that the system is even using the settings generated by FXOtune? Thank you for all your help.