Changed from Trixbox Pro to FreePBX w/ asterisk 1.8 and Freepbx 2.10

After installation of FreePBX, we have quite a bit of echo on analog lines. We are using a four port FXO Digium card with no hardware echo cancellation. We were not getting echo before the change over, but are now.

running Dahdi 2.5.0.1

Oslec my best bet? Purchase the hardware echo cancellation?

This is totally outside my area of expertise, as I have no Digium cards in my system, but have you done the impedence testing/matching that hardware cards require to eliminate echo?

I suspect he ran the fxotune on the trixbox and has not retuned. When it balances the hybrids the levels are downloaded to the card on startup by DAHDI.

Thanks for your replies. Been such a long time since I installed, I didn’t remember doing the fxotune, but am sure I did on the previous install. Will let you know.

Tried to run fxotune, “no such file or directory.”

How did you install? Did you use the ISO or from packages?

I just checked the ISO and it is installed:


[root@vas asterisk]# fxotune -?
Unknown option : -?
Usage: fxotune [-v[vv] (-s | -i <options> | -d <options>)

        -s : set previously calibrated echo settings
        -i : calibrate echo settings
                options : [<dialstring>] [-t <calibtype>]
                [-b <startdev>][-e <stopdev>]
                [-n <dialstring>][-l <delaytosilence>][-m <silencegoodfor>]
        -d : dump input and output waveforms to ./fxotune_dump.vals
                options : [-b <device>][-w <waveform>]
                   [-n <dialstring>][-l <delaytosilence>][-m <silencegoodfor>]
        -v : more output (-vv, -vvv also)
        -p : print the 5 best candidates for acim and coefficients settings
        -x : Perform sin/cos functions using table lookup
        -o <path> : Write the received raw 16-bit signed linear audio that is
                    used in processing to the file specified by <path>
        -c <config_file>

                <calibtype>      - type of calibration
                                   (default 2, old method 1)
                <startdev>
                <stopdev>        - defines a range of devices to test
                                   (default: 1-252)
                <dialstring>     - string to dial to clear the line
                                   (default 5)
                <delaytosilence> - seconds to wait for line to clear (default 0)
                <silencegoodfor> - seconds before line will no longer be clear
                                   (default 18)
                <device>         - the device to perform waveform dump on
                                   (default 1)
                <waveform>       - -1 for multitone waveform, or frequency of
                                   single tone (default -1)
                <config_file>    - Alternative file to set from / calibrate to.
                                   (Default: /etc/fxotune.conf)
[root@vas asterisk]#

installed from iso

type this command:

find / | grep -i fxo

And post the results.