Dahdi: echocancel=1024


I’m running:

cat /etc/schmooze/pbx-version

and installed digium’s HPEC from source.

Step 13 of the install instructions (http://downloads.digium.com/pub/telephony/hpec/README) includes:

Use of HPEC inside of Asterisk is controlled by the chan_dahdi.conf
configuration file, generally found as:


HPEC is controlled by the:


My goal is to enter echocancel=1024

I have attempted to use Freepbx->Connectivity->DADHI->Global Settings to enter the echocancel value. Unfortunately it already appears in the list as “YES” with no way to enter a numeric value. Any suggestions on how to modify such that it won’t be automatically over-written? Adding it to the end of the list doesn’t work.



Try defining the echocancel variable manually in the “Other Global Dahdi Settings” area. I am pretty sure that your manual entry will override because it gets written to the chan_dahdi.conf file after the entry created by the drop down menu.

I did some testing with a slightly outdated version of the Dahdi Config Module and it appears what I wrote above will not work. I have confirmed this works, by adding the custom definition to the file:
and reload dahdi and dialplan. Confirm the change is accepted at the Asterisk CLI with:
dahdi show channel [1]
Substitute an appropriate FXO channel number. I have checked the resource you linked to above, but my understanding of the echocancel variable (which may well be incorrect) is that it can be set to yes, no or a power of 2 between 32 and 256. I am not sure a value of 1024 is acceptable.