Issue with sound quality

system · December 15, 2009, 1:34pm

hello all,
I installed an asterisk 1.6.1.11 with a Digium B410p connected to 2 BRI channels. I use SIP protocol for internal phone.
I created a small IVR and if I call the IVR from internal to internal all works fine and the sound quality is verry good, instead, if I call from PSTN netword (through Digium Board) the sound quality is very low.
I tried with different audio format (gsm, alaw, ulaw, wav, etc.) but the result is always the same.
Could you help me to solve this issue?
thanks,
Ivan

system · December 17, 2009, 3:50pm

hello all,
nobody have any idea how to solve this issue?
thanks,
Ivan

navaismo · December 17, 2009, 4:10pm

You can play with parameters like:

echocancel=yes
echocancelwhenbridged=no
echotraining=800
rxgain=0.0
txgain=0.0

system · December 30, 2009, 1:08pm

I tried to set these value, but nothing is changed. Have you any other idea?
thanks for your answer,
Ivan

fornever · December 30, 2009, 1:46pm

try changing
span=,,<line build out (LBO)>,,
in /etc/dahdi/

system · December 31, 2009, 10:13am

I’m using mISDN and not DAHDI to manage my B410P card. Do you think that I sould use DAHDI drivers? and what values I should insert in your suggested parameters?
thanks,
Ivan

system · January 14, 2010, 5:36pm

thanks all for your help,
I replaced mISDN driver with DAHDI and now the sound quality is much better.
Ivan