Hi all experts, I have a Elastix box 1.6. User report that having intermittent quality issue for IAX trunk. When A site have call with B site, B site can't hear A site clearly, but A site can hear B site quite clear. Similar problem happen when A site have call with C site which C site could not hear A site clearly. Both B site and C site are using Asterisk 1.2. My trunk setting in A site is below. disallow=all allow=alaw&ilbc type=friend username=xxxxxx inkeys=xxxxxx outkey=xxxxxxx auth=rsa host=xx.xx.xx.B_Site context=from-internal qualify=yes sendani=yes trunk=yes qualifyfreqok=60000 requirecalltoken=auto My trunk setting in B site is below: disallow=all allow=alaw allow=ilbc type=friend username=xxxxxxxx inkeys=xxxxxxx ; peer public key outkey=xxxxxxx ; its private key auth=rsa host=xx.xx.xx.A_site ;remote IP address context=default qualify=yes sendani=yes trunk=yes qualifyfreqok = 60000 recalltoken=auto Is there any setting I could add to enhance the quality?