in some constallations it is possible that the dial out fail: cause 20 subscriber absend
read this: https://forum.openwrt.org/viewtopic.php?id=69371
I solve this for me via:
/etc/hotplug.d/iface/90-asterisk-restart
#!/bin/sh
if test "$ACTION" == "ifup" || test "$ACTION" == "ifdown" ; then
case $DEVICE in
pppoe-wan) /etc/init.d/asterisk enabled && /etc/init.d/asterisk restart ;;
esac
fi
but this solution is very rustical