The commands for the Juniper EX4200 switch to setup Qos from the firmware are:

?
cli
configure
load merge /etc/config/ezqos-voip.conf
set class-of-service apply-groups ezqos-voip
set class-of-service interfaces ge-*/0/* scheduler-map ezqos-voip-sched-maps
set class-of-service interfaces ge-*/0/* unit 0 classifiers dscp ezqos-dscp-classifier

commit