Hi,
This is how to limit passing traffic to 100Mbps on QFX switch :
Interface : xe-2/0/12
Limit to Speed : 100Mbps >> 104857600 bit
set class-of-service schedulers be-sched shaping-rate 104857600
set class-of-service traffic-control-profiles be-tcp shaping-rate 104857600
set class-of-service scheduler-maps be-map forwarding-class best-effort scheduler be-sched
set class-of-service traffic-control-profiles be-tcp scheduler-map be-map
set class-of-service forwarding-class-sets be-pg class best-effort
set class-of-service interfaces xe-2/0/12 forwarding-class-set be-pg output-traffic-control-profile be-tcp