Is this ingress, egress or both? For ingress you need to create a meter and then assign that meter to the port or traffic using an ACL. The meter will drop any traffic that is over the meter. For egress you need to define a qosprofile using the command create qosp qp5 for example then assign that traffic to the qosprofile and finally put a maximum setting on the traffic using the command config qosp qp5 peak_rate 2 M ports <port_list>
I hope that helps if there are more questions please let us know.