Chapter 18 Traffic Shaping : Traffic shaping methods : Type of Service priority : ToS in FortiOS
  
ToS in FortiOS
Traffic shaping and ToS follow the following sequence:
The CLI command tos-based-priority acts as a tos-to-priority mapping. FortiOS maps the ToS to a priority when it receives a packet.
Traffic shaping settings adjust the packet’s priority according the traffic.
Deliver the packet based on its priority.