Chapter 17 Traffic Shaping for FortiOS 5.0 : Traffic shaping methods : Enabling in the security policy : Reverse direction traffic shaping
  
Reverse direction traffic shaping
The shaper you select for the security policy (shared shaper) will affect the traffic in the direction defined in the policy. For example, if the source port is port 1 and the destination is port 3, the shaping affects the flow in this direction only, that is, the upload or outbound direction. By selecting Shared Traffic Shaper Reverse Direction, you can define the traffic shaper for the policy in the opposite direction, that is, the download or inbound direction. In this example, from port 3 to port 1.
To add a reverse shaper
1. Go to Policy > Policy > Policy.
2. Select Traffic Shaping.
3. Select Shared Traffic Shaper Reverse Direction and select the shaper from the list.
4. Select OK.
See also 
Setting the reverse direction only
Shared policy shaping
Per-IP shaping
Application control shaping
Type of Service priority
Differentiated Services
Tos and DSCP mapping
Traffic Shaper Monitor