There are many options to assign a QoS policy to Sensor ports. You can assign a QoS policy to multiple Sensor ports. You can also go to the Policy Manager page of a specific Sensor port pair and select a QoS policy for that port. These options are described here.
Click the Policy tab.
Select the domain from the Domain drop-down list.
Go to Intrusion Prevention → Policy Manager.
In the Interfaces tab, double-click the Sensor port to which you would like to assign a QoS policy.
The <Device Name/Interface> panel opens.
In the Quality of Service section, select the inbound and/or outbound policy from the Inbound Policy and/or Outbound Policy drop down.
Click Save.
Deploy the configuration changes to the corresponding Sensor.