Why you want to used Inbound QoS ? What kind of scenario you have ? Yes , you can use inbound QoS just as Outbound QoS by creating a QoS profile and assigning IP TOS OR DCSP value to the different classes of traffic. The best cases to use Inbound QoS are: 1.) When you have no control of traffic coming from say site A to Site B and Also some other traffic from DC to Site B thus creating a competition among both the traffic type (for example a VOIP call directly made from Site A to Site B) 2.)SaaS applications and public cloud services accessed over internet. As far as your question goes, I believe that Inbound QoS applied on the Steelhead will be applied for the traffic from WAN to LAN and if LAN is connected directly to a firewall then the inside interface would come in picture.As far as traffic is concerned the traffic flowing via DMZ will have the policies for that interface but it will not affect the traffic priority defined on the SH as it will behave in same manner as configured (until some modification or remarking is done). Correct me if I am wrong but that's the best I understood your question and tried to answer. Thanks.