Hi,
Nice explanation
We have a setup that a video device is connected to a switch (no qos) and marking done in the router AF41.
Here , the packet will be marking as Default when it goes from switch to router . Router will mark the packet as AF41. When there is a reply packet from the Router it will be AF41 and it send it to Switch as well.
Switch sends a packet to router : Default
Router sends a reply packet to switch : AF41
With same setup ,When we Qos enabled globally in the switch
Packet from switch to router :Default
Reply packet from Router to Switch :Default marking.
Which Scenario you will suggest.