[jggimi]

From the PF User's Guide:

Note that queueing is only useful for packets in the outbound direction. Once a packet arrives on an interface in the inbound direction it's already too late to queue it -- it's already consumed network bandwidth to get to the interface that just received it. The only solution is to enable queueing on the adjacent router or, if the host that received the packet is acting as a router, to enable queueing on the internal interface where packets exit the router.