Setup is pretty simple. A c871 router with various devices (PCs and SIP phones) connected to LAN ports (all in one VLAN), and a trunk with two VLANs towards ISP backbone (two dot1q subi-fs on router). One VLAN is used for data-only, other is used to reach VoIP platform. Phones are marking their traffic with DSCP 46 (EF).
Task - grant a strict priority for voice traffic on uplink.
Question is - I can apply a policy-map on physical interface (in this case FastEthernet4), or I can apply policy-map on subinterfaces. In case I apply it on physical interface - it matches nothing, as traffic is routed on subinterfaces. Plus - I cant apply it on subinterfaces, as it makes no sense to apply it on data interface as there is no VOIP traffic, and it makes no sense to apply it to VOIP subinterface, as all traffic there is VOIP.
Any ideas where and how to configure, that marked traffic gets strict priority compared to non-marked?