A building permits desk marks voice with CoS on campus Catalyst switches, but the routed WAN edge forwards IP. What must operators ensure at the L2/L3 boundary?
Select an answer to reveal the explanation.
Short Explanation
CoS is the sticky note on the Ethernet envelope; DSCP is the stamp once you put it in an IP mailbag. At the L2/L3 desk you need a translation chart so voice still gets VIP treatment after routing. Keep CoS↔DSCP maps consistent end to end.
Full Explanation
Layer-2 QoS often uses 802.1p/CoS while routed hops use DSCP. At campus-to-WAN boundaries, trust and mutation maps must preserve PHB intent—commonly CoS-to-DSCP on ingress to L3 and DSCP-to-CoS when re-entering bridged segments. Blindly zeroing DSCP or discarding CoS without a map breaks end-to-end DiffServ consistency.