checking that qos is working on a switch

[carl_townshend]

Hi all, if I configure my voip phone with mls qos trust qos, how can I check the switch is actually prioritizing them, is there counters of some sort I can check ?

[Joseph W. Doherty]

"is there counters of some sort I can check ?"

Depends on the platform and IOS.

"how can I check the switch is actually prioritizing them"

Oversubscribe a port with non-priorized traffic, if VoIP behavior barely changes, QoS is working. (Or trust the vendor's switch works as documented.)