What is qos. what is the command syntax to configure a trust boundary between an ip phone and a switch?

qos is the overall method used in a network to protect and prioritize time-critical or important traffic.

sw(config)#mls qos

sw(config)#int type mod/no

sw(config-if)#mls qos trust {cos/ip precedence/dscp}

sw(config-if)#mls qos trust device device-name

sw9config-if)#switchport prioritity extend {cos value/trust}

verification sw#sh mls qos int type mod/no

sw#sh int type mod/no switchport

sh running-config int type mod/no

sh auto qos int type mod/no