3550 Basic Setup

vlan d
vlan 100 name voice
vlan 200 name data
apply
exit

config t
int vlan100
ip helper-address x.x.x.x
no shut
int vlan 200
no shut

mls qos
mls qos map cos-dscp 0 8 16 24 34 46 48 56
mls qos map ip-prec-dscp 0 8 16 24 34 46 48 56

int range fa 01 – 3

switchport voice vlan 100
switchport access vlan 200
mls qos trust cos
mls qos trust device cisco-phone
switchport priority extend cos 0