VOIP Query

Hi there,

My company is moving from traditional PABX to IP PBX.

For this I am configuring few access switches. But I am very confused.

I am trying to configure port based configuration. I am using the following configuration:

mls qos map cos-dscp 0 8 16 26 32 46 48 56
mls qos
!
interface GigabitEthernet1/0/1
switchport access vlan 110
switchport mode access
switchport voice vlan 115
mls qos trust dscp
!

Can you please help me in this? If you would like I can send the network diagram too.

I am really confused whether I have to use any acl or class-map for this.

Please advice.

Thanks
Rati