Assuming port GigabitEthernet1/20
in the Cisco switch...
You need to define the vlan interface on the Cisco...
interface Vlan4
description Phones
ip address 10.50.60.1 255.255.252.0
Then assign a switch port to the vlan...
interface GigabitEthernet1/20
switchport access vlan 4
switchport mode access
auto qos voip trust
spanning-tree portfast
spanning-tree bpduguard enable
As far as defining maps for your QoS policy, it may be dependent on the model of your Cisco switch.
You'll want dscp mode 46 for IP 10.50.100.10 (ef) and dscp mode 34 for IP 10.50.20.38 (af41).
My setups look like:
policy-map AutoQos-VoIP-Output-Policy
class AutoQos-VoIP-Bearer-QosGroup
set dscp ef
set cos 5
priority
police cir percent 33
and on the port level...
service-policy input AutoQos-VoIP-Input-Cos-Policy
service-policy output AutoQos-VoIP-Output-Policy
What type of switch are you using?