Configure IP telephony (on Cat 3560)

how to configure voice(ip phone) and data(pc) on a single switch port

enable QoS

SW1(config)#mls qos

conf it to be access mode even tho we sending traffic from two different vlan

SW1(config)#interface gigabitEthernet 0/27
SW1(config-if)#switchport mode access

this is where we identified or separate those two different traffic, data and and voice

SW1(config-if)#switchport access vlan 100
SW1(config-if)#switchport voice vlan 200

by default Cisco IP phone marking the voice frame using Cos and mark it as value 5
and mark all frame from the PC as 0
let say we want to priorities frame from this PC(maybe this pc belong to manager)
instruct the switch to trust the CoS marking

SW1(config-if)#mls qos trust cos

this command to conf the switch to only trust marking from ip phone

SW1(config-if)#mls qos trust device cisco-phone

one might ask how switch know it is connected to phone? answer is.. CDP

SW1(config-if)#do sh cdp ne
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
                  S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone,
                  D - Remote, C - CVTA, M - Two-port Mac Relay
Device ID        Local Intrfce     Holdtme    Capability  Platform  Port ID
SEP0022555D0D74  Gig 0/27          134              H P   IP Phone  Port 1

this command is to manipulate the traffic coming from the PC, by remarking it

SW1(config-if)#switchport priority extend cos 2

now we have a single switch port with two different VLAN, voice have the higher priority with default value 5,
and pc with priority of 2(by manipulating the Cos)
now let's go into the queue-ing
by default
queue 1 = cos0 and cos1
queue 2 = cos2 and cos3
queue 3 = cos4 and cos5
queue 4 = cos6 and cos7
and queue 4 can always go first and get a better treatment, we want to manipulate our voice to be in this queue
.. oh no0oo !!! 3560 don't support wrr, they only support SRR-queue, which is not as function-able as wrr
but this the command to do that
(go inside the int config)

wrr-queue cos-map 4 5
wrr-queue cos-map 3 4 6 7
priority-queue out

we just put cos4 into queue4, and cos4, 6 and 7 into queue3
verify by a few show command

SW1>sh mls qos int gigabitEthernet 0/27
GigabitEthernet0/27
trust state: trust cos
trust mode: trust cos
trust enabled flag: ena
COS override: dis
default COS: 0
DSCP Mutation Map: Default DSCP Mutation Map
Trust device: cisco-phone
qos mode: port-based
SW1>show mls qos interface gigabitEthernet 0/27 queueing
GigabitEthernet0/27
Egress Priority Queue : disabled
Shaped queue weights (absolute) :  25 0 0 0
Shared queue weights  :  25 25 25 25
The port bandwidth limit : 100  (Operational Bandwidth:100.0)
The port is mapped to qset : 1