[c-nsp] Providing QoS on Cisco Catalyst Ethernet network

[Robert Hass]

Hi

I have below network:

VoIP PABX1
|
| FE
|
Cisco Catalyst 2960 (sw1) / Office 1
|
| GE
|
Cisco Catalyst 6503 (sw2)
|
| GE
|
Cisco Catalyst 3560G (sw3)
|
| GE
|
Cisco Catalyst 2960 (sw4) / Office 2
|
| FE
|
VoIP PABX2

I have to provide QoS for traffic between VoIP PABX1 and VoIP PABX2.
Computers are in VLAN101, Servers and PABX on VLAN102.
I have computers and servers on both sides on SW1 and SW4 as well.

I tried below configuration:

1) sw1, 2960

mls qos
!
interface FastEthernet0/6
 description VoIP_PABX_1
 switchport access vlan 100
 switchport mode access
 load-interval 30
 mls qos cos 7
 mls qos trust cos
 no cdp enable
 spanning-tree portfast
!
interface GigabitEthernet0/1
 description TRUNK to SW2
 switchport mode trunk
 load-interval 30
 no cdp enable
 mls qos trust cos

2) sw2, 6503/Sup32

interface GigabitEthernet1/3
 description TRUNK to SW1
 switchport mode trunk
 load-interval 30
 no cdp enable
 mls qos trust cos
!
interface GigabitEthernet1/6
 description TRUNK to SW3
 switchport mode trunk
 load-interval 30
 no cdp enable
 mls qos trust cos
!

3) sw3, 3560G

interface GigabitEthernet0/11
 description TRUNK to SW2
 switchport mode trunk
 load-interval 30
 no cdp enable
 mls qos trust cos
!
interface GigabitEthernet0/12
 description TRUNK to SW4
 switchport mode trunk
 load-interval 30
 no cdp enable
 mls qos trust cos
!

4) sw4, 2960

interface FastEthernet0/21
 description VoIP_PABX_1
 switchport access vlan 100
 switchport mode access
 load-interval 30
 mls qos cos 7
 mls qos trust cos
 no cdp enable
 spanning-tree portfast
!
interface GigabitEthernet0/1
 description TRUNK to SW3
 switchport mode trunk
 load-interval 30
 no cdp enable
 mls qos trust cos
!

Unfortunately we have problems with communications between both PABXes.
Suppiler said that there is problem in our Ethernet network

Is our QoS configuration is correct ? Should be move both IP PABXes to separate
VLAN instead of using Servers VLAN ?

Thanks for help
Robert