QoS Configuration help

[Sujish Sudhakaran]

Hi All,

I am working with a client to implement QoS for their Lync environment. Lync 2013 has this feature to mark dscp values based on packets tagged with logical ports. As an example, packets on port 20000 til 20039 will be marked to dscp 46(ef) and packets on port 20040- 20079 will be marked to dscp 34(af41)

I am connecting our office PC to cisco 2960s(access) switches and 4506e(access) chassis switches then to 4510 core switch from there to 2811 router

Please share a configuration example to achieve QOS in access switches and core switches.

Please not all the access port with default configuration and connected to polycom IP Phones then to PC(we are not created any QoS policy for this IP Phones, so new QoS configuration should not affect the IP Phone’s working).

Thanks

Sujish

[Sujish Sudhakaran]

Hi ,

as of now we are only concentrating on LAN Switches ,

please verify this...

mls qos map cos-dscp 0 8 16 24 32 46 48 56
mls qos

ip access-list extended lync-voip-qos
 remark acl to mark and prioritize lync voip-app traffic to other devices with dscp ef
 permit udp any any range 20000 20039
 permit tcp any any range 20000 20039
ip access-list extended lync-video-qos
 remark acl to mark and prioritize lync video-app traffic to other devices with dscp AF41
 permit udp any any range 20040 20079
 permit tcp any any range 20040 20079
class-map match-all lync-voip-qos
 match access-group name lync-voip-qos
class-map match-all lync-video-qos
 match access-group name lync-video-qos
!
!
policy-map lync-qos
 class lync-voip-qos
  set dscp ef
 class lync-video-qos
  set dscp af41
 
interface GigabitEthernet1/0/2
 description **** Access Port ****
 switchport access vlan 10
 switchport mode access

 switchport voice vlan 160
 mls qos trust dscp
 service-policy input lync-qos

1, what would be the trunk port configuration?

2, how the packets from polycom IP Phones treated (as of now no qos enabled for this), so mls qos trust dscp will make any difference 

3, what are the srr-queue command i have to use in this interface? 

4, srr-queue bandwidth share 1 30 35 5
priority-queue out 

what is this commands do? do have to include this in to my interface configuration

thanks

Sujish

[Sebastian Helmer]

Hi,

I have also a Lync environment. I go just the way to trust the DSCP on the interface and make sure that it is forwarded via priority queue etc..

thats enough I would say..sure U need to make sure the Switch is correclty configured in the back,cos dscp mapping, priority-queue out etc.

But at the access to the PC just trust dscp. I also added a policy to shape it down to just 100Kb to make sure if the client can tag other packet with EF it will not get more bandwidth than necessary for voice..

I can give u an example on monday if you like..

[Sujish Sudhakaran]

Thanks Sebastian,

please give the example for the same

Sujish