Sup7/8E & Cat 4500-X Global COS-DSCP/DSCP-COS Map

braxmaier_kapsch · ‎08-16-2016

Hi,

on the Sup7/8E and 4500-X platforms, is there anything akin to global COS-to-DSCP/DSCP-to-COS maps as on the Sup2T or old-school mls qos?

I find documentation on how to configure a table-map and apply this to an interface via policy-map. Does this mean a global dscp-cos/cos-dscp is not possible anymore and I will have to apply an input policy-map on all ports for common global mapping policy?

Best regards,

Tim

Furose M · ‎08-16-2016

you are right. there is no global mapping in cat4k. you have to apply the table map in interface level service-policy.

braxmaier_kapsch · ‎08-17-2016

Just to be certain - I will have to apply the table map in every class in an input policy to make sure the mapping policy is truly global?

Furose M · ‎08-17-2016

The answer is yes. you can also set the COS/dscp value in every class to a certain value, if you wish to, using "set dscp" or "set cos" commands.

Sup7/4500X qos is MQC based. There is no port trust concept or internal dscp like 6500.
The cos and dscp are independently looked at in sup7, i.e: if you have a policy
matching on dscp and marking dscp, only dscp is marked and cos is untouched.
When there is no policy attached to a port, all the traffic go via default
queue and dscp/cos is untouched. If you require uniformity in cos and dscp
marking, you'd have to mark them independently.

braxmaier_kapsch · ‎08-17-2016

Hi Furose,

thanks for the replies. My idea was, since you do get end-point equipment which can only mark COS or DSCP that the conversion is needed in every class to cover all possiblities such as a port only allowing egress queueing based on COS and/or DSCP (which I could not figure out yet since this is now shown in show int [interface] capabilities on the Cat45).

BR,

Tim

Furose M · ‎08-17-2016

i guess 4500 only provides software based queueing. so, the interface capabilities dont show anything.

it uses standard 1P7Q1T model.

this doc looks interesting.

http://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND_40/QoSCampus_40.html#pgfId-1100873