Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements
You may experience some slow load times, errors, and slight inconsistencies. We ask for your patience as we finalize the launch. Thank you.

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

Catalyst Queueing Principles

I'm experimenting with QoS on a Cat6500 with Sup2.

As a general policy, I want to trust my endpoints, so I set all ports to trust-cos and port-based QoS.

Also as a matter of policy, I want only CoS 5 to go into the priority TX and RX queues where available, otherwise into the highest threshold where there is no priority queue (I have both WS-X6548-GE-TX and WS-X6348-RJ45 modules). But depending on the queuing model available, I may wish to put CoS 6-7 into a higher threshold than CoS 0-4.

My question is this: if I want to treat CoS 0-4 (and sometimes 6-7) with equal priority, is it best to put all these values into the next-to-highest threshold, and reserve the highest queue/threshold for CoS 5, or should I spread the lower CoS values across the different thresholds?

Does this make sense? I'm just starting at looking at this kind of configuration.

  • Other Collaboration Voice and Video Subjects
1 REPLY
Blue

Re: Catalyst Queueing Principles

You should always protect COS 6-7 over 0-4 traffic as that is used by routers for routing protocols etc., and nobody is happy when the routers lose their peer relationships.

A good starting point (and often ending point) is to let autoqos set up your queues and thresholds.

http://www.cisco.com/en/US/products/hw/switches/ps708/products_configuration_guide_chapter09186a00803f5732.html

Please rate helpful posts.

87
Views
4
Helpful
1
Replies