09-10-2018 06:04 AM
Hello guys,
could someone share more info about the introduced QoS feature (from IOS-XR 5.3.2) to support up to 7 priority levels in LLQ?
RP/0/RP0/CPU0:at0f2a-r2n0-gr(config-pmap-c)#priority level ? <1-7> Priority level
I was aware of only about priority levels 1-2 where level1 has higher priority than level2 but both are high priority queues.
Now I am little bit confused as there is no good description of this new capability.
What is the relationship between those different 7 levels now?
How they behave and what is the benefit to have 7 different priority queues?
How to map this to the 8Q/16Q model?
Any help would be much appreciated.
Thank you a lot.
Solved! Go to Solution.
09-11-2018 11:36 AM - edited 06-25-2020 09:59 AM
Priority level 1 is highest, then 2, and so on in descending order until we get to priority none. As it is a strict priority mode, there is a possibility that traffic on lower priority queues will be starved as long as there is continuous traffic on higher priority queues.
Sam
09-11-2018 11:36 AM - edited 06-25-2020 09:59 AM
Priority level 1 is highest, then 2, and so on in descending order until we get to priority none. As it is a strict priority mode, there is a possibility that traffic on lower priority queues will be starved as long as there is continuous traffic on higher priority queues.
Sam
09-21-2018 12:39 AM
Hi Sam,
thank you very much for your reply. I am wondering what is the purpose/usage example to have so many PQs? When there were only 2 PQs, usual usage was to have 1 PQ for Voice and another PQ for Video, but 7 PQs?
Are there any restrictions to use those 7 priority queues?
I didn't find too much information about this feature in cisco webpages, do you know about some good documentation about this?
Thank you again Sam,
have a nice day,
Michal.
09-23-2018 11:04 AM
One example would be if you had the typical QoS classes of video, voice, business class, scavenger / best-effort, etc then you can assign a PQ to each one.
There isn't much in the way of configuration except to assign priority level x to the class.
Sam
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide