Routing
Routing

Strict Priority Queue - Out-of-profile

[ Edited ]
Tuesday

I normally rate-limit a strict priority queue to prevent starvation of lower queues. I recently read that I can set a policer with an action of "out-of-profile" to prevent queue starvation but still allow my strict priority queue to exceed the policed rate when the link is not congested. But how is that scheduled when the link isn't congested? If the strict priority queue is serviced first before other queues, how are out-of-profile strict priority packets serviced compared to packets from lower priority queues?

2 REPLIES 2
Routing

Re: Strict Priority Queue - Out-of-profile

Tuesday

Hi,

Out-of-profile packets are dropped if there the link is congested and over the threshold. Thus these packets will not eat up the queue buffer.

https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/firewall-...

 

**Please mark this answer as accepted if this helps resolve your query so others can benefit from the post.

Routing

Re: Strict Priority Queue - Out-of-profile

Thursday

I'm looking for the scheduling behavior. I understand that it's dropped, but I would like to know the detail on how that works. Something similar to this article:

https://www.juniper.net/documentation/en_US/junos/topics/concept/schedulers-priority-overview-cos-co...

 

Except that article doesn't mention out-of-profile strict priority packets. If strict priority queues are always serviced first before lower priority queues, then how does the scheduling work when the strict priority packets are out-of-profile.