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New Member

Egress Queuing on Catalyst 6500


i have a question regarding egress queuing on cat6500 modules. e.g. WS-X 6704 has 1p7q4t is egress-modell. my goal is to limit the priority queue to 15% of the available bandwidth.

i can put weights on the wrr-queues and limit their ressources: "wrr-queue bandwidth 50 20 15 0 0 0 0." but this isn´t possible for the priority-queue. only available command is "priority-queue queue-limit 15" but this only restricts the buffer to 15%.

at the end of the day i want to prevent that the wrr-queues don´t have remaining bandwidth when the priority-queue is saturated.

is there an easy way to restrict the bandwidth of the priority queue or do i have to implement additionally some kind of policing?



Egress Queuing on Catalyst 6500

allocate bandwidth to other queues as you did and leave 15% which will be used by the PQ

New Member

Egress Queuing on Catalyst 6500

but what happens in thois case if i have 10Gig traffic which is marked with EF. in this case everything is transported in the priority queue and all other queues don´t have any bandwidth. is my assumption correct or do i understand something wrong?

Super Bronze

Egress Queuing on Catalyst 6500


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I believe the "typical" LAN 6500 line card will allow a PQ queue to utilize 100% bandwidth.

For traffic that uses "EF", it ought to be known and subject to admission control.  If this is done, you shouldn't unexpectedly have EF traffic consume all your 10gig bandwidth.

Re: Egress Queuing on Catalyst 6500

Yes Joseph right the PQ always serviced first and could take over other classes bandwidth

If you really have concern about it

The in inbound direction use a policed to police traffic marked with dscp ef to a specified amount

And the higher amount could be marked down instead if drop it


Sent from Cisco Technical Support iPhone App

New Member

Egress Queuing on Catalyst 6500

thanky ou very much. that´s what i wanted to know

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