QOS - Bandwidth and default Queue

[Rupesh Kashyap]

Hi,

I am little bit confused with Bandwidth and Default-queue term in QOS. I have attached QOS below which is applied on 1 Mb link.

I know, Data will get 600kb Minimum bandwidth and Max no guarentee. Default Queue has 10 %.

What about if I have VOIP traffic (30%) and minimum Data traffic (below 20 %), but more traffic (above limit) which is falling in Default-queue. My Question is, if 60 % bandwidth is not fully utilized, will Default-queue use those free bandwidth for default queue traffic and can exceed 10 %.

policy-map Traffic 
  class VOIP 
    Priority percent 30 
  class Data 
   bandwidth percent 60

[milan.kulik]

Hi,

two general rules for queueing on Cisco routers:

1) at the time the outgoing interface is not congested, any traffic can consume as much bandwidth as it needs.

2) at the congestion time, each queue should have some bandwidth reserved which is available for it. Queues are sharing the non-reserved and unused bandwidth. The only exception is the priority queue which can't get more bandwidth than reserver at congestion time (built-in policer).

So the answer to your question is: Yes, the  Default-queue can use those free bandwidth for default queue traffic and can exceed 10 %.

HTH,

Milan

[Rupesh Kashyap]

thanks man.