Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
New Member

QoS without Shape statement Query

Hi Experts,

Am trying to get my head around a conundrum regarding QoS.

To be specific please see below.

 

int s1/0

dsu bandwidth 10000

service-policy output TEST1

 

policy-map TEST1

  class voice

    priority

    police cir 3000000

      conform-action transmit

      exceed-action drop

 

  class BE_any

       bandwidth remaining percent 100

       random-detect dscp-based

 

Given the very simple example above, my question is, what exactly will be the effect if I add a shape statement on the policy map like the below?  From what I understand, the shape command simply buffers excess packets in reference to the dsu bandwidth command or the physical bandwidth and if there is a scheduler like CBWFQ as in this example, then the shape buffer will use the bucket/buffer arrangement of CBWFQ.  If the above is true then my confusion comes from the question: why place a shape statement in the first place since  CBWFQ is effectively doing the shaping/buffering even without the shaping statement?

int s1/0

dsu bandwidth 10000

service-policy output TEST

 

policy-map TEST

class class-default

service-policy output TEST1

 

policy-map TEST1

  class voice

    priority

    police cir 3000000

      conform-action transmit

      exceed-action drop

  class BE_any

       bandwidth remaining percent 100

       random-detect dscp-based

 

Thanks in advance for your help.

1 REPLY
Super Bronze

What shape statement?

What shape statement?

48
Views
0
Helpful
1
Replies
CreatePlease to create content