QoS to limited bandwidth and how to use policy

[julxu]

Hi

could I ask policy question:

1. can I  use same class/policy more than ones? like:

class-map match-any my-class

  .............

!

policy-map policy-1

  class my-class

  prority percent 10

!

policy-map policy1G-int

  class class-default

    shape average 1000000000

      service-policy policy-1

!

policy-map policy10G-int

  class class-default10

      shape average 1000000000000

          service-policy policy-1                    used same policy again?

!

2. if I want use 50% of 10G interface,

    - can I change policy-map policy10G-int as:

        policy-map policy 10G-int

          shape average 5000000000            does it limited to use only 5G bandwidth of link?

              service-policy policy-1

3. what different using QoS to limited bandwith, or use interface bandwith command?

    interface te1/0/1

      bandwidth 5000000000                    is it same as qos "shape average xxxx"?

Could anyone advice me the three question?

Any comments will be appreciated

Thanks in advance

julie

[Joseph W. Doherty]

Disclaimer

The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

Liability Disclaimer

In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.

Posting

# 1 - yes, in fact that's why later CBWFQ supports percentages like your "priority percent 10"

# 2 - yes, although I believe most CBWFQ policers or shapers don't account for all L2 overhead - i.e. to really used 50% of the wire's bandwidth, you may need to use a value lower than 50%

# 3 - no, bandwidth statement within an interface just sets a number using by other processes, it doesn't physically restrain interface usage.  Also bandwidth statement within a CBWFQ policy sets the relative scheduler priority, i.e. it too doesn't limit class bandwidth usage

[julxu]

If both QoS policy10G-int and interface bandwit comamnds could not limit bandwidth usage, how can I limit a 10G interface's allow bandwith to 5Gps at most?

Please advice

[Joseph W. Doherty]

Disclaimer

The   Author of this posting offers the information contained within this   posting without consideration and with the reader's understanding that   there's no implied or expressed suitability or fitness for any purpose.   Information provided is for informational purposes only and should not   be construed as rendering professional advice of any kind. Usage of  this  posting's information is solely at reader's own risk.

Liability Disclaimer

In   no event shall Author be liable for any damages whatsoever (including,   without limitation, damages for loss of use, data or profit) arising  out  of the use or inability to use the posting's information even if  Author  has been advised of the possibility of such damage.

Posting

If both QoS policy10G-int and interface bandwit comamnds could not limit bandwidth usage, how can I limit a 10G interface's allow bandwith to 5Gps at most?

Did I write policy10G-int wouldn't limit bandwidth?  A shaper will limit bandwidth. A bandwidth statement, within a class or on an interface, does not.

[julxu]

Joseph

Great thanks for quick and clear reply. this time I understand, the qustion #2 is ok to use to limit the bandwidth.

Many Regards

Julie