A question on QoS

[chetan_cisco]

Hi,

I am new to QoS. I have a few questions regarding qos. It would be great if someone can help me with it.

1. For shaping, we can either configure a policy-map with "shape peak|average" under it  OR use "mls qos" commands to implement it. My question is, how to decide what to use.

2. If i do not issue any "mls qos" commands and just use "shape peak|average" under the policy-map , are the mls qos value for the port automatically calculated and applied based the value configured using the "shape peak| average" command?

3. When using CBWFQ, do we treat each class of traffic as a different queue? If yes, how is the mapping of this done into the queues at the port?

Thanks and Regards,

Chetan

[Joseph W. Doherty]

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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

What device/IOS?  It sounds like you're asking about QoS on a Catalyst, and on those, QoS features are very much tied to the hardware; on some, even to the line card.

[chetan_cisco]

Thanks Joseph. I am looking for the order flow of qos in a catalyst. For example if i configure MQC based shaping and mls qos based shaping under the interface. What is order of processing? Will the packets be subjected to the MQC shaping first and then put into the hardware queues and subject to mls qos?

[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

What device/IOS?  What specific interface?