Shaping and default class

[Kelvin Willacey]

If I have a nested policy with a child class that matches all traffic destined to a particular location and I am performing shaping on that class to match the bandwidth at the location. Does the service policy applied to that child class require a default class? I assume it needs one because of the fact that all traffic destined to the location is being shaped, correct?

See excerpt below:

policy-map QUE-POLICY

class VOICE-TRAFFIC

priority percent 33

class VOICE-SIGNALLING

bandwidth percent 2

class class-default

fair-queue

policy-map WAN-POLICY

class BRANCH1

bandwidth 2000

shape average 2000000

service-policy QUE-POLICY

[paul driver]

Hello

Whats you thinking regards the BRANCH1 class-map , Do you wish for it to be in the class -default?

As i see this you have LLQ and bandwidth % applied to the voice traffic and everthing else falls in the class default.

Would this more applicable?

policy-map QUE-POLICY

class VOICE-TRAFFIC

priority percent 33

class VOICE-SIGNALLING

bandwidth percent 2

class class-default

fair-queue

policy-map WAN-POLICY

class class-default

shape average 2000000

service-policy QUE-POLICY

res

Paul

Please don't forget to rate any posts that have been helpful.

Thanks.

[Joseph W. Doherty]

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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.

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Posting

There's always a default class, i.e. it's present even if you don't explicitly define it.

PS:

BTW, if you're shaping for an E1, most shapers (I believe) don't account for L2 overhead.  So, if they don't, you'll want to shape up to about 15% "slower".

Shapers vary, based on IOS version, default for Tc.  If Tc is defaulting to 25 ms, recommend setting Bc so Tc is 10 ms.

If you're IOS is pre-HQF QoS, using FQ in class-default can distort bandwidth guarantee for other classes.

[Kelvin Willacey]

Thanks, this should be the hub router configuration, so the idea is that there are several branches mostly with 2 Mbps connections and the head end is only 20 mbps so we want to keep all the branches shaped according to their link speed. We are running a post HQF QoS IOS so that shouldn't be an issue.

Since I am only accounting for voice traffic in the service policy applied to the child class I wanted to make sure all the other traffic falls in the default class of the service policy and not of the parent policy so that it can be shaped accordingly.

[Joseph W. Doherty · Accepted solution]

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

Yup, that's how to do it.

One issue to watch for, is if you have more than 10 of these 2 Mbps sites, their aggregate can exceed your 20 Mbps.

[Kelvin Willacey]

Great thanks Joseph, I will look out for that. As always you are the QoS master.