Re: QoS quiz

Actually... If you are using percentages, your bandwidth statement
needs to reflect the physical speed, as all QoS tools use that value
and not the interface speed to calculate available bandwidth. Only if
you're using children policies is your available bandwidth derived
from the parent shaper.

Also, "max-reserved-bandwidth" is not required/supported when using
HQF (12.4(20)T and above).

--
Marko Milivojevic - CCIE #18427
Senior Technical Instructor - IPexpert
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On Mon, Jun 20, 2011 at 18:21, Alexei Monastyrnyi <alexeim73_at_gmail.com> wrote:
> Cool! One more thing I noticed in your prev example wasbandwidth
> statement missing under interface fa 0/0. This one should align with
> your shaping rate. This one and the max-available-bw is a base line for
> bandwidth allocation inside MQC queues. It is also a way many reporting
> tools pull interfaces for bandwidth utilization reports.
>
> HTH
> A.
>
> On 6/21/2011 8:02 AM, Carlos G Mendioroz wrote:
>> Just to be sure, and because my previous test was in an old platform
>> (2600Xm running 12.4.9T), I just tested it again with 15.1.1T on
>> a 2811.
>>
>> policy-map child
>> B class voice
>> B  B  priority 500
>> B  set dscp ef
>> B class class-default
>> B  set dscp default
>> B  B  bandwidth remaining percent 100
>> policy-map parent
>> B class class-default
>> B  B  shape average 1000000
>> B  service-policy child
>>
>> And now it works. Cool.
>> On the other hand, I would have thought that this worked before, back
>> in the time when 15.0 (or 12.4.20) did not exist.
>> Oh well, seems nothing should be taked for granted.
>>
>> -Carlos
>>
>> Alexei Monastyrnyi @ 20/06/2011 09:23 -0300 dixit:
>>> Well, according to the docs shaping uses FIFO by default which can be
>>> changed to either WFQ or any queuing under nested service-policy.
>>>
>>> http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6558/white_paper_c11-481499.html
>>>
>>>
>>> Default Queuing Implementation for the Shape Feature
>>>
>>> When you configure the shape command in a class, the default queuing
>>> behavior for the shape queue is FIFO instead of WFQ. You can
>>> configure the bandwidth, fair-queue, or service-policy commands in
>>> shape class to achieve different queuing behaviors.
>>>
>>> I can test it in our prof of concept lab but I am quite sure it will
>>> play out exactly that way or else it would be quite a miss by Cisco :-)
>>>
>>> Cheers,
>>> A.
>>>
>>>
>>>
>>> On 6/20/2011 9:57 PM, Carlos G Mendioroz wrote:
>>>> Alexei,
>>>> what you describe is what would happen with only one policy at the
>>>> port,
>>>> which is not the case. When you have parent/child, you basically
>>>> "create" a serial setup where the parent output becomes the child
>>>> input.
>>>>
>>>> The parent is doing shapping for ALL traffic without classification.
>>>> And it's a FIFO queue. So when it kicks in (rate above shape rate) you
>>>> start delaying all traffic.
>>>>
>>>> Don't take my word, test it. May be there's some way to make it work,
>>>> but I don't know it!
>>>>
>>>> -Carlos
>>>>
>>>> Alexei Monastyrnyi @ 20/06/2011 05:23 -0300 dixit:
>>>>> B  Carlos
>>>>> I don't think this is the case.
>>>>>
>>>>> In case of shaping buffer not empty the packet which is about to
>>>>> egress would go into scheduler and based on its marking it would be
>>>>> placed into the right queue, in you case in either LLQ or the
>>>>> class-default one. Now if it is a voice packet scheduled for LLQ it
>>>>> will egress as soon as it can regardless of class-default queue
>>>>> being full or not (well, up to the priority XYZ value, where it
>>>>> will be policed, and we are not taking serialization into account
>>>>> here as all is happening at FE speed).
>>>>>
>>>>> So I reckon your voice traffic should be just fine. I may be
>>>>> missing something so please correct me if I am wring.
>>>>>
>>>>> Cheers
>>>>> A.
>>>>>
>>>>>
>>>>> On 6/18/2011 8:35 AM, Carlos G Mendioroz wrote:
>>>>>> The problem with this configuration, which AFAIK is "by the book",
>>>>>> is that it does not protect the Voip stream.
>>>>>>
>>>>>> If you have a data stream that is going over your shape rate,
>>>>>> the shape buffer will be full and your voip traffic has to cross it!
>>>>>> (Read, you will have jitter at best, lost packets more than likely)
>>>>>>
>>>>>> -Carlos
>>>>>>
>>>>>> David Prall @ 17/06/2011 18:49 -0300 dixit:
>>>>>>> Carlos,
>>>>>>> So I would do:
>>>>>>> Class-map match-all voice
>>>>>>> B Match protocol rtp
>>>>>>> B Match dscp ef
>>>>>>> Policy-map child
>>>>>>> B Class voice
>>>>>>> B  Priority percent 25
>>>>>>> B Class class-default
>>>>>>> B  Bandwidth remaining percent 100
>>>>>>> B  Set dscp 0
>>>>>>>
>>>>>>> David
>>>>>>>
>>>>>>> --
>>>>>>> http://dcp.dcptech.com
>>>>>>>
>>>>>>>
>>>>>>>> -----Original Message-----
>>>>>>>> From: Carlos G Mendioroz [mailto:tron_at_huapi.ba.ar]
>>>>>>>> Sent: Friday, June 17, 2011 5:40 PM
>>>>>>>> To: David Prall
>>>>>>>> Cc: 'Cisco certification'
>>>>>>>> Subject: Re: QoS quiz
>>>>>>>>
>>>>>>>> Right.
>>>>>>>> This is *one* thing I left out. All traffic should be marked.
>>>>>>>> -Carlos
>>>>>>>>
>>>>>>>> David Prall @ 17/06/2011 18:31 -0300 dixit:
>>>>>>>>> You are matching on RTP, is all RTP already marked EF? You are
>>>>>>>>> using
>>>>>>>> shape
>>>>>>>>> average to provide artificial back-pressure at 2Mbps. You have
>>>>>>>> provided for
>>>>>>>>> 500Kbps within the 2Mbps so you will be fine as long as the
>>>>>>>>> carrier
>>>>>>>> is
>>>>>>>>> providing priority for the RTP traffic, if they are providing
>>>>>>>> priority for
>>>>>>>>> EF then you need to confirm that the application is setting EF or
>>>>>>>> remark the
>>>>>>>>> traffic on your own to EF. You also need to confirm that the
>>>>>>>>> traffic
>>>>>>>> that is
>>>>>>>>> not RTP, is not marked EF, otherwise the SP will put it into
>>>>>>>>> their EF
>>>>>>>> queue
>>>>>>>>> along with your RTP EF traffic, so remarking the class-default
>>>>>>>>> to 0
>>>>>>>> may help
>>>>>>>>> here.
>>>>>>>>>
>>>>>>>>> David
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> http://dcp.dcptech.com
>>>>>>>>>
>>>>>>>>>> -----Original Message-----
>>>>>>>>>> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On
>>>>>>>>>> Behalf
>>>>>>>> Of
>>>>>>>>>> Carlos G Mendioroz
>>>>>>>>>> Sent: Friday, June 17, 2011 5:05 PM
>>>>>>>>>> To: Cisco certification
>>>>>>>>>> Subject: QoS quiz
>>>>>>>>>>
>>>>>>>>>> Easy one, I would think.
>>>>>>>>>>
>>>>>>>>>> Say you have a wan link provided over metro (i.e. access rate is
>>>>>>>> well
>>>>>>>>>> over your contracted BW) and you want to apply QoS to protect
>>>>>>>>>> your
>>>>>>>>>> Voip.
>>>>>>>>>>
>>>>>>>>>> You have 2Mbps contract, 25% limit on EF marked traffic.
>>>>>>>>>>
>>>>>>>>>> Will this config do the right thing (i.e. protect your voip
>>>>>>>>>> traffic
>>>>>>>>>> from jitter caused by your data) ?
>>>>>>>>>>
>>>>>>>>>> class-map voice
>>>>>>>>>> B  B match protocol rtp
>>>>>>>>>>
>>>>>>>>>> policy-map child
>>>>>>>>>> B  class voice
>>>>>>>>>> B  B priority 500
>>>>>>>>>> B  class class-default
>>>>>>>>>> B  B bandwidth remaining percent 100
>>>>>>>>>>
>>>>>>>>>> policy-map parent
>>>>>>>>>> B  class class-default
>>>>>>>>>> B  B shape average 2000000
>>>>>>>>>> B  B service-policy child
>>>>>>>>>>
>>>>>>>>>> inferface fastEthernet0/0
>>>>>>>>>> B  service-policy output parent
>>>>>>>>>>
>>>>>>>>>> --
>>>>>>>>>> Carlos G Mendioroz <tron_at_huapi.ba.ar> B LW7 EQI B Argentina
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Blogs and organic groups at http://www.ccie.net
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>> _______________________________________________________________________
>>>>>>>>
>>>>>>>>>> Subscription information may be found at:
>>>>>>>>>> http://www.groupstudy.com/list/CCIELab.html
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>> --
>>>>>>>> Carlos G Mendioroz <tron_at_huapi.ba.ar> B LW7 EQI B Argentina
>>>
>>>
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