Re: QoS quiz

Sounds right to me. "match protocol rtp audio" should be then.
But I was surprised by the other issue...

-Carlos

Adam Booth @ 18/06/2011 03:04 -0300 dixit:
> Just a small question - to really protect voice, should you specify the
> RTP payload types so you are not potentially including video in the class?
>
> Cheers,
> Adam
>
> On Sat, Jun 18, 2011 at 9:26 AM, Carlos G Mendioroz <tron_at_huapi.ba.ar
> <mailto:tron_at_huapi.ba.ar>> wrote:
>
> I know it is the same. This is the configuration that I would have done,
> and that I guess many do. But I was surprised when I realized that
> it does not work, or at least, it does not work as I thought it would.
>
> Hence the quiz. Either I'm confused (more than likely :) or there is no
> easy way to configure what I described. And it does not sound a
> weird requirement...
>
> To really protect the voip flows you have to set the priority class in
> the parent policy. This will side step the shape buffer.
> On the other hand, you will be overrunning your CIR!
> Is there any way to have priority + shape work in synch ?
> Some kind of shape adapt to "rest of" bandwidth...
>
> -Carlos
>
> David Prall @ 17/06/2011 20:07 -0300 dixit:
>
> It is the same as your configuration. I didn't include the
> parent because
> you already had that covered. I used priority percent instead of
> a bandwidth
> value, because then I can use it across multiple shaper values
> with only
> needing to change one parameter for different configurations.
>
> David
>
> --
> http://dcp.dcptech.com
>
>
> -----Original Message-----
> From: nobody_at_groupstudy.com <mailto:nobody_at_groupstudy.com>
> [mailto:nobody_at_groupstudy.com
> <mailto:nobody_at_groupstudy.com>] On Behalf Of
> Carlos G Mendioroz
> Sent: Friday, June 17, 2011 6:35 PM
> To: David Prall
> Cc: 'Cisco certification'
> Subject: Re: QoS quiz
>
> 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
> Match protocol rtp
> Match dscp ef
> Policy-map child
> Class voice
> Priority percent 25
> Class class-default
> Bandwidth remaining percent 100
> Set dscp 0
>
> David
>
> --
> http://dcp.dcptech.com
>
>
> -----Original Message-----
> From: Carlos G Mendioroz [mailto:tron_at_huapi.ba.ar
> <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>
> [mailto: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
> match protocol rtp
>
> policy-map child
> class voice
> priority 500
> class class-default
> bandwidth remaining percent 100
>
> policy-map parent
> class class-default
> shape average 2000000
> service-policy child
>
> inferface fastEthernet0/0
> service-policy output parent
>
> --
> Carlos G Mendioroz <tron_at_huapi.ba.ar
> <mailto:tron_at_huapi.ba.ar>> LW7 EQI Argentina
>
>
> Blogs and organic groups at http://www.ccie.net
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>
> --
> Carlos G Mendioroz <tron_at_huapi.ba.ar
> <mailto:tron_at_huapi.ba.ar>> LW7 EQI Argentina
>
> --
> Carlos G Mendioroz <tron_at_huapi.ba.ar
> <mailto:tron_at_huapi.ba.ar>> LW7 EQI Argentina
>
>
> Blogs and organic groups at http://www.ccie.net
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> --
> Carlos G Mendioroz <tron_at_huapi.ba.ar <mailto:tron_at_huapi.ba.ar>>
> LW7 EQI Argentina
>
>
> Blogs and organic groups at http://www.ccie.net
>
> ___________________________________________________________________________
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-- 
Carlos G Mendioroz  <tron_at_huapi.ba.ar>  LW7 EQI  Argentina
Blogs and organic groups at http://www.ccie.net