Re: LLQ

Hello Edison,
                     from the document you advisepriority

To give priority to a class of traffic belonging to a policy map, use the *
priority* command in policy-map class configuration mode. To remove a
previously specified priority for a class, use the *no* form of this
command.

*priority *{*bandwidth-kbps* | *percent* *percentage*} [*burst*]

*no priority** *{*bandwidth-kbps* | *percent* *percentage*} [*burst*]
Syntax Description

*bandwidth-kbps*

Guaranteed allowed bandwidth, in kbps, for the priority traffic. The amount
of guaranteed bandwidth varies according to the interface and platform in
use. Beyond the guaranteed bandwidth, the priority traffic will be dropped
in the event of congestion to ensure that the non priority traffic is not
starved.

I think they mean in case on congestion in the LLQ class itself.

On Tue, Dec 8, 2009 at 8:31 PM, Edison Ortiz <edisonmortiz_at_gmail.com> wrote:

> The documentation and my testing say otherwise:
>
>
>
> "When the device is not congested, the priority class traffic is allowed to
> exceed its allocated bandwidth. When the device is congested, the priority
> class traffic above the allocated bandwidth is discarded."
>
>
>
>
> http://www.cisco.com/en/US/docs/ios/qos/command/reference/qos_n1.html#wp1048
> 842
>
>
>
>
>
> Edison Ortiz
>
> Routing and Switching, CCIE # 17943
>
>
>
> -----Original Message-----
> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
> Ahmed Elhoussiny
> Sent: Tuesday, December 08, 2009 1:19 PM
> To: Tony Varriale
> Cc: Cisco certification
> Subject: Re: LLQ
>
>
>
> Dear all,
>
> if LLQ is used for VOIP, it will get dropped/policed in case
>
> the traffic exceeds the LLQ size.
>
> And this in case there is congestion and same if there is no congestion.`
>
> LLQ got nothin to do with congestion, this is based on IOS & IOS XR
>
> features & also my testing while designing QOS for my Mobile operator.
>
>
>
> In some references you may find LLQ congestion aware....but this didn't
>
> successfully being implemented till now...
>
>
>
> WHY ?
>
> simply imagine u have an LLQ class with 1 M , and no interface BW
>
> congestion.
>
> VOIP traffic increased to reach 2 M, and no drops cuz of no congestion due
>
> to not used BW on other classes...
>
> SO what if the traffic in other queues increased, and reached its 100 %,
> now
>
> the LLQ will decrease to reach 1 M, and all VOIP calls will get some
> packets
>
> dropped which will affect most of VOIP calls...
>
>
>
> Hope this might help
>
>
>
> Thanks & B.regards
>
> Ahmed Elhoussiny,2x CCIE# 21988 (R&S-SP)
>
> Network Consultant & Cisco Academy Instructor
>
>
>
> On Tue, Dec 8, 2009 at 6:54 PM, Tony Varriale
> <tvarriale_at_flamboyaninc.com>wrote:
>
>
>
> > I thought the priority queue won't use the general bucket when it's over
>
> > its
>
> > defined number? Hence, all packets will get dropped.
>
> >
>
> > tv
>
> >
>
> >
>
> > -----Original Message-----
>
> > From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
>
> > Narbik Kocharians
>
> > Sent: Tuesday, December 08, 2009 10:20 AM
>
> > To: Wouter Prins
>
> > Cc: jack daniels; Cisco certification
>
> > Subject: Re: LLQ
>
> >
>
> > If you like the voice traffic to get 1M and 1M ONLY, then, provide LLQ
> and
>
> > Police that traffic at the same time. Very common.
>
> >
>
> > On Tue, Dec 8, 2009 at 8:10 AM, Wouter Prins <wp_at_null0.nl> wrote:
>
> >
>
> > > Hello Jack,
>
> > >
>
> > > What do you think would happen to the other traffic if the voice
> traffic
>
> > > was
>
> > > allowed to burst to 2M in a LLQ?
>
> > >
>
> > > Depending on whether the interface is congested or not, the traffic
> would
>
> > > be
>
> > > dropped if it exceeds the bw you specify in the priority command. It's
>
> > sort
>
> > > of a conditional policer. The traffic will not end up in the default
>
> > class.
>
> > >
>
> > > 2009/12/8 jack daniels <jckdaniels12_at_gmail.com>
>
> > >
>
> > > > Hi guys,
>
> > > >
>
> > > > Please help me with the understanding of LLQ -
>
> > > >
>
> > > > If I have a link of 2 MB
>
> > > >
>
> > > > and I reserve 1 MB for VOICE ( LLQ) the if voice exceeds 1 MB will it
>
> > be
>
> > > > droppped or be sent in default class.
>
> > > >
>
> > > >
>
> > > >
>
> > >
>
> > > --
>
> > > Wouter Prins
>
> > > wp_at_null0.nl
>
> > > CCIE #25628
>
> > >
>
> > >
>
> > > Blogs and organic groups at http://www.ccie.net
>
> > >
>
> > > _______________________________________________________________________
>
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> > >
>
> > >
>
> > >
>
> > >
>
> > >
>
> > >
>
> >
>
> >
>
> > --
>
> > Narbik Kocharians
>
> > CCSI#30832, CCIE# 12410 (R&S, SP, Security)
>
> > www.MicronicsTraining.com
>
> > Sr. Technical Instructor
>
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> --
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-- 
Thanks & B.regards
Ahmed Elhoussiny,2x CCIE# 21988 (R&S-SP)
Network Consultant & Cisco Academy Instructor
Blogs and organic groups at http://www.ccie.net