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
> >
> >
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>
> --
> Narbik Kocharians
> CCSI#30832, CCIE# 12410 (R&S, SP, Security)
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