From: Nick Griffin (nick.jon.griffin@gmail.com)
Date: Wed Nov 29 2006 - 15:35:56 ART
There are exceptions with default commands that do and do not show up in the
configuration files. Perhaps this is one.
On 11/29/06, Vincent Mashburn <vmashburn@fedex.com> wrote:
>
> That is interesting. However, it is also interesting that when you
> configure class-default, no queuing shows up in the default
> configuration in the "show run". However, if you configure
> "fair-queue", and do a "show run" fair queue now shows up in the
> configuration. This suggests that it is not the default.
>
>
>
> Vince Mashburn
>
> Sr. Voice / Data Engineer
>
> 901-263-5072
>
> CCVP, CCNP
>
> Cisco IP Telephony Support Specialist
>
> Cisco IP Telephony Operations Specialist
>
> ________________________________
>
> From: petrsoft@gmail.com [mailto:petrsoft@gmail.com] On Behalf Of Petr
> Lapukhov
> Sent: Wednesday, November 29, 2006 10:56 AM
> To: Vincent Mashburn
> Cc: Kal Han; Groupstudy; Cisco certification
> Subject: Re: QoS questions.
>
>
>
> This has been a long source of QoS controversy around :)
>
> Actually, DocCD says it's WFQ. let's see if it's true:
>
> -------------------
>
> R1#show policy-map TEST
> Policy Map TEST
> Class class-default
> !
> interface FastEthernet0/0
> service-policy output TEST
> !
> R1#show queueing interface fastEthernet 0/0
> Interface FastEthernet0/0 queueing strategy: none
>
> so it's FIFO when class-default is configured ALONE within policy-map.
>
> --------------------
>
> Let's add some other class:
>
> R1#show policy-map TEST
> Policy Map TEST
> Class VOICE
> Strict Priority
> Bandwidth 10 (%)
> Class class-default
>
> R1#show queueing interface fastEthernet 0/0
> Interface FastEthernet0/0 queueing strategy: fair
> Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
> Queueing strategy: weighted fair
> Output queue: 0/1000/64/0 (size/max total/threshold/drops)
> Conversations 0/1/256 (active/max active/max total)
> Reserved Conversations 0/0 (allocated/max allocated)
> Available Bandwidth 65000 kilobits/sec
>
> It's WFQ now, what about the policy-map?
>
> R1#show policy-map interface fastEthernet 0/0
> FastEthernet0/0
>
> Service-policy output: TEST
>
> Class-map: VOICE (match-all)
> 0 packets, 0 bytes
> 5 minute offered rate 0 bps, drop rate 0 bps
> Match: ip dscp ef
> Queueing
> Strict Priority
> Output Queue: Conversation 264
> Bandwidth 10 (%)
> Bandwidth 10000 (kbps) Burst 250000 (Bytes)
> (pkts matched/bytes matched) 0/0
> (total drops/bytes drops) 0/0
>
> Class-map: class-default (match-any)
> 156 packets, 18988 bytes
> 5 minute offered rate 0 bps, drop rate 0 bps
> Match: any
>
> Note that Priority Queue has been allocated conversation number 264 but
> there's
> nothing said about class-default. Quite confusing!
>
> However, we have to conclude, that conversations 1-256 are actually
> allocated for
> class-default (who else could claim them?), let's see if we can tune
> this:
>
> policy-map TEST
> class VOICE
> priority percent 10
> class class-default
> fair-queue 512
>
> R1#show queueing interface fastEthernet 0/0
> Interface FastEthernet0/0 queueing strategy: fair
> Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
> Queueing strategy: weighted fair
> Output queue: 0/1000/64/0 (size/max total/threshold/drops)
> Conversations 0/1/512 (active/max active/max total)
> Reserved Conversations 0/0 (allocated/max allocated)
> Available Bandwidth 65000 kilobits/sec
>
> Number of conversations is 512 now, and it's the same group of
> conversations
> that was previously allocated for class-default (only the number was
> 256)
>
> R1#show policy-map interface fastEthernet 0/0
> FastEthernet0/0
>
> Service-policy output: TEST
>
> Class-map: VOICE (match-all)
> 0 packets, 0 bytes
> 5 minute offered rate 0 bps, drop rate 0 bps
> Match: ip dscp ef
> Queueing
> Strict Priority
> Output Queue: Conversation 520
> Bandwidth 10 (%)
> Bandwidth 10000 (kbps) Burst 250000 (Bytes)
> (pkts matched/bytes matched) 0/0
> (total drops/bytes drops) 0/0
>
> Class-map: class-default (match-any)
> 208 packets, 25344 bytes
> 5 minute offered rate 0 bps, drop rate 0 bps
> Match: any
> Queueing
> Flow Based Fair Queueing
> Maximum Number of Hashed Queues 512
> (total queued/total drops/no-buffer drops) 0/0/0
>
> This time policy-map reflect our changes...
>
> Go figure the truth now :)
>
> HTH
>
>
>
> 2006/11/29, Vincent Mashburn <vmashburn@fedex.com>:
>
> Actually, the class-default is fifo unless you explicitly configure
> fair-queue under the class-default in your policy map.
>
> Vince Mashburn
> Sr. Voice / Data Engineer
> 901-263-5072
> CCVP, CCNP
> Cisco IP Telephony Support Specialist
> Cisco IP Telephony Operations Specialist
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com ] On Behalf Of
> Petr Lapukhov
> Sent: Wednesday, November 29, 2006 1:37 AM
> To: Kal Han
> Cc: Groupstudy; Cisco certification
> Subject: Re: QoS questions.
>
> Please, see comments inline:
>
> 2006/11/29, Kal Han < calikali2006@gmail.com>:
> >
> > Hi
> >
> > Question 1
> > ---------------
> > When I am want to shape traffic on a frame-relay interface,
> > based on dlci - After create a policy-map and apply it on an
> > interfaces, should I also enable *"frame-relay traffic-shaping"*
> > or is this command only useful when I configure my policy
> > using *"map-class frame-relay"* and individually applying these
> > class per dlci
> > Sorry this could be a dumb question but I didnt understand.
>
>
> You only need to enable "frame-relay traffic-shaping" for legacy FRTS
> configuration, i.e. when you specify CIR/minCIR/Bc/Be whithin
> map-class with "frame-relay cir", "frame-relay mincir" etc command.
>
> MQC FRTS, and pure MQC configs do not require this command.
>
> Question 2 : class-default and fair-queue
> > ----------------------------------------------------------
> > For the class-default, I see there is an option to enable fair-queue.
> > Is it not the default ? if not what is the default ?
>
>
> By default "class-default" uses flow-based WFQ, as per the DocCD. You
> may
> not observe this with "show policy map", however "show queueing
> interface"
> gives a clue. By default, WFQ is able to accomodate for 256
> conversations.
>
> If you want to change the queue to FIFO, you need to specify the
> "bandwidth"
> keyword under class-default.
>
> <DocCD>
> By default, the class-default class is defined as flow-based WFQ.
> However,
> configuring the
> default class with the bandwidth policy-map class configuration command
> disqualifies
> the default class as flow-based WFQ.
> </DocCD>
>
> Question 3: LLQ Vs custom PQ
> > ----------------------------------------------
> > If LLQ itself is a priority queue, is the reason for using the
> priority
> > queuing,
> > because priority queuing offers more choices of prioritizing traffic ?
> >
> > and when I have a priority-list of a particular protocol with a
> > *low*priority,
> > example:
> >
> > access-list 10 permit 239.1.1.0 0.0.0.255
> >
> > priority-list 1 protocol ip *low *list 10
> >
> > does it mean the rest of the traffic (un-classified default)
> > is still* lower* priority than the ip traffic my acl selects ?
>
>
> The biggest difference between legacy PQ and LLQ is that PQ permits
> low-priority queues *starvation*. That is, with LLQ high priority queue
> is
> policed,
> and in contrary, with PQ all queues are served in order - from high to
> low,
> and
> until high has been emptied, no low queues are serverd.
>
> This is the main feature of PQ - it has 4 queues, served in strict
> order.
>
> HTH
>
> Thanks
> > Kal
> >
> >
> _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html
> >
>
>
>
> --
> Petr Lapukhov, CCIE #16379
> petr@internetworkexpert.com
>
> Internetwork Expert, Inc.
> http://www.InternetworkExpert.com
> Toll Free: 877-224-8987
> Outside US: 775-826-4344
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
>
>
>
> --
> Petr Lapukhov, CCIE #16379
> petr@internetworkexpert.com
>
> Internetwork Expert, Inc.
> http://www.InternetworkExpert.com
> Toll Free: 877-224-8987
> Outside US: 775-826-4344
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Fri Dec 01 2006 - 08:05:49 ART