From: Arun Arumuganainar (aarumuga@hotmail.com)
Date: Fri Jul 29 2005 - 14:06:34 GMT-3
FYI : Output Hold Queue is actually Software Queue . This is equal to sum of
the length of all software Queues. In a pure FIFO Hold Queue length is
actually Software Queue . What ever be the implementation if Hold Queue
limit is exceeded , it would be tail Drop for sure .
Note : Actually is Hardware Queue is actually called Transmit Ring . Both
hold queue and transmit ring are configurable .
Ok ... Lets us wind up gracefully . If you agree , We can certainly agree to
dis-agree !!!!
Thanks and Regards
Arun
----- Original Message -----
From: "Chris Lewis (chrlewis)" <chrlewis@cisco.com>
To: "Arun Arumuganainar" <aarumuga@hotmail.com>; "A Molica"
<ajmgrd-groupstudy@yahoo.com>; "Bajo" <bajoalex@gmail.com>;
<gladston@br.ibm.com>
Cc: <ccielab@groupstudy.com>; "san" <san.study@gmail.com>
Sent: Friday, July 29, 2005 7:22 PM
Subject: RE: Queue with GTS
> Arun,
>
> I think you are mis-interpreting that note, but then gain, we could just
> agree to disagree :)
>
> Here is how I read it.
>
> The points you list refer to the actions the interface driver take, as
> indicated by the following text that precedes the points you quote below
> :
>
> "The message is presented to the fast-send routine in the driver which
> does the following steps."
>
> The re-ordering that I'm referring to that are configured by priority or
> bandwidth statements happen before the packet gets to the interface
> driver. The way I look at it is ordering of packets for transmission is
> not dependant on the throughput rate of the egress interface. All the
> queuing policies that we configure with bandwidth and priority
> statements in a policy map do is get the right order of packets ready
> for transmission during times of congestion. Whether the interface can
> transmit at line rate or a lesser shaped rate is irrelevant to that
> action. The correct sequence of packets is processed by the queuing
> policy configured, then the interface driver decides how quickly to send
> that sequence of packets out, depending on interface speed and any
> shaping configured.
>
> One point that may also help is that the software queue in the document
> you refer to, is the output hold queue, that is not the queue where
> policy-map statements like priority and bandwidth take effect.
>
> Cheers
>
> Chris
>
> -----Original Message-----
> From: Arun Arumuganainar [mailto:aarumuga@hotmail.com]
> Sent: Friday, July 29, 2005 7:39 AM
> To: A Molica; Chris Lewis (chrlewis); Bajo; gladston@br.ibm.com
> Cc: ccielab@groupstudy.com; san
> Subject: Re: Queue with GTS
>
> Just check this out for More details . Quoting this for your info ...
>
> http://www.cisco.com/en/US/tech/tk364/technologies_tech_note09186a008009
> 3fdc
> shtml
>
> 1.. If traffic shaping is active, it compares the message arrival rate
> to the message transmission rate for the indicated class of messages. If
> either a shaping queue is forming on the subinterface or the queue is
> not present but the rate has now been exceeded, it places the message
> into a queue on the software interface.
> 2.. If traffic shaping is not active, does not apply to this message,
> or the rate has not been exceeded, the driver now asks whether the depth
> of the output controller's transmit queue is below the tx-queue-limit.
> If it is below the limit, the driver simply queues the message for
> transmission. A message that followed this path is accounted as having
> been fast-switched on input and fast-switched on output.
> 3.. If it cannot be fast-switched, however, the driver diverts the
> message into a software queue, which is generically referred to as the
> "output hold queue". Examples of such hold queues include First In,
> First Out (FIFO) queuing, Priority Queuing, Custom Queuing, and Weighted
> Fair Queuing (WFQ).
>
> Thanks and Regards
>
> Arun
>
> ----- Original Message -----
> From: "A Molica" <ajmgrd-groupstudy@yahoo.com>
> To: "Chris Lewis (chrlewis)" <chrlewis@cisco.com>; "Arun Arumuganainar"
> <aarumuga@hotmail.com>; "Bajo" <bajoalex@gmail.com>;
> <gladston@br.ibm.com>
> Cc: <ccielab@groupstudy.com>; "san" <san.study@gmail.com>
> Sent: Friday, July 29, 2005 5:51 PM
> Subject: RE: Queue with GTS
>
>
> > I would hope Chris is right, as voice and data packets could share the
> same shaper, and I would want priority voice packets to get precedence
> over data packets when entering the shaper.
> >
> > "Chris Lewis (chrlewis)" <chrlewis@cisco.com> wrote:One small
> > correction
> here, packets go in to the software queue first,
> > then the shaper. The software queue is there to order packets based
> > off of priority or bandwidth configurations, then that order of
> > packets is fed in to the shaper, should packets need to be delayed to
> > keep to the shaped rate.
> >
> > Chris
> >
> > ________________________________
> >
> > From: Arun Arumuganainar [mailto:aarumuga@hotmail.com]
> > Sent: Thursday, July 28, 2005 1:04 AM
> > To: Bajo; gladston@br.ibm.com
> > Cc: ccielab@groupstudy.com; Chris Lewis (chrlewis); san
> > Subject: Re: Queue with GTS
> >
> >
> >
> >
> > ----- Original Message -----
> > From: gladston@br.ibm.com
> > To: Bajo
> > Cc: Arun Arumuganainar ;
> > ccielab@groupstudy.com ; Chris Lewis (chrlewis) ; san
> > Sent: Thursday, July 28, 2005 6:46 AM
> > Subject: Re: Queue with GTS
> >
> >
> >
> > Thanks,
> >
> > More clear now.
> >
> > This is from Wendell:
> >
> > "In some cases, IOS does not place the packets into a shaping
> > queue as they arrive, but instead the packets are placed into the
> > Software queue or TX Queue. When the shaping features knows that a
> newly
> > arrived packet does not exceed the shaping rate, there is no need to
> > delay the packet. In that case, a queuing tool used for managing the
> > shaping queue would also have no effect on that particular packet. "
> >
> >
> > [Arun]
> > This is absolutely true and this is how Shaping works . When a
> > packet arrives , it will check the token bucket if credit available it
> > will be sent to Software queue ( or directly to H/W queue if it is not
> > full ) . If credits are not available then this will be placed in the
> > shapping queue ( Read more about token bucket algorithm for Details ).
> > [Arun]
> >
> > But, could you think about an example using a tool for queue
> > created by shaping and a tool queue for the main interface used at the
> > same time?
> > I remember that when we configure fragmentation, IOS creates two
> > queues on the main interface, and we can still use other tools (LLQ,
> CQ,
> > PQ, IP RTP Priority) on the queue created by shaping.
> >
> > Then, correcting my last post, this would occur:
> > |shaping queue|------->|software queue|-------->|hardware queue|
> >
> > LLQ Dual-Fifo
> > Fifo
> >
> > [Arun]
> >
> > See What queueing technique does shaping and software queues
> > uses is implementation specific .
> >
> > For Cisco with GTS the scenario look like this
> >
> > |shaping queue|------->|software queue|-------->|hardware queue|
> >
> > WFQ CQ or PQ or Fifo
> > Fifo
> >
> >
> >
> > For Cisco with FRTS th scenario look like this
> >
> > |shaping queue|------->|software queue|-------->|hardware queue|
> >
> > CQ or PQ or Fifo WFQ
> > Fifo
> >
> > Note :LLQ belong to different category . LLQ = Strict Priority
> > Queue + Policing . An Standalone LLQ can not be used for shapping ( A
> PQ
> > can be used instead of this ).
> >
> > Certainly you can verify this by configuring this in your lab
> >
> >
> > Hope it is clear now
> >
> > [Arun]
> >
> >
> > Any other example besides this one?
> >
> > Cordially,
> >
> > ------------------------------------------------------------------
> > Gladston
> >
> >
> >
> >
> > Bajo
> >
> > 27/07/2005 21:31
> > Please respond to
> > Bajo
> >
> >
> > To
> > Alaerte Gladston Vidali/Brazil/IBM@IBMBR
> > cc
> > san , Arun Arumuganainar ,
> > ccielab@groupstudy.com, "Chris Lewis (chrlewis)"
> > Subject
> > Re: Queue with GTS
> >
> >
> >
> >
> >
> >
> > Hi all,
> >
> > Arun is correct. Take a look at the "Decision Logic for Queuing"
> > in
> > Wendell Odom's Cisco QoS, 2ed, page 358. Here are some points
> > from the
> > book ...
> >
> > Shaping Queues exist separately from the interface software
> > queues ...
> >
> > After passing any Shaping tool (say PQ...etc), if there is any
> > shaping
> > applied, packets are sent into Software Queues associated with
> > the
> > physical interface and then forwarded out the interface.
> >
> > "If Hardware Queue is not full, packet are immediately placed
> > in
> > Hardware Queue, bypassing the interface Software Queue....."
> >
> > On 7/27/05, gladston@br.ibm.com wrote:
> > > Hi San,
> > >
> > > I hope Arun answers it.
> > > As I see the process, there is a hardware queue and software
> > queue. I
> > > don't think it would exist something like this going on:
> > > |shaping queue|----->|sofware queue|---->|hardware queue|
> > >
> > > The shaping queue is itself a software queue.
> > > Would IOS move from a software queue (called shaping queue) to
> > another
> > > software queue(called just "software queue")?
> > >
> > > Cordially,
> > >
> > ------------------------------------------------------------------
> > > Gladston
> > >
> > >
> > >
> > >
> > > san
> > > 27/07/2005 12:29
> > > Please respond to
> > > san
> > >
> > >
> > > To
> > > Arun Arumuganainar
> > > cc
> > > Alaerte Gladston Vidali/Brazil/IBM@IBMBR, "Chris Lewis
> > (chrlewis)"
> > > , ccielab@groupstudy.com
> > > Subject
> > > Re: Queue with GTS
> > >
> > >
> > >
> > >
> > >
> > >
> > > Hi Arun,
> > >
> > > Can you give an example of how to modify a software queue ?
> > Is it by
> > > the command "fair-queue , no fair-queue" under the interface.
> > I know
> > > shaping queue can be modified with shapping configurations
> > > (FRTS/GTS/CBTS).
> > >
> > > Dumb Question, If i use shaping, does the software queue is
> > > overwritten by shapping queue or still packet goes through
> > both the
> > > queues like below
> > > PQ with GTS :
> > > interface serial 0
> > > priority-group 4 ((priority queue to define software queue))
> > > traffic-shape rate xxxx (( to create a shapping queue ))
> > >
> > >
> > > /SAN
> > >
> > > On 7/27/05, Arun Arumuganainar wrote:
> > > > Actually there are 3 queues in IOS .
> > > >
> > > > 1) Hardware Queue :- Single Queue and Always FIFO . We can
> > not do any
> > > thing
> > > > about it
> > > > 2) Software Queue
> > > > 3) Shaping Queue ( Will be used only when shaping is turned
> > on ) .
> > > >
> > > > How Packets are enqued in Software or Shaping Queue ?
> > > >
> > > > Well the answer lies in what kind of traffic shaping you you
> > use . Here
> > > are
> > > > the details .
> > > >
> > > > 1) GTS : Shaping Queue : WFQ only supported . Software
> > Queue : PQ ,
> > > CQ or
> > > > FIFO
> > > > 2) FRTS : Shaping Queue : PQ, CQ and FIFO Software Queue :
> > WFQ only
> > > > 3) CB-Traffic Shaping : Uses WFQ for both Shaping and
> > Software Queue .
> > > >
> > > > Well the " sh interface " o/p tells you only about the
> > software queue
> > > and
> > > > "show traffic " will give you about shaping queue .
> > > >
> > > > Hope this helps .
> > > >
> > > > Thanks and Regards
> > > > Arun
> > > > ----- Original Message -----
> > > > From:
> > > > To: "Chris Lewis (chrlewis)"
> > > > Cc:
> > > > Sent: Wednesday, July 27, 2005 12:37 AM
> > > > Subject: RE: Queue with GTS
> > > >
> > > >
> > > > > No, Chris, thanks a lot.
> > > > >
> > > > > That is what I was looking for.
> > > > >
> > > > > Wendell book confirmed that GTS uses WFQ.
> > > > >
> > > > > I read that before, but nothing like practice to memorize.
> > > > >
> > > > > Cordially,
> > > > >
> > ------------------------------------------------------------------
> > > > > Gladston
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > "Chris Lewis \(chrlewis\)"
> > > > > 26/07/2005 15:52
> > > > >
> > > > > To
> > > > > Alaerte Gladston Vidali/Brazil/IBM@IBMBR,
> >
> > > > > cc
> > > > >
> > > > > Subject
> > > > > RE: Queue with GTS
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > Hi Gladston,
> > > > >
> > > > > This is how I would read the output.
> > > > >
> > > > > GTS acts upon an interface or subinterface. GTS here is
> > configured for
> > > a
> > > > > specific sub-interface and the queue that GTS will build
> > to do shaping
> > > > > on will use WFQ. The main interface can have fifo or wfq
> > configured on
> > > > > it. Are you looking at something else?
> > > > >
> > > > > Chris
> > > > >
> > > > > -----Original Message-----
> > > > > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]
> > On Behalf
> > > Of
> > > > > gladston@br.ibm.com
> > > > > Sent: Tuesday, July 26, 2005 12:20 PM
> > > > > To: ccielab@groupstudy.com
> > > > > Subject: Queue with GTS
> > > > >
> > > > > Hi,
> > > > >
> > > > > GTS is applyed to interface serial 0/0.14.
> > > > > 'sh traffic queue' shows that the queue created by GTS
> > uses WFQ.
> > > > >
> > > > > It seems it does not matter what is configured on the
> > interface, in
> > > this
> > > > > case fifo.
> > > > >
> > > > > Would you comment this?
> > > > >
> > > > > Rack2R1(config-subif)#do sh traf que
> > > > > Traffic queued in shaping queue on Serial0/0.14
> > > > > Queueing strategy: weighted fair
> > > > > Queueing Stats: 9/1000/64/10026 (size/max
> > total/threshold/drops)
> > > > > Conversations 2/4/16 (active/max active/max total)
> > > > > Reserved Conversations 0/0 (allocated/max allocated)
> > > > > Available Bandwidth 96 kilobits/sec
> > > > >
> > > > > (depth/weight/total drops/no-buffer drops/interleaves)
> > 5/32384/380/0/0
> > > > > Conversation 0, linktype: ip, length: 64
> > > > > source: 150.100.1.254, destination: 148.5.4.1, id: 0x03F6,
> > ttl: 254,
> > > > > TOS: 0 prot: 17, source port 55172, destination port 5002
> > > > >
> > > > > (depth/weight/total drops/no-buffer drops/interleaves)
> > 5/32384/766/0/0
> > > > > Conversation 7, linktype: ip, length: 64
> > > > > source: 150.100.1.254, destination: 148.5.4.1, id: 0x0020,
> > ttl: 254,
> > > > > TOS: 0 prot: 17, source port 51068, destination port 5001
> > > > >
> > > > >
> > > > > Rack2R1(config-subif)#do sh int ser 0/0
> > > > > Serial0/0 is up, line protocol is up
> > > > > Hardware is PowerQUICC Serial
> > > > > MTU 1500 bytes, BW 64 Kbit, DLY 20000 usec,
> > > > > reliability 255/255, txload 255/255, rxload 10/255
> > > > > Encapsulation FRAME-RELAY, loopback not set
> > > > > Keepalive set (10 sec)
> > > > > LMI enq sent 95, LMI stat recvd 95, LMI upd recvd 0, DTE
> > LMI up
> > > > > LMI enq recvd 0, LMI stat sent 0, LMI upd sent 0
> > > > > LMI DLCI 1023 LMI type is CISCO frame relay DTE
> > > > > FR SVC disabled, LAPF state down
> > > > > Broadcast queue 0/64, broadcasts sent/dropped 178/0,
> > interface
> > > > > broadcasts 162
> > > > > Last input 00:00:01, output 00:00:00, output hang never
> > > > > Last clearing of "show interface" counters 00:15:49
> > > > > Input queue: 0/75/0/0 (size/max/drops/flushes); Total
> > output drops:
> > > > > 10878
> > > > > Queueing strategy: fifo
> > > > > Output queue: 0/40 (size/max)
> > > > > 1 minute input rate 95000 bits/sec, 183 packets/sec
> > > > > 1 minute output rate 95000 bits/sec, 185 packets/sec
> > > > > 159447 packets input, 10401005 bytes, 0 no buffer
> > > > > Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
> > > > > 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0
> > abort
> > > > > 163288 packets output, 10609440 bytes, 0 underruns
> > > > > 0 output errors, 0 collisions, 0 interface resets
> > > > > 0 output buffer failures, 0 output buffers swapped out
> > > > > 0 carrier transitions
> > > > > DCD=up DSR=up DTR=up RTS=up CTS=up
> > > > >
> > > > >
> > > > > This is the config:
> > > > >
> > > > > interface Serial0/0.14 point-to-point
> > > > > bandwidth 128
> > > > > ip address 148.5.14.1 255.255.255.0
> > > > > traffic-shape rate 96000 12000 1000 1000 frame-relay
> > interface-dlci
> > > > > 104
> > > > >
> > > > >
> > >
> >
> _______________________________________________________________________
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> > > > >
> > >
> >
> _______________________________________________________________________
> > > > > Subscription information may be found at:
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> > > >
> > > >
> >
> _______________________________________________________________________
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> > >
> > >
> >
> _______________________________________________________________________
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> >
> >
> > --
> > Kind Regards,
> >
> > Bajo
> >
> >
> _______________________________________________________________________
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> >
> >
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