From: Chris Lewis \(chrlewis\) (chrlewis@cisco.com)
Date: Thu Jul 28 2005 - 23:22:13 GMT-3
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 <mailto:bajoalex@gmail.com>
Cc: Arun Arumuganainar <mailto:aarumuga@hotmail.com> ;
ccielab@groupstudy.com ; Chris Lewis (chrlewis)
<mailto:chrlewis@cisco.com> ; san <mailto:san.study@gmail.com>
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 <bajoalex@gmail.com>
27/07/2005 21:31
Please respond to
Bajo <bajoalex@gmail.com>
To
Alaerte Gladston Vidali/Brazil/IBM@IBMBR
cc
san <san.study@gmail.com>, Arun Arumuganainar <aarumuga@hotmail.com>,
ccielab@groupstudy.com, "Chris Lewis (chrlewis)" <chrlewis@cisco.com>
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 <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 <san.study@gmail.com>
> 27/07/2005 12:29
> Please respond to
> san <san.study@gmail.com>
>
>
> To
> Arun Arumuganainar <aarumuga@hotmail.com>
> cc
> Alaerte Gladston Vidali/Brazil/IBM@IBMBR, "Chris Lewis
(chrlewis)"
> <chrlewis@cisco.com>, 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 <aarumuga@hotmail.com> 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: <gladston@br.ibm.com>
> > To: "Chris Lewis (chrlewis)" <chrlewis@cisco.com>
> > Cc: <ccielab@groupstudy.com>
> > 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 \(chrlewis\)" <chrlewis@cisco.com>
> > > 26/07/2005 15:52
> > >
> > > To
> > > Alaerte Gladston Vidali/Brazil/IBM@IBMBR,
<ccielab@groupstudy.com>
> > > 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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