Re: shape on 3560

That's what I would expect to happen.
But I'll try to test it to have some more info. It would not be the
first time something does not work the way I thought, if it were the case.
(Hmm, may be lower values, cause I don't have at hand what's needed to
congest a Gb. Ostinato chokes over 87kpps on my PC :)

-Carlos

gp @ 07/08/2011 17:05 -0300 dixit:
> My conclusion from configuration: from which queue will be more traffic sent when interface is congested
>
> if interface of 1Gbps is congested with:
> flow for q1 = 700 Mbps
> flow for q2 = 500 Mbps
> flow for q3 = 500 Mbps
> flow for q4 = 500 Mbps
>
> and the following configuration is on interface:
> priority-queue out
> srr-queue bandwidth shape 0 5 0 0
> srr-queue bandwidth share 1 1 10 10
>
> the result will be:
> q1 = 700 Mbps
> q2 = 200 Mbps
> q3 = 50 Mbps
> q4 = 50 Mbps
>
> traffic in q2 has more bandwidth than q3 and q4, so shaped queue is better as we can influence which queue (q2-4) will get more bandwidth if we don't count priority queue.
>
>
>
>
> -----Original Message-----
> From: Marko Milivojevic [mailto:markom_at_ipexpert.com]
> Sent: Sunday, August 07, 2011 8:44 PM
> To: Carlos G Mendioroz
> Cc: gp; <ccielab_at_groupstudy.com>
> Subject: Re: shape on 3560
>
> What is meant by "not delay guarantee" is that while minimum BW is
> guaranteed (for both shaped and shared), there is no priority in
> processing the queues. Queueing is a two-step process. First, the
> packets are put into the queues and then the queues are serviced
> (packets are dequeued). To guarantee the minimum delay, queue needs to
> be serviced first. In SRR scheduler, this is not the case for any
> non-priority queue. I.e. packets are dequeued in a round-robin fashion
> from queues according to their respective weights.
>
> In plain English, if there are three packets in queue 1 and according
> to the wights for Q1, we can send only 2, the third packet will have
> to wait for Q2-4 to be serviced before it's sent. If the queue was
> shaped, it would be in the next scheduled time interval, or if it was
> shared, once the queues are serviced up to their minimum guarantee,
> packets from all shared queues would be serviced until time interval
> elapses, or queues are fully empty.
>
> Contrary to this, when strict scheduling is used (priority queue on
> Cats, or PQ and LLQ on routers), priority queue is always serviced
> first, regardless of other queues. On Cats and in PQ, you cannot limit
> the amount of traffic sent (creating a queue starvation problem), but
> with LLQ there is a conditional policer, which prevents this, However,
> they all share the same dequeueing strategy - they are always serviced
> before any other queues.
>
> Does this make it more clear? For more details - DQOS by Wendell Odom
> is a fine start.
>
> --
> Marko Milivojevic - CCIE #18427
> Senior Technical Instructor - IPexpert
>
> FREE CCIE training: http://bit.ly/vLecture
>
> Mailto: markom_at_ipexpert.com
> Telephone: +1.810.326.1444
> Web: http://www.ipexpert.com/
>
>
>
> On Sun, Aug 7, 2011 at 11:04, Carlos G Mendioroz <tron_at_huapi.ba.ar> wrote:
>> Marko,
>> you say that all queues have guaranteed BW but not delay.
>> I don't fully understand that.
>>
>> Are you saying that the delay for a packet of some class is not bounded?
>> If not, delay is also guaranteed.
>>
>> If you have 3 queues, one with 50Mb shape and the other two 1/3 the BW
>> on a 100 Mb link, anything below congestion (and below 50Mb) will be
>> just served, but if the 3 queues try to get 40Mb, what will be the effective
>> throughput of each ?
>> I would say 40/30/30.
>>
>> -Carlos
>>
>> Marko Milivojevic @ 07/08/2011 14:22 -0300 dixit:
>>> All queues are guaranteed bandwidth, but not the delay. SRR is round-robin
>>> alghoritm. Shaped queues are assigned bandwidth first and whatever remains
>>> is used by shared queues, but servicing the data in queues is always equal
>>> between all the queues.
>>> When you enable PQ, Q1 is serviced until empty and only then Q2-4 are
>>> processed according to the SRR configuration and remaining bandwidth in the
>>> time interval.
>>> --
>>> Marko Milivojevic - CCIE #18427
>>> Senior Technical Instructor - IPexpert
>>>
>>> Free CCIE Training: http://bit.ly/vLecture
>>>
>>> Mailto: markom_at_ipexpert.com
>>> Telephone: +1.810.326.1444
>>> Community: http://www.ipexpert.com/communities
>>>
>>> :: Sent from my phone. Apologies for errors and brevity. ::
>>>
>>>
>>> On Aug 7, 2011, at 2:42, "gp" <gs4me2me_at_gmail.com> wrote:
>>>
>>>> I read somewhere that shaped queue is processed before shared.
>>>> Unfortunately cannot find it:)
>>>>
>>>> Is it possible to guaranteed some traffic bandwidth to be processed
>>>> before other with limit in task that it cannot be mapped in priority queue
>>>> because some other traffic more important is mapped to priority queue?
>>>>
>>>> For example:
>>>> Q1 - traffic X - priority Q2 - traffic XY - less important than traffic
>>>> X, more important than traffic XYZ
>>>> Q3&Q4 - traffic XYZ
>>>>
>>>>
>>>> Regards,
>>>> Gp
>>>>
>>>>
>>>>
>>>> -----Original Message-----
>>>> From: Marko Milivojevic [mailto:markom_at_ipexpert.com] Sent: Saturday,
>>>> August 06, 2011 10:46 PM
>>>> To: gp
>>>> Cc: ccielab_at_groupstudy.com
>>>> Subject: Re: shape on 3560
>>>>
>>>> Sharing and shaping has nothing to do with priority queueing. I.e.
>>>> shaped traffic is not processed before shared - it's only limited to
>>>> certain percentage of the traffic, while shared queues are simply
>>>> guaranteed a minimum.
>>>>
>>>> You can configure shaping as a percentage of negotiated speed, of
>>>> course. By default 100% of interface bandwidth (negotiated speed) is
>>>> available for all queues. If you want to limit Q2 to say, 33% you can
>>>> configure it as "srr-queue bandwidth shape 0 3 0 0". However, if you
>>>> want to limit it to say 5 Mb/s REGARDLESS of the negotiated speed,
>>>> this cannot be done on 3560, as this is a policing and policing is not
>>>> available in the outbound direction on 3560.
>>>>
>>>> --
>>>> Marko Milivojevic - CCIE #18427
>>>> Senior Technical Instructor - IPexpert
>>>>
>>>> FREE CCIE training: http://bit.ly/vLecture
>>>>
>>>> Mailto: markom_at_ipexpert.com
>>>> Telephone: +1.810.326.1444
>>>> Web: http://www.ipexpert.com/
>>>>
>>>> On Sat, Aug 6, 2011 at 13:19, gp <gs4me2me_at_gmail.com> wrote:
>>>>> Thank you Marko for explanation, it helps.
>>>>>
>>>>> What confusing me if I have a task to guaranteed some traffic for
>>>>> example 10Mbps on giga interface on switch, and I cannot use priority queue,
>>>>> so I want to send that traffic before packet in shared queue in way to put
>>>>> it in shaped queue which will be served before shared queues.
>>>>>
>>>>> The problem is that I donb t know what type of interface will be
>>>>> connected to my switch (1Gbps or 100M) and that is value from which will be
>>>>> calculated value for shaping on particular queue.
>>>>>
>>>>> For example:
>>>>> Negotiated speed = 1Gbps
>>>>> Srr-queue bandwidth shape 0 100 0 0
>>>>> Queue 2 will be shaped to 100Mbps
>>>>>
>>>>> Negotiated speed = 100Mbps
>>>>> Srr-queue bandwidth shape 0 100 0 0
>>>>> Queue 2 will be shaped to 10Mbps
>>>>>
>>>>> In other way as I understand there is no way to hard code shape value
>>>>> regarding to negotiated speed?
>>>>>
>>>>> Regards,
>>>>> Gp
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> -----Original Message-----
>>>>> From: Marko Milivojevic [mailto:markom_at_ipexpert.com]
>>>>> Sent: Saturday, August 06, 2011 7:42 PM
>>>>> To: gp
>>>>> Cc: ccielab_at_groupstudy.com
>>>>> Subject: Re: shape on 3560
>>>>>
>>>>> It will be using the bandwidth available to the SRR.
>>>>>
>>>>> Cat2#sh mls qos interface fa0/18 queueing
>>>>> FastEthernet0/18
>>>>> Egress Priority Queue : disabled
>>>>> Shaped queue weights (absolute) : 25 0 0 0
>>>>> Shared queue weights : 25 25 25 25
>>>>> The port bandwidth limit : 100 (Operational Bandwidth:100.0) <<<<<<<
>>>>> The port is mapped to qset : 1
>>>>>
>>>>> See the "port bandwidth limit" line - that's the BW available to the
>>>>> SRR. It is derived from the negotiated speed by default, but can be
>>>>> limited using "srr-queue bandwidth limit" command on the interface.
>>>>>
>>>>> Now, let's see if configured bandwidth influences this in any way:
>>>>>
>>>>> interface FastEthernet0/18
>>>>> bandwidth 50000
>>>>> !
>>>>>
>>>>> Cat2(config-if)#do sh mls qos int fa0/18 qu
>>>>> FastEthernet0/18
>>>>> Egress Priority Queue : disabled
>>>>> Shaped queue weights (absolute) : 25 0 0 0
>>>>> Shared queue weights : 25 25 25 25
>>>>> The port bandwidth limit : 100 (Operational Bandwidth:100.0)
>>>>> The port is mapped to qset : 1
>>>>>
>>>>> Doesn't look like it does. If I change the bandwidth limit.
>>>>>
>>>>> interface FastEthernet0/18
>>>>> bandwidth 50000
>>>>> srr-queue bandwidth limit 25
>>>>> !
>>>>>
>>>>> Cat2(config-if)#do sh mls qos int fa0/18 qu
>>>>> FastEthernet0/18
>>>>> Egress Priority Queue : disabled
>>>>> Shaped queue weights (absolute) : 25 0 0 0
>>>>> Shared queue weights : 25 25 25 25
>>>>> The port bandwidth limit : 25 (Operational Bandwidth:27.28)
>>>>> The port is mapped to qset : 1
>>>>>
>>>>> Whenever in doubt - ask IOS :-)
>>>>>
>>>>> --
>>>>> Marko Milivojevic - CCIE #18427
>>>>> Senior Technical Instructor - IPexpert
>>>>>
>>>>> FREE CCIE training: http://bit.ly/vLecture
>>>>>
>>>>> Mailto: markom_at_ipexpert.com
>>>>> Telephone: +1.810.326.1444
>>>>> Web: http://www.ipexpert.com/
>>>>>
>>>>> On Sat, Aug 6, 2011 at 01:18, gp <gs4me2me_at_gmail.com> wrote:
>>>>>> Hello experts,
>>>>>>
>>>>>>
>>>>>>
>>>>>> When doing shaping on 3560 interface does reference bandwidth is
>>>>>> configured
>>>>>> bandwidth with bandwidth command or negotiated speed?
>>>>>>
>>>>>>
>>>>>>
>>>>>> For example the switch port is connected on Fast Ethernet router
>>>>>> interface
>>>>>> and I configured bandwidth 1000000 on switch port.
>>>>>>
>>>>>> With srr-queue bandwidth shape 0 100 0 0, will queue 2 be shaped on 10
>>>>>> or 1
>>>>>> Mbps?
>>>>>>
>>>>>>
>>>>>>
>>>>>> Thank you!
>>>>>>
>>>>>>
>>>>>> Blogs and organic groups at http://www.ccie.net
>>>>>>
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>> --
>> Carlos G Mendioroz <tron_at_huapi.ba.ar> LW7 EQI Argentina
>
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-- 
Carlos G Mendioroz  <tron_at_huapi.ba.ar>  LW7 EQI  Argentina
Blogs and organic groups at http://www.ccie.net