Re: shape on 3560

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
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:: 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 donbt 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!
>>> 
>>> 
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