QOS - 2960?

[Amir Yanny]

Need some help in understanding the following:

AutoQoS is running on the 2960 platform, is there a need to remark/reclassify this traffic to match 4 Q's i have configured on the router connected to the switch?

To simplfiy my question, Do i need to tweek the AutoQos running on the 2960's to have proper QOS marking/classification on my routers as well? or Should things just work smoothly?

Keep in mind that on my routers i am doing basic Q's that the provider suggest... Will AutoQos work with that or i need to change it?

Any help is highly appreciated!

Thank,

-ay-

[Joseph W. Doherty]

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Posting

Can't really say as there are different "versions" of AutoQoS (although for a 2960 you're probably have version 4).  Can't say because have no idea what your provider's basic QoS is.  Also can't say because you didn't describe your traffic or your service level requirements.  (For the latter AutoQoS might be exactly what you need or it may make things worse.)

[Amir Yanny]

Hi Joseph,

Any thoughts about QOS for Lync (Audio, Video..etc)

Thanks,

Amir Yanny

[Joseph W. Doherty]

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Posting

If it's real-time like traffic, you might consider PQ or a queue with a very large bandwidth guarantee (and 2 to 3 times more than it should be using on average).  If not real-time, bandwidth preference guaranteed (and 1.5 to 2 time more bandwidth than it should be using on average).

[Amir Yanny]

I think i know what i need to do on the routers.. however the switches is not clear yet for me on how to deploy QOs for Lync..

[Joseph W. Doherty]

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The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

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Posting

http://www.cisco.com/en/US/docs/solutions/Enterprise/WAN_and_MAN/QoS_SRND_40/QoSCampus_40.html#wp1098448

[Amir Yanny]

Great thanks, that is for sure an important link..

From Your experience why is deploying and End to End QOS design on the network a hard task? I am trying to use your expertise here to predict what i am going through.

Thanks

[Joseph W. Doherty]

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In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.

Posting

What makes end-to-end "hard" is insuring you have an end-to-end QoS policy that serves your needs.  Often, defining, monitoring and maintaining a QoS policy can be time consuming.

On many later Cisco devices, Cisco often provides an AutoQoS feature.  If you can "map" traffic into that policy, it can greatly simply end-to-end QoS.

[Amir Yanny]

Hi Joseph,

What are your thoughts about putting both the Voice and Video traffic in the same Class (Priority Class)? do you think this will work?

[Joseph W. Doherty]

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The   Author of this posting offers the information contained within this   posting without consideration and with the reader's understanding that   there's no implied or expressed suitability or fitness for any purpose.   Information provided is for informational purposes only and should not   be construed as rendering professional advice of any kind. Usage of  this  posting's information is solely at reader's own risk.

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Posting

What are your thoughts about putting both the Voice and Video traffic in the same Class (Priority Class)? do you think this will work?

Video streaming - no (don't combine).

Video conferencing - maybe (combine and/or work).

Will it work - depends - on multiple factors - especially bandwidth of video vs. available bandwidth.  Video conferencing service requirements are often very similar to VoIP however per flow bandwidth demand is usually much (or much, much) more, and compressed video is much more "bursty".

If your video conferencing supports split flows for its audio vs. video signals, audio might be just included with VoIP - video might or might not.

[Amir Yanny]

Is there a UDP port range for Video Streaming Vs Video conferencing? I am just trying to know how to classify this traffic when it hits my access layer. This way i know how to pur Video conf traffic in LLQ and Video Straming in a lower Bandwidth Q for example.

Thanks

[Joseph W. Doherty]

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The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

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In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.

Posting

There's not a standard for traffic kind.  I.e. it depends on the video application.

Often modern video conferencing provides a setup option that allows you to define markings.  When it does, you only need to trust the marking.

[Amir Yanny]

I am running AutoQOS on my 2960/3750 and I am proposing the following changes to the 2960/3750 Output Q assignments and BUFFER limits, do you think this might have an impact on the AUTO-QOS Process or the QOS process in general? Q1: Voice, Q2: Guranteed BW, Q3: Best Effort, Q4: Video(Conf, Streaming)

Here are the changes:

no mls qos srr-queue output dscp-map queue 1 threshold 3 32 33 40 41

no mls qos srr-queue output dscp-map queue 1 threshold 3 46 47

no mls qos srr-queue output dscp-map queue 2 threshold 1 16 17 18 19

no mls qos srr-queue output dscp-map queue 2 threshold 1 26 27 28 29

no mls qos srr-queue output dscp-map queue 2 threshold 1 36 37 38 39

no mls qos srr-queue output dscp-map queue 2 threshold 2 24

no mls qos srr-queue output dscp-map queue 2 threshold 3 48 49 50 51

no mls qos srr-queue output dscp-map queue 2 threshold 3 56 57 58 59

no mls qos srr-queue output dscp-map queue 3 threshold 3 0 1 2 3 4 5

no mls qos srr-queue output dscp-map queue 4 threshold 1 8 9 11 13 1

no mls qos srr-queue output dscp-map queue 4 threshold 2 10 12 14

mls qos srr-queue output dscp-map queue 1 threshold 3 47 32

mls qos srr-queue output dscp-map queue 1 threshold 3 46

mls qos srr-queue output dscp-map queue 2 threshold 1 48 49 50 51 56 57

mls qos srr-queue output dscp-map queue 2 threshold 1 36 37 38 93 58 59

mls qos srr-queue output dscp-map queue 2 threshold 1 8 9 11 13 10 12 14

mls qos srr-queue output dscp-map queue 2 threshold 2 24

mls qos srr-queue output dscp-map queue 2 threshold 3 33 26 27 28 29

mls qos srr-queue output dscp-map queue 2 threshold 3 16 17 18 19 39

mls qos srr-queue output dscp-map queue 3 threshold 3 0 1 2 3 4 5

mls qos srr-queue output dscp-map queue 4 threshold 1 41

mls qos srr-queue output dscp-map queue 4 threshold 2 42 40

! ----------- Buffer Size for Qs ------------

no mls qos queue-set output 1 buffers 15 25 40 20

mls qos queue-set output 1 buffers 30 25 35 10

[JohnTylerPearce]

This all depends on what you want QoS to accomplish. When you configure AutoQoS, certain defaults are configured. You will see the cos-dscp and dscp-cos maps, it will change CoS 5 being mapped to DSCP 40 to being mapped to DSCP 46 etc etc, With output queues, you can configure up to two queue-sets. Queue-set 1 is the default for all ports on the switches that you mentioned.

So depending on how you want QoS configured, you will just need to modify

[Joseph W. Doherty]

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The   Author of this posting offers the information contained within this   posting without consideration and with the reader's understanding that   there's no implied or expressed suitability or fitness for any purpose.   Information provided is for informational purposes only and should not   be construed as rendering professional advice of any kind. Usage of  this  posting's information is solely at reader's own risk.

Liability Disclaimer

In   no event shall Author be liable for any damages whatsoever (including,   without limitation, damages for loss of use, data or profit) arising  out  of the use or inability to use the posting's information even if  Author  has been advised of the possibility of such damage.

Posting

I am running AutoQOS on my 2960/3750 and I am proposing the following changes to the 2960/3750 Output Q assignments and BUFFER limits, do you think this might have an impact on the AUTO-QOS Process or the QOS process in general?

Yes, it may very well have an impact - and if it didn't, why do it? 

Whether the changes you propose would be better or worse (or even no effect) would depend on your goals and what you have for traffic.

Do know that 2960/3560/3750 are very sensitive to buffer settings.