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3850 IOS XE QoS Queue Buffers

I'm configuring QoS on a 3850 and came across the "queue-buffers ratio" command. Does anyone know what the ratio is?  I am also assuming that this is software buffers that I'm configuring. Also, what does the command affect in the IOS? If anyone can find a source for it to, that would be awesome. I couldn't find anything online. Here is the documentation on the command I'm referring to. Thank you!

http://www.cisco.com/en/US/docs/switches/lan/catalyst3850/software/release/3.2_0_se/qos/command_reference/b_mqc_qt_32se_3850_cr_chapter_010.html#wp3514062886

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Beginner

3850 IOS XE QoS Queue Buffers

When configuring it looks like it's a percentage. So a value of 5 would be 5%.

VIP Mentor

3850 IOS XE QoS Queue Buffers

Hi John,

Here is my source of reference for this response

End to End QoS Design- Quality of Service for Rich-Media & Cloud Networks

Here is the extract from above reference, which I hope useful to you.

- Hardware allocation of buffers is provided only to the priority queues on both wired & wireless queues of this platform.

- The other queues are allocated bufferes on as-needed basis, making it more flexible within the system to support several queues at once.

- Each queue (class) can leverage additional buffering capacity from the shared buffer pool based on a "queue-buffer ratio x" command.

- This command sets the ratio of buffers received by the class and these are allocated on an as-needed basis

- In general the max rate for the class is upto four times the configured value, the queue-buffer ratio command skew this value based on the overall ratio provided to the queue.

- By default these use 1:1:1... for a wired port & 10:20:50:20 for a wireless port on this platform.

- The recommended buffer allocation for wired interface queue 7 to 1 are 10:10:10:10:10:10:25 in percentage (%). Wireless port should use the default values.

- 3850 does not provide reserve thresholds and maximum(overload) thresholds are based on the queue buffer's ratio for non priority queues.

This post may also help you on this

http://mrncciew.com/2013/12/23/3850-qos-part-2-queuing-models/

HTH

Rasika

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