Understanding "mls qos queue-set output"

[shikamarunara]

Hello,

     I've been  working on breaking down and understanding the default auto qos  configuration on a Cisco 3750 in the hopes of putting together a QoS  strategy that will fit our environment.  I'm having some difficulty  understanding how the "mls qos queue-set output" syntax works.

     From another post, at https://supportforums.cisco.com/thread/2004369 , the author offers the following example and explanation;

mls qos queue-set output <1/2> threshold 2 400 400 100 400

thresshold 1: 400%

thresshold 2: 400%

thresshold 3: 100% (implicit, not configurable)

reserved: 100%

max: 400%

     However, I'm having trouble understanding what is meant.  Here, it looks like it's saying, for example;

mls qos queue-set output 1 threshold 2 400 400 100 400

How  come there is syntax stating "threshold 2" when in the succeeding part  the 400 refers to thresshold 1 and threshold 2 again?  The syntax 400 400 is, apparently, already referring to thresshold 1 and 2, no?

[nkarpysh]

Hello,

The number after threshold identify the hardware queue. So the later numbers are specifications for this particular queue (threshold1, threshold2, reserved, maximum). So you basically configuring QoS template number X for queue Y with specific values with command:

mls qos queue-set output X threshold Y 400 400 100 400

X is either 1 or 2, Y 1-4 (though may vary based on HW specifics)

You can go through this document for more info:

https://supportforums.cisco.com/docs/DOC-8093#_Toc191205654

Nik