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Forum Replies

  1. Hi Joey,

    Configuration-wise, WRR (Weighted Round Robin) and SRR (Shaped Round Robin) are very similar. You can use the examples in this lesson:


    Something to keep in mind is that a lot of commands will only show up in your configuration if you use non-default values. Here’s an example:

    Switch#show running-config | incl mls
    mls qos

    QoS has been enabled on this switch, that’s the only command we have in our config. Let’s check the default cos-dscp map:

    ... Continue reading in our forum

  2. Hi Sze Jie K,

    Let me jump in on this. You are using a 3560 or 3750?

    Once you enable QoS, all CoS/DSCP values get assigned to 4 different queues. You can’t change or disable these. If you want to mimic something where only voice traffic gets priorited then you could configure something like this:

    Q1: 10% of bandwidth
    Q2: 80% of bandwidth
    Q3/Q4: each 5% of bandwidth

    You can assign the CoS/DSCP values that you use for Voice to Q1 and everything else to Q2. It’s a pain to configure QoS on these switches as it affects all your traffic. It’s not as easy as on a route

    ... Continue reading in our forum

  3. These switches only have one priority queue, the other queues are served in (weighted) round robin so Q2 doesn’t have a higher priority than Q3.

    ... Continue reading in our forum

  4. Hello Sebastian

    When you apply QoS to a switch, you apply it to a particular port independently of whether or not it is applied elsewhere on the switch as well. QoS mechanisms begin to function when the egress traffic of a particular port exceeds the maximum speed of that port. Then, frames/packets begin to be queued based on the mechanisms you configure.

    The selection of interface is the one that you desire to provide some sort of prioritization to traffic being sent from that port.

    I hope this has been helpful!


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