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Forum Replies

  1. Hello Rene,

    Thank you very much for the lesson.

    but I’m still a little bit confused, Please, correct me if I’m wrong:
    based on the command below if it’s set AF probability will be considered:
    random-detect dscp-based

    now if we have AF21 and AF33 the class different but the probability of dropping packet from AF33 more than AF21, correct?
    what about if the packets AF21 and AF31? what about if we have AF21 and EF and CS3 and CS4?

    also what is the meaning for fair-queue command? what is the impact when you are using it in the policy map?

    Thank you,
    Samer Abbas

  2. Hello Samer

    Class 4 has the highest priority, so if you have AF33, it will have a lower drop probability than AF21 for example. But within the same class, the higher the number the higher the drop probability, so AF13 will more likely be dropped compared to AF11. So yes, you are correct.

    ... Continue reading in our forum

  3. Hello Ranganna

    When WRED calculates the average queue size, it does so by calculating the actual size of the real queue. Specifically, the average is calculated periodically every few milliseconds. It uses the following formula:


    • o is the old average calculated the previous time
    • n is the weight factor you configure
    • c is the current queue size

    The maximum size of the physical queue will depend on what kind of interface we’re talking about and what plat

    ... Continue reading in our forum

  4. Hello,

    Perhaps a note would be useful informing that the instantaneous queue depth is used for the tail drop (Exponential Weighting Constant chapter).

    Also in the formula for the average queue depth:
    the (instantaneous_old_average) should be change into (instantaneous - old_average)

    Many thanks,

  5. Thanks Stefanita. I fixed this and added something about the instantaneous queue depth.


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