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CoS - Understanding Classifiers and Forwarding Classes

  • 1.  CoS - Understanding Classifiers and Forwarding Classes

    Posted 02-11-2022 12:38
    Hi,

    I'm trying to understand CoS in Junos better, as I don't have a lot of real-world experience with it.

    I was thinking about a theoretical 4-class model:
    • Real-Time (EF and AF41)
    • Network-Control (CS3, CS6)
    • Critical (AF31, AF21)
    • Best-Effort (BE, CS1)

    Would the following config be an appropriate way to implement this?


    Creating queues, leaving room to add more queues later, if needed:
    class-of-service {
     forwarding-classes {
       queue 0 Real-Time;
       queue 3 Network-Control;
       queue 5 Critical;
       queue 6 Best-Effort;
     }
    }


    Using a BA-Classifier to match based on markings.
    I'm not certain about the loss-priority. Does this look right?

    class-of-service {
     classifiers {
       dscp BA-Classifier {
         forwarding-class Real-Time {
           loss-priority low code-points EF;
           loss-priority low code-points AF41;
         }
         forwarding-class Network-Control {
           loss-priority low code-points CS3;
           loss-priority medium-low low code-points CS6;
         }
         forwarding-class Critical {
           loss-priority low code-points AF31;
           loss-priority medium-low code-points AF21;
         }
         forwarding-class Best-Effort {
           loss-priority high code-points BE;
           loss-priority medium-high code-points CS1;
         }
       }
     }
    }


    Thanks for your advice