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Example: Configuring Classifiers, Rewrite Markers, and Schedulers

  1. Define a classifier that matches IP traffic arriving on the interface. The affected IP traffic has IP precedence bits with patterns matching those defined by aliases A or B. The loss priority of the matching packets is set to low, and the forwarding class is mapped to best effort (queue 0):
    [edit]
    class-of-service {
    classifiers {
    inet-precedence normal-traffic {
    forwarding-class best-effort {
    loss-priority low code-points [my1 my2];
    }
    }
    }
    }

    Following are the code-point alias and forwarding-class mappings referenced in the normal-traffic classifier:

    [edit]
    class-of-service {
    code-point-aliases {
    inet-precedence {
    my1 000;
    my2 001;
    ...
    }
    }
    }
     
    [edit]
    class-of-service {
    forwarding-classes {
    queue 0 best-effort;
    queue 1 expedited-forwarding;
    }
    }
  2. Use rewrite markers to redefine the bit pattern of outgoing packets. Assign the new bit pattern based on specified forwarding classes, regardless of the loss priority of the packets:
    [edit]
    class-of-service {
    rewrite-rules {
    inet-precedence clear-prec {
    forwarding-class best-effort {
    loss-priority low code-point 000;
    loss-priority high code-point 000;
    }
    forwarding-class expedited-forwarding {
    loss-priority low code-point 100;
    loss-priority high code-point 100;
    }
    }
    }
    }
  3. Configure a scheduler map associating forwarding classes with schedulers and drop-profiles:
    [edit]
    class-of-service {
    scheduler-maps {
    one {
    forwarding-class expedited-forwarding scheduler special;
    forwarding-class best-effort scheduler normal;
    }
    }
    }

    Schedulers establish how to handle the traffic within the output queue for transmission onto the wire. Following is the scheduler referenced in scheduler map one:

    [edit]
    class-of-service {
    schedulers {
    special {
    transmit-rate percent 30;
    priority high;
    }
    normal {
    transmit-rate percent 70;
    priority low;
    }
    }
    }
  4. Apply the normal-traffic classifier to all SONET/SDH interfaces and all logical interfaces of SONET/SDH interfaces; apply the clear-prec rewrite marker to all Gigabit Ethernet interfaces and all logical interfaces of Gigabit Ethernet interfaces; and apply the one scheduler map to all interfaces:
    [edit]
    class-of-service {
    interfaces {
    so-0/0/0 {
    scheduler-map one;
    unit 0 {
    classifiers {
    inet-precedence normal-traffic;
    }
    }
    }
    so-0/0/1 {
    scheduler-map one;
    unit 1 {
    classifiers {
    inet-precedence normal-traffic;
    }
    }
    }
    ge-1/0/0 {
    scheduler-map one;
    unit 0 {
    rewrite-rules {
    inet-precedence clear-prec;
    }
    }
    unit 1 {
    rewrite-rules {
    inet-precedence clear-prec;
    }
    }
    }
    ge-1/0/1 {
    scheduler-map one;
    unit 0 {
    rewrite-rules {
    inet-precedence clear-prec;
    }
    }
    unit 1 {
    rewrite-rules {
    inet-precedence clear-prec;
    }
    }
    }
    }
    }

    Following is the complete configuration:

    [edit class-of-service]
    classifiers {
    inet-precedence normal-traffic {
    forwarding-class best-effort {
    loss-priority low code-points [my1 my2];
    }
    }
    }
    code-point-aliases {
    inet-precedence {
    my1 000;
    my2 001;
    cs1 010;
    cs2 011;
    cs3 100;
    cs4 101;
    cs5 110;
    cs6 111;
    }
    }
    drop-profiles {
    high-priority {
    fill-level 20 drop-probability 100;
    }
    low-priority {
    fill-level 90 drop-probability 95;
    }
    big-queue {
    fill-level 100 drop-probability 100;
    }
    }
    forwarding-classes {
    queue 0 best-effort;
    queue 1 expedited-forwarding;
    }
    interfaces {
    so-0/0/0 {
    scheduler-map one;
    unit 0 {
    classifiers {
    inet-precedence normal-traffic;
    }
    }
    }
    so-0/0/1 {
    scheduler-map one;
    unit 1 {
    classifiers {
    inet-precedence normal-traffic;
    }
    }
    }
    ge-1/0/0 {
    scheduler-map one;
    unit 0 {
    rewrite-rules {
    inet-precedence clear-prec;
    }
    }
    unit 1 {
    rewrite-rules {
    inet-precedence clear-prec;
    }
    }
    }
    ge-1/0/1 {
    scheduler-map one;
    unit 0 {
    rewrite-rules {
    inet-precedence clear-prec;
    }
    }
    unit 1 {
    rewrite-rules {
    inet-precedence clear-prec;
    }
    }
    }
    }
    rewrite-rules {
    inet-precedence clear-prec {
    forwarding-class best-effort {
    loss-priority low code-point 000;
    loss-priority high code-point 000;
    }
    forwarding-class expedited-forwarding {
    loss-priority low code-point 100;
    loss-priority high code-point 100;
    }
    }
    }
    scheduler-maps {
    one {
    forwarding-class expedited-forwarding scheduler special;
    forwarding-class best-effort scheduler normal;
    }
    }
    schedulers {
    special {
    transmit-rate percent 30;
    priority high;
    }
    normal {
    transmit-rate percent 70;
    priority low;
    }
    }
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