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;

   }

   }