DiffServ Example

In this example, we use DiffServ to signal a class of service throughput and assign any traffic coming from network 10.1.2.x with a specific DSCP. This allows all other network switches to send and observe the DSCP instead of repeating the same QoS configuration on every network switch.

To configure the switch:

  1. Using ACLs, assign a traffic grouping for traffic from network 10.1.2.x to QP3:
    configure access-list qp3sub any

    The following is a sample policy file example:

    #filename: qp3sub.pol
    entry QP3-subnet {
        if {
         } then {
            Qosprofile qp3;
  2. Configure the switch so that other switches can signal calls of service that this switch should observe.
    enable diffserv examination ports all


    The switch only observes the DSCPs if the traffic does not match the configured access list. Otherwise, the ACL QoS setting overrides the QoS DiffServ configuration.