You can configure one QoS profile per subscriber interface. We recommend that you specify the QoS profile in the first set of services applied to the subscriber's interface.
You can modify the QoS profile by modifying configurations referenced by the QoS profile, including QoS parameter instances. You can also attach a new QoS profile when activating a service, but make sure that the QoS profile is attached to the subscriber's interface.
For more information about configuring QoS profiles, see the Configuring and Attaching QoS Profiles to an Interface chapter in JUNOSe Quality of Service Configuration Guide.