CHAPTER 10. QoS212 © SAMSUNG Electronics Co., Ltd.Ingress and egress QoS for IP tunnelsThe QoS configuration for IP tunnels is the same as for regular PPP bundlesexcept CBQ queuing and shaping feature. QoS for IP tunnels providespolicing, and monitoring on both directions.Hardware QoSThis section describes the QoS features implemented in hardware. In thisrelease, QoS hardware features are provided by the Marvel chip set.Hardware-based traffic classification uses the following two look-up tables:y Policy PCL profile tabley Policy Profile(default)The policy PCL profile is an ordered list of rules in policy profile. Each rule iscompared from start of the profile rule list to end of the profile rule list untilone of the rule matches. So it is a sequential search. After matching rule isfound, the matching process terminates and corresponding action is attempted.If IP flow classification look-up fails then policy profile default table is used.For handling congestion on egress queues, the hardware supports three levelsof drop precedence(DP). When congestion occurs on an egress queue, packetswith higher DP can be configured to be dropped, while packets with low DPare enqueued.CoS Attributes MarkingCoS attributed are a set of attributes associated with any packet processed bythe Marvel sub-system. These attributes are the Traffic Class(TC), DropPrecedence(DP), User Priority(UP) and DSCP. They are primarily used to atdifferent stages of the packet processing to decide the appropriate QoStreatment to be given to a packet. CoS attributes can be assigned to a packetby any of the multiple stages of the ingress pipeline.
