CHAPTER 10. QoS170 © SAMSUNG Electronics Co., Ltd.FeaturesThe network administrator manages bundle bandwidth across variouscustomers by defining traffic classes. Each traffic class is assigned the desiredcommitted bandwidth as well as the burst bandwidth. The sum of the CRs ofall classes must be less than or equal to the total bundle bandwidth.CBQ can only be used in the WAN outbound direction.A traffic class is characterized by the following parameters:y Class namey Parent classy Committed rate(CR)y Peak rate(PR)y Classification type based on:− Application ports(TCP or UDP)− Network levely Source or destination IP addresses, address ranges, or subnets− Ethernet MACy VLAN identifiersTraffic classes are arranged in a hierarchical manner. A class has a parentclass and can have one or more child classes. The root class has no parent andis identified as root-out or root-in. The only limit to the number of classes thatcan be created is 1500 per interface.Definitionsy Committed RateEach traffic class can be assigned a CR parameter in Kbps. This is theamount of bandwidth that the class or flow is guaranteed at all times, evenduring congestion. The sum of the CRs for all classes in a given directioncannot exceed the access bandwidth of their parent class. By maintaining amoving average of the bandwidth for each class, the class is not ‘strictly’policed at CR Kbps, and momentary peaks in the flow are permitted.The goal is that each class with sufficient demand will be able to receiveroughly its allocated bandwidth over some interval of time.
