Egress Queuing and Scheduling Sample Clauses

Egress Queuing and Scheduling. The egress queuing at each node is modeled after a DSQueue C++ class. The DSQueue consists of three classes: a classifier, a packet buffer and a scheduler with a well defined interface between them in order to allow interchangeability of these inner classes. The classifier can be a multi-field classifier typically used on ingress nodes, or a Behavior Aggregate classifier typically used in internal nodes. The packet buffer class is composed of objects necessary for building a certain service (e.g. a policer followed by a FIFO queue). For example, one of the defined packet buffer classes contain an array of DSQueues, each having a classifier, a packet buffer and a scheduler (the edge node described below is an example of such a DSQueue). And finally, the scheduler defines an algorithm to determine which of the queues is to be serviced next. The ingress edge node, as shown in Figure 9 below, is composed of a Multifield classifier, a ‘DSPktBufSLA’ packet buffer and a Weighted Round Xxxxx (WRR) scheduler. The ‘DSPktBufSLA’, in turn, is composed of 5 DSQueues (one per client in the first scenario), each composed of a Behavior Aggregate classifier, a ‘DSPktBufDSM’ packet buffer and a WRR scheduler (as it is observed, the edge node has a 2 hierarchy of schedulers). The ‘DSPktBufDSM’ is composed of 3 sets of Meters, Policers and FIFO queues (one per traffic class) as seen in the figure. Figure 9 Ingress edge node DSQueue model At the edge node, ingress packets are presented to the MF classifier, which separates each client’s traffic for further inspection. For example, a particular client’s traffic will be classified into one of the inner DSQueues (the MF classifier will be configured to identify that client and forward its traffic accordingly). The traffic is then BA classified, in the inner DSQueue for traffic class separation, and presented into one of the meters in the DSPktBufDSM, for example the silver traffic will be presented to the second meter which is configured to meter and color the customer’s traffic based on conformant and non- conformant traffic (leaky bucket with CBS, CIR parameters). After the metering stage, the traffic is presented to a “policing” stage that is color-aware and could remark/upgrade the traffic. The traffic is then forwarded, if not dropped, into a FIFO queue waiting to be serviced. When the first level WRR decides that a packet from this client is to be serviced, the second level WRR decides which of the customer’s service queue ...