Abstract: Methods and apparatuses for estimating periodic worst-case delay for a class of traffic. An aggregate (i.e., a class or label on which traffic is classified and queued) has an associated bandwidth (“negotiated rate”), which typically is a maximum average bandwidth that has been agreed upon by the traffic generator (“customer”) and service provider. Delay for an aggregate is obtained by summing all the delays of class queues of each router in the path. Traffic data for the aggregate is collected. A burst-rate profile is calculated for the traffic data, with the rate parameter set to the value of the negotiated rate. A periodic worst-case delay estimate associated with the burst-rate profile is calculated, using the output link capacity allotted to the aggregate (“allocated bandwidth”) as input.

Abstract: A communications network is described having a class-based queuing architecture. Shared class queues receive packet flows from different customers. In one embodiment, there are eight classes and thus eight shared queues, one for each class. A scheduler schedules the output of packets by the various queues based on priority. Each customer (or other aggregate of packet flows) is allocated a certain space in a class queue based on the customers' Service Level Agreement (SLA) with the service provider. A queue input circuit detects bits in the packet header identifying the customer (or other criteria) and makes selections to drop or pass packets destined for a shared queue based on the customers' (or other aggregates') allocated space in the queue.

Abstract: A communications network is described having a class-based queuing architecture. Shared class queues receive packet flows from different customers. In one embodiment, there are eight classes and thus eight shared queues, one for each class. A scheduler schedules the output of packets by the various queues based on priority. Each customer (or other aggregate of packet flows) is allocated a certain space in a class queue based on the customers' Service Level Agreement (SLA) with the service provider. A queue input circuit detects bits in the packet header identifying the customer (or other criteria) and makes selections to drop or pass packets destined for a shared queue based on the customers' (or other aggregates') allocated space in the queue.