| 摘要 |
Methods and systems for providing necessary and sufficient quality-of-service (QoS), in a packet-based core transport network that utilizes dynamic setting of bandwidth management pipes or thresholds to obviate link congestion are disclosed. Congestion avoidance is a necessary and sufficient requirement in order to guarantee Quality of Service (QoS) in packet-based core networks. A typical network is composed of a plurality of backbone links connecting edge nodes where backhaul links are aggregated. The backhaul links connect the backbone links to the remote sites serving the subscribers. In order to enforce bandwidth management policies, Access Controllers, which perform traffic shaping, are situated on each remote site. In the event of a violation of certain link threshold settings, dynamic adjustment of the bandwidth management policies on affected Access Controllers is enforced. Various algorithms in determining the correlation between the link nearing congestion and the source or destination of traffic streams are also discussed. This invention implements a feedback control loop wherein probes at various points in the network checks for congestion states to guide bandwidth management threshold decisions in order to maintain the condition of non-congestion throughout the network. Capacity planning and congestion avoidance mechanisms work hand-in-hand to fulfill Service Level Agreements (SLA).
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