Alcatel-Lucent USA Inc.

Alcatel Lucent

Sanjay Jain

Gregory S Mathews

Avinash Gyanendra Mani

Deepak Aatresh

Jorge Alejandro Aguilar

Daniel M Hegglin

A network flow controller to manage network traffic bandwidth is described. Embodiments of the network flow controller include a hierarchical flow creditor, a proportional flow creditor, and a rate limiter. The hierarchical flow creditor is configured to manage a plurality of hierarchical credit accounts. The hierarchical credit accounts include a shared credit account associated with a plurality of distinct network traffic flows for a shared bandwidth resource. The proportional flow creditor is configured to track an oversubscription of the shared bandwidth resource by the plurality of distinct network traffic flows. The rate limiter is coupled to the hierarchical flow creditor and the proportional flow creditor. The rate limiter is configured to limit at least one of the distinct network traffic flows based on the oversubscription tracked by the proportional flow creditor.

Hierarchical rate limiting with proportional limiting

A prime number based pointer allocation technique. A packet-forwarding system incorporating the technique stores cells of a packet in packet memory, according to allocated pointers that have a fixed correspondence to locations in the packet memory. Each packet input interface of an ingress module has a memory parameter counter that is incremented by a different prime number each time a memory pointer is allocated to that input interface. The memory parameter counter includes a memory interface portion and a memory bank portion that correspond to the memory interfaces and memory banks of a packet memory with which the memory pointers are associated.

Pointer allocation by prime numbers

A hardware-based rate control engine is designed to allow credits to be accumulated over multiple time-slices up to a maximum credit limit. The rate control engine is also allowed to dispatch packets up to a maximum drain rate during each time-slice as long as sufficient credits are available. Allowing credits to accumulate over multiple time slices allows unused bandwidth to be saved during times of little or no traffic and used when the subsequent traffic bursts arrive. Additionally, limiting the maximum drain rate puts a cap on how fast the saved bandwidth can be consumed by subsequent traffic bursts. The rate control settings can be adapted in response to a characteristic, or characteristics, of the traffic flow. For example, one group of settings of a traffic flow can be used for bursty traffic, while a different group of settings can be used for smooth traffic.

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Saratoga, CA, United States of America

Sanjay Jain