Nortel Networks Corporation

Ciena Corporation

Bernard St Denis

Reshad Rahman

John Frank Pillar

Yuri Tsier

Bernard Marchand

Stuart C White

Sitaram Patro

In Asynchronous Transfer Mode (ATM) communications networks, certain congestion control features, such as Partial Packet Discard (PPD) and Early Packet Discard (EPD), operate on ATM cells that have been segmented from ATM Adaptation Layer #5 (AAL5) frames (packets). AAL5 frames are automatically detected by observing transitions of an indicator in the ATM cell header unique to AAL5 traffic. Automatic detection of AAL5 traffic allows enablement of packet-aware cell discarding techniques such as PPD and EPD on a Virtual Channel Connection (VCC) basis, whether in a switch for a VCC or for a Virtual Path Connection (VPC) to which the VCC belongs.

Method and apparatus for auto detection of AAL5 type frames for VCC and VPC switches

A data traffic policer includes a classifier for separating a packet stream in accordance with class, a first bucket for a first traffic class representing a first transmission rate and a first burst capacity and a plurality of second buckets for a plurality of second traffic classes representing a corresponding second transmission rates and a second burst capacities, the plurality of second buckets being nested within the first bucket thereby being subordinate to the rate and capacity of the first bucket, with the rate of the second bucket being disabled when a fill condition exists in the first bucket. The second bucket for a second traffic class may include a plurality of buckets for a corresponding plurality of traffic classes, with each bucket of the plurality of buckets having a corresponding capacity and rate. The rate defined as a corresponding weight.

Data traffic policer

A multi-way tree data structure is provided that supports a longest match lookup. Data elements stored therein that have no overlapping prefixes are arranged in a standard B-tree arrangement. Data elements that have overlapping prefixes are arranged within the tree such that a respective one of these prefixes contains the prefixes of all such data elements that succeed it.

Method of and apparatus for generating a tree data structure supporting longest match lookup

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Nepean, Canada

Bernard St Denis