Nortel Networks Corporation

Northern Telecom Limited

James Leslie Watchorn

John Edward Vincent

Gary Michael Depelteau

George Frank Irwin

David Anthony Fisher

Tony Huang

Osama Bahgat

Melhem I Chaar

James C McLaughlin

Robert Allan Aston

Michael F Kemp

Paul Fong-Yan Hung

A packet switch has a switching unit (SU) for switching packets between network links and a computing unit (CU) connected to the SU through a network link for implementing software control functions over the SU. The SU is formed of different functional components interconnected by generic buses. The components communicate with one another using program data units (PDUs) that are formatted and transmitted according to a shared device protocol. The communication between the components occurs by placing PDUs in bus frames that are passed from component to component. Information is exchanged between the components by adding information to or dropping information from the fields of the PDUs, or by concatenating new fields to the PDUs, as the frames pass from component to component. By using a generic bus to implement PDU-based interconnections within the SU, all the components are forced to support a common interface. Changes to the implementations of any component's interface can thus be accommodated by changing the PDU format as opposed to changing the interfaces of connected components. The new packet switch architecture decouples the components on the switch so that they can be upgraded or otherwise modified independently of one another.

Message based packet switch based on a common, generic bus medium for transport

A communication system consisting of a number of modules that communicate with one another through a shared communications bus which accommodates different protocols. The system includes a bus clock for defining a frame having a plurality of time slots for communicating signals on the bus; and a bus management algorithm for specifying a receive assignment definition and a transmit assignment definition. The receive assignment definition defines a receive channel for each of the modules representing a set of the time slots, where the modules receive signals from the bus during the set of time slots prescribed by the receive channel. The transmit assignment definition defines a transmit channel for each of the modules representing a set of the time slots, where the modules transmit signals to the bus during the set of time slots prescribed by the transmit channel.

Generic bus system

A virtual port scheduler is provided optionally for inclusion as part of a partitioned packet scheduler comprising a queue manager. The virtual port scheduler maintains a plurality of statuses for remote ports which do not have their own scheduling functionality. On the basis of those statuses, the virtual port scheduler determines which virtual port to service next.

Virtual port scheduler

The present invention relates to a control device, for use on an electronic circuit board, to perform high-speed data transmission bus entrainment. The control device includes a signal processing component acquiring either one of two modes of operation, specifically a diagnostic mode and a bus entrainment diagnostic mode. When in diagnostic mode, the signal processing component performs a diagnostic procedure on the electronic circuit board. When in bus entrainment mode, the signal processing component performs a bus entrainment procedure.

Method and apparatus for high-speed data transmission bus entrainment

Methods and apparatus are described for translating identifiers that are used by computers to reference various entities such as data structures, external objects, or connections in a telecommunications network, from a bulkier less manageable format to a smaller more manageable format. Such translations are carried out to reduce the needless processing and memory demands that are made of a localized set of components when the large identifiers the set receives from other components include fields that none of the members of the set need to access. The invention is centerd around a two-stage look-up method wherein an inputted external identifier is divided into two parts. The first part of the inputted external identifier is used as an address into a first look-up table that contains base-addresses of a second look-up table. The second part of the inputted external identifier is used as an offset-address into the second look-up table. The offset-address and the base-address are combined to access the second look-up table, which contains all the internal identifiers. The invention can be easily scaled to handle a larger range of external identifiers, and a larger number of internal identifiers. The invention operates at a fast and predictable speed. Use of the invention also leads to a significant savings in memory costs.

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Nepean, Canada

James Leslie Watchorn