Northern Telecom Limited

Nortel Networks Corporation

Other

Northern Electric Company Limited

Uortel Networks Limited

Ernst A Munter

Maged E Beshai

Delfin Y Montuno

James Aweya

Gary Michael Depelteau

Carmine A Ciancibello

Claude J Champagne

Alan Frank Graves

Herman Kwong

Wayne D Grover

Martin Ridgway Handforth

Paul Anthony Kirkby

Rolf Georg Meier

Richard Vickers

Chi Wu

Robert Geoffrey Wood

James Wilson Parker

Piers James Dawe

Hasler Hayes

Youssef A Geadah

Barry B Hagglund

Paul Andrew Senyshyn

Eric Bierman

Frank Mellor

Real Gagnier

John B Bourne

Rolf Einar Olsen

Ceasar Cesaratto

Conrad W Lewis

Brian T Paley

John J Den Otter

Andreas L Aczel

Mahmood Sultan

Robert W Pfeffer

Van C Au

Andrew L Aczel

Bao Chau L Nguyen

Ian Perryman

Chris W L Hobbs

Eric J Dormer

A rotator switch including more tandem buffers than inputs is disclosed. An input data conditioner formats data to be transferred from the multiple inputs to the tandem buffers. Excess tandem buffers allow data to be transferred from inputs to tandem buffers at a rate less than the rate at which data arrives at the inputs. Excess capacity of the switch fabric may be used to carry overhead, or slow the rate at which data is transferred to the switch fabric.

High throughput rotator switch having excess tandem buffers

A rotator switch includes active and redundant tandem buffers used to switch information units through the switch. The tandem buffers are interconnected to inputs and outputs by way of commutators. Information provided to one or more of the active buffers is provided to a redundant buffer. If an active tandem buffer fails, the switch may use the redundant buffer in place of the failed active buffer. A further rotator switch is formed using a plurality of switching blocks. Each switching block includes its own set of tandem buffers, and ingress and egress commutators to interconnect the tandem buffers to inputs and outputs. The plurality of switching blocks is interconnected using additional commutators. At least one of these switching blocks is redundant and is provided with information provided to an active switching block. In the event of failure of an active block, the switch may use a redundant switching block in place of the failed or replaced active block.

Rotator communication switch having redundant elements

Methods and apparatus for transferring data segments of a data stream across multi-channel links in a high-capacity network, so that the segments are equitably smeared across the channels of each multi-channel link, are described. The high-capacity network comprises a multiplicity of distributed high-capacity edge nodes interconnected by multi-channel links to a plurality of core nodes. Each edge node comprises a source node and a sink node which may share memory and control. A path from a source node of a first edge node to a sink node of a second edge node traverses two links, a first link from the source node to a selected core node and a second link from the selected core node to the destination sink node. Tandem switching through an intermediate edge node is not required, even for data streams of very low bit rate. Two types of core nodes are described. A core node of a first type is constructed as a high-capacity single-plane switch. A core node of a second type is constructed as a very-high capacity multiple-plane switch. Accordingly, traffic-load balancing across each multi-channel link in the network is realized by a data smearing process that is tailored to the core node type. A first-order data smearing method that balances the traffic loads among the channels of a first multi-channel link in a two-link path is used in conjunction with said first-type core nodes. A second-order data smearing method that balances the traffic load of each data stream across the channels of both links in a two-link path is used in conjunction with said second-type core nodes. Both first-order and second-order smearing methods are exercised at each source node, and the core nodes, regardless of their type, perform rudimentary tasks and are deliberately kept devoid of quality-control capability.

Multi-channel sharing in a high-capacity network

A method is described for segmenting a data stream comprising variable-size packets, a data stream being defined by its source node, sink node, assigned network route, and other attributes. The segments are of equal size and the method concatenates the packets in successive segments in a manner that attempts to minimize segmentation waste without undue delay. The method facilitates the construction of efficient networks that scale to very high capacities while respecting service-quality specifications. Apparatus for implementing the method are also described.

Compact segmentation of variable-size packet streams

A packet switch includes ingress modules, egress modules, and a switch core. Packets of variable sizes may be divided into segments of predetermined sizes to facilitate switching within the switch core. The segmentation process may require null-padding which increases the flow rate within the switch. The segments are transferred from ingress to egress under flow-rate control based on inflating specified flow rates. Null padding is removed at egress. Ingress modules sort segments or packets according to their destination egress modules and egress modules sort segments or packets according to their ingress-module origin. Thus, segments of the same packet, and packets of the same stream, are properly concatenated as they appear in a logical buffer at egress. To enable growth of the packet switch to accommodate a very large number of ingress and egress modules, the switch implements a method of fast matching to schedule packet transfer across the switch core.

Rate-controlled multi-class high-capacity packet switch

A high-capacity switch for transferring variable-sized packets under rate control is described. The packets are divided in the switch into segments of predetermined equal size. The packets are reconstructed before egress from the switch. The switch serves traffic of different classes of service, but the class of service distinction is relevant only at the ingress or egress modules. The switch control is preferably centralized to facilitate effective sharing of the inner capacity of the switch. The control is based on modulating the ingress/egress rate according to traffic load, the central control being unaware of the class of service disposition of the traffic it controls. The advantage is a high capacity switch adapted to transfer variable-sized packets with guaranteed rate control.

An improved electrical interconnection between a first circuit board and a second circuit board is provided. In one embodiment, the first circuit board has a substantially rigid circuit portion having a plurality of circuit layers, including a first signal layer, and a first interconnection portion, including the first signal layer, for mating with a second interconnection portion of the second circuit board. The first circuit board also includes a flexible portion, including the first signal layer, for connecting the substantially rigid circuit portion to the first interconnection portion. The flexible portion allows the first interconnection portion to be oriented substantially perpendicular to the substantially rigid circuit portion such that a mating of the first interconnection portion with the second interconnection portion results in a substantially orthogonal electrical interconnection arrangement between the first circuit board and the second circuit board.

High performance orthogonal interconnect architecture without midplane

A switch interface connected between a fiber optic cable and a switching fabric includes a line interface block, a fabric interface block, and ingress and egress data transfer blocks coupled independently between the line interface and fabric interface blocks. The ingress data transfer block has a cross-connection block connected to the line interface block, four memories, two processors, and the fabric interface block. With use of the cross-connection block, at any one time, one memory is coupled to the line interface block, one memory is coupled to one processor, one memory is coupled to the other processor, and the last memory is coupled to the fabric interface. Controlled by a memory control, the memories rotate which block each is coupled to, so that each memory is coupled to every block within a single cycle. Therefore, data information units traversing the ingress data transfer block do not require to be transferred between memories during the processing stages. The egress data transfer block operates in a similar fashion.

Service independent switch interface

A forwarding table data structure and a memory optimization process that involves variable multi-stage lookups. The data structure for an address translation system includes, a plurality of blocks, each of the plurality of blocks includes a contiguous set of data records; each data record includes a pointer and an action indicator; if the action indicator is equal to a prescribed value the pointer represents an address of a translation target in the data structure; and if the action indicator is not equal to the prescribed value the pointer represents an address of a selected one of the plurality of blocks in the data structure. The data structure is built based on the input data set (e.g. IP routing table) to be memory optimized. The number of stages can be flexibly determined based on memory restrictions, input data set etc. Since the data structure is essentially &ldquo;customized&rdquo; optimal routing speeds can be obtained.

Address translation method and system having a forwarding table data structure

A forwarding table data structure and a memory optimization process that involves variable multi-stage lookups. The data structure for an address translation system includes, a plurality of blocks, each of the plurality of blocks includes a contiguous set of data records; each data record includes a pointer and an action indicator; if the action indicator is equal to a prescribed value the pointer represents an address of a translation target in the data structure; and if the action indicator is not equal to the prescribed value the pointer represents an address of a selected one of the plurality of blocks in the data structure. The data structure is built based on the input data set (e.g. IP routing table) to be memory optimized. The number of stages can be flexibly determined based on memory restrictions, input data set etc. Since the data structure is essentially 'customized' optimal routing speeds can be obtained.

Address translation method and system having a forwarding table data

A telecommunications switch has a matrix architecture of n.times.m bus-interconnected, or space-switch interconnected, switch nodes together with additional switch nodes and n.times.m switch peripherals connected to the switch nodes externally of the bus (space-switch) interconnected switch node matrix. Fault protection redundancy is provided by providing each one of the peripherals with connections to two different switch nodes only one of which is enabled at any one time.

Telecommunications switches

A system for displaying graphic information such as a facial representation on a communications terminal. The facial representation is digitized, compressed and stored in memory at the appropriate control center of a communications network. Upon receipt of a display command the digitized data is retrieved from memory and transmitted to the called party's display terminal using modem technology.

Visual calling person display

An ATM switch architecture expandable to multi-terabits/s uses data transfer in a heterogeneous burst of a constant length. It employs rotators connecting stages in a three-stage switch configuration. In one embodiment, the cells are sorted at ingress and a matching process is performed between the first and middle stages. The switch is simple to control and has high performance at both the call and cell levels. It also meets the basic requirements that cells be delivered in the proper order, and that the rate of any individual connection be as high as the inlet-port rate. With a small internal expansion, the switch is non-blocking in the sense that any bit-rate acceptable to both the inlet and outlet ports will be guaranteed a path through the core. This feature is particularly useful in services which may require frequent bit-rate change during the connection time.

High capacity ATM switch

An ATM switch has an ATM switch core comprising an N.times.N optical cross-connect core and a set of N port cards, each including a selector. Associated with each port card is a satellite. Wavelength shift keyed signals that are wavelength division multiplexed are employed for routing ATM cells between the satellites via the core by way of optical fibres.

Switched optical interconnect

A programmable wavelength discriminator for isolating individual wavelength carriers from an optical signal including a plurality of wavelength carriers. The discriminator preferably has a pair of waveguides, with each waveguide having imprinted therein a reflecting grating whose period is chosen to reflect the wavelength to be isolated. A receiver such as a photodetector interrogates the selected wavelength. A programmable optical switch determines through which waveguide the composite optical signal will travel. A method of isolating discrete wavelengths from an optical signal comprising a plurality of wavelengths is also discussed.

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Kanata, Canada

Ernst A Munter