Tellabs Operations, Inc.

Robert B Magill

Philip J Lin

Terry Jon Hrabik

John Belden Kenney

Kent Daniel Benson

R Michael Schafer

Kenneth P Laberteaux

Ravi Chandran

Tara Javidi

The present invention provides for a method for reserving spare bandwidth for a link in a communication network including a plurality of links. The method provides for monitoring the volume of traffic routed through each link of the communication network. A single link failure for each link is then simulated and the volume of traffic which would be rerouted through each link for maintaining communication and the volume of traffic removed from each link are determined for each simulated single link failure. The difference between the volume of traffic which would need to be rerouted through each link and the corresponding volume of traffic removed from each link is then computed, and a maximum difference value is determined for each link for all simulated single link failures. An amount of spare bandwidth equivalent to the determined maximum difference is then reserved for each link.

Bi-directional ring network having minimum spare bandwidth allocation and corresponding connection admission control

Packets having at least one cell are switched using input queues, output queues, a switch fabric, and a controller. Each input queue stores cells to be switched, and each output queue stores switched cells. The switch fabric couples the input queues to the output queues and has memory. The switch fabric stores cells moved from the input queues to the switch fabric and stores cells based on the output queues. The controller couples to the input queues and the switch fabric and determines input priorities for cells moving from the input queues to the switch fabric and output priorities for cells moving from the switch fabric to the output queues.

Apparatus and method to switch packets using a switch fabric with memory

Bi-directional ring network having minimum spare bandwidth allocation and corresponding connection admission controls

An apparatus for replacing lost PSTN data in a packet network and for generating variable power white noise, includes a lost packet detection unit () for detecting lost data packets, a data processing unit () for producing in response a lost data output indicating when replacement data needed, data playout unit () or data replacement unit (), each may be implemented as a variable power white noise generator (FIG.) to generate replacement data by reusing data stored in an extended playback buffer, and placing the re-used replacement data on an external network.

Method and apparatus for replacing lost PSTN data in a packet network

The present invention provides for a method for reserving spare bandwidth for a link in a communication network including a plurality of links. The method provides for monitoring the volume of traffic routed through each link of the communication network. A single link failure for each link is then simulated and one volume of traffic which would be rerouted through each link for maintaining communication and the volume of traffic removed from each link are determined for each simulated single link failure. The difference between the volume of traffic which would need to be rerouted through each link and the corresponding volume of traffic removed from each link is then computed, and a maximum difference value is determined for each link for all simulated single link failures. An amount of spare bandwidth equivalent to the determined maximum difference is then reserved for each link.

An arbitration unit according to an embodiment of the present invention is disclosed. The arbitration unit includes an allocation unit that assigns a first number of slots in a frame to a first flow and a second number of slots in the frame to a second flow. The arbitration unit includes a scheduling unit that assigns first slot positions to the first number of slots in the frame and second slot positions to the second number of slots in the frame using a binary distribution tree.

Method and apparatus for scheduling packetized data flows in a calendar-based arbitration scheme

In allocating bandwidth to data for transfer through a network device, bandwidth is allocated to committed data traffic based on a guaranteed data transfer rate and a queue size of the network device, and bandwidth is allocated to uncommitted data traffic using a weighted maximum/minimum process. The weighted maximum/minimum process allocates bandwidth to the uncommitted data traffic in proportion to a weight associated with the uncommitted data traffic.

Allocating network bandwidth

Data switching systems for use in ATM and other packet and cell switching networks can more smoothly switch data if incoming data packets to be switched are re-ordered to avoid overwhelming an output port with too many consecutive packets to a particular destination. An apparatus and method for simply re-ordering data samples in a non-consecutive manner is computationally efficient and effective.

Data packet scheduler

A data routing mechanism is disclosed. The data routing mechanism includes virtual output queues (VOQs), corresponding to a first input port, that store data to be sent to one of a first and second output port. The data routing mechanism includes VOQs, corresponding to a second input port, that store data to be sent to one of the first and second output port. The data routing mechanism includes a switch fabric that includes a plurality of buffers at crosspoints between the first and second input ports and the first and second output ports. The data routing mechanism includes a first input scheduler that transmits a first data from the VOQs corresponding to the first input port to one of the plurality of buffers based on lengths of the VOQs corresponding to the first input port and a credit state of the plurality of buffers.

Methods and apparatus for managing traffic through a buffered crossbar switch fabric

Non-consecutive data readout scheduler

A method and apparatus for replacing lost PSTN data in a packet network and for generating variable power white noise are disclosed. In one embodiment, the method for replacing data includes the steps of receiving data packets, detecting lost data packets, and producing in response a lost data output indicating when replacement data needs to be provided. The method preferably generates the replacement data by re-using data stored in an extended playback buffer (with the re-used replacement data starting with the oldest output data byte stored in the extended playback buffer), and placing the re-used replacement data on an external network. Another aspect of the invention is a variable power white noise generator for providing replacement data. The variable power white noise generator may use, for example, a multi-bit register that stores a magnitude, and a pseudo-random sign bit generator to change the positive and negative sense of the magnitude. In one preferred embodiment, a linear feedback shift register (LFSR) is used in conjunction with a feedback network corresponding to a polynomial generating function. The pseudo-random output sequence of the LFSR then produces a pseudo-random output bit to control the positive and negative sense of the magnitude bits.

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South Bend, IN, United States of America

Robert B Magill