International Business Machines Corporation

Metin Aydemir

Clark Debs Jeffries

Michael Steven Siegel

Marco C Heddes

Brian Mitchell Bass

Norman Clark Strole

Anthony Matteo Gallo

Ken Van Vu

Sonia Kiang Rovner

Jeffrey James Lynch

Brahmanand Kumar Gorti

Jorge Rolando Rodriguez

Gerald Arnold Marin

Anoop Ghanwani

Andrew J Rindos, Iii

Steven Paul Woolet

A data flow control method and system within a data switch. The data switch includes a plurality of input sections each having an associated input buffer and each transmitting data to an output section. In response to a detection of congestion within the output section, data transmissions from the plurality of input sections to the output section are paused. Input buffer occupancies of each of the input sections are then determined. Thereafter, and in response to a backpressure relief signal, the restart of said data transmission from each of the input sections to the output section is delayed in inverse proportion to each of the determined input buffer occupancies.

Delayed-start method for minimizing internal switch congestion

A method and system for controlling a flow of a plurality of packets in a computer network is disclosed. The computer network includes a queue. The method and system include determining a queue level for the queue and determining an offered rate of the plurality of packets to the queue. The method and system also include controlling a transmission fraction of the plurality of packets to the queue, based on the queue level, the offered rate and a previous value of the transmission fraction so that the transmission fraction and the queue level are critically damped if the queue level is between at least a first queue level and a second queue level.

Method and system for controlling transmission of packets in computer networks

A network switch as well as methods, systems and computer program products for controlling congestion at a granularity of less than a link are provided. Such finer granularity may be provided by pausing traffic at a source port level of a network switch. The network switch which transmitted a message which resulted in congestion being detected is notified of the congestion and pauses the communications from the source port of the message while maintaining communications over the link from other source ports. Such source port level congestion control may be provided by a network switch having a sub-queue of its output queues where each sub-queue corresponds to an input port. Source port level pausing of transmissions may then be provided by pausing the sub-queue associated with a source port.

Network switch having source port queuing and methods, systems and computer program products for flow level congestion control suitable for use with a network switch having source port queuing

A system having a high speed switching interface between remote buses is disclosed herein. The system includes a switch fabric to which multiple remote bus interfaces are connected. A programmable flow queue that includes multiple parallel logic flow queues is utilized for scheduling packets in accordance with protocol requirements of the remote bus interface.

Flow architecture for remote high-speed interface application

A method and system within a telecommunications network for allocating available bandwidth among a plurality of sessions that share a common data link. First, a repeating unit time interval is designated for conducting the plurality of sessions. Next, the input flow rate from the source node of each of the sessions into the common data link is monitored. Thereafter, a target flow rate is computed and assigned to each of the sessions. The sum of the target flow rates is equal to the available bandwidth of the common data link. Finally, for each of the sessions in which the monitored input flow rate exceeds the assigned target flow rate, the source node is dynamically paused during each repeating unit time interval, such that the monitored input flow rate conforms to the assigned target flow rate for each of the sessions.

Enhanced flow control in ATM edge switches

A method and apparatus for flow control for sources in packet switched networks is implemented. A data rate for the source is determined based on a critically damped second-order system in response to a congestion signal sent by a destination node or other network device. The data rate is damped toward a share value that is also based on a critically damped second-order system. The resulting flow control reduces packet loss and improves network utilization.

Growing community of inventors

Durham, NC, United States of America

Metin Aydemir