International Business Machines Corporation

Hoyt Edwin Bowen, Jr

Clark Debs Jeffries

Patrick Droz

Roman Alexander Pletka

Mircea R Gusat

Andreas Kind

Bernard Metzler

Lukas Kencl

Soenke V Mannal

Lakas Kencl

The present invention provides for congestion and flow control for a data transmission between computers in a network (e.g., a lossless network) by repeatedly setting a transmission rate for the data transmission at predetermined time intervals. Under the present invention, a ratio of a current occupancy to a maximum occupancy of a queue used for the data transmission is provided (e.g., the ratio can be calculated under the present invention, or obtained as input from an external source). The queue can be that of the receiving computer or of any component (e.g., a switch) that resides in the path of the data transmission. In any event, once the ratio is known, the present invention will set the transmission rate for the data transmission based on a comparison of the ratio to at least one threshold.

Method, system and program product for setting a transmission rate in a network

Load balancing apparatus for a data communications network comprises hash logic for computing a hash function on incoming data packets. A threshold detector is connected to the hash logic for triggering, in response to utilization of the downstream objects exceeding a predefined threshold, redefinition in the hash logic of parameters of the hash function from a first set of parameters to a second set of parameters for redistributing the data packets amongst the downstream objects. In use, the hash logic, directs the packets for routing to downstream objects in the network via a first routing path based on a hash computation using the first set of parameters, and, if the threshold is exceeded, selectively directs the packets to one of the first routing path and a second routing path in dependence on separate hash computations using the first and the second sets of parameters for subsequent routing of the packets via the selected one of the first and second routing paths based on the results of one of the separate hash computations.

Load balancing in data networks

Methods and apparatus are provided for controlling flow rates of a plurality of data packet flows into a queuecorresponding to a resourceof a network device. The flows comprise a setof non-responsive flows, and a setof other flows which may comprise responsive flows and/or flows whose responsiveness is unknown. The flow rates are managed in accordance with a queue management scheme such that adjustments are made to each flow rate in dependence on excess bandwidth in the resource, the amounts of the adjustments being dependent on one or more adjustment parameters for each flow. An error signal is generated based on the deviation from a desired allocation ratio of the ratio of the total flow rates into the queuefor the sets of flows. At least one adjustment parameter for at least one flow is then varied in dependence on the error signal in such a manner as to reduce the aforementioned deviation. A closed-loop control scheme thus operates in conjunction with the underlying queue management scheme to promote fair bandwidth allocation even in the presence of a mix of responsive and non-responsive flows.

Flow control in network devices

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Cary, NC, United States of America

Hoyt Edwin Bowen, Jr