International Business Machines Corporation

Jpmorgan Chase Bank, N.a.

Cisco Technology, Inc.

Cisco Systems Inc.

Brad Alan Makrucki

Ken Van Vu

Edward Stanley Suffern

Anoop Ghanwani

Jeffrey Robert Warren

John Walter Linville

Raymond F Bird

Ralph Benjamin Case

James John Martin

Embodiments of the present invention are directed to a computer implemented web based application and infrastructure performance analysis and forecasting system and method for improving the performance of at least one application and infrastructure and reducing complexity of analyzing the performance of the application and infrastructure. The system and method receive infrastructure input from a user regarding application and infrastructure configuration, as well as performance objective(s). Based on the infrastructure input received from the user, a modeling engine determines at least one application and infrastructure performance model. The system and method then receive model specific input from the user for each model. Based on the information received from the user, a model computation engine computes output for the models which is then displayed to the user.

Application and infrastructure performance analysis and forecasting system and method

Data bandwidth on a congested link of a Carrier Sense Multiple Access with Collision Detection (CSMA/CD) network, is controlled by a Pause MAC Frame which carries information identifying devices causing the problem on the link. The Recipient of the Pause MAC Frame can use the information to deactivate selected devices on the congested link. As a consequence, the data bandwidth is reduced without shutting down the link.

Flow control mechanism

A technique for adapting receiver thresholds to improve rate-based flow control in a data communications network. With this invention, the flow control process becomes self-calibrating such that threshold values are dynamically adjusted to adapt to current network conditions, without requiring user intervention. Several different indicators of network conditions are monitored, and appropriate adjustments are made to the threshold(s) upon detecting these specific indicators. One monitor enables the threshold to increase when the network is uncongested, enabling the sender to increase its transmission rate. Conversely, the threshold is lowered if the network is congested, so that the transmission rate will be decreased. Another monitor balances bandwidth allocation among connections sharing a bottleneck resource, by lowering the threshold (and therefore decreasing the send rate) when a connection uses a high share of the resource. A third monitor detects the presence of traffic from protocols not using adaptive receiver thresholds, and adjusts the threshold (including an upper and lower threshold bound) in order to compete fairly for resources with these other protocols. The monitors may be implemented individually or in combination.

Adapting receiver thresholds to improve rate-based flow control

A data transfer flow control system for a packet ATM communications system includes a plurality of nodes interconnected by transmission links. Available bandwidth allocation for data packets or cells is improved by defining a Nrm parameter to be the product of an allowable cell rate and a sampling period. Nrm is related to the number of data cells being transmitted between resource management cells in a transmission session, and is set to a number that is independent of round trip times between source and destination nodes, but varying with the allowable cell rate of the source. The allocation fairness problem is solved by normalizing the Nrm value to ensure that the inter-RM cell times for all sessions are fixed at a predetermined time interval. The selection of the predetermined time interval value is a trade-off between network overhead and the responsiveness of the traffic source to network congestion. The predetermined time interval is a function of link speed, buffer size and &ldquo;burstiness&rdquo; level of real time traffic sources.

Method and apparatus for allocation of available bandwidth

A data transfer flow control system for a packet communications system includes a plurality of nodes interconnected by transmission links. The rate at which a sender node transmits information to a destination node in a network is modified in accordance with congestion information returned to the sender node from nodes along the path of the transmission or from the information receiver. The rate change for information being sent from the sender node is modified based upon the amount of elapsed time occurring since the last rate change of the same type. In first and second examples, the rate change is implemented in accordance with exponential and linear relationships, respectively, between the modified flow rate and the elapsed time since the last rate change.

Method and apparatus for network flow control

Methods, apparatus and computer products are provided for allocating network resources for data transport between a source network node and a destination network node by selecting a transport mechanism from a plurality of transport mechanisms based upon a prediction of the cost of the utilization of the transport mechanism so as to provide the transport mechanism having the lowest predicted cost.

Traffic flow cutover to virtual connection transport

Flow control is implemented at a given node in a network of LAN switches by having the node monitor the occupancy levels of buffers or queues. When a buffer is found to be occupied or filled beyond a predetermined threshold level, a pause command is generated for the source currently supplying traffic to the buffer. A pause time PT is calculated using an equation which takes into account: the transmission rate of the identified source, the transmission rate of the output link servicing the congested buffer and queue length that can be occupied without a congestion condition being declared. To reduce the chance that queue lengths will &ldquo;oscillate&rdquo; about their threshold point due to multiple sources resuming transmission at the same time, each calculated pause time is adjusted to a randomly selected value PT(ran) falling within a range of PT&plusmn;kPT where k may be on the order of fifty percent.

Growing community of inventors

Durham, NC, United States of America

Brad Alan Makrucki