International Business Machines Corporation

Daniel Crisan

Casimer M DeCusatis

Cyriel Johan Minkenberg

Mircea R Gusat

Robert Birke

Keshav G Kamble

Nikolaos Chrysos

Mitch Gusat

Fredy Daniel Neeser

Cyriel J A Minkenberg

Claude Basso

Kenneth Michael Valk

Rolf Clauberg

Andreea-Simona Anghel

Congestion management for data traffic in a virtual domain identifies a congestion source and sends a message to the source to adjust data traffic rates. The source may be a virtual machine hosted by a physical server with one or more virtual servers incorporated. A congestion manager may identify the source and send the message to the source without affecting other data sources hosted by the physical server or the virtual servers. In some embodiments, information about the congestion source may be encapsulated in a packet payload readable only by the congestion source so only the congestion source receives the instruction to adjust the transmission rate.

Virtual quantized congestion notification

Embodiments relate to controlling workload flow on converged Ethernet links. An aspect includes coupling, by a processing device, a first control loop to a second control loop. The second control loop monitors the operation of the first control loop. An equilibrium set point is initialized for the second control loop prior to commencing operation of the first control loop. Accordingly, the equilibrium set point value is adjusted in the second control loop continuously based on a rate of operation of the first control loop.

Adaptive setting of the quantized congestion notification equilibrium setpoint in converged enhanced ethernet networks

Adaptive setting of the quantized congestion notification equilibrium setpoint in converged enhanced Ethernet networks

A virtual network is implemented on a physical network. A virtual network data packet is tunneled through the physical network via encapsulation within a physical network data packet and via transmission of the physical network data packet through the physical network. A network congestion notification capability of the virtual network is preserved and modified during transmission of virtual network data through the physical network and vice-versa. Congestion notification metadata can be copied from a header of a virtual network data packet to a header of a physical network data packet when the virtual network data packet is encapsulated into the physical network data packet. Congestion notification metadata can be copied from a header of a physical network data packet to a header of a virtual network data packet when the virtual network data packet is decapsulated from the physical network data packet.

Network congestion notification preservation and modification during transmission of network data between physical network and virtual network

In one embodiment, a system includes a hardware processor and logic integrated with and/or executable by the processor, the logic being adapted to receive a traffic flow having a plurality of packets, classify the traffic flow into a traffic class based on a characteristic of the traffic flow, the traffic class being selected from a plurality of traffic classes, store an identifier of the selected traffic class to one or more of the packets, and transmit the traffic flow according to its destination based on a priority of its selected traffic class. In more embodiments, additional systems, methods, and computer program products for prioritizing traffic flow handling are described.

Virtual enhanced transmission selection (VETS) for lossless ethernet

A method to investigate congestion in a computer network may include network devices to route data packets throughout the network. The method includes, for example, sending a probe packet to network devices from a source node to gather information about the traffic queues at each network device that is examined by the probe packet. A routing table at each network device that receives the probe packet is based on the gathered information for respective each traffic queue.

Network data congestion management probe system

Flow control of data packets in a network may be enabled to at least one side of a virtual switching interface to provide a lossless environment. In some embodiments, wherever two buffer queues are in communication with at least one buffer queue being connected to a virtual switching interface, flow control may be used to determine if a threshold has been exceeded in one of the buffer queues. When exceeded, the transmission of data packets may cease to one of the buffer queues to prevent packet dropping and loss of data.

Virtual switching based flow control

According to one embodiment, a method for handling congestion in a network includes determining that there is congestion on a first device in a network, setting a congestion indicator in a header of a packet to indicate an amount of congestion at the first device, sending the packet to all devices that send traffic to the first device, receiving the packet having the multi-bit indicator in a header thereof at a device that sends traffic to the first device, and reducing a congestion window by a factor of between about 5% and about 50% based on a severity of the congestion indicated by the multi-bit indicator, wherein the congestion window is reduced by a greater factor when the congestion is indicated as being more severe. Other systems and methods for handling congestion in a network are described according to more embodiments.

Multi-bit indicator set according to feedback based on an equilibrium length of a queue

A method of monitoring transmission of data in a network is provided. The method includes: receiving data packets for one or more data flows by at least one of a plurality of network switches; sampling queue data in each of the plurality of network switches, the sampled queue data taken from at least one queue attached to a switch port to which the one or more data packets have been forwarded; and transmitting the sampled queue data to a logically centralized network controller connected to the plurality of switches, the network controller configured to control the plurality of network switches, the network controller configured to determine whether a congestion, unfairness or Service Level Agreement (SLA) infringement condition exists in one or more switches based on the sampled queue data and send a control message to one or more data flow sources based on the congestion, unfairness or SLA infringement condition.

Software defined network-based load balancing for physical and virtual networks

Embodiments relate to bypassing congestion points in a network. An aspect includes sampling queues of a plurality of switches in a network. When packet congestion is detected at a congestion point of a first switch, the packet flow contributing to the packet congestion is identified. A congestion notification message indicating the identified packet flow is then propagated to upstream switches, which are upstream from the first switch in the network. The congestion notification message is then snooped by the upstream switches. Virtual queues within the upstream switches are associated with the identified packet flow to hold packets associated with the identified packet flow. The packets associated with the identified packet flow are then re-routed to bypass the packet congestion in the first switch.

Bypassing congestion points in a converged enhanced ethernet fabric

Embodiments relate to proactively probing the packet queues of elements in a physical or virtual network to predict and prevent the occurrence of congestion points. An aspect includes receiving a first feedback request at a central controller connected to a plurality of switches in a network. The first feedback request includes a request to periodically probe a status of queues of switches in the network. A second feedback request is then transmitted to one or all the switches in a path leading to a designated destination. Responses to the second feedback request are received at the central controller from a designated proxy switch, which aggregated the responses into a single data packet. Accordingly, the responses extracted from the single data packet at the central controller are used to preventing future congestion points.

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Zug, Switzerland

Daniel Crisan