Cisco Technology, Inc.

Vmware, Inc.

Davide Bergamasco

Silvano Gai

Thomas James Edsall

Dinesh Ganapathy Dutt

Flavio Giovanni Bonomi

Valentina Alaria

Andrea Baldini

Rong Pan

Subrata Banerjee

Ankur Jain

Bruno Raimondo

Luca Cafiero

Rajeev Bhardwaj

Fabio Rodolfo Maino

Keith McCloghrie

Irfan Ahmad

Claudio Desanti

Guglielmo Marco Morandin

Dante Malagrino

Chiara Piglione

Ray Kloth

Rajesh R A

Michele Caramello

Deepak Sharma

Vibin P Thomas

Rajeev Bharadwaj

Claudio De Santi

Robert L Hoffmann

Rajesh Ra

Vibin Thomas

Subrata Benerjee

The present invention provides improved methods and devices for managing network congestion. Preferred implementations of the invention allow congestion to be pushed from congestion points in the core of a network to reaction points, which may be edge devices, host devices or components thereof. Preferably, rate limiters shape individual flows of the reaction points that are causing congestion. Parameters of these rate limiters are preferably tuned based on feedback from congestion points, e.g., in the form of backward congestion notification ('BCN') messages. In some implementations, such BCN messages include congestion change information and at least one instantaneous measure of congestion. The instantaneous measure(s) of congestion may be relative to a threshold of a particular queue and/or relative to a threshold of a buffer that includes a plurality of queues.

Methods and devices for backward congestion notification

Embodiments determine communication delay along a network path between a source and a destination in a network. A target injection rate is calculated based on the determined delay and a predetermined maximum queuing delay threshold. Data packets are transmitted along the network path using an inter-packet delay that is based on the target injection rate.

Network congestion management based on communication delay

In one embodiment, an apparatus comprises a network interface system having at least one input port configured for receiving frames and a logic system comprising at least one logic device. The logic system may be configured to perform the following functions: determining a source address and a destination address of a frame received at an ingress port; calculating a flow hash based at least upon the source address and the destination address; forming a congestion management ('CM') tag that includes the flow hash; inserting the CM tag in the frame; and forwarding the frame to the destination address.

Backward congestion notification

A Fiber Channel Switch which enables end devices in different Fabrics to communicate with one another while retaining their unique Fiber Channel Domain_IDs. The Switch is coupled to a first fabric having a first set of end devices and a second fabric having a second set of end devices. The Switch is configured to enable communication by the first set of end devices associated with the first fabric with the second set of end devices associated with the second set of end devices using the unique Domain_IDs of each of the first set and the second set of end devices. In one embodiment of the invention, the first and second fabrics are first and second Virtual Storage Array Networks (VSANs) respectively. In an alternative embodiment, the first fabric and the second fabric are separate physical fabrics.

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The present invention provides methods and devices for implementing a Low Latency Ethernet ('LLE') solution, also referred to herein as a Data Center Ethernet ('DCE') solution, which simplifies the connectivity of data centers and provides a high bandwidth, low latency network for carrying Ethernet and storage traffic. Some aspects of the invention involve transforming FC frames into a format suitable for transport on an Ethernet. Some preferred implementations of the invention implement multiple virtual lanes (&#x201c;VLs&#x201d;) in a single physical connection of a data center or similar network. Some VLs are &#x201c;drop&#x201d; VLs, with Ethernet-like behavior, and others are &#x201c;no-drop&#x201d; lanes with FC-like behavior. Some preferred implementations of the invention provide guaranteed bandwidth based on credits and VL. Active buffer management allows for both high reliability and low latency while using small frame buffers. Preferably, the rules for active buffer management are different for drop and no drop VLs.

Ethernet extension for the data center

In one embodiment, a method comprises the following steps: receiving a first set of inputs comprising a first plurality of entities and a first traffic behavior; determining a first region of a buffer corresponding to the first traffic behavior; assigning the first plurality of entities to the first region; determining hierarchical relationships between at least some of the first plurality of entities; determining a first shared buffer space of the first region; and assigning at least one threshold for each of the first plurality of entities. The threshold may comprise a maximum amount of the first shared buffer space that may be allocated to an entity. The method may also involve configuring a logic device to allocate the first shared buffer space dynamically according to the hierarchical relationships and the thresholds.

Flexible and hierarchical dynamic buffer allocation

Methods and devices are provided for implementing flow control coordination in a gateway between a TCP/IP network and a second network. The second network may be any type of network, including another TCP/IP network. In some implementations, the throughput of the TCP/IP network is controlled by modifying the round trip time observed by a TCP connection. In other implementations, the throughput of the TCP/IP network is controlled by modifying the size of the TCP window.

Methods and devices for the coordination of flow control between a TCP/IP network and other networks

A Fibre Channel Switch which enables end devices in different Fabrics to communicate with one another while retaining their unique Fibre Channel Domain_IDs. The Switch is coupled to a first fabric having a first set of end devices and a second fabric having a second set of end devices. The Switch is configured to enable communication by the first set of end devices associated with the first fabric with the second set of end devices associated with the second set of end devices using the unique Domain_IDs of each of the first set and the second set of end devices. In one embodiment of the invention, the first and second fabrics are first and second Virtual Storage Array Networks (VSANs) respectively. In an alternative embodiment, the first fabric and the second fabric are separate physical fabrics.

Network device architecture for consolidating input/output and reducing latency

Methods and devices are provided for controlling congestion in a network such as a Fibre Channel network. According to some implementations, a node within a network fabric detects congestion caused by an edge device outside of the fabric and notifies the edge device of the congestion. The edge device applies a congestion reaction mechanism in response to the notification. In some implementations, the congestion reaction mechanism is applied on a per-exchange basis, in order to mitigate congestion caused by a particular operation.

End-to-end congestion control in a Fibre Channel network

Novel methods and devices are provided for AQM of input-buffered network devices. Preferred implementations of the invention control overall buffer occupancy while protecting uncongested individual VOQs. The probability of setting a 'global drop flag' (which is not necessarily used to trigger packet drops, but may also be used to trigger other AQM responses) may depend, at least in part, on the lesser of a running average of buffer occupancy and instantaneous buffer occupancy. In some preferred embodiments, this probability also depends on the number of active VOQs. Moreover, a global drop flag is set in conjunction with a drop threshold M associated with the VOQs. Whether an AQM response is made may depend on whether a global drop flag has been set and whether a destination VOQ contains M or more packets. Different M values may be established for different classes of traffic, e.g., with higher M values for higher-priority traffic. AQM responses (e.g., to drop packets) may be taken more aggressively when there is a larger number of active VOQs.

Active queue management methods and devices

Growing community of inventors

Sunnyvale, CA, United States of America

Davide Bergamasco