Extreme Networks, Inc.

Agere Systems Inc.

Dhaani Systems

Ethernovia Inc.

Samsung Electronics Co., Ltd.

Cisco Technology, Inc.

Korea Advanced Institute of Science and Technology

Jean C Walrand

Ayman Fawaz

John T Musacchio

Roy Thomas Myers, Jr

Nicholas Bambos

Shankar Mukherjee

Jeonghoon Mo

Gaurav Agarwal

Rajarshi Gupta

Hossein Sedarat

Ramin Shirani

Darren S Engelkemier

Shyam Parekh

Keith McCloghrie

Jong-Ho Bang

Chung Kuang Chin

Yongsuk Park

Su-won Lee

Jeong-Hoon Mo

Jae-Wook Kwak

Stephan Robert

Andrew Bierman

Matthew Kenneth Siler

Fadi Abourjeily

Brian Anthony Fuller

Roy T Myers

Disclosed is a method of managing power consumption of a system with a first device coupled to a communication device of a communication network by way of a first communication link and a second device coupled to the communication device of the communication network by way of a second communication link.

Power management of networked devices

Disclosed are systems, methods, and non-transitory computer-readable media for configuration of time-sensitive networks. Time-sensitive networks utilize traffic shaping to provide for efficient and predictable flows of data through the network. A network configuration tool can be used to determine how data should be routed and shaped through the network towards its destination. The network configuration tool calculates the maximum burst size at an output port of a switch by analyzing groups of data flows that pass through the output port, rather than analyzing the data flows individually.

Configuration of time-sensitive networks

A network-centric, power management system and method is disclosed for monitoring and controlling device nodes attached to a network. The monitoring and controlling includes collecting and processing information available on the network about the device nodes and using the collected information to manage power on the device nodes.

Roughly described, a packet switching fabric contains a separate queue scheduler for each combination of an input module and a fabric output port. The schedulers may also be specific to a single class of service. Each queue scheduler schedules its packets without regard to state of other input queues and without regard to packets destined for other output ports. In an aspect, the fabric manages per-flow bandwidth utilization of output port bandwidth capacity by monitoring the same and asserting backpressure toward the queue scheduler for any thread that is exceeding its bandwidth allocation. In another aspect, a switching fabric uses leaky buckets to apply backpressure in response to overutilization of downstream port capacity by particular subflows. In another aspect, a switching fabric includes a cascaded backpressure scheme.

Backpressure mechanism for switching fabric

A method and apparatus for optimizing a cross layer in an ad-hoc wireless network are provided. A link price is set using the number of packets of a queue. A flow rate is set using the link price. A channel access rank is set by comparing the link price with a link price of a neighboring node. A channel access backoff time is set based on the channel access rank. The method and apparatus for optimization may not be subject to interference and can simultaneously obtain fairness and efficiency while adaptively setting link capacities.

Method and apparatus for optimizing a queue based cross layer in a wireless ad-hoc network

A striping algorithm selects a route on which to transmit each next data segment, in dependence upon relative channel loading so far, taking account of multicast. Input modules can keep a channel loading history for each route it has, and can update its history for each route that a data segment follows through the fabric. In an embodiment, the input module transmits each data segment toward an i'th intermediate stage module, where i minimizesq(i,a(G),c)+q(i,b(G),c)+ . . . +q(i,k(G),c),where q(i, j, c) indicates the number of bytes of data sent, during a given prior time period, from the input module to each j'th one of the output modules via each i'th one of the intermediate stage modules, and a(G), b(G), . . . , and k(G) are the output module(s) in the multicast group G to which the data segment is destined.

Striping algorithm for switching fabric

In one embodiment, data segments routed through a switch fabric are identified as being either a first or a second type. First and second counters are maintained for a destination node to characterize the transmission of data segments of the corresponding type within the switch fabric. For each first-type time period, all transmitted data segments are identified as being the first type. For each second-type time period, all transmitted data segments are identified as being the second type. The first- and second-type time periods are interleaved. The first counter is reset after termination of each first-type time period and the second counter is reset after termination of each second-type time period to correct for a possible error in characterizing the transmission of the data segments within the switch fabric during the corresponding time period.

Characterizing transmission of data segments within a switch fabric using multiple counters for each destination node

Roughly described, a striping algorithm selects a route on which to transmit each next data segment, pseudorandomly from among a subset of eligible routes, the subset being chosen in dependence upon relative channel loading so far. Preferably each ingress node to a switching system chooses an outgoing route for each given next data segment, according to a pseudorandom algorithm, from among a respective given subset containing only those routes via which the amount of data sent from the ingress node during a respective prior time period is no greater than an average of the amount of data sent from the ingress node via any of its outgoing routes during the same prior time period.

Deficit-based striping algorithm

In accordance with the invention, a system and method for providing QoS to packets formatted in accordance with one protocol (e.g., IP or Ethernet) carried over networks that are originally designed to be used with another protocol (e.g., ATM, WDM, or TDM). In one embodiment of the invention, such a switch is modified in order to allow the switch to become 'IP-aware.' Such a modified switch can identify IP packets, determine if any packets should be dropped, classify the packets with a queue, and schedule the packets of each queue in a manner that provides quality of service to the packets in the queue. Moreover, some embodiments of a modified switch further include a monitor to keep statistics on the packets in the modified switch, a protection mechanism that monitors fault information for at least part of the network, and a provisioning mechanism that determines normal and backup paths for each connection.

Provisional IP-aware virtual paths over networks

A packet-switched communication network in accordance with the invention provides a guaranteed minimum bandwidth between pairs of Packet Switches by defining Service Level Agreements (SLAs). An SLA is defined by at least a source identifier, a destination identifier, and a minimum data rate although other information can also be used. Upon arrival at certain networked nodes, packets are classified according to an SLA by reading the source and destination addresses in the packet. Once classified, the packets are placed in a queue and scheduled for transmission. A scheduler ensures that packets are transmitted at the minimum defined data rate for the SLA. The scheduler may use a statistical multiplexing method, such as deficit round robin, or deficit golden ratio, which is part of the present invention. The deficit golden ratio method assures a minimum rate to packets for a particular SLA, but minimizes jitter and delay. Further, the present invention implements congestion control that does not require nodes to be entirely turned off in congested conditions.

Method and apparatus to minimize congestion in a packet switched network

The invention provides a method and system for collecting aggregate information about network traffic, while maintaining processor load relatively constant despite substantial variation in network traffic, and capable of substantially accurate frequency measurement even for relatively infrequent events. A packet monitoring system includes an input port for receiving network packets, a sampling element for selecting a fraction of those packets for review, and a queue of selected packets. The packets in the queue are coupled to a packet-type detector for detecting packets of a selected type; the system applies a measurement technique for determining a frequency measure for those detected packets. The system includes a feedback technique for adaptively altering the sampling rate fraction, responsive to the queue length and possibly other factors, such as processor load or the detected frequency measure. The measurement technique also determines an error range and a measure of confidence that the actual frequency is within the error range of the measured frequency. The system can detect packets of multiple selected types essentially simultaneously, and provide measured frequencies and error ranges for all of the multiple selected types at once. Also, the measurement technique is selected so as to impose relatively light processor load per packet.

Growing community of inventors

Berkeley, CA, United States of America

Jean C Walrand