132 results about "Active queue management" patented technology

A utility employs an active load management system (ALMS) to estimate available operating reserve for possible dispatch to the utility or another requesting entity (e.g., an independent system operator). According to one embodiment, the ALMS determines amounts of electric power stored in power storage devices, such as electric or hybrid electric vehicles, distributed throughout the utility's service area. The ALMS stores the stored power data in a repository. Responsive to receiving a request for operating reserve, the ALMS determines whether the stored power data alone or in combination with projected energy savings from a control event is sufficient to meet the operating reserve requirement. If so, the ALMS dispatches power from the power storage devices to the power grid to meet the operating reserve need. The need for operating reserve may also be communicated to mobile power storage devices to allow them to provide operating reserve as market conditions require.

A method optimizes performance in a data network including a plurality of ingress ports and output queues. Ingress rates of a plurality of flows are monitored, where each flow includes a sequence of packets passing from an ingress port to an output queue and each flow has a profile related to flow characteristics. Each packet is marked with a marking based on criteria including the ingress flow rate and the flow profile. A drop probability of each packet is adjusted at an output queue according to a value of a drop function taken as a function of a queue size. The drop function is selected according to the marking on the packet. The drop functions are zero for queue sizes less than a lower threshold range and positive for queue sizes greater than the lower threshold range. By selecting drop functions according to ingress flow rate measurements and flow profiles, the data network can be optimized for overall system performance.

Systems and methods are provided that facilitate active queue management of internet-protocol data packets generated in a data packet switched wireless network. Queue management can be effected in a serving base station as well as in an access terminal, and the application that generates the data packets can be executed locally or remotely to either the base station or access terminal. Management of the generated data packets is effected via a marking/dropping of data packets according to an adaptive response function that can be deterministic or stochastic, and can depend of multiple communication generalized indicators, which include packet queue size, queue delay, channel conditions, frequency reuse, operation bandwidth, and bandwidth-delay product. Historical data related to the communication generalized indicators can be employed to determine response functions via thresholds and rates for marking/dropping data packets.

A technique for an improved active queue management scheme which dynamically changes its threshold settings as the number of connections (and system load) changes is disclosed. Using this technique, network devices can effectively control packet losses and TCP timeouts while maintaining high link utilization. The technique also allows a network to support a larger number of connections during congestion periods.

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 (“VLs”) in a single physical connection of a data center or similar network. Some VLs are “drop” VLs, with Ethernet-like behavior, and others are “no-drop” 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.

A utility employs a method for generating available operating reserve. Electric power consumption device(s) serviced by the utility is determined during period(s) of time to produce power consumption data, stored in a repository. A determination is made that a control event is to occur during which power is to be reduced to one or more devices. Prior to the control event and under an assumption that it is not to occur, power consumption behavior expected of the device(s) is generated for a time period during which the control event is expected to occur based on the stored power consumption data. Additionally, prior to the control event, projected energy savings resulting from the control event, and associated with a power supply value (PSV) are determined based on the devices' power consumption behavior. An amount of available operating reserve is determined based on the projected energy savings.

An active queue management (AQM) process for network communications equipment. The AQM process is queue based and involves applying at a queue size threshold congestion notification to communications packets in a queue of a link via packet dropping; and adjusting said queue size threshold on the basis of the congestion level. The AQM process releases more buffer capacity to accommodate more incoming packets by increasing said queue size threshold when congestion increases; and decreases buffer capacity by reducing said queue size threshold when congestion decreases. Network communications equipment includes a switch component for switching communications packets between input ports and output ports, packet queues for at least the output ports, and an active queue manager for applying congestion notification to communications packets in the queues for the output ports via packet dropping. The congestion notification is applied at respective queue size thresholds for the queues, and the thresholds adjusted on the basis of the respective congestion levels of the queues of the output ports.

According to the teachings presented herein, a base station implements active queue management (AQM) for uplink transmissions from user equipment (UE), such as a mobile terminal. The base station, e.g., an eNodeB in a Long Term Evolution (LTE) network, uses buffer status reports, for example, to estimate packet delays for packets in the UE's uplink transmit buffer. In one embodiment, a (base station) method of AQM for the uplink includes estimating at least one of a transmit buffer size and a transmit buffer queuing delay for a UE, and selectively dropping or congestion-marking packets received at the base station from the UE. The selective dropping or marking is based on the estimated transmit buffer size and/or the estimated transmit buffer queuing delay.

Methods and apparatus are provided for managing a data packet queue corresponding to a resource of a network device. A token count T_C is maintained for a predefined flow of data packets, and the transmission of packets in the flow into the queue is controlled in dependence on this token count. The token count is decremented when packets in the flow are transmitted into the queue, and the token count is incremented at a token increment rate C. A bandwidth indicator, indicative of bandwidth availability in the resource, is monitored, and the token increment rate C is varied in dependence on this bandwidth indicator. The bandwidth-dependent variation of the token increment rate C is such that, when available bandwidth is indicated, the increment rate C is increased, and when no available bandwidth is indicated the increment rate C is decreased.

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.

Disclosed are a queue management system and a method of managing a queue. This system and method are for use with a parallel processing system including a plurality of clients and a plurality of processors. The clients receive messages and transmit the messages to a shared queue for storage, and the processors retrieve messages from the shared queue and process said messages. The queue management system includes a mirror queue for maintaining a copy of each message transmitted to the shared queue by one of the clients; and the queue management system stores to the mirror queue, a copy of each message transmitted to the shared queue by that one of the clients. The mirror queue provides the system with continuity in case of an outage of the shared queue. In the event of such an outage, each instance of an application can simply discontinue using the shared queue and process requests from the mirror queue. The mirror queue is used until the shared queue is once again available. Preferably, the copy of each message transmitted to the mirror queue is provided with a reference, such as a poiner, to the location of the message on the shared queue.

An ATM switch supporting multicast transmissions and efficient transmission of frames. A cell is received on a multicast connection and transmitted on several branches/ports. Instead of copying a multicast cell several times for each output branch, only one copy of each multicast cell is maintained. The cell order and the stored cell data form a physical queue. Several logical queues are maintained, one for each output branch. In one embodiment, linked lists are used to maintain the queues. A cell in the physical queue is deleted after all logical queues traverse that cell. A shared tail pointer is used for all the logical queues to minimize additional processing and memory requirements due to the usage of logical queues. The queues enable cells forming a frame to be buffered until the end of frame cell is received, which provides for efficient handling of frames.

In a packet-queue management system, a bandwidth allocation approach fairly addresses each of n flows that share the outgoing link of an otherwise congested router. According to an example embodiment of the invention, a buffer at the outgoing link is a simple FIFO, shared by packets belonging to the n flows. A packet priority-reduction (e.g., packet dropping) process is used to discriminate against the flows that submit more packets/sec than is allowed by their fair share. This packet management process therefore attempts to approximate a fair queuing policy. The embodiment is advantageously easy to implement and can control unresponsive or misbehaving flows with a minimum overhead.

A method for classifying the Quality of Service of the incoming data traffic before the traffic is placed into the priority queues of the Active Queue Management Block of the device is disclosed. By employing a range of mapping schemes during the classification stage of the ingress traffic processing, the invention permits the traffic from a number of users to be coalesced into the appropriate Quality of Service level in the device.

A method and system for managing loads powered by a standby generator. The method includes utilizing a transfer switch control unit to selectively shed loads each associated with one of a series of priority circuits. The loads are shed in a sequential order based upon the priority circuit to which the load is applied. Once a required load has been shed, the control unit determines whether any of the lower priority loads can be reconnected to the generator without exceeding the rating of the generator while one of the higher priority circuits remains open.