Abstract: A method for buffer occupancy based congestion management includes receiving, by a computing device, a data stream including a plurality of packets from a plurality of sources and storing the packets in a buffer that includes multiple storage units. The method also includes determining if the buffer is congested, responsive to determining that the buffer is congested randomly selecting an occupied unit of the buffer and determining the source of the packet stored in the occupied unit of the buffer and sending a congestion notification message to the source of the packet stored in the occupied unit of the buffer.

Abstract: In one embodiment, a system includes a processor and logic integrated with and/or executable by the processor, the logic being adapted to: receive a plurality of flows, each flow comprising packets of data, assign a service credit to each of the plurality of flows, assign a weight parameter to each of the plurality of flows, select a flow from a head of a first control queue unless the first control queue is empty or there is indication that the first control queue should be avoided, wherein a flow is selected from a head of a second control queue when the first control queue is empty or there is indication that the first control queue should be avoided, provide a number of units of service to the selected flow, and decrease the selected flow's service credit by an amount corresponding to the number of units of service provided thereto.

Abstract: Exemplary embodiments include RDMA methods and systems for sending application data to a computer memory destination in a direct but non-blocking fashion. The method can include posting a new work request for an RDMA connection or association, determining if there is a prior work request for the same connection or association enqueued for processing, in response to a determination that no prior work request is enqueued for processing, processing the new work request directly by sending RDMA frames containing application data referred to by the work request to the computer memory destination, performing direct sending while there is sufficient send space to process the new work request, and delegating the new work request to asynchronous transmission if a prior work request is already enqueued for processing or lack of send space would block a subsequent transmission operation.

Abstract: A method for deadlock resolution in end-to-end credit protocol includes receiving a data frame and determining a number of credits required to transmit the data frame. The method also includes requesting and receiving credits from an end controller and responsively incrementing a credit counter. The method further includes determining if a value of the credit counter is greater than the number of credits required to transmit the data frame. Based on determining that the value of the credit counter is at least the number of credits required, the method includes transmitting the data frame to the end controller and decreasing the value of the credit counter by the number of credits required to transmit the data frame. Based on determining that the value of the credit counter is less than the number of credits required, the method includes transmitting a credit shortage notification to the end controller.

Abstract: A system for deadlock resolution in end-to-end credit protocol includes a plurality of source controllers configured to receive data frames on an incoming link, wherein each source controller includes a plurality of credit counters. The system also includes a plurality of end controllers configured to receive data frames from the plurality of source controllers, wherein each end controller includes a buffer credit counter, a plurality of request counters, and an output buffer. Each of the plurality of credit counters corresponds to one of the plurality of end controllers and stores a number of credits received from that end controller. The buffer credit counter of each end controller stores a number of available credits of the end controllers. Each of the request counters corresponds to one of the plurality of source controllers and stores a number of credit requests received from that source controller.

Abstract: A method for data transmission on a device without intermediate buffering is provided. An application request is received to transmit data from the device to a second device over a network. The data from application memory is formatted for transmitting to the second device. The data are transmitted from the device to the second device without intermediate buffering. A send state is retrieved. The send state is compared to expected send state. If the send state meets the expected send state, a completion of the data transmit request is generated.

Abstract: A system for deadlock resolution in end-to-end credit protocol includes a plurality of source controllers configured to receive data frames on an incoming link, wherein each source controller includes a plurality of credit counters. The system also includes a plurality of end controllers configured to receive data frames from the plurality of source controllers, wherein each end controller includes a buffer credit counter, a plurality of request counters, and an output buffer. Each of the plurality of credit counters corresponds to one of the plurality of end controllers and stores a number of credits received from that end controller. The buffer credit counter of each end controller stores a number of available credits of the end controllers. Each of the request counters corresponds to one of the plurality of source controllers and stores a number of credit requests received from that source controller.

Abstract: A method for deadlock resolution in end-to-end credit protocol includes receiving a data frame and determining a number of credits required to transmit the data frame. The method also includes requesting and receiving credits from an end controller and responsively incrementing a credit counter. The method further includes determining if a value of the credit counter is greater than the number of credits required to transmit the data frame. Based on determining that the value of the credit counter is at least the number of credits required, the method includes transmitting the data frame to the end controller and decreasing the value of the credit counter by the number of credits required to transmit the data frame. Based on determining that the value of the credit counter is less than the number of credits required, the method includes transmitting a credit shortage notification to the end controller.

Abstract: A reliability system for a Converged Enhanced Ethernet network may include a plurality of end points each comprising a layer 4 transport layer, where each end point is connected to a data center bridging (DCB) layer 2 network. The system may also include an adaptor between the layer 4 transport layer and the DCB layer 2 network to translate at least one of flow and congestion control feedback signals, provided by at least one of the DCB network and the transport layer, to consolidated feedback signals for controlling transmission by the transport layer.

Abstract: A system to improve a Converged Enhanced Ethernet network may include a controller having a computer processor connected to a layer 2 endpoint buffer. The system may also include a manager executing on the controller to monitor the layer 2 endpoint buffer by determining buffer data packet occupancy and/or rate of change in the buffer data packet occupancy. The system may further include a reporter to notify a congestion source of the layer 2 endpoint buffer based upon the buffer data packet occupancy and/or rate of change in the buffer data packet occupancy.

Abstract: IEEE 802.1Q and Enhanced Transmission Selection provide only eight different traffic classes that may be used to control bandwidth in a particular physical connection (or link). Instead of relying only on these eight traffic classes to manage bandwidth, the embodiments discussed herein disclose using an Enhanced Transmission Selection scheduler that permits a network device to set the bandwidth for an individual virtual LAN. Allocating bandwidth in a port based on a virtual LAN ID permits a network device to allocate bandwidth to, e.g., millions of unique virtual LANs. Thus, this technique may increase the granular control of the network fabric and its performance.

Abstract: A method for hierarchical occupancy based congestion management includes receiving, by a computing device, a plurality of data flows, each of the plurality of data flows is received from a source and includes a plurality of data packets and storing the plurality of data packets in a buffer including multiple storage units. The method includes determining if the buffer is congested, responsive to determining the buffer is congested randomly selecting at least two occupied units of the buffer and identifying a source of each of the data packets stored in the occupied units of the buffer and generating a congestion notification message. The method also includes comparing a selection criterion associated with each identified source to determine which identified source has a higher selection criterion and sending the congestion notification message to the identified source with the higher selection criterion.

Abstract: A system for hierarchical occupancy based congestion management includes a buffer embodied in a computer readable storage medium including a plurality of buffer units for storing packets of a data flow received from sources. The system includes a buffer manager that stores information about the packets stored in the buffer, including a selection criterion associated with each of the plurality of sources and a congestion estimator that monitors a congestion level in the buffer. The system also includes a occupancy sampler that randomly selects at least two occupied buffer units from the plurality of buffer units and identifies the source of the packet stored in each of the occupied buffer units and a congestion notification message generator that generates a congestion notification message; wherein if the congestion level in the buffer exceeds a threshold value the congestion notification message is sent to the identified source with a higher selection criteria.

Abstract: A method for hybrid arrival-occupancy based congestion management includes increasing a recent arrivals counter associated with a data flow from one or more sources in response to receiving a data packet from one of the sources and storing the data packet in a buffer including multiple storage units. The method includes determining if a buffer is congested, randomly selecting an occupied unit of the buffer and determining the source of the packet stored in the occupied unit of the buffer, generating a congestion notification message, sending the congestion notification message to the source of the packet stored in the occupied unit of the buffer if the recent arrivals counter exceeds a threshold value and decreasing the recent arrivals counter associated with the source of the packet stored in the occupied unit of the buffer and discarding the congestion notification message if the recent arrivals counter has a zero value.

Abstract: A method for buffer occupancy based congestion management includes receiving, by a computing device, a data stream including a plurality of packets from a plurality of sources and storing the packets in a buffer that includes multiple storage units. The method also includes determining if the buffer is congested, responsive to determining that the buffer is congested randomly selecting an occupied unit of the buffer and determining the source of the packet stored in the occupied unit of the buffer and sending a congestion notification message to the source of the packet stored in the occupied unit of the buffer.

Abstract: A method for adjusting a set of primary rate limits for transmission rates of data flows having a certain priority in a transmitter is provided. A mean value is determined of a duty cycle of the certain priority at the port as obtainable from the transmission or flow control, wherein the data flows having different priorities including said certain priority are transmitted by a port of the transmitter, transmissions for rate-limited data flows having the certain priority are limited by secondary rate limits (r1?, r2?, . . . rn?) per data flow, and transmissions for all data flows having the certain priority are controlled by a transmission or flow control per priority. The secondary rate limits (r1?, r2?, . . . rn?) are obtained by adjusting the primary rate limits for the transmission rates of the data flows having the certain priority based on the determined mean value of the duty cycle.

Abstract: A device for adjusting a set of primary rate limits for transmission rates of data flows having a certain priority in a transmitter is provided, wherein data flows of different priorities including said certain priority are transmitted by a port of the transmitter. The transmission of the data flows having the certain priority is limited by secondary rate limits per data flow and by a transmission or flow control per priority. The device comprises a determiner and a number of adjusters. The determiner is configured to determine a mean value of a duty cycle of the certain priority at the port provided by the transmission or flow control. The adjusters are configured to adjust the primary rate limits for the transmission rates of the data flows having the certain priority based on the determined mean value of the duty cycle to obtain the secondary rate limits.

Abstract: A method for data transmission on a device without intermediate buffering is provided. An application request is received to transmit data from the device to a second device over a network. The data from application memory is formatted for transmitting to the second device. The data are transmitted from the device to the second device without intermediate buffering. A send state is retrieved. The send state is compared to expected send state. If the send state meets the expected send state, a completion of the data transmit request is generated.

Abstract: Exemplary embodiments include RDMA methods and systems for sending application data to a computer memory destination in a direct but non-blocking fashion. The method can include posting a new work request for an RDMA connection or association, determining if there is a prior work request for the same connection or association enqueued for processing, in response to a determination that no prior work request is enqueued for processing, processing the new work request directly by sending RDMA frames containing application data referred to by the work request to the computer memory destination, performing direct sending while there is sufficient send space to process the new work request, and delegating the new work request to asynchronous transmission if a prior work request is already enqueued for processing or lack of send space would block a subsequent transmission operation.

Abstract: Receivers, methods, and computer program products can be used to demodulate a data signal transmitted from a digital source, which has a network sampling rate that is synchronized with a network clock. In an illustrative embodiment, a receiver includes a two-stage interpolator that receives digital samples of the data signal as an input and produces an interpolated digital sample stream to be filtered by an adaptive fractionally spaced decision feedback equalizer. The digital samples received in the interpolator are synchronized with a local clock; however, the interpolated sample stream is synchronized with the network clock. A slicer generates symbols for the samples output from the decision feedback equalizer by comparing the samples with a reference signaling alphabet. The receiver can be used in a V.90 client modem to demodulate pulse code modulated (PCM) data transmitted as pulse amplitude modulated (PAM) signals from a digital network.