Microsoft Technology Licensing, LLC

Other

Microsoft Corporation

Sanjay N Kaniyar

Abolade Gbadegesin

James T Pinkerton

Murari Sridharan

Nk Srinivas

Deepak Bansal

Kevin T Weston

Alireza Dabagh

Bhupinder Singh Sethi

Christian F Huitema

Henry L Sanders

Avnish Kumar Chhabra

Jameel Hyder

Aditya Dube

Nelamangala Krishaswamy Srinivas

Robert Victor Welland

Aamer Hydrie

Joseph M Joy

Nelamangal Krishnaswamy Srinivas

Xinyan Zan

Arvind M Murching

Art Shelest

Shaun David Cox

Rajesh Sundaram

Sean B House

Scott K Holden

N K Srinivas

Robert V Welland

Methods of tuning a receive window. A receiving device and a sending device may be in communication over a network. The receiving device may advertise a receive window to the sending device. The size of the receive window may be adjusted over time based on one or more connection parameters, application parameters and/or operating system parameters.

Receive window auto-tuning

In one embodiment, to determine what tasks may be offloaded to a peripheral hardware device (e.g., to be performed in hardware on the peripheral device, rather than on the CPU(s) of the host computer), an indication from the at least one peripheral hardware device may be provided, without the peripheral hardware device first being queried to determine the task offload capabilities provided by the peripheral hardware device. In one embodiment, a large packet that includes a plurality of extension headers may be offloaded to the peripheral hardware device for segmentation. An indication of the offset where the extension headers end may be provided in connection with the large packet. In another embodiment, a packet with extension headers that come before an encryption header in the packet are not offloaded to peripheral hardware device for encryption, while packets with no extension headers before the encryption header may be offloaded.

Task offload to a peripheral device

Efficiently polling a DMA module to determine if the DMA copying of a packet payload to an application buffer is complete. For communication packets received from a network, a processing module may be configured to poll the DMA module at times when it is likely that the DMA copying of packet payloads is complete. Packets may be received and processed in batches. The polling of the DMA module for a packet belonging to a first batch may be deferred until the processing of a next batch. An exception may occur if a predefined amount of time elapses following the completion of the processing of the first batch before the next batch is received. In response to the predefined amount of time elapsing before the receipt of the next batch, the DMA module may be polled, i.e., prior to the next batch being processed.

Efficiently polling to determine completion of a DMA copy operation

A method for the synchronization of network neighbor reachability between a host networking stack and a peripheral device, which offloads one or more network protocols is provided. The network neighbor reachability represents the reachability of another computer on the network. This invention enables conventional neighbor reachability to be extended to seamlessly support some network connections to a specific remote host to be offloaded to a peripheral device, while other network connections are not.

Offloaded neighbor cache entry synchronization

Techniques are provided for adjusting to changes to the latency for a connection between two nodes on a network. In accordance with some embodiments, when a transmitting node encounters a retransmission timeout for a packet sent to a receiving node, the latency for the connection is newly measured and used to calculate a new retransmission timeout period for subsequent transmissions by the transmitting node. In some embodiments, the latency is not newly measured if a selective acknowledgement is received indicating that congestion on the network is only temporary.

Adjusting to network latency changes

Creating different congestion control modules (CCMs) that can be plugged into a network communications stack (e.g., a TCP/IP stack). Software abstractions defining transport control events, congestion control algorithms and other information may be exposed by an application programming interface, e.g., of an operating system, and these abstractions may be used to define a CCM. The network communications stack may be configured to select one of multiple available CCMs to control congestion for a given connection. This selection may be based on any of a variety of factors including, but not limited to: network environment; connection path characteristics; connection link characteristics; a value of a socket parameter of an application; other factors; and any suitable combination of the foregoing. Thus, CCMs may be selected and implemented on a per-connection basis.

Enabling network devices to run multiple congestion control algorithms

The invention provides mechanisms for transferring processor control of secure Internet Protocol (IPSec) security association (SA) functions between a host and a target processing devices of a computerized system, such as processors in a host CPU and a NIC. In one aspect of the invention, the computation associated with authentication and/or encryption is offloaded while the host maintains control of when SA functions are offloaded, uploaded, invalidated, and re-keyed. The devices coordinate to maintain metrics for the SA, including support for both soft and hard limits on SA expiration. Timer requirements are minimized for the target. The offloaded SA function may be embedded in other offloaded state objects of intermediate software layers of a network stack.

Method and apparatus for secure internet protocol (IPSEC) offloading with integrated host protocol stack management

Disclosed is a method for slowing down the spread of viruses by limiting the number of Transmission Control Protocol ('TCP') connection attempts to arbitrary Internet Protocol ('IP') addresses that can be in progress at any given time&#x2014;a common method employed by viruses to spread to other hosts from an infected host. This is achieved by setting a small limit on the number of connection attempt requests that can be in progress at any given time and can be implemented regardless of whether anti-virus software is installed on the system.

Outgoing connection attempt limiting to slow down spreading of viruses

A new method and framework for scheduling receive-side processing of data streams received from a remote requesting client by a multiprocessor system computer is disclosed. The method receives data packets from the remote requesting client via a network and, for each data packet, applies a cryptographically secure hashing function to portions of the received data packet yielding a hash value. The method further applies the hash value to a processor selection policy to identify a processor in the multiprocessor system as a selected processor to perform receive-side processing of the data packet. The method queues the received data packet for processing by the selected processor and invokes a procedure call to initiate processing of the data packet.

Receive side scaling with cryptographically secure hashing

A computer system with black hole management. The black hole management system shares black hole status information among connections that employ the same path. The black hole status information may indicate either that a black hole exists on the path or that communications have been performed successfully on the path, indicating that no black hole exists. By sharing this information, delays in transmission caused by black hole probing may be reduced. Additionally, status information for a connection is reset when information indicates that the connection has been altered. By resetting the status information, delays in transmission associated with sending reduced sized packets over connections for which black holes were previously detected but may have been eliminated by changes in the connection, are avoided.

Computer system with black hole management

Growing community of inventors

Redmond, WA, United States of America

Sanjay N Kaniyar