Microsoft Technology Licensing, LLC

Gregory O'Shea

Antony Rowstron

Austin N Donnelly

Paolo Costa

Michael Roe

Thomas Christian Zahn

David G Thaler

Richard John Black

Brian Don Zill

Art Shelest

Antony Ian Taylor Rowstron

Dinan Srilal Gunawardena

Hitesh Ballani

Peter Bernard Key

Thomas Karagiannis

Thomas M Talpey

Eno Thereska

An application programming interface (API) supporting server and key based networking is described. In an embodiment, the API receives either a key or a server address from a service running on a server in a direct-connect topology and returns data which identifies suitable next hops for transmission of a packet of data which has a destination of the received server address or of a server address which is encoded within the received key. In another embodiment, the key also encodes information specifying alternative server addresses for use in the event that the original server is unreachable. This information may also be used to define servers for replication of the key. A further embodiment describes a method of queuing packets for transmission against multiple links, where the packet is transmitted on the first available link and at this time is removed from the queues for the other links.

API supporting server and key based networking

Controlling data storage input/output requests is described, for example, to apply a policy to an end-to-end flow of data input/output requests between at least one computing entity and at least one store. In various examples a plurality of queues are configured at one or more stages of the end-to-end flow and controlled to adhere to a policy. In examples, each stage has a control interface enabling it to receive and execute control instructions from a controller which may be centralized or distributed. For example, the control instructions comprise queuing rules and/or queue configurations. In various examples queues and queuing rules are dynamically created and revised according to feedback about any of: flow behavior, changes in policy, changes in infrastructure or other factors. In examples, high level identifiers of the flow endpoints are resolved, on a per stage basis, to low level identifiers suitable for use by the stage.

Systems and methods based on policy criteria for controlling the flow of data storage input/output requests between endpoints

Content transfer between nodes in a communications network is required in many situations. For example, between fixed nodes in a data center, between a fixed node such as a base station and a mobile node such as a mobile telephone and between mobile nodes themselves such as personal digital assistants. In an embodiment a content transfer process for use between nodes where one node knows the size of content to be transferred is described. For example, a file is divided into blocks to be sent between the nodes. A node receiving a block keeps a record of the received blocks and sends that record to the sending node at certain times. By controlling the times at which the records are sent the number of messages that need to be sent to transfer the records is low and the blocks are transferred in an efficient manner.

Content transfer

Supporting distributed key-based processes is described. In an embodiment, servers at a data center provide a key-based process for carrying out computationally expensive tasks and are connected using point to point connections in a geometric topology such as a torus. In an example, aggregation trees are built on top of the geometric topology of the data center, each aggregation tree being a sequence of servers in the data center that forms a tree structure. In an embodiment packets of data are sent from the leaves of the trees to the root and at each server along the tree the packets are aggregated using a combiner function of the key-based process. In an embodiment, if a server fails, the trees are dynamically recomputed and a recovery phase is triggered to resend any packets lost at the failed server. In some embodiments, packets are scheduled by inspecting the content of the packets.

Supporting distributed key-based processes

Disclosed is an authentication mechanism that enables an information recipient to ascertain that the information comes from the sender it purports to be from. This mechanism integrates a private/public key pair with selection by the sender of a portion of its address. The sender derives its address from its public key, for example, by using a hash of the key. The recipient verifies the association between the address and the sender's private key. The recipient may retrieve the key from an insecure resource and know that it has the correct key because only that key can produce the sender's address in the message. The hash may be made larger than the sender-selectable portion of the address. The recipient may cache public key/address pairs and use the cache to detect brute force attacks and to survive denial of service attacks. The mechanism may be used to optimize security negotiation algorithms.

Methods and systems for unilateral authentication of messages

Content discovery and content transfer between mobile communications nodes is often required, for example, to synchronize maps, traffic hot spot information and the like for vehicle mounted satellite navigation devices, pedestrian hand-held personal digital assistants and other mobile communications nodes. In an embodiment, content discovery processes using a tree-based data structure for transferring data between two mobile communication nodes is described.

Content discovery and transfer between mobile communications nodes

Control of background data transfers is described. In an embodiment, a background data transfer is controlled at a receiver node by measuring a time period taken to receive from a sender node a data sequence of the same size as a receive window. The time period is used to evaluate available network capacity, and the network capacity used to calculate a new window size. The new window size is applied and communicated to the sender node. In another embodiment, a background data transfer is controlled at a receiver node by measuring a quantity of data received from a sender node during a first control interval. The measured quantity is used to evaluate available network capacity, and the network capacity used to calculate a new receive window size and a second control interval duration. The new window size is applied for the second control interval, and communicated to the sender node.

Control of background data transfers

Content discovery and content transfer between mobile communications nodes is often required, for example, to synchronize maps, traffic hot spot information and the like for vehicle mounted satellite navigation devices, pedestrian hand-held personal digital assistants and other mobile communications nodes. In an embodiment, content discovery processes using data structures designed in particular ways and sent using a single packet enable nodes to identify files to be transferred whilst keeping overheads down. In an embodiment a first and a second data structure are used, each being formed from slightly different information about a subset of the files to be synchronized. In another embodiment a single tree-based data structure is used. A process for transferring data between two mobile communications nodes is also described.

A system and method for authentication verifies the address of an information sender based on the sender's address, public key, and a digital signature. A portion of the sender's address is derived from the public key, such as by incorporating a portion of a hash of the public key with or without a modifier. The sender provides information including content data, the public key, the address, and the digital signature generated using the private key corresponding to the public key. Upon reception, the recipient verifies the address by recreating it from the public key. The signature is verified using the network address and public key. The recipient accepts the content data when both the address and signature are verified. The content data may include a communications parameter of the sender, such as a care-of address where the sender is a mobile device and the recipient is the sender's home agent.

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Cambridge, United Kingdom

Gregory O'Shea