Abstract: In one embodiment, a method for supporting recovery from failure of a path in a network of nodes interconnected by links. An intermediate node between an ingress point and an egress point of the network is selected to minimize the sum of (i) a capacity constraint between the ingress point and the intermediate node and (ii) a capacity constraint between the intermediate node and the egress point. The selection identifies two link-disjoint path sets, each comprising a backup path and at least one primary path, with a first path set between the ingress point and the intermediate node, and a second path set between the intermediate node and the egress point. To maximize network throughput, packets are routed in two phases, first to the intermediate node via the first path set in predetermined proportions, and then from the intermediate node to the final destination via the second path set.

Abstract: In various embodiments, methods and systems are disclosed for a hybrid rate plus window based congestion protocol that controls the rate of packet transmission into the network and provides low queuing delay, practically zero packet loss, fair allocation of network resources amongst multiple flows, and full link utilization. In one embodiment, a congestion window may be used to control the maximum number of outstanding bits, a transmission rate may be used to control the rate of packets entering the network (packet pacing), a queuing delay based rate update may be used to control queuing delay within tolerated bounds and minimize packet loss, and aggressive ramp-up/graceful back-off may be used to fully utilize the link capacity and additive-increase, multiplicative-decrease (AIMD) rate control may be used to provide fairness amongst multiple flows.

Abstract: In one embodiment, a method for supporting recovery from failure of a link in a network of nodes interconnected by links. An intermediate node between an ingress point and an egress point of the network is selected to minimize the sum of (i) a capacity constraint between the ingress point and the intermediate node and (ii) a capacity constraint between the intermediate node and the egress point. The selection identifies two path structures, each comprising a primary path and one or more link backup detours protecting each link on the primary path, with a first path structure between the ingress point and the intermediate node, and a second path structure between the intermediate node and the egress point. To maximize network throughput, packets are routed in two phases, first to the intermediate node via the first path structure in predetermined proportions, and then from the intermediate node to the final destination via the second path structure.

Abstract: A scheme for routing packets of traffic to their destination after ensuring that they pass through one or more pre-determined intermediate nodes, thereby permitting all permissible traffic patterns to be handled without knowledge of the traffic matrix, subject to edge-link capacity constraints. In one embodiment, a request for a path with a service demand for routing data between the ingress point and the egress point is received. A set of two or more intermediate nodes between the ingress point and the egress point is selected. Based on a bandwidth of the network, respective fractions of the data to send from the ingress point to each node of the set of intermediate nodes are determined. The data is routed in the determined respective fractions from the ingress point to each node of the set of intermediate nodes, and routed from each node of the set of intermediate nodes to the egress point.

Abstract: Techniques are described for sharing content among peers. Locality domains are treated as first order network units. Content is located at the level of a locality domain using a hierarchical DHT in which nodes correspond to locality domains. A peer searches for a given piece of content in a proximity guided manner and terminates at the earliest locality domain (in the hierarchy) which has the content. Locality domains are organized into hierarchical clusters based on their proximity.

Abstract: This patent application relates to an agile network architecture that can be employed in data centers, among others. One implementation provides a virtual layer-2 network connecting machines of a layer-3 infrastructure.

Abstract: Improved p-cycle restoration techniques using a signaling protocol are disclosed. For example, a technique for use in at least one node of a data communication network for recovering from a failure, wherein the data communication network includes multiple nodes and multiple links for connecting the multiple nodes, comprises the following steps/operations. Notification of the failure is obtained at the at least one node. A determination is made whether the failure is a single link failure or one of a node failure and a multiple link failure. A pre-configured protection cycle (p-cycle) plan is implemented when the failure is a single link failure but not when the failure is one of a node failure and a multiple link failure, such that two independent paths in the network are not connected when implementing the pre-configured protection cycle plan.

Abstract: Transmission delays are minimized when packets are transmitted from a source computer over a network to a destination computer. The source computer measures the network's available bandwidth, forms a sequence of output packets from a sequence of data packets, and transmits the output packets over the network to the destination computer, where the transmission rate is ramped up to the measured bandwidth. In conjunction with the transmission, the source computer monitors a transmission delay indicator which it computes using acknowledgement packets it receives from the destination computer. Whenever the indicator specifies that the transmission delay is increasing, the source computer reduces the transmission rate until the indicator specifies that the delay is unchanged. The source computer dynamically decides whether each output packet will be a forward error correction packet or a single data packet, where the decision is based on minimizing the expected transmission delays.

Abstract: Peer-to-peer communications sessions involve the transmission of one or more data streams from a source to a set of receivers that may redistribute portions of the data stream via a set of routing trees. Achieving a comparatively high, sustainable data rate throughput of the data stream(s) may be difficult due to the large number of available routing trees, as well as pertinent variations in the nature of the communications session (e.g., upload communications caps, network link caps, the presence or absence of helpers, and the full or partial interconnectedness of the network.) The selection of routing trees may be facilitated through the representation of the node set according to a linear programming model, such as a primal model or a linear programming dual model, and iterative processes for applying such models and identifying low-cost routing trees during an iteration.

Abstract: Difficulties associated with choosing advantageous network routes between server and clients are mitigated by a routing system that is devised to use many routing path sets, where respective sets comprise a number of routing paths covering all of the clients, including through other clients. A server may then apportion a data stream among all of the routing path sets. The server may also detect the performance of the computer network while sending the data stream between clients, and may adjust the apportionment of the routing path sets including the route. The clients may also be configured to operate as servers of other data streams, such as in a videoconferencing session, for example, and may be configured to send detected route performance information along with the portions of the various data streams.

Abstract: The invention includes a method and apparatus for generating a link transmission schedule for handling traffic variation in wireless networks without dynamic scheduling or routing. The method includes determining fixed traffic capacities associated with respective wireless links of a wireless network according to a routing algorithm, and generating, using the routing algorithm and the fixed traffic capacities, a link transmission schedule including at least one condition by which traffic is transmitted using each of the network links. The link transmission schedule is adapted to remain substantially fixed during dynamic traffic changes. The routing algorithm may be a two-phase routing algorithm in which traffic is distributed by each node in the wireless network to every node in the wireless network using traffic split ratios.

Abstract: Peer-to-peer communications sessions involve the transmission of one or more data streams from a source to a set of receivers that may redistribute portions of the data stream via a set of routing trees. Achieving a comparatively high, sustainable data rate throughput of the data stream(s) may be difficult due to the large number of available routing trees, as well as pertinent variations in the nature of the communications session (e.g., upload communications caps, network link caps, the presence or absence of helpers, and the full or partial interconnectedness of the network.) The selection of routing trees may be facilitated through the representation of the node set according to a linear programming model, such as a primal model or a linear programming dual model, and iterative processes for applying such models and identifying low-cost routing trees during an iteration.

Abstract: Exemplary methods, systems, and computer program products describe selecting a gateway based on health and performance information of a plurality of gateways. The techniques describe gateways advertising health and performance information, computing devices creating a table of this health and performance information, and selecting a gateway using the table. In response to changes in the health and performance information, the computing device may select a different gateway. The process allows network traffic load to be distributed across a plurality of gateways. This process further provides resilience by allowing a plurality of active gateways to substitute for a non-functioning gateway.

Abstract: An ISP-friendly rate allocation system and method that reduces network traffic across ISP boundaries in a peer-to-peer (P2P) network, Embodiments of the system and method continuously solve a global optimization problem and dictate accordingly how much bandwidth is allocated on each connection. Embodiments of the system and method minimize load on a server in communication with the P2P network, minimize ISP-unfriendly traffic while keeping the minimum server load unaffected, and maximize peer prefetching. Two different techniques are used to compute rate allocation, including a utility function optimization technique and a minimum cost flow formulation technique. The utility function optimization technique constructs a utility function and optimizes that utility function. The minimum cost flow formulation technique generates a minimum cost flow formulation using a bipartite graph have a vertices set and an edges set. A distributed minimum cost flow formulation is solved using Lagrangian multipliers.

Abstract: Systems and methods that distribute load balancing functionalities in a data center. A network of demultiplexers and load balancer servers enable a calculated scaling and growth operation, wherein capacity of load balancing operation can be adjusted by changing the number of load balancer servers. Accordingly, load balancing functionality/design can be disaggregated to increase resilience and flexibility for both the load balancing and switching mechanisms of the data center.

Abstract: Difficulties associated with choosing advantageous network routes between server and clients are mitigated by a routing system that is devised to use many routing path sets, where respective sets comprise a number of routing paths covering all of the clients, including through other clients. A server may then apportion a data stream among all of the routing path sets. The server may also detect the performance of the computer network while sending the data stream between clients, and may adjust the apportionment of the routing path sets including the route. The clients may also be configured to operate as servers of other data streams, such as in a videoconferencing session, for example, and may be configured to send detected route performance information along with the portions of the various data streams.

Abstract: A method of networking a plurality of servers together within a data center is disclosed. The method includes the step of addressing a data packet for delivery to a destination server by providing the destination server address as a flat address. The method further includes the steps of obtaining routing information required to route the packet to the destination server. This routing information may be obtained from a directory service servicing the plurality of servers. Once the routing information is obtained, the data packet may be routed to the destination server according to the flat address of the destination server and routing information obtained from the directory service.

Abstract: A system for commoditizing data center networking is disclosed. The system includes an interconnection topology for a data center having a plurality of servers and a plurality of nodes of a network in the data center through which data packets may be routed. The system uses a routing scheme where the routing is oblivious to the traffic pattern between nodes in the network, and wherein the interconnection topology contains a plurality of paths between one or more servers. The multipath routing may be Valiant load balancing. It disaggregates the function of load balancing into a group of regular servers, with the result that load balancing server hardware can be distributed amongst racks in the data center leading to greater agility and less fragmentation. The architecture creates a huge, flexible switching domain, supporting any server/any service, full mesh agility, and unregimented server capacity at low cost.

Abstract: A given network of nodes that are interconnected by links having corresponding capacities has each link's capacity divided into working capacity and restoration capacity without a priori information about network traffic characteristics. Allocation of working capacity and restoration capacity for the network might be optimized by characterization of the network in accordance with a linear programming problem (LPP) subject to network constraints and then generating a solution to the LPP either exactly or with an approximation. Partitioning the capacity of each link in the network into working and restoration capacities minimizes the restoration capacity overhead in the network to allow for higher network utilization.

Abstract: Various object de-duplication techniques may be applied to object systems (such as to files in a file store) to identify similar or identical objects or portions thereof, so that duplicate objects or object portions may be associated with one copy, and the duplicate copies may be removed. However, an object de-duplication technique that is suitable for de-duplicating one type of object may be inefficient for de-duplicating another type of object; e.g., a de-duplication method that significantly condenses sets of small objects may achieve very little condensation among sets of large objects, and vice versa. A multimodal approach to object de-duplication may be devised that analyzes an object to be stored and chooses a de-duplication technique that is likely to be effective for storing the object. The object index may be configured to support several de-duplication schemes for indexing and storing many types of objects in a space-economizing manner.