Abstract: Embodiments disclosed herein relate to source-based symmetric routing of network traffic in virtual networks. In particular, a source of network traffic in the virtual network is equipped with a routing table that causes the source of the network traffic to route the network traffic symmetrically across zones of the virtual network.

Abstract: Embodiments disclosed herein relate to source-based symmetric routing of network traffic in virtual networks. In particular, a source of network traffic in the virtual network is equipped with a routing table that causes the source of the network traffic to route the network traffic symmetrically across zones of the virtual network.

Abstract: A method and system for improving spatial reuse in a wireless local area network (WLAN) by per-client dynamic power management. Each access point of the WLAN associates each of its clients with a minimum power level. A central controller of the WLAN generates a schedule for transmission at different power levels, and each access point varies its transmission power level based on the schedule. An access point transmits data packets, at the scheduled transmission power level, to clients associated with a minimum power level that is less than the scheduled power level.

Abstract: Traditional networked file systems like NFS do not extend to wide-area due to network latency and dynamics introduced in the WAN environment. To address that problem, a wide-area networked file system is based on a traditional networked file system (NFS/CIFS) and extends to the WAN environment by introducing a file redirector infrastructure residing between the central file server and clients. The file redirector infrastructure is invisible to both the central server and clients so that the change to NFS is minimal. That minimizes the interruption to the existing file service when deploying WireFS on top of NFS. The system includes an architecture for an enterprise-wide read/write wide area network file system, protocols and data structures for metadata and data management in this system, algorithms for history based prefetching for access latency minimization in metadata operations, and a distributed randomized algorithm for the implementation of global LRU cache replacement scheme.

Abstract: A multipath routing architecture for large data transfers is disclosed. The architecture employs an overlay network that provides diverse paths for packets from communicating end hosts to utilize as much capacity as available across multiple paths while ensuring network-wide fair allocation of resources across competing data transfers. A set of transit nodes are interposed between the end-hosts and for each end-to-end connection, a transit node can logically operate as an entry gateway, a relay or exit gateway. Packets from the sender enter the entry node and go to the exit node either directly or through one of a plurality of relay nodes. The exit node delivers the packets to the receiver. A multipath congestion control protocol is executed on the entry node to harness network capacity for large data transfers.

Abstract: A method according to the invention includes determining a PHY layer model for a single interferer in an 802.11 wireless network responsive to an input of measured pair wise of at least one of a delivery ratio and received signal strength RSSI values in the 802.11 wireless network; ascertaining a deferral probability for a given node in the network in the presence of multiple interferers in a MAC layer model of the 802.11 network responsive to the determining step in the PHY layer model; and deriving from the ascertaining step at least one of sending capacity in the presence of multiple interferers, packet collision probability in the presence of multiple interferers and available capacity in a given link for a corresponding link delivery ratio.

Abstract: In accordance with the invention, a method includes i) obtaining first for each AP hopping sequences of other interfering APs; and ii) determining for the AP a respective hopping sequence that maximizes each APs throughput. Preferably, the step of determining comprises for each slot AP choosing a channel that minimizes the number of edges which violate a k-coloring property. In an exemplary embodiment, the method further includes the step of the AP selecting one of (a) a channel uniformly at random from all such channels and (b) selecting a channel that distributes interference evenly as possible among neighboring APs.

Abstract: A method includes determining for each access point and each associated client that has traffic to exchange with the access point in either directions of a link a pattern of slots of times that causes minimum interference to clients of other access points in a wireless local area network; deriving a conflict graph of pair wise patterns of different access points representing which patterns conflict on a particular client, the conflict graph representing which patterns of the slots cannot be scheduled simultaneously in a slot so as to avoid interference; and generating a schedule for each access points in the slots such that no two conflicting patterns for two different access points are scheduled in the same slot.

Abstract: A system and method for path provisioning in a network calculates an optimal path using a greedy algorithm with backtracking to execute service level agreements (SLAs). More specifically, a sequential path shifting (SPS) algorithm compares a cost of a suboptimal path for a present quadruplet with the cost of switching a path for a previous quadruplet configured for alteration. If the present path is already an optimal path, then no further operations are performed. However, if the cost of a suboptimal path is greater than the switching cost, the previous path is altered so that an optimal path may be configured for the present quadruplet. Otherwise, the present quadruplet maintains its existing path. The capacity of the network is iteratively adjusted to compensate for path selection. The present system may be applied to a differentiated services network or an optical network.

Abstract: A method and system for improving spatial reuse in a wireless local area network (WLAN) by per-client dynamic power management. Each access point of the WLAN associates each of its clients with a minimum power level. A central controller of the WLAN generates a schedule for transmission at different power levels, and each access point varies its transmission power level based on the schedule. An access point transmits data packets, at the scheduled transmission power level, to clients associated with a minimum power level that is less than the scheduled power level.

Abstract: A method for sharing window-based joins includes slicing window states of a join operator into smaller window slices, forming a chain of sliced window joins from the smaller window slices, and reducing by pipelining a number of the sliced window joins. The method further includes pushing selections down into chain of sliced window joins for computation sharing among queries with different window sizes. The chain buildup of the sliced window joins includes finding a chain of the sliced window joins with respect to one of memory usage or processing usage.

Abstract: A multipath routing architecture for large data transfers is disclosed. The architecture employs an overlay network that provides diverse paths for packets from communicating end hosts to utilize as much capacity as available across multiple paths while ensuring network-wide fair allocation of resources across competing data transfers. A set of transit nodes are interposed between the end-hosts and for each end-to-end connection, a transit node can logically operate as an entry gateway, a relay or exit gateway. Packets from the sender enter the entry node and go to the exit node either directly or through one of a plurality of relay nodes. The exit node delivers the packets to the receiver. A multipath congestion control protocol is executed on the entry node to harness network capacity for large data transfers.

Abstract: A method of transporting Voice-Over-Internet-Protocol Packets in a wireless mesh network wherein VoIP packets from independent call flows are aggregated prior to transmission over multiple hops of the wireless network. Significant performance improvements are realized including the number of simultaneous VoIP calls supported and overall Quality-of-Service (QoS) for the individual calls.

Abstract: In an infrastructure solution for content-based forwarding, filter pipelining enables handling of the high-rate message streams. Documents are distributed in the network by forwarding from publisher proxy servers to attribute trees associated with particular attributes in the message. The trees filter the messages based on attribute values, and deliver the messages to subscriber proxy servers for predicate-based distribution to subscribers. To maximize throughput, the attribute trees utilize the concept of weak filtering, wherein a message may be delivered to a node in the attribute tree that is associated with a range of attribute values that does not include the attribute value of the message.

Abstract: Disclosed is a data replication technique for providing erasure encoded replication of large data sets over a geographically distributed replica set. The technique utilizes a multicast tree to store, forward, and erasure encode the data set. The erasure encoding of data may be performed at various locations within the multicast tree, including the source, intermediate nodes, and destination nodes. In one embodiment, the system comprises a source node for storing the original data set, a plurality of intermediate nodes, and a plurality of leaf nodes for storing the unique replica fragments. The nodes are configured as a multicast tree to convert the original data into the unique replica fragments by performing distributed erasure encoding at a plurality of levels of the multicast tree.

Abstract: Traditional networked file systems like NFS do not extend to wide-area due to network latency and dynamics introduced in the WAN environment. To address that problem, a wide-area networked file system is based on a traditional networked file system (NFS/CIFS) and extends to the WAN environment by introducing a file redirector infrastructure residing between the central file server and clients. The file redirector infrastructure is invisible to both the central server and clients so that the change to NFS is minimal. That minimizes the interruption to the existing file service when deploying WireFS on top of NFS. The system includes an architecture for an enterprise-wide read/write wide area network file system, protocols and data structures for metadata and data management in this system, algorithms for history based prefetching for access latency minimization in metadata operations, and a distributed randomized algorithm for the implementation of global LRU cache replacement scheme.

Abstract: A scalable broker publish/subscribe broker network using a suite of active load balancing schemes is disclosed. In a Distributed Hashing Table (DHT) network, a workload management mechanism, consisting of two load balancing schemes on events and subscriptions respectively and one load-balancing scheduling scheme, is implemented over an aggregation tree rooted on a data sink when the data has a uniform distribution over all nodes in the network. An active load balancing method and one of two alternative DHT node joining/leaving schemes are employed to achieve the uniform traffic distribution for any potential aggregation tree and any potential input traffic distribution in the network.

Abstract: Disclosed is a method and apparatus for delivering information of interests from content providers to clients via a data network. A network architecture includes two types of edge servers, referred to as forward proxy servers and reverse proxy servers. The forward proxy servers are assigned to serve particular clients with respect to particular information and the reverse proxy servers are assigned to serve particular forward proxy servers with respect to particular information. Each of the forward proxy servers stores information identifiers associated with information for which the forward proxy server is assigned to serve to at least one client. Each of the reverse proxy servers stores information identifiers and the associated forward proxy servers that the reverse proxy server is assigned to serve with respect to information associated with the information identifiers.

Abstract: A system and method are herein disclosed for parallel streaming of stored media from multiple sources. The architecture utilizes the notion of indirect streaming and provides a local proxy streaming server which is responsible for interacting with the multiple servers and scheduling downloads of media blocks and for dealing with possible rate fluctuations and server failures.

Abstract: Disclosed is a content based router, system and method of operation. Upon receipt of a data packet at in ingress router, the ingress router matches the content of the data packet against stored user subscriptions. In one embodiment, the content is described using XML data and the user subscriptions are defined by XML queries. The router assigns a routing label to the data packet based on the matching, and transmits the data packet to a second network router. Intermediate routers along the packets path then use the assigned label in combination with stored routing tables in order to determine next hop routing. Upon receipt at an egress router, the content of the message is matched against user subscriptions for those users serviced by the egress router, and the egress router provides the data packet to those end users whose subscriptions match the content. The assigned routing labels may define routing paths or routing trees.