Lucent Technologies Inc.

Bulent Yener

Avishai Wool

Yuval Shavitt

Xiaodong Sun

Marvin Kunio Nakayama

James Igor Pelech

A method for mapping a network, in accordance with the present invention, includes providing distance measurements between tracers in the network, determining routes along which the distance measurements are made, and creating a system of equations which links the distance measurements between the nodes with a sum of the delays between the nodes which comprise the routes. Additional information is extracted about distances of subpaths of the routes to provide additional details to a map of the network. The additional information provides a capability of estimation of distances between nodes without tracers.

Method and apparatus for network mapping using end-to-end delay measurements

A system and method for providing secured file dispersal and access control protocols based on combinatorial techniques to reduce the security overhead associated with information retrieval systems employing parallel access to mirror sites. In one aspect, a system for providing secured access to information on a network comprises a plurality of mirror servers; and at least one trusted authority (TA) server comprising file partition means for partitioning a file into a plurality of elements; combinatorial file dispersal means for permuting the elements of the file and assigning each of the permuted elements to at least one of a plurality of blocks; distribution means for distributing the plurality of blocks to at least a portion of the plurality of mirror servers; and key generation means for generating a combinatorial key comprising access information for accessing the mirror servers having blocks of the file and reconstruction information for reconstructing the file from at least a portion of the plurality of blocks.

Light weight security for parallel access to multiple mirror sites

A method and message router that breaks up files to be transferred over a network connection within a specified deadline into fixed-sized pieces. Each piece contains enough redundant information so that a subset (but not all) of the pieces will be sufficient to construct the file at the destination. The method and router determine optimal values for the number of pieces the file should be split into and the subset of pieces required to reconstruct the full contents of the file in order to maximize the probability that the file can be reconstructed at the destination by the specified deadline. The method and router provide an expected QoS guarantee by using redundancy with a deadline rather than reservations.

Redundant routing with deadlines in data networks

A method and apparatus are disclosed for designing multi-ring networks based on generalized quadrangles of combinatorial design theory, together with a scaling algorithm for realizing networks of arbitrary size. Multi-ring networks based on generalized quadrangles ensures that the path between any two nodes is either confined to a single ring, or traverses exactly two rings (passing through a single bridge node), referred to herein as the &ldquo;one-bridge property.&rdquo; The one-bridge property allows the construction of networks with small rings and low degree, while also permitting efficient congestion-free flow control protocols. Routing, access and flow control protocols are provided for the multi-ring network that capitalize on the combinatorial properties of the disclosed multi-ring networks. A &ldquo;self-routing&rdquo; routing protocol is disclosed wherein a source node does not need to know how to route a packet to a destination node that is not a neighbor. The access control mechanism disclosed herein utilizes a quota counter, k, and allows each node to transmit up to the predefined quota of k packets on each ring, R , that the node belongs to, during any cycle. A set of flow control buffers, consisting of a local queue, LQ , a remote queue, RQ (x), and a buffer queue, BQ , and a flow control quota matrix, Q , are utilized to implement a flow control mechanism. The routing, flow and access control protocols, together with the disclosed network architecture, ensure that (i) no loss due to congestion occurs inside a network, under arbitrary traffic patterns; (ii) all the packets reach their destinations within a bounded time; and (iii) the bandwidth is allocated fairly and no host is starved.

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New York, NY, United States of America

Bulent Yener