Lucent Technologies Inc.

Alcatel-lucent USA Inc.

Yuri J Breitbart

Rajeev R Rastogi

Abraham Silberschatz

Srinivasan Seshadri

Minos N Garofalakis

Henry F Korth

Raghavan V Komondoor

Yigal Bejerano

Clifford Eric Martin

Stephen Michael Blott

Vinod Anupam

Bharat Kumar

Amit Kumar

Juliana Freire Silva

Thomas M Cliff, Jr

Ariel Orda

Alexander Sprintson

Frank Frastaci, Jr

Radek Vingralek

A system for, and method of, determining a physical topology of a network having multiple subnets. In one embodiment, the system includes: (1) a skeleton path initializer that uses addressing information from elements in the network to develop a collection of skeleton paths of direct physical connections between labeled ones of the elements, the skeleton paths traversing multiple of the subnets and (2) a skeleton path refiner, coupled to the skeleton path initializer, that refines the collection by inferring, from the direct physical connections and path constraints derived therefrom, other physical connections in the skeleton paths involving unlabeled ones of the elements.

System and method for determining the physical topology of a network having multiple subnets

Systems and methods for provisioning QoS paths with restoration in a network. In one embodiment, one system includes: (1) a primary path generator configured to identify a suitable primary path between source and destination nodes in a network, (2) an auxiliary graph generator, associated with the primary path generator, configured to construct a directed auxiliary graph from an undirected graph representing the network by reversing each link in a primary QoS path of the undirected graph and replacing each other link in the undirected graph by two directed links, (3) a walk identifier, associated with the auxiliary graph generator, configured to identify a walk in the auxiliary directed graph corresponding to a set of bridges in the network and (4) a bridge identifier, associated with the walk identifier, configured to identify a set of bridges in the network such that at least one link of the primary path is protected by a bridge.

System and method for provisioning QoS paths with restoration in a network

Systems and method for selecting open shortest path first (OSPF) aggregates and aggregate weights for a particular area. In one embodiment, an aggregate selecting system includes: (1) a database for containing data pertaining to candidate OSPF aggregates and corresponding weights and (2) an aggregate selector, associated with the database, that selects at least a subset of the OSPF aggregates such that the shortest path length between the particular source and destination subnets resulting from advertisement of a set of weighted aggregates approaches the shortest path length between the particular source and destination subnets irrespective of the advertisement. In one embodiment, a weight selection system includes: (1) a database for containing data pertaining to candidate OSPF aggregates and (2) a weight assigner, associated with the database, that assigns, for the OSPF aggregates, weights based on either an average distance of subnets in the area for a particular area border router (ABR) of the area or a search heuristic.

System and method for optimizing open shortest path first aggregates and autonomous network domain incorporating the same

A personal Web view is created that includes a plurality of Web clippings. Each Web clipping contains information from a user-selected Web page, which can be essentially any Web page that is accessible on any Web server. In creating the page, the user loads a personalization applet into his browser and retrieves each Web page of interest. The applet then generates an access script for automatically accessing that Web page and the user specifies the attributes of the Web clipping derived from that Web page. A specification of the Web view is then stored in a file. When the Web view specification is later replayed, the Web page for each Web clipping is retrieved and the specified information is extracted. The plural Web clippings are then displayed in a browser in accordance with the specified layout.

Method and apparatus for web-site-independent personalization from multiple sites having user-determined extraction functionality

A method and apparatus for communicating files over a communications network in which links, such as hyperlinks, to files are logical in nature, rather than physical in nature, i.e., associated with a particular electronic address. An up-to-date replication directory is maintained on each server and each server inserts current physical references corresponding to a file's logical references into a requested parent file, along with a reference to a server selection program, before the parent file is transmitted to the requesting client. The server selection program selects physical references in the order of their likelihood of providing the fastest response. If a queried server does not currently store the file, an alternate server is queried. Servers communicate with each other to create and delete replicas of files and to make corresponding updates to each server's replication directory.

Method and apparatus for retrieving a network file using a logical reference

Duplicate processing at network operators is avoided by applying once-only processing at operators which are adjacent to either the source or destination host of a data packet. An operator is adjacent to a host if there exists a path between the operator and the host containing no other operators. In one embodiment, an operator determines that it is adjacent to a host if it receives a special broadcast data packet from the host. To ensure that no other operators receive the special broadcast data packet, the adjacent operator drops the packet. In another embodiment, operators determine whether they are adjacent to identified hosts by transmitting special ping packets to the hosts. If an operator receives a ping response from the host, the operator determines that it is adjacent to the host. To ensure that only adjacent operators receive ping responses, intervening operators drop special ping packets received from other operators.

Method and apparatus for applying once-only processing in a data network

Physical connectivity is determined between elements such as switches and routers in a multiple subnet communication network. Each element has one or more interfaces each of which is physically linked with an interface of another network element. Address sets are generated for each interface of the network elements, wherein members of a given address set correspond to network elements that can be reached from the corresponding interface for which the given address set was generated. The members of first address sets generated for corresponding interfaces of a given network element, are compared with the members of second address sets generated for corresponding interfaces of network elements other than the given element. A set of candidate connections between an interface of the given network element and one or more interfaces of other network elements, are determined. If more than one candidate connection is determined, connections with network elements that are in the same subnet as the given network element are eliminated from the set.

Determination of physical topology of a communication network

A real-time event processing system (EPS) for processing a sequence of events generated by one or more applications. In an illustrative embodiment, the EPS includes a set of real-time analysis engines (RAEs) operating in parallel, e.g., a set of clusters each including one or more RAEs, and one or more mappers for mapping a given input event to a particular one of the clusters. A main-memory database system is coupled to the RAEs, and the RAEs process events associated with input streams from one or more data sources and deliver output streams to one or more data sinks. The data source and data sinks may be, e.g., network elements, clients, databases, etc. The events are processed in accordance with services implemented in the RAEs, and utilize data stored in a memory portion of the main-memory database system accessible to the RAEs. The data may include, e.g., a subscription table storing subscription information indicating the service or services that should be executed for a given event. The services are generated in a service authoring environment (SAE) in the EPS, using a declarative language. The SAE generates the services in the form of object code components, e.g., dynamically linked libraries, which may be dynamically linked into the RAEs without interrupting event processing. Recovery information regarding a recovery point for a given RAE or set of RAEs in the EPS may be stored in a memory portion of the main-memory database system, and utilized to implement a roll-back of the RAE to the recovery point.

Real-time event processing system with service authoring environment

A system for, and method of, ensuring serialization of lazy updates in a distributed database described by a directed acyclic copy graph. In one embodiment, the system includes: (1) a timestamp module that creates a unique timestamp for each of the lazy updates and (2) a propagation module, associated with the timestamp module, that employs edges of the directed acyclic copy graph to propagate the lazy updates among replicas in the distributed database according to said unique timestamp and ensure the serialization.

Timestamp-based system and method for serializing lazy updates in a distributed database

A system for, and method of, ensuring serialization of updates from a replica site in a distributed database that is described by a copy graph and a distributed database incorporating the system or the method. In one embodiment, the system includes: (1) a directed acyclic copy graph (DAG) creation module that identifies backedges in, and removes the backedges from, the copy graph to yield a DAG and (2) a propagation module, associated with the DAG creation module, that initially employs eager updating to propagate the updates along the backedges and thereafter employs lazy updating to propagate the updates along edges of the directed acyclic copy graph to ensure the serialization.

System and method for serializing updates to ancestor sites in a distributed database

A system for, and method of, ensuring serialization of lazy updates in a distributed database described by a directed acyclic copy graph. In one embodiment, the system includes: (1) a forest construction module that creates a forest having trees and edges from the directed acyclic copy graph and (2) a propagation module, associated with the forest construction module, that employs the edges of the forest to propagate the lazy updates among replicas in the distributed database and ensure the serialization.

System and method for serializing lazy updates in a distributed database without requiring timestamps

The invention provides protocols for managing transactions operating on replicated data items at multiple physical sites in a distributed database system. The protocols make use of dynamically changing sets of data items referred to as 'virtual sites' and a replication graph or other suitable globally consistent representation of the relationships between the transactions and the virtual sites. Illustrative embodiments of the invention include a static global serializability (SGS) protocol, a commit-oriented protocol (COP) and a multiversion optimistic protocol (MOP). The SGS protocol broadcasts the data access set of a given transaction to all physical sites, and applies the Thomas Write Rule (TWR) to write-write conflicts on secondary copies of data items. The COP protocol defers testing of the replication graph until a transaction is ready to commit, and each transaction is allowed to proceed at its origination site independently of other transactions that are executing at other sites. The MOP protocol uses two versions of each data item to ensure global multiversion serializability. The two versions are the current version of the data item, and a 'last certified version' of the data item. All read-only transactions read the last certified version, and can therefore proceed without delay. The protocols ensure global serializability while substantially reducing communication overhead relative to conventional protocols.

Concurrency control protocols for management of replicated data items in

Method and system for managing transactions operating on replicated data items at multiple physical sites in a distributed database system. The transactions include local transactions each being processed at one of the physical sites and global transactions each being processed at multiple physical sites. Each transaction originates at one of the physical sites, and is permitted to read data items only at that physical site. In addition, only transactions originating at a physical site at which a primary copy of a data item is located are permitted to update that data item. A number of virtual sites are defined such that a given virtual site VS.sub.i.sup.j at a particular point in time includes a set S.sub.i.sup.j of all data items at a physical site s.sub.j that a given transaction T.sub.i has accessed from an initial operation up to that point in time. A replication graph is maintained to represent the relationships between the transactions and the virtual sites. The replication graph includes a first set of nodes for the transactions, and a second set of nodes for the virtual sites. A node for a transaction T.sub.i and a node for a virtual site VS.sub.i.sup.j are connected in the graph if a schedule of transaction operations includes a write operation by transaction T.sub.i on a replicated data item in the set of data items associated with virtual site VS.sub.i.sup.j. The replication graph is maintained as part of a concurrency-control protocol and the absence of cycles in the graph may be used to indicate whether a given schedule is globally serializable.

Growing community of inventors

Silver Lake, OH, United States of America

Yuri J Breitbart