Abstract: In an asynchronous message queuing network, a data processing method of finding a lost message includes the steps of: sending a first message from an originating data processing unit to an intermediate data processing unit, the message including an indication that the message is traceable; sending a tracer message from an originating data processing unit to an intermediate data processing unit, the tracer message identifying the first message as a lost message which the originating data processing unit would like to find; at the intermediate data processing unit, upon receiving the tracer message, checking to determine whether the first message exists within the intermediate data processing unit, and sending a reply message back to the originating unit if the first message is found within the intermediate data processing unit; and at the intermediate data processing unit, if the first message is not found within the intermediate data processing unit, determining whether the first message has passed through th

Abstract: A data conferencing system includes at least two computer workstations linked by a data network. Each computer workstation is able to store and display an electronic sheet, the electronic sheet being logically divided into a set of cells, each cell being able to contain a single character. A user can select a portion of the electronic sheet, a portion comprising at least one cell, and then perform different editing operations on the selected portion of the electronic sheet. Updates resulting from editing the electronic sheet are then distributed to the other computer workstations in the data conferencing system, so that all the workstations in the data conferencing system share the same electronic sheet.

Abstract: A data communications apparatus connected to a network through which datagrams flow from the data communications apparatus to at least one other data communications apparatus also connected to the network, the apparatus having: a means for receiving data which is to be transmitted over the network, such data being broken up into data records; and a means for packing the data records into datagrams for transmission over the network, including a means for assigning data records to datagrams; wherein the means for packing takes the data records out of sequential order when assigning data records to datagrams.

Abstract: A method for securing sparse access control list (ACL) data in a relational database used as a backing store for a hierarchical-based directory service. The sparse ACL data is secured in a plurality of tables. An owner table stores data objects with explicitly set ACLs. A propagation table stores data on whether individual ACLs are inherited by descendant objects. A permissions table stores data regarding permissions which a user may perform on an object. A source table stores data for a set of ancestor objects having respective ACLs for each of a set of descendant objects. Preferably, the tables are stored in the relational database together with the objects. For a given object, data in the tables is used to determine the given object's entry owner and ACL. The inventive technique has particular applicability in a Lightweight Directory Access Protocol (LDAP) directory service having a relational database as a backing store.

Abstract: A communications system may be used for transmitting and/or receiving data over a network. The communications system includes means responsive to requests for a desired quality of service specifying at least two quality of service parameters, such as bandwidth, latency, error rate, and so on, for determining whether or not the requested quality of service is available. The quality of service requests specify the desired quality of service in terms of logical expressions involving two or more of said at least two quality of service parameters. This allows, for example, a desired quality of service to accept a higher error rate if the available bandwidth is higher. In the preferred embodiment, each quality of service parameter is specified in terms of a range between minimum and a maximum acceptable values.

Abstract: A data retrieval system in which a plurality of objects having a multi-level hierarchical relationship are stored is disclosed. Thus, each object has a respective parent and a set of children. The system includes an index table comprising a respective name and associated identifier for each object, and a data table comprising a respective set of attributes and a position key associated with each object in the system. Each position key comprises a series of components, each component corresponding to a level of the hierarchy. A first component of said key stores the identifier of an associated object, and each successive component stores the identifier of the parent of the object stored in the previous component.

Abstract: Provided is a method and apparatus for improved access to material via the World Wide Web Internet service. Web page URLs are stored as attribute-values of directory objects and Web page hyperlinks to those directory objects are provided together with access logic responsive to the hyperlinks for retrieving the URLs for use by a client. This indirect access to Web pages via hyperlinks to directories has significant advantages for Web page organization and facilitates more flexible methods of Web page access than the known use of hyperlinks which include URLs pointing directly to the target Web pages.

Abstract: A data retrieval system stores a plurality of objects having a multi-level hierarchical relationship, each object having a respective parent and a set of children. The system stores one or more base tables, the or each base table comprising a respective set of attributes associated with a sub-set of objects in the system, and generates for the or each base table a respective complementary table, the or each complementary table comprising a set of attributes excluding the attributes of the associated base table. The system further includes an expression optimiser adapted to interpret a query comprising an expression including one or more operations, each operation having a respective operator and one or more associated operands. The optimser tracks a number of objects associated with the or each operation and any attributes associated with the operation; and re-formulates the expression accordingly.

Abstract: A communications system may be used for transmitting and/or receiving data over a network. The system needs to exchange capability information with other systems in the network, in order to determine which forms of communication can be mutually supported. The exchange of information includes logical expressions involving two or more parameters. This allows, for example, a system to indicate that a higher error rate will occur if the throughput is increased. In the preferred embodiment, each capability parameter is specified in terms of a range between a minimum and a maximum acceptable value.

Abstract: A system and method for establishing a communication channel between a source node and a destination node via a heterogeneous communication network comprising at least one intermediate node is disclosed. A request for a communication channel having specified characteristics is issued by the source node to the most immediately adjacent of a possible plurality of intermediate nodes. Each intermediate node determines whether or not it has the available communication resources to support the request. If so, sufficient communication resources are reserved in order to support the request and the request is forwarded to the next intermediate node. The determination by each intermediate node is continued until the destination is reached. After determination by the intermediate node as to whether or not the communication channel can be supported, an indication reflecting the determination is returned to the source node via the intermediate nodes.

Abstract: A programmable workstation for collaborative working in a network comprises a conventional operating system and network control layer for controlling physical routing of data between nodes. A collaborative application subsystem which interfaces with conventional telephones is responsive to a predetermined call from a collaboration call manager to establish the call manager at the node to handle incoming events which are not specific to any application program instances at the node.

Abstract: A programmable workstation for collaborative working in a network comprises a conventional operating system and a network control program layer. Additionally, the workstation includes a collaborative application support subsystem for interfacing with application programs. The subsystem is responsive to predetermined application program calls to create a logical network model of a collaborative environment. The model comprises sharing sets of application programs, which share data and resources across nodes and logical dedicated data channels connecting members of the sharing set. The subsystem cooperates with the network layer to establish the physical links necessary to implement the model in a physical network, transparently to the application program.