Abstract: A barrier synchronization system in a distributed computing environment. A group of members, including a plurality of related processes executing on one or more processors of the distributed computing environment, is provided a protocol having a dynamic number of synchronization phases. The protocol is voted on by one or more members of the group to determine how the protocol should proceed for the group of members. The protocol may complete successfully, continue to another synchronization phase or be rejected. The group of members determines how many synchronization phases the protocol is to include.

Abstract: A transmitting device and a receiving device are interconnected through two transmission paths, i.e. a data signal line for transmitting serial data, and a delimiting signal line for transmitting a delimiting signal. The delimiting signal causes the receiving device to recognize breaks between bits when the consecutive bits of the transmitted serial data have the same value. The level of the delimiting signal remains unchanged in the event of a change in the logical value of consecutive bits of the transmit data. The level of the delimiting signal is changed when consecutive bits of the transmit data have the same value. The receiving end, receiving the data signal and delimiting signal, reads as digital data the logical value of each bit in the data signal by regarding a point of time of a level change in either one of the data signal and delimiting signal as a break between bits.

Abstract: In a client having (i) an upstream device driver for controlling an upstream device which sends data to a server; (ii) a downstream device driver for controlling a downstream device which receives data from the server; and (iii) a dialer application for establishing an upstream connection using the upstream device driver, the present invention initiates a connection in response to upstream traffic generated by an application including the steps of receiving the upstream traffic in the downstream device driver; constructing a dial packet in the downstream device driver in response to the upstream traffic; transferring the dial packet from the downstream device driver to the dialer application; and, issuing a call command to the upstream device driver.

Abstract: In a communication network wherein a management station is connected to at least one agent station, an execution request message is first transmitted from the management station to the agent station for requesting it to execute a process. In response, the agent station estimates a length of time taken to execute the process and transmits a first reply message to the management station, and subsequently estimates a length of time remaining to complete the execution of the process. The management station sets a timer according to the length of time contained in the first reply message and starts the timer. When the timer expires, the management station transmits a time request message to the agent station. In response, the agent station transmits a second reply message containing the remaining time. In response to the second reply message, the management station determines that the requested process has been executed if the remaining time is zero.

Abstract: A device and method to control a node within a network is disclosed. The node can have any number of ports N where N is an integer greater than one. The device has N-port modules, corresponding to the number of ports in the node, each port module associated with one port for controlling reception and transmission of information through the associated port. The port modules are substantially identical and the device can be manufactured by replicating N-port modules, one port module for each port. The port modules have a priority within the node. The priority can be created by connecting the port modules in a daisy chain configuration. The port module having the highest priority compares the unique identifier of the node with the unique identifier being received by the port associated with the highest priority port module. The results of this comparison are sent to the next highest priority port module.

Abstract: Apparatus, and accompanying methods for use therein, for an ISDN LAN modem that is suited for small user environments and which contains an internal ISDN router having a self-contained network hub for inter-connecting multiple network devices, such as workstations, to each other through a local area network (LAN) and for permitting each of those devices to each gain access through the router to any one of a number of different remote networks. Through use of a multi-tiered routing hierarchy including both destination- and source-based routing, the LAN modem accommodates several modalities of network communication not heretofore possible in a conventional router. Specifically, several different workstations can simultaneously communicate through the LAN modem with a common remote network and share a single user account at a corresponding network service provider.

Abstract: A method of synchronizing an initiating processing unit in a multi-processor computer system with other processing units in the system, by assigning a unique tag for each processing unit, and issuing synchronization messages which include the unique tag of an initiating processing unit. The processing units each have a snoop queue for receiving snoop operations and corresponding tags associated with instructions issued by an initiating processing unit, and the processors examine their respective snoop queues to determine whether any snoop operation in those queues has a tag which is the unique tag of the initiating processing unit. A retry message is sent to the initiating processing unit from any of the other processing units which determine that a snoop operation in a snoop queue has a tag which is the unique tag of the initiating processing unit.

Abstract: The present invention is an object-oriented apparatus stored in the memory of a computer system for executing a method for synchronizing schemas between a database and an object-oriented repository. The method includes the steps of initializing a variable, object X, which is of type, Type, with the object on which this method was called and obtaining values for each attribute of the object X from the database. Next, for each attribute of the object X, a comparison is made of the value obtained in the preceding step with value of attribute stored in the repository. A determination is next made as to whether or not any differences were found in the preceding step. If no differences were found, then a determination is made as to whether or not there are more attributes in the object X, and if so, repeat all steps except the first one.

Abstract: A way of synchronizing the contents of commonly-owned mailboxes (108, 111) in disparate messaging systems, such as an e-mail system (100) and a multimedia system (101), networked via the Internet (102). The e-mail system uses the existing auto-forwarding feature (115) of the Internet e-mail community to send a copy of every message arriving at the e-mail mailbox to the other system's synchronized mailbox. The other system applies a 3-part synchronization rule (113) to every message (200) arriving at its synchronized mailbox. If it detects a syncmark (204)--an identifier--of its own mailbox in the header (201) of the message, indicating that the message was previously copy-forwarded from this system, it just deletes the message.

Abstract: A barrier synchronization program product in a distributed computing environment. A group of members, including a plurality of related processes executing on one or more processors of the distributed computing environment, is provided a protocol having a dynamic number of synchronization phases. The protocol is voted on by one or more members of the group to determine how the protocol should proceed for the group of members. The protocol may complete successfully, continue to another synchronization phase or be rejected. The group of members determines how many synchronization phases the protocol is to include.

Abstract: A method for displaying streamed digital video data on a client computer. The client computer is configured to receive the streamed digital video data from a server computer via a computer network. The streamed digital video data is transmitted from the server computer to the client computer as a stream of video frames. The method includes receiving a first plurality of video frames at the client computer. The plurality of video frames represents a subset of the stream of video frames. The stream of video frames comprises independent playable video frames and dependent playable video frames. The method further includes displaying the first plurality of video frames on a video display terminal associated with the client computer. There is further included issuing a rewind command from the client computer to the server.

Abstract: An apparatus for synchronizing operator commands with a failover process in a distributed system having a control workstation and a plurality of nodes. One of the nodes of the distributed system is designated a primary node and one of the nodes is designated a backup node. The backup node includes a backup daemon for performing a failover process if the primary node fails such that the backup node becomes the primary node. Shell scripts send a command string to be synchronized with the operation of the backup daemon from the control workstation to the backup node. The backup daemon is then checked to determine if the backup daemon is sleeping, and, in the event the backup daemon is sleeping, commands derived from the command string are enqueued in a work queue for processing by the backup daemon. The backup daemon is then awakened such that the derived commands in the work queue are processed.

Abstract: A tightly integrated the palmtop computer system and personal computer system is disclosed. The palmtop computer system and personal computer system synchronize with each other to share information. The synchronization software recognizes different synchronization environments including: synchronizing multiple palmtop computer systems with a single personal computer system, synchronizing a single palmtop computer system with multiple personal computer systems, synchronizing a palmtop computer system with a remote personal computer system across a network using a local personal computer system, and remotely synchronizing with a personal computer system across a telephone line. The synchronization software handles each different synchronization environment appropriately with minimal user interaction.

Abstract: In a computer network of a base station and one or more remote units, data transmission from the base station to the or each remote unit is by way of a wireless (e.g. infrared) signal, and by way of a radio signal in the other direction. Infra-red receivers can be used in the remote units which are cheap and have low power consumption compared with radio receivers, and radio transmitters can be used in the remote units which have low power consumption compared with infra-red transmitters. This therefore facilitates the provision of cheap, battery-powered remote units. The wireless signal is used to send instructions to control selection by each remote unit of a transmission channel for its radio signals.

Abstract: A quiesced and synchronous distributed data processing system includes a primary node, a secondary node and a switch between the primary and secondary nodes. The TOD for the primary node is set depending on the system. The invention sets the TOD for the switch based on the TOD of the primary node. The primary node then verifies the switch TOD. If verified, the TOD for the secondary node is set, based on the TOD of the primary node. Finally, the secondary node self-verifies its TOD.

Abstract: The present invention is directed to a novel system and method for sharing common data and state information between network connected application clients participating in an application session. The application session is invoked by a host client. The host client is responsible for selectively admitting other network connected clients into the application session, and is also the application client that is responsible for distributing a common set of application data for storage at each admitted application client. The application data includes a unique identifier, assigned by the host client, for each application client in the application session. In the event that an application client effects a change to the application data, that change is communicated to each of the other application clients in the session. In this way, each client is always operating on a common set of application data.

Abstract: Entertainment content complementary to a musical recording is delivered to a user's computer by means of a computer network link. The user employs a browser to access the computer network. A plug-in for the browser is able to control an audio CD or other device for playing the musical recording. A script stored on the remote computer accessed over the network is downloaded. The script synchronizes the delivery of the complementary entertainment content with the play of the musical recording.

Abstract: A method and apparatus for interactive communication between a first application program and a second application program over a network having delays. The first application program receives a message from the second application program. The message contains a previous state and one or more projected or future states of an object corresponding to the second application program. Each projected state includes a plurality of possible scenarios, each scenario including an associated probability value indicating a probability of the scenario. An updated state of the object corresponding to the second application program is determined based on the received message and displayed.

Abstract: An external portion or burb of a host computer receives messages from external servers representative of accurate time from one or more peer computers coupled by a network. A process called a client on the external burb processes the messages and then accurately sets a host computer clock. Processes called servers running on an internal burb which may not communicate directly with peers, then access the clock to obtain a correct indication of network time without having to communicate directly with the peer computers. The time is then provided to internal clients. This allows a host computer without an expensive clock to update its clock and enable it to provide accurate time to processes running on the host.

Abstract: A system includes a general synchronization module at the client site for operating within a first firewall and for examining first version information to determine whether a first workspace element has been modified. The system further includes a synchronization agent at a global server for operating outside the first firewall and for forwarding to the general synchronization module second version information which indicates whether an independently-modifiable copy of the first workspace element has been modified. A synchronization-start module is maintained at the client site for operating within the first firewall and for securely initiating the general synchronization module and the synchronization agent when predetermined criteria have been satisfied.

Abstract: An information processing system is connected to a common storage and executes programs by use of processors. This system includes a common storage; a plurality of processors, connected to the common storage.

Abstract: An arrangement for monitoring clock frequency variations on a peripheral bus is provided to improve operations of the peripheral device despite changes in the clock frequency. In one aspect of the arrangement, a processing unit is coupled to a host bus which in turn is coupled to a peripheral bus which is coupled to a peripheral device. A monitoring arrangement is provided which detects a change in the clock frequency of the peripheral bus and determines if the frequency change exceeds a threshold associated with the peripheral device. If the threshold is exceeded, the peripheral device is informed that the clock frequency of the peripheral bus has changed. A peripheral device operating a different operating levels may use the information from the monitoring arrangement to alter the operating level of the peripheral device to conform to the new bus clock frequency.

Abstract: An apparatus and method for providing PCI slot expansion. An asynchronous PCI to PCI bridge for insertion into a host PCI slot is coupled via a cabled PCI bus to an expansion module. The bridge establishes two distinct time domains. An expansion clock signal is generated and its timing matched for consistent arrival throughout the expansion clock domain. An expanded number of PCI slots are thereby available to the host system.

Abstract: Described is a mechanism for dependably managing web synchronization and tracking operations among multiple consumer browsers. A session is created for each of one of the consumer browsers when an individual consumer downloads an initial web page from an HTTP server. A unique ID is assigned to that session. After the session has been created for an individual browser, the information about all activities from that consumer browser will be recorded into the session. Such a mechanism overcomes the difficulty to organize and manage the activities from the multiple consumer browsers that are stateless in nature. An administration browser can select any one of the sessions created, display the activities previously performed in that session, and conduct bi-direction synchronization with the consumer browser associated with the selected session.

Abstract: Described is a mechanism for dependably organizing and managing information for web synchronization and tracking among multiple consumer browsers. A session is created for each of one of the consumer browsers when an individual consumer downloads an initial web page from an HTTP server. A unique ID is assigned to that session. After the session has been created for an individual browser, the information about the all activities from that consumer browser will be recorded into the session. Such a mechanism overcomes the difficulty to organize and manage the activities from the multiple consumer browsers that are in stateless nature.

Abstract: Described is a mechanism for dependably synchronizing data element activities on web pages among a group of browsers. The web browsers retrieve web pages from an HTTP server. Each of the web pages contains at least one data element and embeds a Master Applet and at least one DTS Applet (DTS stands for data tracking and synchronization). In response the data element activities (such as entering data into a data field) performed at a browser, the DTS Applet passes the activities to the Master Applet, which in turn reports the activities (together with the URL of the web page on which the data element activities have occurred) to a tracking server. The tracking server sends the activity report (together with the URL of the web page on which the data element activities have occurred) to the Master Applets at all participant browsers. The participant Master Applets then instruct their respective DTS Applets to display the data element activities on the web page identified by the URL.

Abstract: Described is a mechanism for dependably synchronizing web pages among a group of browsers. Each of the web page embeds an applet. In response the activities (such as loading or unloading of a web page) performed at a browser, the applet reports activities (together with the URL of the web page) to a page synchronizing server, which in turn relays the activities (together with the URL) to all participant browsers. The participant browsers can load and unload the web page according to the report of the activities.

Abstract: A parallel computing system and method having improved performance where a program is concurrently run on a plurality of nodes for reducing total processing time, each node having a processor, a memory, and a predetermined number of communication channels connected to the node and independently connected directly to other nodes. The present invention improves performance of performance of the parallel computing system by providing a system which can provide efficient communication between the processors and between the system and input and output devices. A method is also disclosed which can locate defective nodes with the computing system.

Abstract: One aspect of the invention relates to a method for detecting synchronization violations in a multiprocessor computer system having a memory location which controls access to a portion of memory shared by the processors, the memory location having at least one lock bit indicating whether the portion of memory is locked by one of the processors and a plurality of bits for storing a data value. The method comprises reading the memory location by an individual processor; testing the lock bit to determine whether the portion of memory is locked; if the portion of memory is not locked; asserting the lock bit to indicate the portion of memory is locked; incrementing the data value to represent a global access count; writing the lock bit and the data value back to the memory location; and incrementing a data value stored in a memory location associated with the individual processor to indicate an individual access count by the individual processor.

Abstract: A distribution element composed of a crossbar-type switch with four independent ports and direct multicast transfer capability which effects a direct interface to applications with an instruction sets for the distribution element, the sets providing for global memory sharing, synchronization, and lossless flow control.

Abstract: A quiesced and synchronous distributed data processing system includes a primary node, a secondary node and a switch between the primary and secondary nodes. The TOD for the primary node is set depending on the system. The invention sets the TOD for the switch based on the TOD of the primary node. The primary node then verifies the switch TOD. If verified, the TOD for the secondary node is set, based on the TOD of the primary node. Finally, the secondary node self-verifies its TOD.

Abstract: A method and apparatus for improving the performance of Building Environmental Control networks by efficiently storing network routing information and by checking that the data exchanged between two computer applications operating on the network is consistent. The present invention efficiently stores network routing information by having the Building Environmental control network routers only store routing information when that router acts as a bridge for communicating that message further downstream. The present invention also checks that the exchange of data between two building environmental control applications is done by forming a special identifier from the existing data and using that identifier to validate data exchanges. The special identifier is formed by segmenting one field found within the data and having a portion of that segmented field be indicative of the identifying name of the data.

Abstract: A handheld computing device is used to copy files from the screen of a fixed computer. The display of the handheld device is linked to that of the underlying computer and file and directory icons together with their underlying files are copied to the handheld device. Files from the handheld device can also be transferred to the fixed computer. When a user is running a program on the fixed computer, he may capture the state of that computer and transfer everything needed to permit execution of that program to continue uninterrupted on the handheld device. Thus files and executing programs may be lifted from the fixed computer and used on the handheld device.