Abstract: The present invention provides improved techniques for managing storage resources, such as disk drives, I/O ports, and the like in a network based storage system according to a user position within the network. Embodiments according to the present invention can provide a relatively high performance storage access environment for the mobile users moving around a wide area. For example, in one applicable environment, there are several data centers in the wide area, and each data center has a local storage system that is connected to the other storage systems through a network. Copies of a user's volume can be made in some of the storage systems. A remote copy function is utilized for making real time copies of the user's volume.

Abstract: A diagnostic system and method for repairing computing devices comprises a diagnostic application running on a same computing system having a failed operating system (O/S). The diagnostic application is provided with access to the file system of the failed O/S image. The diagnostic software application collects relevant configuration information from the file system of the failed O/S image, and transports this information to a proxy system running the same operating system as the computing device being diagnosed. The proxy system utilizes the collected data to diagnose the subject failed O/S system. Once the proxy makes a determination it synthesizes repair information comprising new or modified files and instructions to be transported back to the diagnostic software system to apply. A network connection is provided between the computer running the diagnostic application and the proxy system that enables data to be easily transported between the two systems without human intervention.

Abstract: The present invention provides a method for handling reordered data packets. A method comprises receiving a data packet and determining if the data packet is received out of order. The method further comprises delaying transmission of an acknowledgement indicating that a data packet is missing in response to determining that the data packet is received out of order.

Abstract: Disclosed are systems and methods for controlling transaction draining for error recovery comprising asserting a control signal to prevent system resources associated with a particular error from issuing new requests, dropping transactions tracked by an out-of-order queue, and issuing transactions not tracked by the out-of-order queue.

Abstract: An element management system that can itself be used to perform automatic remote backup of the network elements. A backup procedure is launched on a programmed schedule, to maintain a centrally located copy of the local data stored in the network elements (or their subcomponents). In accordance with a particular embodiment of the present invention, a computer/software system for managing telecommunication network elements includes one or more operator-driven processes which monitor and manage network elements in real time, using at least one telecommunications network control channel. Background processes which remotely back-up information which had been locally stored in ones of said network is automatically initiated.

Abstract: A method is described in which a computing system creates an object containing information that describes a reference. The reference is used to implement a communication session. The computing system serializes the object into a byte stream. The computing system causes the byte stream to be stored outside the computing system so that the communication session can be restored on another computing system should the computing system fail.

Abstract: Automated facsimile monitoring methods, systems, and computer program products can track response data from multiple facsimiles sent to different locations and generate electronically accessible failure reports to allow for error or faults to be tracked and assessed to thereby allow corrective action to be initiated in a more timely manner.

Abstract: In a tape recording apparatus having a write head and a read head, a data block is stored by writing to a tape via the write head. The tape moves past the write head in a predetermined direction and writes a first data block responsive to transmitting the first data block from the computer system. The read head then reads the written data block from the tape. For reading, the tape moves past the read head in the same, predetermined direction as the writing, and the reading of the first data block occurs without reversing the tape movement after the writing of the first data block. Portions of the transmitted and read data blocks are compared and a corruption indication is sent responsive to the comparing.

Abstract: A method for backing up data in a computer system that is occasionally connected to a network is performed by resuming the backup operations even when the backup operations were not successfully completed due to a previous loss to the network connection, according to one embodiment. The backup operations use checksum information to determine changes between a current source file and a version of the backup file. The changes are then used to update the backup file without having to restart the backup operations from the beginning.

Abstract: A system and method for reliably transmitting large amounts of data over a high speed network with large latency, such as a communication satellite based network. A transmitting device transmits data transfer units (DTUs) to one or more receiving devices. The transmitting device forms and transmits burst consisting of reliably delivered sets of multiple DTUs. Both the transmitting device and the receiving devices process multiple bursts in parallel, such that subsequent bursts can be transmitted and received prior to the correct receipt of a previously transmitted burst at all of the receiving devices, and/or prior to receipt of a status report at the transmitting device regarding a previously transmitted burst. The transmitting device operates to transmit subsequent bursts even before the receipt of a status information regarding a previous burst, and the receiving devices process subsequently received bursts while awaiting retransmission of a lost or damaged DTU from a previous burst.

Abstract: In some embodiments an apparatus includes a transmission error detector to detect an error of a transmission of an interconnect and a transmitting agent to retry the transmission in response to the detected error. The apparatus also includes a hard failure detector to detect a hard failure of the interconnect if the retry is unsuccessful, and a transmission width reducer to reduce a transmission width of the interconnect in response to the hard failure detector. Other embodiments are described and claimed.

Abstract: A method is provided for transmitting messages between bus users that are each linked with a communication bus for the purpose of exchanging messages and with a diagnostic device for detecting the failure of the communication bus. In a diagnostic operation mode that is different from the normal operation mode, the bus user receiving the message is requested by the diagnostic device to output the message to the communication bus, thereby diagnosing a message transmission between two bus users.

Abstract: Apparatus and methods to improve the speed, scalability, robustness and dynamism of data transfers to remote computers across a network are provided. The fully distributed data transfer and data replication protocol of the present invention permits transfers that minimize processing requirements on master transfer nodes by spreading work across the network. The result is higher scalability than current centralized protocols, which are static and cannot guarantee retention of replicated data and files. The present invention further provides for more dynamism and allows fault-tolerance by distribution of functionality. The ability to distribute data is simplified through asynchronous and autonomous data transfer.

Abstract: A method and apparatus for performing power control using control information of a traffic channel in a mobile communication system that transmits the control information of the traffic channel over a control channel.

Abstract: A method and device for managing a data buffer that stores packets for transmission. Packets are loaded into the data buffer, which is managed as a first-in-first-out (FIFO) circular queue, at the tail of the queue. Three sequence numbers index a pointer array addressing the buffer. These sequence numbers correspond to the tail of the queue, the point in the queue from which the next packet is to be transmitted and the head of the queue, corresponding to the last packet acknowledged as correctly received plus one. When a packet is negatively acknowledged, the sequence number corresponding to the next packet to be transmitted is reset to the head of the queue.

Abstract: In the absence of a continuous channel from the mobile terminal that incorporates a CRC in each transmitted frame from which the base station can derive a power control signal for feedback to the mobile station for maintaining the mobile station's pilot Eb/N0 level at a desired target that corresponds to a particular frame error rate, the pilot signal received by the base station from the mobile terminal itself is arranged in a frame format. Each pilot frame is compared with an a prioi known transmitted pilot signal bit pattern to determine whether it has been received in error. In response to a comparison of a received pilot frame with the expected known bit pattern of the pilot frame, an error signal is derived, which in the described embodiment is either a step-up or step-down signal that is fed back to the mobile terminal to increase or decrease its transmitted pilot Eb/N0 level, respectively.

Abstract: In a wireless USB data transfers over UWB, software configures hardware thresholds to control data transfer in a manner that uses bandwidth for good connections over bad connections, given the high error rate experienced with wireless USB. Periodic transfers are first attempted before asynchronous transfers, as long as the periodic transfers are successful. When failures are occurring, the hardware includes a mechanism having a software-configurable threshold specifying the number of errors a given endpoint can tolerate before it is paused in the schedule. By pausing transfer attempts that are likely to again fail, endpoints with successful transfers are favored over those experiencing errors. When the number of active transfers pending exceeds a software-configurable notification threshold for isochronous endpoints, the hardware notifies the software of this state, corresponding to a low-buffer condition at the receiver.

Abstract: In a command line environment, an error object is used to store information about each occurrence of an error during processing of a command-line instruction. In an object-based command line environment, each command in a complex command-line instruction stores sufficient information in the error object to completely describe the error. That information may be later used either by subsequent commands or in conjunction with another command-line instruction to further process the unprocessed resources.

Abstract: Methods and systems for efficient and accurate re-starting of data transfers using volatile data transfer mechanisms, such as pipes, following an error. According to one embodiment, portions of the transferred data can be saved in a fallback file. In addition, checkpoint commands can be periodically provided, upon which much of the data in the fallback file can be overwritten. During the original transmission, the data that has passed through the mechanism can be counted, and a signature for the data that has passed can be accumulated. After certain error conditions, the data in the fallback file can be recovered and passed to the receiving process and the transmission can then be resumed at the point where it had left off. After other errors requiring a complete re-start, a second signature of the re-transmitted data can be accumulated and original and second signatures compared to determine if the data is valid.

Abstract: A method and system for collecting and transmitting data across or through a firewall using HTTP and/or XML between computer systems that do not otherwise grant access to each other. A method and system for preparing data reports using data and report generation modules using HTTP and/or XML between computer systems.

Abstract: The present invention provides an input and output device for computer system storage that can prevent a computer system being fatally damaged by a computer virus, and also provides a software execution method that by using the input and output device, enables trial software, trial data and mail data to be safely tried. For this, a virtual computer system is used that runs on a computer system. Writes to a hard disk in the virtual computer system are made via a disk cache, and whether or not data is transferred from the disk cache to the hard disk is controlled. Application program snapshot data created by the computer system is recorded on a recording medium that is substantially read-only or transmitted to a different computer system. The snapshot data from the recording medium is read or received by the different computer system and a processing by the application program is resumed in the state in which data transfer from the disk cache to the first storage has stopped.

Abstract: A method, system, and computer program product provides automatic and consistent resolution of in doubt branches of a transaction, and which will provide reduced cost of operating the system and improved overall performance of the system. A method of managing transaction branches comprises the steps of beginning execution of a transaction, storing information relating to branches of the transaction in a data structure, iterating over the data structure to identify branches of the transaction that are eligible for an action, executing a first action for at least some branches of the transaction identified as eligible for an action, and changing a state of the transaction and applying a second action to branches of the transaction, if the first action returns an error.

Abstract: Recovering data provided in chunks to a plurality of secondary storage devices includes, for each of the secondary storage devices, discarding data corresponding chunks for which all data thereof has not been received, and, for each of the secondary storage devices, restoring a chunk of data thereto where all of the chunks of data restored to the plurality of secondary storage devices correspond to a particular transmission cycle of primary storage devices that provide data to the plurality of secondary storage devices. Recovering data may also include, following discarding and prior to restoring, for each of the plurality of secondary storage devices having two different chunks, waiting for external intervention to indicate whether to restore a particular one of the chunks. The external intervention may be provided by a host computer that is proximate to at least one of the secondary storage devices or may be provided by a host computer that is proximate to at least one of the primary storage computers.

Abstract: Hitless Switching provides a method of delivering data to a remote point in a reliable fashion. However, no guarantee or acknowledgement is provided that data has been written to a remote storage device. This is problematic for remote data mirroring. Apparatus and methods are provided to guarantee that data arriving at a remote terminal is correctly stored. Interaction with hitless switching and remote optical mirroring systems are described.

Abstract: Methods and systems for utilizing and recording, writing, or logging data regarding system events occurring within a computer are provided. These systems and methods define a unique erased value, such as the hexadecimal value 0FFh, that identifies unused memory records in an event log. When the computer system receives notification that an event has occurred, it searches for the next memory record containing the erased value in a memory record field designated as a search byte field. Once the unused record is found, the event data concerning the event that occurred is stored in the identified memory record, without updating a pointer to the next unused record. A power event method is provided to update the pointer. A utility application is also provides functions for reading, displaying, erasing, and compiling and displaying statistics concerning the event data in the event log independent of a next unused memory record pointer.

Abstract: A communication system and method includes the steps of: a) transmitting an ACK signal indicating a received packet includes no error or a NACK signal indicating the received packet includes error from a reception end to a transmission end, and performing automatic repeat request; b) obtaining reliability of the received packet when demodulating it at the reception end; and c) reporting from the reception end to the transmission end the reliability of the received packet utilizing the ACK/NACK signal by using not less than three levels.

Abstract: An electronic control unit includes a serial communication circuit capable of easily confirming presence or absence of communication error while regular transmission/regular report between master station and sub station are performed timely. First and second control circuit sections 200a (master station) and 200b (substation) communicate mutually via series-parallel converters 117, 127. The master station includes regular transmission device 201 and irregular transmission device 211. The substation includes regular report device 221, confirmation reply device 205 and report reply device 215 relative to transmission data from the master station, and unprocessed data table 204. The confirmation reply device 205 and report reply device 215 confirm whether or not downstream communication from the master station to sub station is normal.

Abstract: I/O measurement data associated with the performance of an I/O operation process is gathered during the I/O process. The I/O measurement data is saved in an IRB memory location specified by a test subchannel instruction. An I/O interrupt signals the completion of the I/O operation process.

Abstract: The invention is a computerized mobile robot with an onboard internet web server, and a capability of establishing a first connection to a remote web browser on the internet for robotic control purposes, and a capability of establishing a second short range bi-directional digital radio connection to one or more nearby computerized digital radio equipped devices external to the robot. The short-range bi-directional digital radio connection will typically have a maximum range of about 300 feet. In a preferred embodiment, this short-range wireless digital connection will use the 2.4 gHz band and digital protocols following the IEEE 802.11, 802.15, or other digital communications protocol.

Abstract: A method for resynchronizing a primary volume in a primary system and a secondary volume in a secondary system over a network includes, when a network connection between the primary system and the secondary system is interrupted, creating a snapshot of the primary volume and determining data updates transmitted from the primary system to the secondary system that were not acknowledged by the secondary system. The method further comprises, when the network connection is reestablished, determining differences between the snapshot and the primary volume, transmitting the differences and the unacknowledged data updates from the primary system to the secondary system, and updating the secondary volume with the differences and the unacknowledged data, wherein the secondary volume becomes an updated copy of the primary volume.

Abstract: An apparatus and method for re-transmitting erroneous packet data is disclosed. Each of the physical layers of the system includes a buffer, a timer, a controller, and a radio frequency unit. The buffer temporarily stores transmitted data in the form of a final data frame capable of being transmitted on a transmission line without any processing. The timer is a time counter adapted to limit the time, for which the transmission end waits for an acknowledgment to a transmission of data after the data transmission is made. If no acknowledgment signal is received when the timer expires the buffered data in the physical layer is re-transmitted. This reduces the data transmission delay resulting from the inter-layer movement of data generated during a re-transmission of erroneous data, and the transmission delay of packet data resulting from overhead time.

Abstract: Methods and systems for managing disk capacity allocated to a data log in a source data storage system during a merge process are disclosed. Data in the data log may be merged into corresponding data on a destination storage system connected to the source data storage system by at least one communication link. In one embodiment a method comprises maintaining a ratio of merge writes out of the data log to writes from a host computer into the data log within a desired range until the write process reaches a predetermined distance from the end of the data log, and quiescing writes from a host computer into the data log until the data log is fully written to the destination storage system.

Abstract: A data transmitting apparatus and a data receiving apparatus, which are capable of retransmitting a packet even when a retransmission request is made by a client after transmitting a session close notice packet to the client. A session is closed by a session closing means 105 when a predetermined period of time has passed after transmitting the session close notice packet, which is generated by a control command generating means 102 as the session close notice packet, from a packet transmitting means 103 to the client.

Abstract: Disclosed are systems and methods for determining time-outs with respect to a plurality of transactions comprising utilizing a first time-out clock for simultaneously determining time-out states with respect to a first set of transactions of the plurality of transactions, and determining when transactions of the first set of transactions have reached a timed-out state of the time-out states.

Abstract: A client system stores messages and sends the messages to a server system. The messages are included in a request formatted according to a protocol that can traverse a firewall. Then the client system waits for a response from the server system. The response will also be formatted according to the protocol that can traverse the firewall. The response will include an indication of which messages the server system received from the client system in the last request. If a certain number of messages accumulate at the client system, or a certain amount of time passes before the response is received, the client system will send a second request. The server system also stores messages and sends the messages to the client system. The server system waits for a first request and a second request from the client system. If the first request has been received and a particular number of messages have accumulated at the server system, then the server system will send a response corresponding to the first request.

Abstract: Reliable multicast communication is provided by sending data from a transmitting device to receiving devices as “bursts” of data transfer units. Each receiving device provides status describing which data transfer units within each previously transmitted burst require retransmission. The transmitting device generates correction data based on this status information by determining a number of subsets of the data transfer units in the burst. Each data transfer unit subset must meet the following condition: if a data transfer unit is included in a given subset, for each receiving device in the group of receiving devices, that data transfer unit must be the only data transfer unit lost by that receiving device and included in that subset. The correction data for a given subset is obtained by applying an exclusive-OR (XOR) operation to all the data transfer units in the subset, and the output is sent to at least one of the receiving devices.

Abstract: The invention is a computerized mobile robotic router with an onboard internet web server, and a capability of establishing a first connection to a remote web browser on the internet for robotic control purposes, and a capability of establishing a second short range bi-directional digital radio connection to one or more nearby computerized digital radio equipped computers or devices external to the robot. The short-range bi-directional digital radio connection will typically have a maximum range of about 300 feet. In a preferred embodiment, this short-range wireless digital connection will use the 2.4 gHz band and digital protocols following the IEEE 802.11, 802.15, or other digital communications protocol.

Abstract: A data management system or “DMS” provides an automated, continuous, real-time, substantially no downtime data protection service to one or more data sources associated with a set of application host servers. To facilitate the data protection service, a host driver embedded in an application server captures real-time data transactions, preferably in the form of an event journal that is provided to other DMS components. The driver functions to translate traditional file/database/block I/O and the like into a continuous, application-aware, output data stream. The host driver includes an event processor that provides the data protection service, preferably by implementing a finite state machine (FSM). In particular, the data protection is provided to a given data source in the host server by taking advantage of the continuous, real-time data that the host driver is capturing and providing to other DMS components.

Abstract: A checkpointing method and system that utilize a write back controller. The system can include a first controller for implementing a first function, wherein the first function comprises part of a checkpoint operation and wherein the checkpoint operation comprises a series of contiguous checkpoint cycles. The system can also include a second controller, the second controller for implementing a second function, wherein the second function comprises a write back operation from a first memory location to a second memory location and wherein the write back operation occurs before a checkpoint cycle ends. Information already at the second memory location can be selectively written back to a third memory location.

Abstract: A validation system is disclosed for validating function of a packet-management unit operationally coupled through a system interface to a processing unit of a processor system. The validation system comprises a user interface for creating an inputting test parameters and test code into the system, a test generator coupled to the user interface, the test generator for generating input packet activity in the form of a packet stream, a model coupled to the test generator for emulating separate and integrated function of the packet management unit, the system interface, and a stream-processing unit and an evaluation software for checking and validating or not validating results. The system validation function relies, in a preferred embodiment, on comparing output results with criteria of the selected test code resulting in an indication of pass or failure of the test. In a preferred embodiment, the system also notifies to cause of failure.

Abstract: It is an object of the invention to provide a channel adapter and a disk array device that can retransmit partial data via an IP network and which are configured to be able to conduct a data guarantee of the partial data. CHA transmit data to host computers. The CHA compute an input guarantee code when the CHA store the data from a cache memory to a local memory. The CHA generate an output guarantee code when the CHA read the data from the local memory and transmit the data to a port unit. In a case where retransmission of partial data is requested after the transmission of the data, the CHA transmit the partial data to the host computers. Thereafter, the CHA again compute the output guarantee code of the data and compare it with the previously computed input guarantee code. In a case where both codes match, it is guaranteed that data transmission has been conducted normally.

Abstract: At a data receiving terminal, if a received-data of a particular time section received from a data sending terminal does not satisfy a predetermined accumulation quality as the result of discrimination by a received-data quality discriminating section, an alternative-data sending requesting section requests a data sending terminal for alternative data satisfying the accumulation quality for the unsatisfied data of the particular time section. The result is that the data receiving terminal can realize both reproduction of data with less sending delay and accumulation of high-quality data.

Abstract: An expert system that provides an analysis of protocol exchanges and protocol relationships across multiple data units, such as packets, of a network and within data units themselves is described. The system collects a number of facts and based on rules governing the data units, new rules and facts are gained from the analysis. The invention is extensible for additional protocols and diagnostics by updating a knowledge database with dynamic rules for any application or protocol desired.

Abstract: The present invention is related to a method and system for interlayer control where a Protocol Data Unit (PDU) is received from a lower protocol layer at a upper layer where the lower and upper layer are both involved in a retransmission function, a re-sequencing function, or both functions. The lower layer signals the upper layer for retransmission of a PDU when the retransmissions of that PDU have been exhausted and failed at the lower layer. The signaling scheme from the lower layer to the upper layer is an ABORT notification. This ABORT notification comes with associated parameters to indicate to the upper layer which PDU can be requested for retransmission from the upper layer.

Abstract: In a data transfer apparatus 10, first, second, third data transmitters 141, 142, 143 are located in a data transmission device 11. Data which must not be influenced by delay of transmission timing of the other data are stored in first, second, third data transmitters 141, 142, 143. The data selector 16 selects these at a predetermined order or frequency to be transmitted to a data reception device 12. As a result, when an uncorrectable trouble is detected by a trouble detecting section 27, a re-issue instruction 21 is issued at a predetermined timing based on information stored in an information round robin section 36. The corresponding data from the corresponding data transmitter 141, 142, or 143 is selected by the data selector 16 and then re-sent.

Abstract: Methods and systems for managing disk capacity allocated to a data log in a source data storage system during a merge process are disclosed. Data in the data log may be merged into corresponding data on a destination storage system connected to the source data storage system by at least one communication link. In one embodiment a method comprises maintaining a ratio of merge writes out of the data log to writes from a host computer into the data log within a desired range until the write process reaches a predetermined distance from the end of the data log, and quiescing writes from a host computer into the data log until the data log is fully written to the destination storage system.

Abstract: The present invention provides a reliable and high-speed data transfer method that achieves a high transfer efficiency and a high application processing efficiency concurrently and a disk control unit (disk controller) using such a method. In reliable data transfer in which, when data is transferred from an initiator to a target, the data received by the target is checked for validity by using an error check code attached to the data, a transfer status indicating whether the data is valid is returned from the target to the initiator, and, if a transfer error occurring during the data transfer is detected by the transfer status, the initiator retries to transfer the data to the target, a data transfer method for logical records that are units of data transfer between the initiator and the target is disclosed.

Abstract: Systems and methods for performing error recovery in a system utilizing redundant communication links. In one embodiment, a host device is coupled to a sequential device such as a tape drive by a pair of Fibre Channel links. The host is configured to associate an identifier with each command. Upon detecting a failure of the transmission of the command via the first link, the host re-transmits the command via the second link. When the link failure is detected, the status of the last command transmitted before the failure is requested. After receiving the status of the command, a request that recovery start (possibly at a point indicated by the status information) is transmitted to the sequential device. If the recovery request is accepted, performance of the command is completed.

Abstract: A method for data journaling includes writing data into at least one block in a journal storage area, and marking each written block as dirty. If the number of blocks in the journal storage area marked as dirty is greater than the number of blocks in a corresponding data storage area that have been used and whose corresponding blocks in the journal storage area are not marked as dirty, then those used blocks are copied to the corresponding blocks in the journal storage area, and a message is transmitted instructing a meta-data server to swap the data storage area and the journal storage area. If this condition is not so, the blocks in the journal storage area marked as dirty are copied to corresponding blocks in the data storage area, and a message is transmitted instructing the meta-data server to commit the data stored in the journal storage area.

Abstract: A reception apparatus records a content distributed from a content distribution apparatus on a hard disk. Following an instruction from a viewer, the reception apparatus reproduces the content. The reception apparatus transmits management information including identification information about the content recorded on the hard disk to a management apparatus. The management apparatus stores the information in a management information storage. When the hard disk of the reception apparatus fails, a replacement hard disk is attached to the management apparatus. The management apparatus retrieves, based on the stored management information, the same content as the content recorded on the hard disk of the reception apparatus from a content distribution apparatus, etc., and records the retrieved content on the replacement hard disk. The hard disk of the reception apparatus is then replaced with the replacement hard disk with the content recorded thereon.