Abstract: A method facilitates providing appropriate quality of service guarantees to a plurality of virtual hosts on a single physical host computer. A server application program and its child processes service communication requests made to the plurality of virtual hosts. Quality of service parameters associated with the virtual hosts are stored. Communication requests made to a specific one of the virtual hosts are detected. The quality of service parameters associated with the specific virtual host are obtained. Operating system resources are utilized to guarantee, to a child process of the server application program, a quality of service according to the obtained quality of service parameters associated with the virtual host. Communication between the virtual host and the client is allowed to proceed, the communication being managed by the child process.

Abstract: Resource requests from a plurality of schedulable entities are scheduled while limiting the maximum and minimum quality of service allocated to each schedulable entity. The resource scheduler of the present invention requires less memory maintain state information than existing rate-controlling schedulers, and is thus more easily scalable to large numbers of users. The resource scheduler also schedules resources fairly among competing schedulable entities. A fair-share scheduling algorithm is used by a resource scheduler to select resource requests to service. A rate controller checks to ensure that servicing the selected request will not cause the associated user's maximum quality of service to be exceeded. If the maximum quality of service will not be exceeded, the virtual time used in the scheduling algorithm is incremented, and the request is serviced. If the maximum quality of service will be exceeded, the virtual time is still incremented, but the request is not serviced and remains pending.

Abstract: File access rates of processes are regulated according to file type. An association table stores entries associating processes to be regulated with specific access rates for various file types. System calls that access files are intercepted, and a system call wrapper executes. The system call wrapper determines the type of file that is being accessed by the process. The system call wrapper examines the association table in order to determine if the calling process is associated with an access rate for the file type being accessed. If so, the system call wrapper regulates access to the file according to the appropriate rate.

Abstract: Communications between network devices on a logical subnet are restricted between devices authorized to communicate with each other, even though other network devices may be present on the subnet. When a network device receives a request to provide it L2 address to a requesting network device, it responds with its L2 address only if the requesting device is authorized to request L2 address. Optionally, a network device only transmits requests for the L2 addresses of other devices if it authorized to do so. The information describing authorized devices maybe store as list of L2 and L3 addresses, which list may be loaded by each network device when starting up. Preferably, authorized devices include routers on the device's logical subnet, to allow the routers to communicate with, and route packets to, the network devices.

Abstract: An I/O multiplexing operation involving a cross-domain file descriptor set is intercepted. The cross-domain set is divided into a first subset corresponding to a first file type and a second subset corresponding to a second file type. System calls are initiated in parallel for performing separate I/O multiplexing operations on the first and second subsets of file descriptors. In response to one of the parallel system calls identifying at least one file descriptor ready for communication, the other parallel system call is unblocked. Sets of file descriptors identified as ready for communication by the parallel system calls are combined and returned to a calling process.

Abstract: Apparatus and method of cluster computing are described. The present invention provides a useful compromise between the manageability, power, and ease of use of centralized systems and the reliability, fault-tolerance, upgradability, and scalability of distributed systems. Moreover, the present invention provides fault-tolerance and security while adhering to real-time to respond constraints or bounds. The invention is described in preferred embodiment examples in the context of two clustered applications: a telecommunication switch-controller and a Web servers, although many practical applications will benefit from the present invention.

Abstract: Disclosed are methods and systems for authenticating a unique article utilizing a generated unique data signature. The unique data signature is generated by encrypting a received data set representative of a unique identification number fixed to a substantially unforgeable document. The unique data signature is fixed to the unique article or to an optionally generated ownership certificate or the like. The unforgeable document is retained, possibly as the ownership certificate, or the like, or as a part thereof, to thereby authenticate the unique article.

Abstract: A method and system adaptively substitutes a single dialing button sequence for a selected action in a voice menu of a telephone system. A shortcut message in the voice menu prompts a caller to select a shortcut button to achieve a shortcut action. The system then accumulates counts related to frequencies of occurrence of a plurality of actions prompted by the voice menu. The system then ranks the plurality of actions by their respective accumulated counts and determines if any one of the plurality of actions has an accumulated count greater than an accumulated count of the shortcut action. If it does, then the system causes the substitution the one of the plurality of actions and a corresponding message for the shortcut action and the shortcut message in the voice menu.

Abstract: A method and apparatus for transferring encrypted information to a database. First certification information is transferred from a first database to a second database. Second certification information is then transferred from the second database to the first database, where both the first certification information and the second certification information is authenticated. If both certifications are authenticated, the transfer of the encrypted information to the second database is enabled.

Abstract: A method and an apparatus that improves a data transmission rate in a TCP connection having an asymmetrical path. An intermediate node transmits a predetermined number k of data packets to a destination node, and measures a time period A between transmitting the k data packets and receiving a receipt acknowledgment signal at the intermediate node indicating receipt of the k data packets at the destination node. The intermediate node then transmits to a source node k acknowledgement signals with a time interval of A/k between each acknowledgement signal.

Abstract: A method and system for handling incoming calls when no destination stations are available. When an incoming call from an originating station is received, it is determined whether a destination station is available. If a destination station is not available, a telephone number of the originating station is stored, Shortly before its current call is concluded, a destination station indicates its approaching availability. Responsive to this indication, an outgoing call is placed to the originating station. If the originating station does not answer the outgoing call within a predetermined time, the outgoing call is terminated and rescheduled. If the originating station answers the call within a predetermined time, the outgoing call is connected to the available destination station.

Abstract: Disclosed are methods and systems for achieving and maintaining data transmission rates in processing system networks, independent of communication between the node and the processing system network, and including techniques for data transmission initialization, data retransmission, and buffer management. Data transmission initialization includes transmitting data packets from a source node over a network at an adaptive exponential transmission rate from a current operating point to an optimal operating point. The optimal operating point is a data transmission rate wherein data buffers are neither overflowing nor under-flowing. Data retransmission includes transmitting data packets at the optimal set point, detecting the loss of a transmitted data packet as a function of a timer-less acknowledgement signal, and retransmitting the lost data packet.

Abstract: The methods and systems of the invention enable connectionless-oriented server and client programs operating on processing systems to communicate with connection-oriented routines operating on different processing systems linked to connectionless or connection-oriented networks by establishing connections or communications virtual circuits between such programs. The connectionless-oriented server and client programs may be modified to communicate with a connection manager to establish a virtual circuit before initiating communications with the connection-oriented routines. The invention further utilizes encapsulators and decapsulators to enable communication programs to transfer data packets in a first format on an established virtual circuit over a network transmitting data in a second format.

Abstract: A data transmission system and method employing either a renegotiated variable bit-rate ("RVBR") network or a renegotiated constant bit-rate ("RCBR") network. Within these networks, data transmission rates between a sender and a recipient are rapidly renegotiated as a function of previously stored data transmission rate information and system buffer levels. Such a system and method can be readily implemented within existing CBR and/or VBR network architectures. The RCBR and RVBR networks allow for the implementation of an intelligent data traffic management systems that are responsive to the rate at which new calls or requests for connections enter and leave the network, the frequency and duration of extended peak rate data bursts, as well as the occurrence of short duration data transmission peaks.

Abstract: A system and method for the segmentation of data exhibiting an intrinsic long-term average data rate, punctuated with periods of peak rate data bursts. This segmentation conditions the data for efficient transmission via either a renegotiated constant bit-rate ("RCBR") network or a renegotiated variable bit-rate network ("RVBR") network. Within these networks, data transmission rates between a sender and a recipient are rapidly renegotiated as a function of previously stored data transmission demand information and system buffer levels. Such a system is responsive to the rate at which new calls or requests for connections enter and leave the network, the frequency and duration of extended peak rate data bursts, as well as the occurrence of short duration data transmission peaks.

Abstract: Apparatus and methods for time multiplexing a resource among a plurality of entities at average rates and with deterministic delays between accesses to the resource by an entity. An entity accessing the resource receives a time slot on the resource; a fixed number of time slots constitute a frame. Each entity receives a fixed allocation of time slots in the frame. When an entity has work for the resource to do, it receives access to the resource for a number of slots in each frame equal to the lesser of the number of slots required to do the work and the number of slots in the allocation. A rate-controlled server is disclosed which defines a frame and allocations therein, as well as a hierarchy of servers which combines rate-controlled traffic with best effort traffic. In the hierarchy, a rate-controlled server activates a round-robin server when the entities served by the rate-controlled server do not require all the slots in a frame.