Abstract: A method of determining that protected software is running in a virtualized environment includes obtaining a set of baseline measurements of system call timings in native operating system environments. Statistical thresholds are established based on the baseline measurements such that there is a predetermined probability that protected software running in a native environment will experience system call durations that exceed the thresholds. The protected software is analyzed and instructions are incorporated within the software such that particular system calls, demonstrated to be differentiating using the set of baseline measurements and the threshold analysis, are executed during the normal running of the protected software. The incorporated instructions are used to estimate the parameter values that are to be compared with the established statistical thresholds.

Abstract: A method of determining that protected software is running in a virtualized environment includes obtaining a set of baseline measurements of system call timings in native operating system environments. Statistical thresholds are established based on the baseline measurements such that there is a predetermined probability that protected software running in a native environment will experience system call durations that exceed the thresholds. The protected software is analyzed and instructions are incorporated within the software such that particular system calls, demonstrated to be differentiating using the set of baseline measurements and the threshold analysis, are executed during the normal running of the protected software. The incorporated instructions are used to estimate the parameter values that are to be compared with the established statistical thresholds.

Abstract: Methods, systems and computer program products for controlling scheduling in an ATM node in a network are provided which aggregate connection information for connections to the ATM node to provide a set of aggregate connection information for the ATM node. The set of aggregate connection information is distributed to other ATM nodes in the network and may be used in accepting connections to the ATM network based on the aggregate connection information. Scheduling may be provided by associating a timestamp value in each cell associated with an accepted connection as it is received by the ATM node. Received cells are grouped into a plurality of cell groups in timestamp order based upon characteristics of the cells and cells are selected from each group so as to transmit the cells in earliest deadline first order.

Abstract: Methods, systems and computer program products are provided for evaluating requests for a network connection combining the requested network connection with existing connections so as to provide a representation of the total network connections and accepting the request for a network connection if sufficient resources are available to accept the request for a network connection based upon the representation of the total network connections. Particular embodiments of the present invention determine if sufficient resources are available to accept the request for a network connection based upon diffusion based representations of the existing network connections and the requested network connection and accepting the request for a network connection if sufficient resources are available to accept the request for a network connection. The diffusion based representation may be used to determine the capacity required for existing connections and the requested connection based upon a predefined maximum loss ratio (L).

Abstract: Methods, systems and computer program products for controlling scheduling in an ATM node in a network are provided which aggregate connection information for connections to the ATM node to provide a set of aggregate connection information for the ATM node. The set of aggregate connection information is distributed to other ATM nodes in the network and may be used in accepting connections to the ATM network based on the aggregate connection information. Scheduling may be provided by associating a timestamp value in each cell associated with an accepted connection as it is received by the ATM node. Received cells are grouped into a plurality of cell groups in timestamp order based upon characteristics of the cells and cells are selected from each group so as to transmit the cells in earliest deadline first order.

Abstract: Method and apparatus for managing internal-node communications in a packet switching network by calculating optimal routes for packets and addressing subnodes within packet nodes using a specific message format. Internal communication facilities called intranode links connect multiple subnodes within nodes. Each subnode contains a switching mechanism and routes packet to other nodes, subnodes, or user applications using a specific message format. The message format allows specific subnodes anywhere in the network to the addressed by any other subnode, making communications more efficient and simplifying the management of internode links.

Abstract: Method and apparatus for making limited internal-node communication facilities externally visible in a packet switching network. Internal-node communication facilities are called intranode links, can include any cable, channel, bus, etc. over which data passes, and are used to connect the multiple subnodes within a given node. Each subnode contains a switching mechanism and routes packets to other nodes, subnodes, or user applications. Each node provides network control functions such as topology, directory, path selection, and bandwidth management which can manage intranode links in the same manner that internode links are currently managed.

Abstract: Access control for a packet communications network includes a dynamic bandwidth updating mechanism which continuously monitors the mean bit rate of the signal source and the loss probability of the connection. These values are filtered to remove noise and then used to test whether the values fall within a pre-defined acceptable adaptation region in the mean bit rate, loss probability plane. Values falling outside of this region trigger bandwidth updating procedures which, in turn, result in acquiring a new connection bandwidth, and determining new filter parameters and new parameters for a leaky bucket access mechanism.

Abstract: A congestion control system for packet communications networks in which access to the network is controlled to prevent such congestion. Packets within the prespecified statistical description of each packet source are marked as high priority ("green" packets) while packets exceeding the pre-specified characteristics are marked with a lower priority ("red" packets). The overall red packet rate is limited to prevent red packet saturation of the network. Packets are marked red for a continuous train of successive red packets. The introduction of red packets into the network is subjected to a degree of hysteresis to provide better interaction with higher layer error recovery protocols. The amount of hysteresis introduced into the red packet marking can be fixed or varied, depending on the statistics of the incoming data packets at the entry point to the network.

Abstract: A data distribution system and method for the timely, efficient and reliable distribution of data to an unlimited number of remote receiver installations. A data source assembles data packets, and upon filing or after the lapse of a predetermined interval of time, broadcasts a respective data packet to all receivers and recovery means along a communication network. Each receiver is intelligent, in that it copies the data packets into a buffer and has the responsibility of selecting out data needed to perform the receiver's intended functions. As a result, intermediate data selecting and routing means between the data source and receivers are avoided, resulting in data delivery which is both rapid and timely. For reliability, each receiver monitors the sequence numbers of the data packets which have been received and, also, whether a data packet is received at least as frequently as the predetermined interval of time.