Abstract: Techniques are described for monitoring performance of a network. Particularly, network devices within the network exchange routing communications in accordance with one or more routing protocols, such as the Border Gateway Protocol (BGP), to automatically establish a community for monitoring performance throughout the network. Upon establishing the community, the network devices of the community exchange performance probes to collect comprehensive performance information for the network. This performance information may be aggregated via one or more computing devices. Using the aggregated performance information, numerous network performance characteristics may be computed, including delay, jitter, throughput, availability and packet loss.

Abstract: A network router includes a set of interface cards to receive packets from a network, and a set of accounting modules to calculate flow statistics for the packets. The router further includes a control unit to adaptively update routing information in response to the calculated flow statistics, and to route the packets in accordance with the routing information. The control unit identifies potentially malicious packet flows for the received packets based on the flow statistics, and applies an intercept filter to intercept the packets of the identified packet flows. The control unit analyzes the intercepted packets in real-time to determine the presence of a network event, and updates the routing information based on the determination, e.g., by terminating routing for packets associated with malicious packet flows. In this manner, the router may adaptively respond to network events, such as network security violations.

Abstract: A device comprises a programmable communication interface and a processor. The programmable communication interface communicates data via a set of signals. The processor configures the programmable communication interface to communicate the data in accordance with a programmed override state for at least one of the signals and actual states for the remaining signals. The programmable communication interface may be configured, for example, to programmably treat an overridden signal as asserted or de-asserted regardless of actual voltages present on one or more electrical connectors associated with the overridden signal. As a result, incorrectly wired electrical connectors of the programmable communication interface may be programmably overridden. Consequently, a technician need not manually rewire the programmable communication interface.

Abstract: A network device integrates accounting functionality for generation of flow statistics with packet intercept functionality to provide a comprehensive traffic analysis environment. The device comprises a set of network interface cards to receive packets from a network, and a set of accounting service cards to calculate flow statistics for the packets. The device further comprises a control unit to receive the network packets from the interface cards and distribute the packets to the set of accounting service cards. The accounting service card comprises an interface for insertion within a slot of a network device. Accounting service cards may be added to easily scale the network device to support higher bandwidth communication links, such as OC-3, OC-12, OC048 and higher rate links. Additional accounting service cards may be used for purposes of redundancy to support continuous, uninterrupted packet processing and accounting in the event of a card failure.

Abstract: A device comprises a programmable communication interface and a processor. The programmable communication interface communicates data via a set of signals. The processor configures the programmable communication interface to communicate the data in accordance with a programmed override state for at least one of the signals and actual states for the remaining signals. The programmable communication interface may be configured, for example, to programmably treat an overridden signal as asserted or de-asserted regardless of actual voltages present on one or more electrical connectors associated with the overridden signal. As a result, incorrectly wired electrical connectors of the programmable communication interface may be programmably overridden. Consequently, a technician need not manually rewire the programmable communication interface.

Abstract: A network router includes a set of interface cards to receive packets from a network, and a set of accounting modules to calculate flow statistics for the packets. The router further includes a control unit to adaptively update routing information in response to the calculated flow statistics, and to route the packets in accordance with the routing information. The control unit identifies potentially malicious packet flows for the received packets based on the flow statistics, and applies an intercept filter to intercept the packets of the identified packet flows. The control unit analyzes the intercepted packets in real-time to determine the presence of a network event, and updates the routing information based on the determination, e.g., by terminating routing for packets associated with malicious packet flows. In this manner, the router may adaptively respond to network events, such as network security violations.

Abstract: A network device integrates accounting functionality for generation of flow statistics with packet intercept functionality to provide a comprehensive traffic analysis environment. The device comprises a set of network interface cards to receive packets from a network, and a set of accounting service cards to calculate flow statistics for the packets. The device further comprises a control unit to receive the network packets from the interface cards and distribute the packets to the set of accounting service cards. The accounting service card comprises an interface for insertion within a slot of a network device. Accounting service cards may be added to easily scale the network device to support higher bandwidth communication links, such as OC-3, OC-12, OC048 and higher rate links. Additional accounting service cards may be used for purposes of redundancy to support continuous, uninterrupted packet processing and accounting in the event of a card failure.

Abstract: A network router integrates routing functionality with accounting functionality for generation of flow statistics, and provides packet intercept functionality to provide a comprehensive traffic analysis environment. The router includes a set of interface cards to receive packets from a network, and a control unit to generate a first and second duplicate stream of the packets. The control unit provides the packets of the first stream to accounting modules for calculation of flow statistics, and applies an intercept filter to intercept at least a subset of the packets of the second stream for selected packet flows.

Abstract: A network router includes a set of interface cards to receive packets from a network, and a set of accounting modules to calculate flow statistics for the packets. The router further includes a control unit to adaptively update routing information in response to the calculated flow statistics, and to route the packets in accordance with the routing information. The control unit identifies potentially malicious packet flows for the received packets based on the flow statistics, and applies an intercept filter to intercept the packets of the identified packet flows. The control unit analyzes the intercepted packets in real-time to determine the presence of a network event, and updates the routing information based on the determination, e.g., by terminating routing for packets associated with malicious packet flows. In this manner, the router may adaptively respond to network events, such as network security violations.

Abstract: A system for processing packets of data may include a gather unit configured to gather data elements from a number of non-contiguous locations in a packet of data. The gather unit may place the data elements in a number of contiguous locations in the packet. A processor may be configured to process the data elements from the number of contiguous locations to generate processed data elements. A scatter unit may be configured to scatter the processed data elements to the number of non-contiguous locations in the packet.

Abstract: A multimedia communication arrangement processes and multiplexes different types of data, including data from an adaptive data rate data source and a nonadaptive data rate data source, to substantially increase data throughput over a communication channel. The rate at which data is collected from the adaptive data rate data source varies based on the available channel bandwidth of the modem. The transmission rate is optionally adjusted in response to a detected error rate. Furthermore, the amount of filtering performed by a video camera on an image before the image is encoded by a codec can be adjusted. In addition, a data recovery terminal optionally selectively adjusts intervals at which received audio data is sampled to potentially reduce latency periods.

Abstract: A videophone apparatus with an on-screen telephone keypad user-interface. The videophone communicates video and audio data over a plain old telephone service (POTS) line and includes a video source and a communication channel interface circuit coupled to a programmable processor. The programmable processor is configured and arranged to execute a user interface program for user controlled operation of the videophone apparatus, display a first menu on the display, the first menu referencing a first plurality of options for operating the videophone apparatus and having associated therewith respective indicators of telephone keypad buttons, receive from the telephone keypad a first selection signal indicative of a pressed button, and initiate an operation to control the videophone apparatus in response to the first selection signal.

Abstract: A video communications device used as part of a communication terminal in a video-conferencing arrangement provides the capability of real-time captioning along with real-time visual communication for the individuals that are hearing- or language-impaired and others whose speech is not understandable or non-existent. The device enhances the ability of people with communication disabilities to communicate quickly and effectively with those who are similarly afflicted as well as with those who are not. In one example embodiment, the video communications device includes a camera and a teletype device (TTY) for transmitting and receiving teletype information. The camera captures local images and generates a set of video signals representing those images. A teletype device captures input data from a user and generates a set of data signals. The device can be configured for compatibility with conventional equipment and for alerting users of incoming calls nonaudibly.

Abstract: In one embodiment, a cost-effective videophone device includes a programmable processor circuit capable of communicating over a conventional communications channel, such as a POTS line, and of generating video data for display on a television set. The device includes a video source, an interface circuit, including a modem transmitting and receiving video and audio data over the channel; an EEPROM circuit for storing a program to control the videophone apparatus; and a display driver circuit for generating video data to the display. The programmable processor circuit includes a DSP-type processor for processing video data and a RISC-type processor executing the stored program and controlling the operation of the videophone apparatus. Further, a housing arrangement, enclosing each of the above structures, mounts adustably on the top of the display.

Abstract: A cost-effective videophone includes a programmable video/general-purpose processor capable of readily updating program-related data. The processor includes a first circuit section used to process data for videoconferencing and to detect codes data used for revising software-related data provided from a remote location, and a second circuit section used for executing the executable program data stored in the second memory circuit. A volatile memory circuit is coupled to and accessed by the programmable video/general-purpose processor, and is used for storing the revision data until it is validated. Once validated, the revision data is transferred from the first memory circuit to a non-volatile memory circuit. The non-volatile memory circuit is then used by the processor in a subsequent video-related application, such as a videoconferencing application or a web browser application.

Abstract: Configuring a communication arrangement that transmits video and other signal types using operational modes includes constructing a hierarchy of nodes representing the operational modes. The hierarchy also includes null nodes and a root node. Scores are collected as the nodes are traversed. The score represents a difference between the operational modes represented by the nodes along the path and desired operational modes received from a data recovery terminal. When the sum of scores collected for a set of nodes exceeds a threshold, the order of traversal is reversed. Reversing the order discards inefficient solutions and avoids dedication of system resources to evaluating such solutions. In addition, decreasing the number of paths evaluated permits more rapid determination of the operational modes best matching the desired operational modes.

Abstract: A multimedia communication system processes and multiplexes different types of data, including data from an adaptive data rate data source and a nonadaptive data rate data source, to substantially increase data throughput over a communication channel. The system includes: a first data source, responsive to a control signal, including a video image processor constructed to capture images and to present the images as a first type of data at a rate determined as a function of the control signal; at least one additional data source generating at least one additional data signal; a data signal processor that determines an available bandwidth factor for the communication channel, generates the control signal in response to this factor, collects the first type of data at a rate that varies in response to the available channel bandwidth of the modem, and collects the at least one additional type of data at at least one established rate.

Abstract: A video communications device used as part of a communication terminal in a video-conferencing arrangement provides the capability of real-time captioning along with real-time visual communication for the individuals with impaired hearing and others whose speech is not understandable or non-existent. The device enhances the ability of people with communication disabilities to communicate quickly and effectively with those who are similarly afflicted as well as with those who are not. The video communications device includes a camera and a teletype device (TTY) for transmitting and receiving teletype information. The camera captures local images and generates a set of video signals representing those images. A teletype device captures input data from a user and generates a set of data signals. The device can be configured for compatibility with conventional equipment and for alerting users of incoming calls nonaudibly.

Abstract: A flat directory organization is used to create a flat cache-only multi-processor architecture. Directory memories are uniformly distributed among all the processor nodes. Every valid memory partition has an associated physical address, which is used to determine a statically assigned home node for that partition. The home directory at the home node is the only directory that maintains state information for that partition. The home directory keeps track of which nodes have a copy of a partition and the current state of that partition. The flat directory organization does not depend on any specific interconnection. Any scalable network can be used to interconnect the processing nodes.