Abstract: High-speed transceiver devices, such as GBIC-type transceivers, are accessed and addressed. Identification information (including manufacturer name, model, compliance codes) is placed in data fields of the transceivers. An algorithm checks each port in each module of a host system to determine if a transceiver is present. If a particular transceiver is present, then algorithms store the port address of the transceiver in memory and enable the transceiver to be read from or written to. Reading from the transceiver includes reading the identification information, and writing to the transceiver includes writing the identification information. If a transceiver is initially determined not to be present or if the reading/writing/enabling processes fail, then a recovery process determines if the transceiver was present the last time it was checked. If it was present the last time, then the process continues to try to recover the transceiver data—otherwise, the port is marked as empty.

Abstract: A method for identifying a remote radio unit in a communication system comprises a plurality of remote radio units communicating with a central unit and pattern providing means for providing information about dedicated gain change patterns of the remote radio units. The method comprises receiving a signal from a station by a remote radio unit of the plurality of remote radio units. The method also includes changing the gain of at least one remote radio unit according to a dedicated gain change pattern of the at least one remote radio unit. The method also includes detecting a gain change pattern for the received signal and identifying the remote radio unit by comparing the detected gain change pattern with information about dedicated gain change patterns of the remote radio units provided by the pattern providing means. An example may be locating a station, such as a user equipment, in a distributed radio system.

Abstract: A system for testing a software client or hardware module in a voice-over-IP (VoIP) network path includes a VoIP client, a test tool, and an analyzer. The VoIP client, connected to the VoIP network, makes a series of calls to a destination. The calls activate the software client or hardware module under test. The test tool, which has access to the network, plays a series of audio files over the VoIP during the calls. The test tool also polls the software client or hardware module over the network for status information after the calls are completed. While the audio files are being played, the analyzer records the audio files at the destination for measurement the quality of the calls. Accordingly, the quality of voice connection on the VoIP network can be measured, and specific components on the network can be tested.

Abstract: The present invention relates to a message transmission system, and more particularly, to a control apparatus and method for relay node duplexing. In the invention, when the exchange of the active node relaying a message by buffering is requested, the duplexing control unit of the active node controls such that the active node performs only the message transmission function, and the duplexing control unit of the standby node controls such that the standby node performs only the message receiving function. When the messages already inputted to the active node before the exchange request are all transmitted, the completion of the exchange is controlled, and when the exchange is completed, the standby node obtains the active right, thereby preventing the loss of a message during the exchange operaiton.

Abstract: A repeater for HDSL transmission is presented. The repeater replaces the regenerator commonly used in HDSL by utilizing the activation/deactivation process in the HDSL specification. The repeater is adjusted to detect an activation/deactivation sequence, whereby a flip-flop in the repeater is alternated. A first state of the flip-flop allows transmission passing through the repeater to the terminating point, e.g. a network terminal, and a second state loops transmission back to the originating point, e.g. a line terminal. The looping may then be utilized for maintenance and error detection and recovery. By use of one of the free bit in the overhead channel in the HDSL transmission as an origin bit, wherein “1” is set in the upstream direction, and “0” is set in the downstream direction, it is possible to detect at the line terminal whether there is a loop in the repeater.

Abstract: A method of testing a network physical layer device (PHY) having a media independent interface (MII) includes sending information between the PHY and a tester along the data buses of the MII. The information may be sent in the form of special frames, the special frames being sent from the tester to the PHY including an identifier. The PHY includes means for detecting the identifier, for extracting control information from the special frames, and for using the control information to execute write operations to and read operations accessing the memory registers of the PHY, and for sending information to the tester. The information may be passed between the PHY at an exemplary rate of 100 Mb/sec.

Abstract: A computer network employs a fault-tolerant or redundant switch architecture. The network includes redundant data paths coupling end nodes and switches. Fault-tolerant repeaters (FTRs) can be stand-alone devices or can be incorporated into the switches. Using error detection, the FTR checks to see if the data is good on all paths. If the data received on one path is “bad” and the data is “good” on another path, the FTR transmits the “good” data in place of the “bad” data. For any switch, a pair of incoming ports may be configured as redundant incoming ports and a pair of outgoing ports may be configured as redundant outgoing ports.

Abstract: A multiplex communication system having a data repeater, which can prevent data from being lost so as to improve reliability of data communication, when a data repeater of a multiplex communication system repeats data. A multiplex communication system is made up of a plurality of communication groups including a plurality of communication lines and a data repeater. The data repeater is made up of receiving buffers, sending buffers, a data controller and a transfer-address table. The data controller selects multiplex communication lines through which the received data is to be repeated and transfers the received data thereto. The data controller has a priority-reset means for increasing a priority of a received data before being sent. The priority-reset means prioritizes a sending of the data from the data repeater, even if the data sent from the data repeater collides with the other data on the multiplex communication lines through which the received data is to be repeated.

Abstract: The present disclosure relates to a method for communicating and applying adaptive security to a data stream comprising a plurality of data packets. The method comprises the steps of identifying a desired security level range and a desired actual security level which falls within the desired security level range. The availability of a number of security processor operations at the host is determined so that, if needed, computing resources at the host can be reallocated to ensure that the data stream can be verified at the desired actual security level. If there are not sufficient resources available for reallocation at the host, communication resources can be reallocated, for example by changing the bandwidth of the data stream or another incoming data stream. With this method, the actual security level will be kept within the desired security level range.

Abstract: An aggregate link system and process is provided with cooperating link aggregation member devices defining a link aggregation. An connected devices is provided. Network links connect the connected devices to each of the link aggregation member devices. One or more of the network links define an aggregate link. A coordinating system is provided between the link aggregation member devices in the link aggregation of cooperating devices. The coordinating system is defined by the connected devices and the network links. The coordinating system determines a packet type received from the link aggregation. If the packet is one of predetermined packet types, the coordinating system either sends the packet back to the originating link aggregation member device or to the other link aggregation member devices.

Abstract: The present invention is directed to a telecommunications system and access panel for providing direct metallic access to a telecommunications carrier's signal pairs by a competitor while providing isolation between the telecommunications POTS service and the competitor's digital line service. The isolation is provided by placing DC blocking capacitors in the access panel. In another embodiment, direct metallic access is achieved by placing the access panel as an intermediate distribution frame member.

Abstract: A node device in an ATM communication network is provided which is capable of generating a cell for creating a failure alarm rapidly so as not to apply a load to a processor. The node device copies header data from an ATM cell, and uses the copied header data to generate a failure alarm cell (e.g., an Alarm Indication Signal (AIS)). The node device obtains a VPI (Virtual Path Identifier) or VPI/VCI (VPI/Virtual Connection Identifier) for the failure alarm notification cell from a header of the cell on the VP (Virtual Path) which forms the pair of the failed VP. Accordingly, the processor does not need to process data from a header conversion table.

Abstract: Disclosed is a WDM network which has: a lightwave path which connects between clients and each of which is provided with an overhead, and a sub-network which is defined by dividing the WDM network. In this WDM network, the sub-network has a partial lightwave path to go through the sub-network, the overhead has a partial lightwave path supervisory control information region which is terminated at both nodes of the partial lightwave path, and when a fault occurs on a lightwave path, the fault information of partial lightwave path including the position information of fault occurred is added to the partial lightwave path supervisory control information region of the overhead.

Abstract: In an image forming device management system and method, a failure in any of a plurality of image forming devices on a first LAN is detected by a management apparatus. A failure message is transmitted from the management apparatus to a center system via a public switched telephone network when the failure is detected, the failure message including a failure code provided to identify the failure. The failure message, transmitted by the management apparatus, is received at the center system. A database of the center system is accessed by using the failure code of the received failure message so as to produce results of the accessing at the center system. A service department ID is extracted from the database based on the accessing results. A service request message is transmitted from the center system to a service department indicated by the service department ID.

Abstract: A tap device comprises a network entry connection, a network exit connection, and a network interconnection path there between. A high impedance tap circuit is electrically connected to the network connection path, and comprises an isolation transformer and active buffer element. Advantageously, a power interruption to said tap circuit does not affect network communications.

Abstract: A method and systems to test a communication system (200) comprising a plurality of emitters (205), receivers (210) and channels (220) are disclosed. According to the method of the invention the data used for the test are preprocessed so as to be analyzed on the fly by the receivers during the test. In a preferred embodiment, a connection identifier value characterizing emitter and receiver addresses as well as data properties, if any, is associated to each data and CRC bits are computed to format frames comprising data, connection identifier value and CRC bits (410). During the test, the communication system transmits frames from emitters to corresponding receivers. Upon frames reception, receivers extract data (455), connection identifier value (460) and CRC bits (465) and compute CRC bits on received data (470). The comparison (475) of transmitted and computed CRC bits in receiver allows determining whether or not frames have been well transmitted.

Abstract: A clock selection controller is shown which allows a user to assign a priority scheme to recovered clock signals obtained from communication facilities. The clock selection controller also receives a plurality of alarm signals corresponding to the communications facilities for each of the recovered clock signals. The clock selection controller then automatically selects, for output as a reference clock signal, the highest priority clock input available for which the corresponding alarm signals are inactive. In the absence of an available clock input in the priority scheme, the processor selects a free running clock input.

Abstract: In order to integrate repeater management with network management in a wireless telecommunication network, a database is added to the network management center (NMC), said database including the data on the network repeaters (R1, R2, R3), which include for each repeater (R1, R2, R3) at least the identifier of the base station (BTS) corresponding to the repeater concerned; a repeater plan is made for changing repeater parameters to correspond to the changed configuration of the base stations; and each repeater is sent an update message (B1, B2, B3) containing parameters for the reconfiguring of the repeater (R1, R2, R3) to correspond to the repeater plan. The invention also relates to a network management system in which the method of the invention can be applied. In addition, the invention relates to a repeater, which can be utilized in the method and system of the invention.

Abstract: A system and method for data communication with adaptive security in which a send host transmits a data stream to a receive host in packets which contain an authentication data block with an authentication header and a signature block. The authentication header advantageously contains various fields including a verification type, a security algorithm, a minimum security level, a target security level, and an actual security level. The receive host adaptively performs verification of the data packets using varying security levels based in part on the availability of security operations per second (SOPS) in the receive host. Where a data stream in the receive host is delayed by a security processing bottleneck, the receive host may alter the verification type, security algorithm, or the actual security level to speed up the processing of the data stream by reducing the amount of security processing performed.

Abstract: Trunking or other relationship is defined between ports on different devices in a cascade connected stack of network devices. When network communications are passed via the cascade connection an indication is included of whether it originated from a port which is part of a trunk and thereby port-mismatch errors can be avoided.

Abstract: An intermediate repeater that can make available at least a minimum of information to the end user sites connected with it even in the event of a power failure. The intermediate repeater has a broadband amplifier (AMP) for the amplification of the received broadband signals and for the subsequent forwarding of the amplified broadband signals, as well as a first device (HP1, LP1; S1,LP, C1), which is connected in series to the broadband amplifier (AMP) and is set to separate the received narrow band signals from the received broadband signals according to frequency, and to forward them without amplification by bypassing the broadband amplifier (AMP). Thus, the transmission of the narrow band signals is guaranteed even during a disturbance.

Abstract: The invention is for a system and method for performing forward error correction on an MPEG-2 transport stream that has optional error correction information embedded within the transport stream. An error correction operation is performed on a super group of packets within the transport stream. The error correction data is inserted into a created trailer group of MPEG-2 compliant transport stream packets having no payload, but only an adaptation field The trailer group packets are optional and therefore can be discarded by a standard MPEG-2 decoder, but can also be used to recover data lost in the transmission of the transport stream. The invention results in a system and method to correct an MPEG-2 transport stream that can be used in any one of the digital video broadcast (DVB) formats, without the need for error correction decoders which are specific to the DVB format.

Abstract: The present invention relates to an apparatus for measuring input and output levels of base station transmitters in the mobile communication system, for allowing measurement of an input/output level of a transmitting stage so as to check an operation state of a digital block through detection of an intermediate frequency (IF) output level of the transmitting stage and an operation state of a transmitter by the frequency allocation (FA) through measurement of an output level of the transmitter. The present invention has splitters on paths to split transmitting intermediate frequency (IF). A split signal over one path is regularly coupled to the system and a split signal over another path is sent to a power detector to measure power. A phase locked loop (PLL) local signal is generated and transmitting RF signals up-converted by the FA are converted into specified IF signals to measure power. The two measured power values are compared to determine a state of the transmitter.

Abstract: A repeater for HDSL transmission is presented. The repeater replaces the regenerator commonly used in HDSL by utilizing the activation/deactivation process in the HDSL specification. The repeater is adjusted to detect an activation/deactivation sequence, whereby a flip-flop in the repeater is alternated. A first state of the flip-flop allows transmission passing through the repeater to the terminating point, e.g. a network terminal, and a second state loops transmission back to the originating point, e.g. a line terminal. The looping may then be utilized for maintenance and error detection and recovery. By use of one of the free bit in the overhead channel in the HDSL transmission as an origin bit, wherein “1” is set in the upstream direction, and “0” is set in the downstream direction, it is possible to detect at the line terminal whether there is a loop in the repeater.

Abstract: Through the use of a least squares minimization concept, the loop length, the number of bridged taps and length of the bridged taps on a transmission line can be determined from readily available modem data. In particular, the loop length, the number of bridge taps and the length of bridged taps can be estimated by comparing a measured frequency domain channel impulse response of the transmission line to a model of a loop that is comprised of multiple sections and multiple bridge taps.

Abstract: An electronic filter has an input connector adapted for electrical connection to a complimentary output connector of an asymmetrical digital subscriber line. The input connector has an input voltage node for providing electrical input signals to the electronic filter. Similarly, the filter has an output connector adapted for electrical connection to a complimentary input connector of a data receiving device. The output connector has an output voltage node for providing electrical output signals from the electronic filter. The filter selectively passes frequency components of the electrical signals, frequency components below a predetermined corner frequency passing from the input connector to the output connector, frequency components above the predetermined corner frequency not passing from the input connector to the output connector.

Abstract: A system and method are disclosed for redirecting a connection from a first server having a first server IP address. Incoming SYN packets sent from a client are intercepted. The SYN packets have a destination IP address corresponding to the connection and the SYN packets are sent from the client for the purpose of establishing the connection, which is supported by the first server. The number of incoming SYN packets sent from the client to the first server is monitored and it is determined whether the number of unanswered SYN packets sent by the client to the first server exceeds a ditched connection threshold number of unanswered SYN packets. The destination IP address of intercepted incoming SYN packets is changed for the connection received after determining that the number of unanswered SYN requests sent by the client to the first server exceeds a ditched connection threshold number of unanswered SYN requests to the destination IP address of a second server.

Abstract: A stack position determination circuit in a stackable repeater is disclosed that includes an input connector, an output connector, an initial pin driving circuit, and a pin rotating circuit. The input connector includes a plurality of input connector repeater stack position pins arranged in an hierarchical order so that each input connector repeater stack position pin corresponds to a possible physical position of the repeater in a stack of repeaters. An output connector includes a plurality of output connector repeater stack position pins arranged in an hierarchical order so that each output connector repeater stack position pin corresponds to a possible position of the repeater in a stack of repeaters. An initial pin driving circuit is connected to an initial pin in the input connector repeater stack position pin hierarchical order. The initial pin corresponds to a first position in the stack of repeaters and the initial pin driving circuit is responsive to an initial repeater signal.

Abstract: In a repeating unit testing system, a first tester includes first packet transmission means for transmitting a plurality of packets, whose transmission destination address is a second repeating unit, to a first repeating unit for a fixed period of time, and line connection-disconnection log information collection means for collecting log information regarding connection and disconnection of a line from the first or second repeating unit. The first repeating unit includes line connection-disconnection means for connecting a line to a second communication network or disconnecting the line if transmission of packets is not received for more than a fixed period of time, and second packet transmission means for receiving the packets and transmitting the packets to a third port.

Abstract: A DSL device performs a frame check sequence operation in a digital signal processor (DSP), i.e., layer one of the OSI seven layer model, heretofore performed only in layer two of the OSI seven layer model. Performing the layer two framing and calculating the frame check sequence in the DSP allows the DSP to use the layer two error detection results, and optionally, the mean squared error vector, to more accurately determine whether to update adaptive receiver parameters.

Abstract: In a 100BASE-T4 protocol network, the “carrier_status” signal associated with an incoming packet on a PMA of a given port of a Clause 27 repeater is obviated and a direct connection between PMAs and a Clause 27 repeater in the network is eliminated by transmitting synthetic preamble signals over the PMA-Repeater Data Interface to the Clause 27 repeater corresponding to the given port at an early time prior to the time that the actual preamble information of the packet is transmitted over that data interface. Receipt of the synthetic preamble signals causes the repeater to awaken and to repeat the synthetic preamble signals to other ports of the repeater. In turn, the other ports become quiet in anticipation of data to be repeated from the given port to the other ports of the repeater.

Abstract: A repeater for a computer network, and a network incorporating such a repeater are described in which repeater communication addressed to a subset of the devices connected to the repeater are transmitted in a corrupt or scrambled form to other network devices. The processing load is thus reduced for such other network devices, in particular in the context of high volume multicast traffic such as in video conferencing.

Abstract: A stack position determination circuit in a stackable repeater is disclosed that includes an input connector, an output connector, an initial pin driving circuit, and a pin rotating circuit. The input connector includes a plurality of input connector repeater stack position pins arranged in an hierarchical order so that each input connector repeater stack position pin corresponds to a possible physical position of the repeater in a stack of repeaters. An output connector includes a plurality of output connector repeater stack position pins arranged in an hierarchical order so that each output connector repeater stack position pin corresponds to a possible position of the repeater in a stack of repeaters. An initial pin driving circuit is connected to an initial pin in the input connector repeater stack position pin hierarchical order. The initial pin corresponds to a first position in the stack of repeaters and the initial pin driving circuit is responsive to an initial repeater signal.

Abstract: An apparatus and method for testing a communication device using a loopback path. A circuit is used to internally generate a test packet and to check the test packet once the test packet is transmitted through a loopback path within the communication device. The loopback path includes a data path from a test transceiver, through a first path within the core logic, at least one selected physical transceiver, a second path within the core logic and back to the test transceiver.

Abstract: A high-speed sprchronous multiplexing apparatus has a low-speed device and a high-speed device and employs electrical signals to interface the devices with each other. The low-speed device is connected to a low-speed digital circuit. The high-speed device is connected to a high-speed synchronous multiplexing circuit. The apparatus also has a clock supplier for supplying a reference clock signal that defines a communication rate, to each of the low- and high-speed devices. The apparatus further has an alarm processor for separating faults in the low- and high-speed devices. The low- and high-speed devices are interfaced with each other with the use of the reference clock signal and electrical STM-0/STS-1 signals that employ a frame signal synchronized with the reference clock signal.

Abstract: A system tests a repeating installation having transmitter-receivers (3, 4) and a line controller (2). The system includes the repeating installation to be tested, a first tester (10), a second tester (11), an input unit (12) for entering a first virtual network into the first tester (10), an input unit (13) for entering a second virtual network into the second tester (11), and a line control table which is provided for the transmitter-receiver (3) and into which the destination transmitter-receiver (4) is written according to address information added to the data input to the transmitter-receiver (4). Test data transmitted from the first tester to the virtual network of the second tester is received by the second tester, and the received test data is examined. This greatly reduces facility costs and installation space and realizes performance evaluation of a repeating installation under a large-scale network environment.

Abstract: A multiport repeater for a local area network installation has (in addition to its conventional functions) storing access rules for the items of equipment connected to it. It reads a portion of each frame, which may be all or part of the destination address segment and/or of the source address segment and/or of the control segment of each incoming data frame, or it could be a frame or protocol identifier incorporated in opening bytes of the data segment. It compares the data that it reads with the stored access rules to determine whether the frame is permitted or not. If not, it corrupts the frame which it is in the course of re-transmitting, for example by overwriting it with meaningless digits. It may also report the source address, destination address and reason for deciding to corrupt the frame to the network controller.

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 feed imbalance detector in a repeated line for detecting a feed imbalance in a PCM repeated line and for displaying an alarm includes: a constant current feeder for transmitting an operating voltage to the repeated line; a virtual ground unit for detecting the voltage difference between a plus output port and a minus output port of the constant current feeder; a comparator for comparing the voltage difference with a ground voltage, a detector for determining feed imbalance based on the output level value of the comparator after a predetermined detection time and for outputting a driving signal if feed imbalance is detected, and a display for displaying an alarm upon receiving the driving signal.

Abstract: A digital telephone circuit is transferred from an old line to a new line. Before the transfer, a first stage delay circuit is inserted, wherein the delay of the data is incrementally adjusted to match the delay of a data control element. The data control element is then inserted in series with the data on the old line. The data control element incrementally adjust the delay and amplitude of the data on the old line to match that of the data on the new line. The incremental adjustments to delay and amplitude are within the specifications of the circuit, so as to minimize interruptions to the circuit. Interruptions are also minimized when the circuit is transferred to the new line. The data control element also introduces variations into the data at an upstream location. These are detected at a downstream location and are used for testing and communication purposes. The variations are removed from the data at the downstream end.

Abstract: A loopback mechanism uses frame relay OAM loopback frames which eliminate the need for location identifiers and reduces overhead and complexity. The frames replace source and destination loopback location identifiers by a loopback indicator field, a send node count field and a return node count field. The originating node of the loopback procedure sets the number of intermediate frame relay nodes to be traversed. The intermediate frame relay nodes simply increment or decrement the node count, depending on the direction of the loopback frame.

Abstract: A system is provided for use in a network to provide authentication of packets of data, provide security to ensure the prevention of unauthorized receipt of data, to provide improved monitoring of the packets of data transmitted and received over such a network, and to detect changes in the network topology. Repeaters utilized in the network are provided with the capability to detect and interpret packet data and the source address (SA) and destination address (DA) fields to provide the improved features.

Abstract: A repeater for use in a control network includes isolating transformers at its root input/output and at a plurality of branch input/outputs. There is a line receiver and a line driver circuit associated with each of the isolating transformers. To determine the direction of transmission of signals through the repeater, there is a common mode voltage detector which detects a common mode voltage imposed on the wiring to the root side of the root transformer. A corresponding common mode voltage is imposed by the repeater on the branch side of each of the branch transformers. The repeater also includes a logic circuit for testing the validity of signals received from the branches and ensuring that only valid signals are passed to the root transformer.