Abstract: One embodiment of the present invention provides a system for high-throughput asynchronous communication that includes a sender and a receiver. A sender's first-in, first-out (FIFO) buffer is coupled to an input of the sender, a receiver's FIFO buffer is coupled to an input of the receiver, a forward communication channel is coupled between the sender and the receiver's FIFO buffer, and a reverse communication channel is coupled between the receiver and the sender's FIFO buffer. The forward communication channel, the receiver's FIFO buffer, the reverse communication channel, and the sender's FIFO buffer operate collectively as a network FIFO between the sender and the receiver. The network FIFO is configured to ensure that asynchronous communication between the sender and the receiver takes place reliably and without unnecessary waiting by the sender or the receiver.

Abstract: A communication quality measuring apparatus comprising a connecting section establishing a connection to the packet exchange network, a capturing section capturing packets transferred over the packet exchange network, an accumulating section accumulating the packets, a control section repeating the capturing of packets in sections of fundamental processing times, a setting section setting the capturing time and the interval time within each fundamental processing time, and a determining section determining whether or not the amount of load on hardware resources of the communication-quality measuring apparatus is greater than a predetermined value.

Abstract: A temporary (temp) dedicated channel (DCH) is used to support communications. The temp-DCH channel is a channel that is assigned to a user having a set duration. After the duration expires, the channel is automatically released to the user. Embodiments of the invention relate to establishing the temp-DCH channel, determining the data rate and duration of the channel. Other embodiments relate to establishing back-to-back temp-DCH channels and the implementation details of these embodiments. Additionally, one embodiment relates to adding a start/stop function to the medium access controller which can be used in conjunction with temp-DCH as well as other applications.

Abstract: A local network, particularly an Ethernet network having redundancy properties, in which coupling devices (K1, K2, K3) and a redundancy manager (RM) are interconnected in a ring-shaped topology. The redundancy manager opens the ring to create a linear topology if test messages (T11, T12) emitted by the redundancy manager (RM) are received at the other port (P42, P41) within a given period of time, otherwise the redundancy manager (RM) closes the connection. As a so-called redundancy manager observer, at least one of the coupling devices (K3) is configured such that it evaluates messages received at the port (P32) thereof, the port (P32) being connected to the redundancy manager, opens the ring to create a linear topology, and signals an error if more than initial test messages (T11) have been received at this port (P32) and if the status “ring opened” has been indicated by the redundancy manager (RM) in the last-received initial test message (T11), whereby messages are prevented from circulating on the ring.

Abstract: A test packet generator of an entry device generates a delay test packet including priority information. A test packet transmitter of the entry device transmits the delay test packet to an exit device through a route corresponding to the priority information. A test packet receiver of the exit device receives the delay test packet. A reply packet transmitter of the exit device returns a reply-delay test packet toward the entry device through the same route in the counter direction. A reply packet receiver of the entry device receives the reply-delay test packet. A delay calculator of the entry device calculates a delay time on the basis of the time of transmitting the delay test packet and the time of receiving the reply-delay test packet. A route changer of the entry device changes routing appropriately on the basis of the delay time.

Abstract: The present invention enables the network to determine the true state of events that appear normal but produce service disruptions by periodically probing the status of all network elements and endpoints and comparing this status to historical graphs of the network. Events that deviate from a historical view will be alarmed to determine their true status.

Abstract: The present invention relates to a device and method for injecting a noise signal into a wire pair of a communication link. In operation a first current source and a second current source are disposed in series with a node therebetween coupled resistively to a wire of the wire pair. A current flow path is provided for balancing the current from the two current sources. A similar circuit is also coupled to the other wire of the wire pair.

Abstract: An access network includes a test system controller that provides a test request in Signaling Network Management Protocol (SNMP) messages to an element management system. A network gateway, in conjunction with the element management system, provides test commands to a customer gateway over a Local loop Emulation Service Embedded Operations Channel (LES-EOC). The customer gateway performs a subscriber loop test on derived subscriber lines connected therewith. Results of the subscriber loop test are provided over the LES-EOC to the gateway. The network gateway sends the results to the test system controller through the element management system in SNMP messages.

Abstract: The present invention relates in general to a method, apparatus, and article of manufacture for providing high-speed digital communications through a communications channel. In one aspect, the present invention employs a variable rate back channel, incorporated within an existing communication that does not increase or adversely impact the transmission rate of data on the communication channel.

Abstract: In a wireless communication system (20) configured for default communication of subsectional signals of a first transmit signal (72/73) over multiple wireless channels (46), a signal selector (82) and method (138) detect an intent to convey a voice signal (86) over one of the wireless channels (46) from a handset (58). The signal selector (82) and method (138) prevent communication of one of the subsectional signals (72A) over the wireless channel (46) for a predetermined interval, and enable a transmission attempt of the voice signal (86). When a complete dialed digits sequence is detected within the time interval, the handset (58) is enabled to utilize the wireless channel. However, when a transmission attempt of the voice signal (86) is unsuccessful or when transmission of the voice signal (86) terminates, the signal selector (82) and method (138) restore default communication of subsectional signals of the first transmit signal (72/73).

Abstract: The method and system provides for receiving at a local base transceiver station a wireless signal and for routing that signal from the local base transceiver station to a remote base station controller. In exemplary embodiments, control logic stored in local components of a wireless telecommunications network can select one of multiple remote base station controllers to which to route the signal. Further, local telecommunications components can make these selections based on the occurrence of various triggering events, such as the occurrence of a particular time/day/date, or such as the involvement of a particular client station, or the signal having a particular form or content.

Abstract: A remote test unit (RTU) and method of operation are provided for utilizes the ability of an access matrix ability to route signals. The RTU can emulate a central Digital Subscriber Line Modem (DSLM-C) for testing customer premises equipment containing a remote Digital Subscriber Line Modem (DSLM-R). The RTU can also emulate a DSLM-R for testing central offices equipment including a digital subscriber line access multiplexer (DSLAM) containing a DSLM-C. The RTU can also emulate a concentrator connected to the DSLAM, a router connected to the concentrator, an Internet service provider (ISP) connected to the router, and a web site connected to the ISP over the Internet. The RTU can further test, using emulation, ISO/OSI layers defined in the ISO/OSI reference model which are connected to the DSLAM.

Abstract: A system, apparatuses, a method, and a computer program for producing signals for testing radio frequency communication devices are provided. The system comprises a non-real-time domain which includes a data generator for supplying a temporally discontinuous data stream which data stream includes signal waveform data and control data defining characteristics of a conversion from the signal waveform data into a radio frequency test signal. The temporally discontinuous data stream is fed into a transformer which transforms the temporally discontinuous data stream into a temporally continuous data stream, thus providing a transformation between the non-real-time domain and a real-time domain. The real-time domain includes a radio frequency unit which uses the temporally continuous signal data stream as input, and performs the conversion from the signal waveform data into the radio frequency test signal according to the control data.

Abstract: Shared secret data is used to authenticate and encrypt between a CDMA network and a GSM network such that a mobile station having a subscription in a GSM network can roam into a CDMA network and be authenticated to use the CDMA network and have messages encrypted without having a CDMA subscription. The goal of authenticating a GSM subscriber in a CDMA network using GSM authentication credentials is achieved by substituting a key Kc as SSD-A and messages are encrypted substituting Kc as SSD-B using a CAVE algorithm.

Abstract: A high speed, two-way serial interface with a scrambler and de-scrambler may be tested by sending a single word repeatedly through the scrambler to create a pseudo-random sequence. The pseudo-random sequence is then passed through the transmitter and looped back through the receiver of the serial interface. The pseudo-random sequence is then descrambled and compared to the input word. Since the input sequence is only a single word rather than a series of words, the comparison is very simple and capable of being performed within the serial interface itself without the need for external test equipment.

Abstract: A transceiver circuit having 10 mb and 100 mb transmit and receive circuitries using the power saving methods allows for power consumption of the transceiver circuit to be significantly reduced. This is accomplished by providing each defined subcircuit with its own power supply and means of activation and deactivation. However, the method for activating and deactivating digital subcircuits and analog subcircuits are different and therefore different types of control signals and methods are provided. Furthermore, there are two general types of power-saving situations. The first type is near total circuit power-down and the second type is partial circuit power-down. In yet another embodiment, a method for minimizing energy usage during the idle period is utilized.

Abstract: A VDSL customer drop testing arrangement and equipment utilizes a test set top box having a sign-on identifier unique to an authorized test device to perform testing of the customer drop without the need to provision the drop for receipt of video programming or data services from any network information or service providers (VIPs or DSPs). Because the test arrangement of the present invention does not require such provisioning, isolation of the customer drop is achieved. Such isolation insures that the test set is not being affected by problems originated from a VIP or DSP.

Abstract: A method for determining the suitability of a copper line, used for transmitting voice band signals and having one or more user devices coupled thereto for transmitting signals on the copper line, for use in transmitting data signals out-of-band with the voice band signals is provided. The method includes applying a test signal at one point in the copper line. The test signal has a known relationship to a particular out-of-band data transmission scheme. A response of the copper line to the test signal is monitored, as influenced by the one or more user devices. The monitoring takes place at about the point where the test signal was applied. The suitability of the copper line for data transmission using the particular out-of-band data transmission scheme is determined based on the monitored response of the copper line. A method for determining the suitability of a communication line for transmitting data using an out-of-band data transmission protocol is provided.

Abstract: A base station receives a signal resulting from multiplexing a communication signal spread using a signal-specific spreading code and sent by mobile station apparatus and a calibration (CAL) signal spread using a signal-specific spreading code and sent for each unit frame for a predetermined time by a CAL radio signal generator in a same frequency band. An A/D conversion/despreading section and an A/D conversion/despreading section extract the communication signal and CAL signal from the received signal. A calibration processing section carries out calibration processing using the CAL signal in parallel with a communication using the communication signal. An array combining/signal processing section carries out demodulation processing on the communication signal using the calibration processing result.

Abstract: A home network system that makes it possible to build a network with assured security, wherein network users need not have security expertise. For access attempts offered from a home node 21-1 in a community area network 5-1 toward an outside public network 1 through a path N2, a security server 11-1 need not execute an authentication process. The home node 21-1 rejects access attempts directly transferred from the public network 1. The security server 11-1 executes the authentication process for an access attempt transferred from the public network 1 through a path N42. When the authentication is successful, connection of the access attempt to the home node 21-1 through a path N9 is permitted.

Abstract: A test set includes at least one signal input port, a test circuitry, a processor, a user-input device, and a display. The test circuitry couples to and receives signals from the at least one signal input port. The test circuitry then generates test data corresponding to the received signals. The processor couples to and receives test data from the test circuitry and generates test results. The processor also couples to and receives commands from the user-input device. The processor further operatively couples to the graphical display that receives and displays the test results from the processor. In one embodiment, the test set is capable of performing line qualification and connectivity testing. A modem module can be used to facilitate connectivity testing. The modem module can be a plug-in module with a common interface to the test set. The modem module can also contain a fingerprint value that identifies the module type and the software revision number to the test set.

Abstract: A test set includes at least one signal input port, a test circuitry, a processor, a user-input device, and a display. The test circuitry couples to and receives signals from the at least one signal input port. The test circuitry then generates test data corresponding to the received signals. The processor couples to and receives test data from the test circuitry and generates test results. The processor also couples to and receives commands from the user-input device. The processor further operatively couples to the graphical display that receives and displays the test results from the processor. In one embodiment, the test set is capable of performing line qualification and connectivity testing. A modem module can be used to facilitate connectivity testing. The modem module can be a plug-in module with a common interface to the test set. The modem module can also contain a fingerprint value that identifies the module type and the software revision number to the test set.

Abstract: Methods and associated hub arrangements are described for use in diagnosis and recovery in high performance digital loops such as, for example, those seen in Fiber Channel systems. In one system having a hub configured for interconnection of a plurality of stations as part of a digital system such that digital data flows between the stations based on operational status of the system, an arrangement forms part of the hub which arrangement is connectable at points within the hub and between at least two different pairs of the stations for, monitoring certain characteristics of the data in a way which provides for non-invasive identification of one or more conditions related to the operational status of the system.

Abstract: A digital subscriber line access multiplexer overlay onto a digital loop carrier system for transporting high speed digital data over an existing backplane which carries voice, data, and test signals between voice line cards and a carrier line. The voice signals are time division multiplexed into frames. The system includes a data bus interface for impressing the high speed data on a subset of existing backplane buses for transport along the backplane and for retrieving high speed digital data from the backplane buses. The system further includes a plurality of data line cards for connecting to the backplane and backplane subset conductors, the data line cards being adapted to couple the high speed data between the subscriber line and the backplane, whereby the high speed digital data can be routed over the backplane subset to any of the digital data line cards without interfering with the voice signals routed to voice line cards.

Abstract: A method for reducing communications in a peer-to-peer wireless network having nodes includes sending an RTS-TOA ranging communication from a first node (N0) in a node group to another node (Nr, I) in the group, receiving the RTS-TOA communication with the second node (Nr, I) and sending a multi-cast CTS-TOA/RTS-TOA ranging communication from the second node (Nr, I) as a reply to the received RTS-TOA communication, and successively and sequentially repeating the multi-cast sending step for each of the nodes. A CTS-TOA message is a reply to the received RTS-TOA message and, simultaneously, is an RTS-TOA ranging communication to a new destination node (J). The method applies for a randomized communications approach when node identifications are not sequenced and to a sequential approach where nodes are sequenced, and also applies to completely connected and multi-hop networks. Also provided is a node for carrying out the method of the present invention.

Abstract: A method for establishing a connection with a guaranteed bandwidth for transmitting data over a logical link that includes a plurality of parallel physical links between first and second endpoints. A link bandwidth is allocated on each of the physical communication links so as to include a predefined safety margin, based on either a failure protection policy, or a measure of fluctuation that occurs in a rate of data transmission over the physical links, or both. A sum of the allocated link bandwidth over the plurality of the parallel physical links is substantially greater than the guaranteed bandwidth of the connection. The data are conveyed over the logical link by distributing the data for transmission among the physical links in accordance with the allocated link bandwidth.

Abstract: A method and apparatus for handling persistence measurement of channel associated signaling for a plurality of line circuits, eg, T1, E1, OC3, STM 1 circuits, which extracts channel associated signaling data from a plurality of line circuits; assembles the channel associated signaling data into a data frame; contains the data frame in a suitable carrier, eg, an AAL 0 cell; monitors a continuous stream of the data frames, to check for changes in line status; and generates an event message data frame when a persistent change of line state has been detected. The extracting of associated signaling data may be provided on a separate card to a call control processor, and using separate processor functionality.

Abstract: A method and system is provided for monitoring the quality of signal transmissions in a communications network by calculating Quality of Services (QoS) scores and corresponding Transmission Impairment Test (TIT) scores, and then monitoring a QoS score to predict a corresponding TIT score. When the predicted TIT score goes below a minimum value, an administrator of the communications network will be informed so that the administrator can determine if services may be needed to restore the quality of signal transmissions. In an embodiment, the communications network includes a cable modem termination system (CMTS); a voice band tester (VBT) coupled to the CMTS; a cable modem tester coupled to the CMTS; and a Voice over Internet Packet (VoIP) monitoring device coupled to the CMTS and the voice band tester. The cable modem tester is located at a location remote from the VBT.

Abstract: A method for testing a network element includes receiving from a network element into a buffer (40) a first clock signal (25) of the network element. The method includes receiving into the buffer (40) from a first port (31) of the network element a first plurality of data values to be verified in response to the first clock signal (25). The method also includes transferring a second plurality of data values to be verified to a second port (32) of the network element in response to a second clock signal (29), and comparing the second plurality of data values with the first plurality of data values. A system for testing a network element includes a testing element operable to couple a first port (31) to a second port (32) of a network element. The testing element is operable to receive a first plurality of data values from the first port of the network element and to transfer a second plurality of data values to the second port of the network element.

Abstract: The present invention manages information about support incidents on a computer. The invention gathers information about a support incident, associates the support incident with a support channel, and collects current and historical information from the computer. Implementations of the invention may also package and send the gathered and collected information to a support vendor. The invention comprises methods of performing these tasks, systems that perform them, computer-readable media that contain computer-executable instructions that when executed perform the methods or provide the systems, and data structures stored on computer-readable media having fields that represent software objects useful in performing the methods or providing the systems.

Abstract: An MDI crossover incorporated in a converter that automatically detects if a cable connection has been made to an MDI port and if so, is the orientation of the cable correct. If the orientation of the cable is not correct, effecting a crossover. The crossover may be made by detecting when a cable has been plugged into a first device indicating that a signal connection has been made between a second device and the first device and determining if the orientation of the cable is correct with respect to a signal input and output of the first device. A crossover of the orientation of the cable is performed if it is determined that the orientation is not correct.

Abstract: An integrated web-based system for performing telecommunications system testing includes an application server that includes a plurality of test applications. The application server provides a graphical user interface to a plurality of workstation clients. Users can launch tests and monitor test results at the workstation clients. The test are performed by a plurality of telecommunications system test devices. The test devices include such devices as protocol analyzers, bit error rate testers, sniffers, and the like. A test access server provides an interface or bridge between the application server and each of the test devices. The test access server routes and provides appropriate translation of messages and commands between the test devices and the application process server.

Abstract: A technique for detecting and responding to a loopback condition on an ISDN PRI of a telecommunications switching system. The technique involves storing the Call Reference Value of the most recently transmitted call SETUP command as the Last Sent CRV. An incoming call SETUP command is considered to have looped back when it is assigned a Call Reference Value identical to the Last Sent CRV, and it requests a PRI channel that is occupied. The PRI is considered to be in a loopback condition after a predetermined number of call SETUP commands have looped back. The PRI can be removed from service while the loopback condition persists.

Abstract: A protocol test device has at least two channels which each have a transmit and a receive side, the protocol test device being designed to switch a signal transmitted from a first channel to the receive side of a second channel. A method for determining, by approximation, a transmit time of a data package in the protocol test device includes the following steps: a) transmitting a signal via the transmit side of the first channel, b) forwarding the signal to the receive side of the second channel, and, c) in the receive side of the second channel allocating a time stamp to the signal.

Abstract: When there is an error in setting of a companding law of an encoder or a decoder, there is a problem of an error in judgment although it should be originally judged that the continuity of the testing channel does not exist. Therefore, a channel check test system includes a transmitting side DCME for inserting a nonlinear quantized input test pattern into a channel to be tested, and a receiving side DCME.

Abstract: The invention concerns a method which consists in modelling the system under study using a system of automatons synchronised by a set of messages; in deriving from said modelling a system of linear equations whereof the unknowns are related to the status of the automatons, to the occurrence of transitions in the automatons, and to the production of synchronisation messages between automatons. These unknowns have in principle a value of 0 or 1, and they each concern an operating step among T successive steps; in defining a property to be verified using additional linear constraints to which the equation system unknowns are subjected; then in applying a method of resolution by linear programming to the equation system subjected to the additional constraints, thereby enabling to prove that the property is verified, by displaying a solution, or that the property is not verified, by displaying an absence of solution.

Abstract: A VDSL customer drop testing arrangement and equipment utilizes a test set top box having a sign-on identifier unique to an authorized test device to perform testing of the customer drop without the need to provision the drop for receipt of video programming or data services from any network information or service providers (VIPs or DSPs). Because the test arrangement of the present invention does not require such provisioning, isolation of the customer drop is achieved. Such isolation insures that the test set is not being affected by problems originated from a VIP or DSP.

Abstract: A monitor is provided that is used to transmit data being exchanged over a NTDS Type E interface to an instrumentation system. The monitor is electrically isolated from the instrumentation system and comprises a directional coupler that passes and inhibits selected data to and from the instrumentation system.

Abstract: When there is an error in setting of a companding law of an encoder or a decoder, there is a problem of an error in judgment although it should be originally judged that the continuity of the testing channel does not exist. Therefore, a channel check test system includes a transmitting side DCME for inserting a nonlinear quantized input test pattern into a channel to be tested, and a receiving side DCME.

Abstract: The present invention relates to a system and method for creating multiple logical channels across a single virtual circuit on a hybrid asynchronous transfer mode (ATM)/frame relay network and an ATM network. The logical channels include a single primary channel and multiple secondary channels. The secondary channels are created by the addition of a secondary channel flag and secondary header to the user information field of the data frames transmitted. Also, one of the secondary channels is designated as a diagnostic channel for conducting diagnostics across the virtual circuit. The diagnostic channel is reserved exclusively for diagnostic data traffic from an ATM digital service unit (DSU) to a frame relay DSU, or in the alternative, to a second ATM DSU.

Abstract: The present invention provides a test access path (TAP) concentration function. The apparatus supports subscriber loop testing for special access configurations (e.g., fiber-to-the-curb (FTTC)), where network units are physically clustered together into two or more non-collocated clusters. The apparatus supports test access to twisted wire pair subscriber loops, the lengths of which vary over a wide range. In one embodiment, the apparatus is a TAP expander that connects the TAP of an integrated digital terminal of a local digital switch with a derived TAP corresponding to one of the ONU clusters. The present invention allows an integrated digital terminal with as few as one test access path to be configured in a network having two or more non-collocated network unit clusters (e.g., ONU clusters), thereby supporting loop testing for all of the subscriber loops served by the integrated digital terminal without unnecessarily limiting the number of those subscriber loops.

Abstract: A link device establishes links automatically to all 10Base-T and 100Base-TX partners regardless of their capability thereby assuring that the link device establishes links with all partners without the need to select a mode of operation manually. The modes of operation provided include 10Base-T half duplex, 100Base-TX half duplex, and 100Base-TX full duplex. The technique includes an algorithm that assures linkability between 10Base-T and 100Base-TX devices that are not 100% compliant with IEEE 802.3u, Clause 28. Using this algorithm, a link device links with 10Base-T and 100Base-TX half duplex legacy partners. Such devices also link with compliant 10Base-T and 100Base-TX auto-negotiating partners at 100Base-TX full duplex, and with non-compliant 10Base-T and 100Base-TX auto-negotiating devices at 100Base-TX half duplex.

Abstract: An apparatus for monitoring selected one of multiple channels comprises a counting unit for increasing a count value when an up mode is selected and for decreasing the count value when a down mode is selected, wherein the count value corresponds to a channel number of the multiple channels; a mode selecting unit for selecting one of the up and the down modes; a unit for inputting a channel number; a unit for generating a count value corresponding to the channel number from the inputting unit and a write-enable signal; a source selecting unit for selecting one of the count values from the counting unit and from the generating unit; a signal generating unit for generating a channel selecting signal corresponding to the count value; a converting unit for extracting data from a channel depicted by the channel selecting signal and converting transmission rate of the data; and an analyzing unit for monitoring the data from the converting unit to check whether or not the data is transferred properly.

Abstract: A circuit for performing a switching of a protection line between a common section and a channel section includes a common section and a channel section connected by signal lines. The common section has a working interface circuit and a protecting interface circuit. The channel section only has a working interface circuit. The working interface circuit of the common section is operably connected to the working interface circuit of the channel section by a working cable. The protecting interface circuit of the common section is connected to the working interface circuit of the channel section by a protecting cable. When a disconnection or a slip of the working cable occurs, a signal from the working interface circuit of the common section is transmitted and inputted into the protecting interface circuit via the protecting cable.

Abstract: A subscriber multiplexer includes a receiver for receiving signals transmitted from subscriber interfaces a feeder and for feeding those signals further to a telephone exchange via a respective PCM connection, and a feeder for feeding signals transmitted from the telephone exchange via the respective PCM connection further to the subscriber interfaces. For detecting the condition of the subscriber interfaces, the subscriber multiplexer includes measuring devices for checking the condition of the subscriber interface of the subscriber multiplexer, and a controller for activating the measuring devices in response to a measurement request signal transmitted by the telephone exchange via the respective PCM connection to achieve a measurement result, and for transmitting a message describing the measurement result to the telephone exchange to a telephone system and a method for communicating the condition of a subscriber interface of a subscriber multiplexer.

Abstract: In a fault evaluating system for a transmission apparatus having four packages which are mutually duplexed in both transmission and reception directions and bridged to oppose each other, each package includes a fault detection unit, a fault information extraction unit, a fault information insertion unit, and a fault evaluating unit. The fault detection unit individually detects an abnormality in signals transmitted from duplexed opposing packages. The fault information extraction unit individually extracts fault information representing a fault package, which is contained in the signals transmitted from the duplexed opposing packages. The fault information insertion unit generates fault information representing the fault package in accordance with a detection output from the fault detection unit, inserts the generated fault information and the fault information extracted by the fault information extraction unit in a signal to be transmitted, and sends back the signal to the duplexed opposing packages.

Abstract: A system and method are provided for providing non-disruptive diagnostics between a first device and a second device in communication through a virtual circuit of a frame relay network. In accordance with one aspect of the invention, the method defines a diagnostic channel by assigning it a unique channel address, transmits a test command from the first device to the second device across the unique channel address, monitors the unique channel address for a response to the test command, and then evaluates the response to determine whether it reflects a fault in the virtual circuit. In accordance with one embodiment, the test command could be a pattern message, a connectivity request, a start send pattern command, a start loopback command, a start monitor pattern command, and a start send pattern command.

Abstract: The present invention provides means by which a switch controller that manages lines directly notifies receivers of ineffectiveness of received data upon line disconnection instead of any transmitter indirectly notifying receivers; and according to the invention, an optical transmitter is provided within the optical switching unit, and a switch controller controls the optical transmitter within the optical switching unit and an optical switch having at its input ports one or more dummy ports capable of multicast-transmission. According to this control, upon line disconnection, receivers are connected to the optical transmitter within the optical switching unit that transmits control code in real time, thereby preventing receivers from receiving ineffective data and obviating superfluous signal lines and communication processes between the switch controller and transmitters.

Abstract: A method and apparatus for monitoring telecommunication signals carried by a telecommunication network (10) including a signal transfer point device (12) for routing data, clock and control signals over a link (14) and a link monitor (16) operable for monitoring the link (14) is disclosed. The method and apparatus provides for the monitoring of the data and clock signals routed over the link (14) without tapping into the control signals routed over the link (14).