Abstract: Three data formats for telecommunication networks are provided. One format is an asynchronous packet bus overlay datagram format (122) constructed to include an internal datagram header (140) and a datagram payload (141) concatenated with the internal datagram header. The internal datagram header comprises a destination address (146), a weighted age (152), and a source address (14). A second format is a wideband bus overlay format (126) comprising three header octets and a plurality of payload octets such that the data is formatted into one of a plurality of industry standard isochronous wideband data formats. A third format is a narrow band bus overlay format (124) comprising a plurality of signaling octets, a plurality of octets concatenated with the first plurality of signaling octets to hold data, and a common system multiframe structure.

Abstract: A system and method for communicating audio data in a packet-based computer network wherein transmission of data packets through the computer network requires variable periods of transmission time.

Abstract: A multi-service switch for a telecommunications network (10) is provided. A system bus (13) has an ingress portion (14) and an egress portion (16). The system bus (13) is operable to carry data in a plurality of time slots. A system bus control (11) comprises a head-of-bus control (12) having an output. The output of the head-of-bus control is coupled to the ingress portion (14) of the system bus (13). The system bus control (11) also comprises a tail-of-bus control (15) coupled to the head-of-bus control (12). The tail-of-bus control (15) has an input coupled to the egress portion (16) of the system bus (13). A plurality of interface modules (28.sub.1 through 28.sub.n) each have an input and an output. The input of each interface module (28.sub.1 through 28.sub.n) is coupled to the egress portion (16) of the system bus (13), and the output of each interface module is coupled to the ingress portion (14) of the system bus (13). An ingress/egress bridge (18) has an input and an output.

Abstract: A polled digital multiport, multidrop system is described. The inbound frame for sending information from remote terminals to the host terminals is arranged such that a plurality of bytes are provided by a first terminal, followed by a guard band, followed by a plurality of bytes provided by a second terminal, followed by another guard band, etc. The guard band permits signalling between the DSU and the OCU which in turn permits the OCU to signal the MJU that no data will be coming from the OCU. In this manner, control mode idle is accomplished and data mode idle is avoided. In addition, because of the guard band, if the delay from a remote site changes, no data will be lost. Means for monitoring the system to follow changes in delay are also provided, and the system can cause a remote location to accommodate a change in delay.

Abstract: A computer-based conferencing system capable of selectively conferencing with a remote node over two or more different transports. A host processor controls the generation of local conferencing signals for transmission to the remote node over either a first transport or a second transport. The host processor also controls the processing of remote conferencing signals received from the remote node over either the first transport or the second transport. In a preferred embodiment, the first transport is an ISDN network and the second transport is a LAN network. In one embodiment, the computer system has a combined audio/ISDN board, a video board, and a LAN card. In an alternative embodiment, the computer system has a combined audio/video board, an ISDN board, and a LAN card.

Abstract: A data demultiplexer for separating multiplex data including at least coded video data, coded audio data, timing data indicative of a video decoding start time, timing data indicative of an audio decoding start time, and timing data indicative of a system clock reference time. The demultiplexer comprises a circuit for separating the multiplex data into the component data, and comparators for comparing input data with the reference timing data. When the timing data indicative of a video decoding start time is inputted and detected, the video data is written in a video code buffer at the maximum transfer rate. During such time period, the reference timing data indicative of the current time is monitored, and the operation of decoding the video data is started when the reference timing data has become equal to the video timing data.

Abstract: A port system interfaces digital PBX's to any transmission facility having DSX-1 communications ports via a microprocessor controlled PBX port board connected between PBX switch fabric and a first DSX-1 communications port. A channel service unit (CSU) module coupled directly to the port board for communications with DS1 transmission lines defines a second DSX-1 communications port which is coupled to the first DSX-1 communications port. The CSU module also includes a T1 transceiver and line interface circuitry for coupling the CSU module to a DS1 transmission line. The combination of the port board and CSU module provide full functionality of conventional CSU's while the port board alone permits direct coupling of transmission facilities utilizing a DSX-1 communications port. For remote maintenance, a microprocessor of the port board is coupled to a control processor of a PBX for control of the port board microprocessor via the PBX control processor.

Abstract: In a base station of a mobile cellular telephone system of the type having time division multiple access (TDMA) channels, a radio frequency test loop is established between a predetermined downlink channel of a base station transmitter and a predetermined uplink channel of a base station receiver. The test loop is in real time, thereby eliminating the time offset of the radio channels used for communications. The radio frequency test loop includes a circuit for transposing the frequency of the carrier signal from the transmitter to a frequency that can be received by the receiver. The signal having the transposed frequency is used in tests for determining values such as bit error rate (BER), transmission signal level, or reception sensitivity.

Abstract: An elementary stream packetizing unit for an MPEG-2 system comprising a system time clock generator for sampling an external system clock signal at a resolution of a predetermined frequency, first and second time stamp generators for latching a sampled value from the system time clock generator to generate a first presentation time stamp and a decoding time stamp for the process of video elementary stream data and a second presentation time stamp for the process of audio elementary stream data, respectively, first and second stream interface circuits for inputting the video and audio elementary stream data and generating a group-of-picture detect signal and an audio frame synchronous word detection start signal, respectively, first and second buffers for storing the video and audio elementary stream data and generating first and second header generation start signals, respectively, first and second header generators for generating first and second headers, respectively, a first multiplexer for multiplexing th

Abstract: A communication control apparatus connected between a transmission path and a processing unit which apparatus includes a table memory for storing the number of received frames which are in the state waiting for protocol processing in correspondence with connection identifiers, a first processor responsive to reception of a new frame from the aforementioned transmission path for making decision by referencing the memory table mentioned above as to whether or not the number of the received frames corresponding to the connection identifier of the newly received frame and waiting for the protocol processing has reached a threshold value for thereby abandoning the aforementioned newly received frame when that number has reached the threshold value and, if otherwise, placing the newly received frame in the state waiting for the protocol processing, and a second processor for executing a predetermined protocol processing on the received frame in the state waiting for the protocol processing.

Abstract: A switchable data rate ISDN terminal for group G.sub.4 facsimile operation s disclosed. A decoder in the terminal automatically responds to a hexadecimal 7F formed by an extra bit added to the HDLC communications-starting flag when a 64 kb/s system transmits a 56 kb/s communication. The decoder responds by causing a speed controller in the terminal to reduce the effective data transfer rate.

Abstract: An LAN system provided with a host system connected to an LAN through a plurality of LAN adapters, and a plurality of terminal systems for communicating with the host system through the LAN. A plurality of logical addresses for the host system are set correspondingly to physical addresses of the LAN adapters. One of the logical addresses is selected arbitrarily as a key (common) logical address. When the host system is to send a message to one of the terminal systems, the host system sets the key logical address of the host system as a source logical address included in the message, selects one of the LAN adapters and sends the message to the LAN through the selected LAN adapter.

Abstract: A system for controlling the transmission of cells from a network node over multiple Virtual Circuits (VCs) is disclosed. The system performs traffic shaping, as required by connection based systems such as Asynchronous Transfer Mode (ATM), for each VC connected with a network node, so that the Quality of Service (Qos) parameters established when the connection was established are not exceeded. The system includes a process for scheduling the transmission of cells from the network node. The scheduling process periodically scans a table having entries corresponding to virtual circuits connected with the network node. During each scan of the table, the scheduler increments a sustainable rate accumulator field, a peak rate accumulator field, and a latency accumulator field of each table entry that corresponds with a virtual circuit that is open, and for which there is a cell ready to be transmitted.

Abstract: A cell multiplexing apparatus includes a transmitting section in which information fields of a plurality of ATM cells intended for transmission along the same path are multiplexed and stored into an information field of one multiplexed cell. A representative VPI, globally representing the VPIs of the plurality of ATM cells intended for transmission along the same path, is assigned as the VPI of the multiplexed cell for transmission. A receiving section detects the representative VPI from received cells and the plurality of ATM cells having individual VPIs and transmitted along the same path are reconstructed from the multiplexed cell having the representative VPI. The VPI area of the ATM header of the multiplexed cell is divided into two segments. The representative VPI designating the path for the multiplexed cell is carried in one segment and VPI information of the plurality of ATM cells intended for transmission along the same path is carried in the other segment.

Abstract: A network management facility is adapted so that it obtains information including connectivity data as well as the identities of discrete network elements from an associated network and then uses the information to determine the configuration of the network. The management facility then generates, for storage in a network management database, data records characterizing the configuration of the network, as defined by the components, circuits, etc., forming the network. Once the database has been created in this manner, the network management system may then use the contents of the database to provision requests entered by network users, for example, a request for additional transmission bandwidth. The database may also be used to evaluate a network condition, such as a condition characterized by a trouble alarm.

Abstract: A circuit arrangement sets up conference calls in a digital time-division multiplex telecommunications switching center. For setting up three-party connections, a conference unit (KE) having a PROM is provided wherein are stored all possible, companded sum and difference values of individual contributions of respectively two conference participants. These are selected by the individual contributions as read selection addresses. The PROM thus realizes the functions of linearization of the sum and difference and of companding that are performed by separate sub-units in previous conference units.

Abstract: An apparatus for controlling cells which are to be input to an ATM switch includes a buffer circuit for storing a cell directed to the ATM switch, and a memory for storing, for each of different calls, the number of cells which are in the ATM switch. The apparatus includes a periodic calculation circuit for periodically changing the number of cells for each of the different calls by an operation value, and a control part for determining whether the cell stored in the buffer circuit should be output to the ATM switch or discarded by referring to the number of cells which is stored in the memory and related to the cell stored in the buffer circuit.

Abstract: An amount-of-data identifying portion identifies the amount of data transmitted by referring to a specific portion in the upper layers of the information transmitted from the terminal of a LAN, and a bandwidth control line monitor portion calculates the band which is necessary for communication. Communication between LANs is executed through the number of wide area network interface portions which is determined on the basis of the calculated band. In the case that the communication is performed after securing the band corresponding to the traffic characteristics (transfer speed, etc.

Abstract: A conferencing server accepts a conferencing session call from a conferencing node over a communications link. The conferencing server receives a message from the conferencing node requesting confidence testing over the communications link. The conferencing server transmits confidence test signals to the conferencing node over the communications link for playing by the conferencing node. The conferencing server receives a status of the playing of the confidence test signals from the conferencing node. The conferencing server transmits the status of the playing of the confidence test signals to a customer support node.

Abstract: A method and an arrangement for link allocation which provide selecting a free link for a requested connection from a plurality of available route coordinated links according to a particular resource requirement of the requested connection and depending on the current resource seizure of connections that have already been established on utilized links. The establishment of a requested connection and the connections already established have the same or different resource requirement. The current resource seizure for each link resulting from the established connection or connections is stored in a memory. Each link is sorted in the memory in a link allocated memory site which corresponds to the current resource seizure of the link concerned, or the free resource capacity of the link.