Abstract: Line card control in an ATM or other packet-based switch is provided using an in-band device configuration in which control messages from a control processor of the switch are transmitted in one or more cells to a transmission convergence device in a line card. The transmission convergence device filters a stream of cells received in the line card in order to identify cells including control messages directed to the line card. The transmission convergence device then executes one or more commands associated with a given control message. Each control message may be transmitted in a single cell including a header and a payload. A message trailer portion of the payload may include device-specific data which specifies an interpretation of the payload structure. For example, the payload may include a series of commands, each including a read or write opcode, an address, and a data field.

Abstract: Methods and apparatus are disclosed for suppressing transmitter burst mode disturbances in an audio band. The method and apparatus detects those signal frames wherein the input signal contains signal energy comprised substantially of only the disturbance signal; characterizes the disturbance signal in the detected signal frames to obtain a disturbance signal correction; and compensates the input signal, only for those signal frames where a transmission burst exists, using the obtained disturbance signal correction so as to remove the disturbance signal from those signal frames that contain voice, and also from certain signal frames that do not contain voice. Frequency hopping embodiments of disturbance removing circuitry are also disclosed.

Abstract: A trading communication system. A line control unit includes a channel switch circuit, a number of line trunks connected to the channel switch circuit and adapted to be connected to a line network, and a number of line circuits connected to the channel switch circuit. A number of first terminal adaptors are connected to the line circuits. Some of the first terminal adaptors are adapted to be connected to a commercial switched circuit, while one of the first trading call terminals is connected to one of the first terminal adapters. A number of second trading call terminals are at locations remote from the line control unit. A number of second terminal adaptors are connected to the second trading call terminals and are adapted to be connected to the commercial switched circuit to connect the channel switch circuit to the second trading call terminals.

Abstract: The present invention relates to an improved method and apparatus for echo cancellation in a communication system utilizing a bidirectional transmission medium. The invention significantly reduces computational overhead associated with echo cancellation by using sub-Nyquist sampling in the echo path. In particular, the invention relates to a method and apparatus for echo cancellation in a communication system utilizing different signaling or baud rates in the transmit and receive directions, whereby the computational overhead of the echo cancellation is significantly reduced as compared to traditional methods. In a preferred embodiment herein, the present invention reduces by one-half the computational overhead associated with echo cancellation in a data communications system utilizing symmetrical information rates at asymmetrical signal rates.

Abstract: A transmission apparatus for half duplex communication using HDLC is provided, in which a simple logic circuit is added to a general HDLC controller to transmit a frame, adding flags before and after the frame all the time, without modification of program even when a transmission speed is changed, thereby enabling rapid and reliable communications.

Abstract: An apparatus transmits digital signals between a higher-ranking station and one or more subordinate stations through transmission devices. A signal transit time is automatically measured in the transmission devices, differences in transit time are automatically compensated for and useful signals in the various subordinate stations are automatically synchronized with one another.

Abstract: In the transmission device, a time-shared signal distributed and outputted from the separator 101 and a transmission delay signal while the time-shared signal being delayed by the delay circuit 102 are added and combined by the adder 103, outputted as the transmission adding signal, the transmission adding signal is convolved to the chirp signal by the chirp filter 104 to cause the outputted transmission convolved signal to be modulated by the modulator 105 and then the signal is outputted as the modulation signal. In the signal receiving device, each of the received convolved signal having the modulated signal convolved by the inverse chirp filter 110 with the signal having a characteristic opposite to that of the chirp signal and the received delay signal delayed by the delay circuit 111 is sampled with the samplers 112, 113 so as to output sample signals, these sample signals are added and combined by the adder 114 to output the received adding signal indicating the demodulated receiving signal.

Abstract: A buffered distributor having a plurality of network ports serving respective network nodes includes a distribution core having a filter for selectively supplying a data packet to a selected network port based on the destination address of the received data packet relative to the network address of the network node corresponding to the selected network port. The buffered distributor distributes the received data packet to all network ports. Each network port includes a transmit buffer that loads the distributed data packet in response to an enable signal from the distribution core. The filter logic outputs a filter signal that prevents generation of the enable signal for a selected transmit buffer if a review of the destination address indicates the distributed data packet is not relevant to the corresponding network port.

Abstract: A clock signal supplying apparatus of the present invention permits each of sync detectors 11i to extract a clock signal CKi and a sync signal SYNi from a cell input data CIi and delivers in synchronism with the sync signal SYNi an input data DIi derived from the cell input data CIi. The clock signal CKi is transferred to a master clock generator 12 for generating a master clock MC. The input data DIi is delivered along with the sync signal SYNi to a clock signal supplying circuit 20i where it is judged from the first bit of the input data DIi whether the input data DIi is eligible or not.

Abstract: A switching apparatus, for use in an ATM network, includes a switch fabric for switching ATM cells, a segmentation-and-reassembly device for reassembling packets from ATM cells, and a plurality of traffic management devices. Each traffic management device receives ATM cells delivered to associated ports of the apparatus and is connected by a first data delivery path to the switch fabric and by a second data delivery path directly to the segmentation-and-reassembly device. The traffic management device identifies those received ATM cells that belong to one or more predetermined types of packets, requiring reassembly by the segmentation-and-reassembly device, as respective reassembly cells. The traffic management device then delivers received cells other than such identified reassembly cells to the switch fabric via its first data delivery path for switching by the switch fabric, and then delivers the reassembly cells to the SAR device via the second data delivery path for reassembly into packets.

Abstract: A method and apparatus for performing virtual connection merging in an output port of a network switch are disclosed. In the event no completely assembled packets have been received and scheduled for transmission, a partially received packet is selected for cut-through transmission prior to receipt of all cells comprising the packet. Transmission of the selected packet is initiated and a timer is started. If the timer expires prior to the receipt of an end of packet indication for the packet for which transmission has commenced, and end of packet signal is generated and transmitted and the transmission of additional cells for the cut-through packet is aborted. In this manner, delays associated with packet reassembly may be avoided and buffer sizes of reassembly buffers may be reduced.

Abstract: A method and arrangement for reclaiming buffers used to store frames, following the transmission of a frame, checks to determine whether the transmission of a frame is the last copy of that frame to be transmitted. If it is the last copy, or the only copy, the buffers storing that frame are reclaimed for reuse after the contents of each buffer are transmitted. If the frame is not the last copy, or it cannot be determined whether it is the last copy, then the frame is transmitted and a count of the number of transmitted copies of that frame is decremented. Once all of the copies have been transmitted, the buffer reclaiming process is initiated.

Abstract: A port for connecting a node to a network loop is disclosed. The port includes a detect element, a frame termination generator, a buffer data generator, a switching element, and a control element. The detect element monitors data from the node and sets an error flag when invalid data is received at the port. The frame termination generator generates frame termination primitives. The buffer data generator generates buffer data. The switching element has a control input, an output, and a plurality of data inputs. Each of an output of the node, the upstream node, the frame termination generator, and the buffer data generator is connected to a corresponding data input. The control element is connected to the detect element and the control input of the switching element. The control element selects, according to the error flag, one of the data inputs of the switching element. The selection connects to the output of the switching element to be output by the port to a downstream node.

Abstract: A telecommunications switch includes a plurality of digital signal processing modules resident on a communications services card, wherein each module includes its own time slot interchange (TSI). Significantly, this allows each digital signal processing module to simultaneously receive all information transmitted from the line cards. In addition, since each digital signal processing module includes its own dedicated TSI and each of these TSIs is connected in parallel to the same TDM bus, one or more TSIs may simultaneously output data onto the TDM bus during a time slot. Advantageously, this allows multiple TSIs to be assigned to the same transmit time slot and mux transmit time slots at the bit level. For example, if a first TSI on the digital signal processing module needs only three bits of an eight bit time slot, and a second TSI needs five or less bits, then both TSIs can be assigned to transmit during the same time slot.

Abstract: A method and system for delivering multimedia data to a user. The multimedia data is stored on a computer network which can consist of a private network or intranet or a public network like the Internet. The multimedia data to be delivered is typically stored in a combination of hypertext markup language (HTML) and audio file formats (WAV, MPEG, AU, etc.) and typically delivered using hypertext transfer protocol (HTTP). The multimedia data contains a visual portion of data such as text and graphics and an audio portion of data such as music. The visual portion of the data is delivered to the user's computer via a computer network. The audio portion of the data is delivered to the user's telephone via a telecommunications network.

Abstract: When a virtual channel handler terminating a virtual path tries to expand its capacity by signalling and the trial has failed, the virtual channel handler delivers an expansion request to a reconstruction server. Supplied with the expansion request, the server delivers a reduction request to each of virtual channel handlers terminating other virtual paths passing the same physical links as the virtual path. Supplied with the reduction request, each of the virtual channel handlers calculates a required VP capacity value, reduces by signalling current capacity to the required VP capacity thus calculated, and delivers to the server a reduction response including a reduction value. The server is responsive to the reduction response and delivers an expansion response to the virtual channel handler with a minimum reduction value as an expandable value.

Abstract: A system and method using enhanced processing, responsive to domain name translation requests, to provide selective routing services through a public packet switched data network. The name processing applies to translation of a domain name into a group of Internet Protocol (IP) addresses and to providing routing information for a packet data network such as the Internet. Following name translation into a group of addresses communication is automatically established between a calling terminal and a terminal designated by one of the addresses and determined through processing which effects linkage with the first terminal to respond. The selective routing is particularly advantageous for processing of voice telephone communications through the Internet packet data network based on domain name translations.

Abstract: A method is provided for optimally setting the receiver window size in a flow controlled protocol in order to minimize queuing in a packet telecommunications network. Embodiments according to the present invention are operable at an explicit path to identify per connection information from host address or physical interface, flow direction, or any combination of these elements. The present invention may function in conjunction with a rate detection method that determines both a message serialization delay component and a data size invariant delay component.

Abstract: The idle capacity of a packet network channel is dynamically estimated by transmitting only a single window of test packets at whatever window size is presently in use on the channel and by measuring the time intervals between acknowledgments (the inter-acknowledgment time) of adjacent packets. This value is used, for example, to dynamically allocate the idle bandwidth to applications. Preferably, an average value for the inter-acknowledgment time interval is calculated from all of the acknowledgment intervals associated with the window of packets. The idle capacity of the channel is then calculated from the formula C=1/IAvg, where C is the idle capacity in packets per second and IAvg is the average acknowledgment time between packets. Additionally, the same parameters that are collected to calculate the idle capacity are used to calculate the optimal window size, also on a dynamic basis.

Abstract: Disclosed is a mechanism to control telecommunication connections via digital switching networks like the ISDN. Frequently observed scenarios are a caller who is connected to an answering machine, although he intended to talk to a human individual, or where a node is shared by more than one individual and the caller wants to talk to a definite person likewise. Subscriber information is interchanged between a calling device and a called device before setting up the connection which is utilized to inform the caller about the device type at the called side or to inform the called side about the desired person. In the ISDN, a called device sends an ALERTING message to a switching center before accepting the connection. The switching center forwards a part of that message to the calling device which includes the so-called USER—USER Information Element (UUIE). In that USER—USER IE, an information like “UNDER THE CALLED NUMBER AN ANSWERING MACHINE IS BECOMING ACTIVE” can be coded.