Abstract: A SS7 signalling router receives SS7 signalling regarding narrowband calls to be routed over the ATM network. When the SS7 router receives signalling from the SS7 network, it does not process the signalling, but reads the originator point code (OPC) and forwards the signalling via the ATM network to the ATM switch which is attached to the originator of the message. An interworking function (IWF) at the ATM switch processes the SS7 signalling by generating the appropriate ATM signalling to set up a circuit between the originating ATM switch and the destination ATM switch. The IWF at the originating ATM switch also processes the SS7 signalling by returning it to the SS7 router with the destination point code (DPC) of the PSTN switch coupled to the destination ATM switch. When the SS7 router receives an SS7 signalling message from an ATM switch, it forwards it to the SS7 network where it is sent to the DPC.

Abstract: A informational element (IE) is provided which permits the user to assign a precedence level to a call. A precedence/preemption connection admission control (P/P CAC) for use with any bandwidth allocation algorithm is also provided for processing a virtual circuit connection (VCC) request having an assigned precedence level, and for preempting one or more VCCs when a VCC request having a relatively higher precedence level is received at an ATM switch. Preferably, a resource allocator containing two databases, one listing all active virtual circuit connections and a second listing all preempted virtual circuits, is provided for storing the call parameters of preempted VCCs. According to a preferred embodiment, preempted VCCs may be reestablished. Reestablishment occurs according to various criteria. In addition, a second embodiment of a P/P CAC is provided in which active VCCs identified for preemption are buffered until the requested VCC is accepted by a downstream ATM switch.

Abstract: An ATM data network switch having two separate but simultaneously active switch fabrics and a plurality of slot controllers is disclosed. Each slot controller has at least one external data link thereto and is separately connected to the two separate switch fabrics. Each switch fabric was the ability to switch a data cell transmitted from any one of the slot controllers to any of the other slot controllers. Each slot controller is arranged to determine the availability of the data paths to all the other slot controllers through both switch fabrics and to select for each cell to be switched a data path through one or the other of the switch fabric according to the availability determined.

Abstract: A card panel includes a conductive bracket and a circuit board coupled to the bracket. The bracket includes a front side, and first and second lateral sides. The board is coupled to an inner surface of the first side of the bracket, while an outer surface of the first side operates as a conductive contact. The outer surface of the second side of the bracket includes an integrally molded T-shaped track, and a hole at each end of the track. An elongate conductive spring having a generally triangular cross-section with two inwardly directed lower flanges and a raised portion is positioned on the track such that each of the lower flanges is held by track and further such that the ends of the spring are positioned between the holes in the track. Rivets are provided in the holes and maintaining the spring on the track. The integrally molded track permits easy installation of the spring to the bracket. The integration of the components provides an assembly having relatively few components and a relatively low cost.

Abstract: A voice server module for an ATM switch is provided and generally includes an interface block which receives and multiplexes high speed preprocessed data, a voice processing block which compresses voice data and which is coupled to the interface, an ATM adaptation layer (AAL) processor which receives uncompressed data and compressed data and which formats the uncompressed data into ATM AAL1 format and the compressed data into ATM AAL2 format, and a management processor which configures the interface block, the voice processing block, and the AAL processor. The interface means receives data which originated from up to four E1 or T1 lines, and multiplexes the data into a high speed serial data stream. The data stream is then sent both to the voice processing block and to the AAL processor, with the voice processing block ignoring all but the voice data portion of the data stream, and the AAL processor ignoring the voice data portion of the data stream.

Abstract: An intelligent data service unit (DSU) which terminates a digital subscriber loop is provided and includes a digital subscriber loop interface which receives incoming data from a DDS line of the service provider, a framing and signal converter for taking the incoming data and formatting the data for output, an output interface, a processor connected to the framing and signal converter and to each of the interfaces, and a data memory buffer coupled to the processor. All data provided to the DSU from the digital subscriber loop is reformatted by the framing and signal converter and propagated to the output interface as it is received. At the same time, a copy of the data is buffered into the memory, and the processor scans the memory to find and synchronize with an networking protocol frame (e.g., an IP frame) Once synchronized, the processor compares the destination address in the IP frame to the network address of the DSU. If the addresses match, the IP frame is stored for processing (e.g.

Abstract: A connection admission control system for the link of an ATM switch generally includes a system for accepting a proposed call if the tangent effective bandwidth, a conservative approximation for the bandwidth, of the proposed call when added to the sum of the tangent effective bandwidths of all other calls being handled by that link are less than the capacity of the link is less than the capacity of the link. The proposed call may also be accepted if the zero-loss effective bandwidth for the proposed call when added to the sum of the zero-loss effective bandwidths of all other calls being handled by that link is less than the capacity of the link. The tangent effective bandwidths and zero-loss effective bandwidths are calculated off of the switch by a processor and stored in a table at the switch. When a call request is received it is placed into a connection class, and the tangent effective bandwidth and zero-loss effective bandwidth relating to that connection class is found in the table.

Abstract: A power block includes an insulative block which is mounted to a panel and a plurality of connection mounts which are coupled to the insulative block. The insulative block includes a plurality of molded dividers and the connection mounts are located therebetween. Each connection mount includes at least one stud extending upward from the block and a conductor having first and second portions. The first portion of each conductor is conductively coupled to the one or more studs and the second portion extends through the block in a direction opposite the one or more studs. The second portion includes a free end provided with a connector directly couplable to a destination point. A preferred aspect of the invention is that the conductor is a copper braid partially covered in a tin plated copper sleeve. According to a first embodiment, the connector at the free end of the conductor is a sleeve extending over the free end and having a hole for directly receiving a lead from a power filter.

Abstract: An ATM billing system includes a data (billing) generator at each slot of an ATM switch, a plurality of billing collectors, and a billing center coupled to the ATM network. The data generators are provided with SNMP communication capability and with a modified TFTP communication capability. The data generators monitor the MIBs in their respective slots in ATM switches and, in particular, monitor the contents of tables which contain accounting information. When a table is 90% full, the data generator sends a trap to the billing collector associated with the particular switch and the billing collector sends a TFTP GET request to the data generator. The modified TFTP protocol in the data generator creates a pseudo filename, generates TFTP data packets containing the entire contents of the MIB billing table, and sends the packets according to TFTP protocol to the billing collector. The billing collector uses standard TFTP protocol to receive the TFTP packets and assemble them as a file which is stored.

Abstract: A processor of an ATM switch is adapted for inserting a call correlation tag (CCT) information element (parameter) into all call initiating messages (e.g., CALL SETUP or INITIAL ADDRESS) of which it is the source. The CCT is unique over a period of time such that two ongoing calls originating at the same interface cannot have the same CCT. The CCT is stored in memory at the ATM switch with other relevant information regarding the call. After the call initiating message is forwarded through the network, the processor of the destination ATM switch obtains the CCT and stores it in memory with other relevant information regarding the call. After the call is terminated, the stored information along with the CCT is forwarded by each processor to a billing management center. According to one preferred aspect of the invention, the CCT assumes the form of a thirty-two bit value contained in an information element (IE).

Abstract: An MMS circuit set-up system includes a real time link manager (RTLM) which is coupled to the audio video controller (AVC) of the MMS. The AVC receives data from the MMS reservation system about the starting and ending times for conferences and sends commands to the RTLM to set up connections for the conference. The RTLM is provided with a database of configuration and location information about remote sites and has access to the resource database of one or more ATM switches and/or other networking equipment. The RTLM sends configuration messages to ATM switches and/or other networking equipment in order to set up a conference. According to a presently preferred embodiment, the ATM switches are controlled by the RTLM using SNMP (simple network management protocol) via an ETHERNET.TM. connection to the slot controllers of the ATM switches and networking equipment which does not support SNMP are controlled by the RTLM using TCP/IP (transaction control protocol/internet protocol) via an ETHERNET.TM.

Abstract: A multimedia conference reservation controller and reservation acceptance system includes a database of all presently reserved resources on each MMS controlled by the reservation controller which includes an identification of each resource together with the starting time and ending time of the reservation. The acceptance system is designed to accept a reservation query which includes a list of required resources and a list of flexible resources, where flexible resource are considered desirable resources, but not absolutely necessary resources. In response to a reservation query involving a single MMS, the acceptance system accesses the database and builds a list of resources together with the times during which those resources are already reserved. This list is used to create a Resource Availability Matrix which is then analyzed and a list of time periods is generated during which the requested resources are available.

Abstract: Methods and apparatus are provided for handling asynchronous transfer mode (ATM) cells sent from first user equipment through a plurality of ATM nodes and destined for second equipment, when the second equipment does not support ATM operations and maintenance (OAM) functionality. In particular, an ATM node connected to the second equipment is configured as an OAM proxy connection end-point for the second equipment such that ATM data cells which are destined for the second equipment are sent in a usual fashion, but ATM OAM cells destined for the second equipment are terminated and acted upon by the ATM node and are not forwarded to the second equipment. The proxy connection end-point functionality is preferably obtained by providing a user-friendly management information database (MIB) which stores configuration information for the ATM node.

Abstract: A mapper for a PAM encoder is provided and includes apparatus for generating desired code levels, and a constellation matrix memory which stores indications of a plurality of different N-dimensional constellations. The plurality of different constellations are used individually or together to support a plurality of different modem data (bit) rates. In order to maximize performance in the presence of robbed bit signalling, multidimensional constellations having different numbers of points are used together in the coding of a single group of bits.

Abstract: A pulse amplitude modulated (PAM) mapper includes a constellation matrix memory which stores indications of a plurality of different constellations, wherein at least one of the different stored constellations is of different dimension than another of the stored constellations. The constellations are used individually or together to support a plurality of different modem data rates. In a preferred embodiment, the mapper also includes a logic block, a constellation controller, a PAM code generation block, and an output register. The logic block receives incoming bits and groups the bits as a function of the desired or agreed upon bit rate as indicated by the constellation controller, and provides a plurality of each group of bits to the PAM code generation block, and one or more sign bits to the output register. The PAM code generation block uses the provided bits to choose at least one point from one of the constellations, and uses each chosen constellation point to generate a PAM code (typically .mu.

Abstract: Multimedia conferencing systems are provided and include a plurality of audio/video terminals which are coupled together via a telecommunications network, with the network including switches and an audio bridge. The audio/video terminals are provided with interface modules which receive local audio and video signals, process the signals, and provide separate streams of properly formatted audio data and video data to the network. The video data is switched in the preferably ATM network (i.e., routed) to its desired destination, while the audio data is first routed to the audio bridge for mixing, and then to the desired destination. At the desired destination, the separate audio and video signals are processed and synchronized by the interface module of the destination and provided to the audio/video terminal. Various different synchronization methods for the audio and video data streams are disclosed. In a simple synchronization method, a fixed delay of, e.g., 65 milliseconds is added to the audio stream.

Abstract: An ATM network switch is provided with a switch fabric linking a plurality of slot controllers. Each slot controller receives ATM cells from an external data link and has at least one input port to the switch fabric. The switch fabric switches a data cell received from any one port to one or more other ports. Each slot controller is provided with a separate group of buffers for each slot controller in the switch, and stores ATM cells intended for those other slot controller in the buffers. Each group of buffers includes a separate buffer for each class of cell traffic, so that the ATM cells are stored by intended slot controller and by class. The slot controller also includes a buffer control circuit which controls the passing of cells from the buffer to the switch fabric. The switch fabric includes input FIFOs, an indication of the fullness of which is measured and signaled back to the buffer control circuit.

Abstract: A spectral and power shaping mapper for high data rate signaling modem functions in a first mode having spectral and power shaping and using convolutional encoding, a second mode having power shaping, a third mode having power shaping using convolutional encoding, and a fourth mode having straight-forward mapping. Based on data rates and other criteria, incoming bits are grouped together, with a first subgroup of bits used in the first mode to generate two sign vectors (and in the other modes a single vector), a second subgroup of bits used in conjunction with an appended bit in the first, second and third modes to generate at least two magnitude manipulation vectors, and a third subgroup of bits used in a modulus converter to generate a plurality of quotients. The quotients and magnitude manipulation vector(s) are used to select one, two or four sequences of constellation points from a multidimensional constellation depending on mode.

Abstract: A spectral and power shaping mapper for high data rate signaling modem is provided. Based on data rates and other criteria, groups of incoming bits are grouped together, with a first subgroup of bits being used to generate two sign vectors, a second subgroup of bits being used in conjunction with an appended bit to generate two magnitude manipulation vectors, and a third subgroup of bits being used in a modulus converter to generate a plurality of quotients (r.sub.k). The quotients and magnitude manipulation vectors are used to select two or more sequences of constellation points from a multidimensional constellation. The sequences of selected points are combined with the sign vectors to generate four sequences of octets for a shaping selector. The shaping selector, preferably in the form of a convolutional encoder state machine uses criteria such as lowest cost paths and/or lowest average power in order to select which sequence of octets to output.

Abstract: A two-level or three-level probing signal is generated by a transmitter for transmission over a channel and for detection and analysis by a receiver. The two-level probing signal is a signal having a first PCM .mu.-law level over a first frame, and a second PCM .mu.-law level over a second frame. The two-level probing signal when combined with detection and analysis is generally sufficient for determining the presence and order of RB-signaling and PAD attenuation, and the extent of PAD attenuation may also be determined. The three-level probing signal is similar to the two-level probing signal but includes a third .mu.-law level over a third frame. A preferred two-level probing signal is a signal having a PCM .mu.-law level of .+-.975 for a first frame, and a signal having a PCM .mu.-law level of .+-.1023 for a second frame (or vice versa), although other sets of signals such as .+-.1087 and .+-.879 can be utilized. One preferred three-level probing signal is a signal having a PCM .mu.-law level of .+-.