Abstract: An ATM network switch includes a switch fabric (14), and a plurality of slot controllers (11) coupled to the switch fabric. Each slot controller has at least one external data link (12, 13), cell receiving circuitry (21) for receiving ATM cells from the data link and cell transmitting circuitry (22) for transmitting ATM cells outwardly on the data link. The cell transmitting circuitry of each slot controller includes traffic shaping circuitry (23) arranged to set, for each cell presented to the transmitting circuitry, a current onward transmission time where onward transmission at the input rate meets a predetermined flow rate criterion, and a delayed onward transmission time where onward transmission at the current time would cause the traffic on a VC to exceed a predetermined flow rate criterion.

Abstract: Multimedia multipoint conferencing and distance learning sessions utilizing the ATM network use multimedia conferencing equipment at remote sites coupled to the ATM network via ATM network interface switches. All ATM switches are coupled to, and receive control information from a network manager (NM). An application server (AS) is coupled to the NM, and is also coupled to conferencing equipment via an out-of-band connection such as ETHERNET, to which the conferencing equipment is also connected. To establish a multimedia multipoint conference, the AS sends information regarding the participants to the NM. At conference time, the NM establishes a plurality of SPVC multicast trees from each participating site to all other participating sites in the conference, and activates one multicast tree and deactivates all others. An application running on a computer system at a main site tracks requests from remote sites for recognition.

Abstract: A shaping filter for a PAM mapper is provided which manipulates incoming PAM code level signals to produce outgoing PAM code level signals whose frequency spectrum is shaped to meet desired criteria. In manipulating input code level values in(t), the shaping filter preferably utilizes previous output signal values without using previous incoming signal values. In a preferred embodiment, the output code level values out(t) are constrained to an output alphabet which is a predefined subset of code levels within the .mu.-law constellation, and are obtained by manipulating the input signals according to an integer-valued shifting function such that out(t) are code level values within the output alphabet. The preferred shifting function S "shifts" in(t) by a number of places in the output alphabet in the direction opposite the sign of ##EQU1## to provide out(t), where out(t) are .mu.-law code output level values at times t, and a.sub.i are weighting factors chosen to shape the frequency spectrum of out(t).

Abstract: In accord with the objects of the invention, methods and apparatus for controlling communications network equipment are provided. The apparatus is used in a telecommunications network having a plurality of coupled nodes and a network controller coupled to at least one of those nodes, and generally comprises a node apparatus having a backplane and a plurality of functional cards coupled to the backplane. Each of the functional cards has a processor and memory for storing software which is used by the processor. One of the functional cards has memory for storing a current running version of software for each of the other of the plurality of functional cards, and a receiver and memory for storing in background incoming updated versions of software for the plurality of functional cards. The updated versions of software are provided in the overhead portion of the telecommunications signal frame, thereby being non-disruptive to the system.