Abstract: A method and apparatus are disclosed for measuring the usage of a communications network, based on a two level sampling and measuring technique. A sampling interval, T, represents the intervals at which the network resource is observed. In addition, during each sampling interval, a measurement window of length, ?, is utilized. Generally, while the values for the sampling interval, T, and the measurement window, ?, are calibrated, actual measurements are only taken for the smaller measurement window, ?, and the actual measurements are extrapolated to estimate the usage over the larger sampling interval, T. The sampling interval, T, and measurement window, ?, values may be periodically recalibrated.

Abstract: Station apparatus used at a Local Serving Office (LSO) and at one or more stations reduces contention for communication access over time slots and/or wavelengths and/or fibers of an optical facility. The station apparatus enables Space-Wavelength-Time Division Multiple Access (SWT-DMA) communications using a combination of two or more different communication modes selected from a group including (1) a space division multiplexed access (SDMA) mode which selects a fiber(s) of the optical facility, (2) a wavelength division multiplexed access (WDMA) mode which selects a wavelength(s) on a fibers, and (3) a time division multiplexed access (TDMA) mode which selects time slot(s) of a wavelength. Communication mode selection may utilize (1) out-of-band signaling, (2) optical tag signaling, or (3) time marker signaling over a wavelength of one or more of the optical fibers.

Abstract: A connection admission control mechanism for packet, circuit, or hybrid packet and circuit networks whereby the signaling message (i.e., “query”) delay in a control channel of a network switch is maintained (i.e., “locked”) in a timed control interval at a desired level using feedback parameters relating to an estimated current amount of delay in the packet network switch during one or more previous timed control intervals, to guarantee or closely achieve a desired signaling message or query delay performance. The processing delay of the network is bound or “locked” at a desired delay performance level based on substantially real-time estimation or measurement of the current signaling message delays of queries or call control packet streams during one or more previous control intervals.

Abstract: A method is provided for verifying that optical signals are properly routed between inputs and outputs of an optical cross-connect according to the prescribed routing paths defined in the cross-connect map. More specifically, optical signals are independently tagged at the cross-connect input ports with connection verification messages containing identification information. Connection verification messages can include, among other information, a message identification, incoming and outgoing wavelength information, incoming and outgoing port information, a time stamp, user verification data, and so on. At the cross-connect output ports, the messages are retrieved (and optionally removed) from the optical signals so that the identification information from the retrieved messages can be compared to the routing defined in the cross-connect map.

Abstract: An optical internet router apparatus uses optical tags to send and receive command and response messages between routers of an optical network for establishing, maintaining or changing a packet data connection over the network between a source router and a destination router. The optical router comprises (1) optical tag apparatus for reading a message and writing a message modulated on one or more wavelengths which are used for communicating with another router of a network connection, the control message being modulated onto the one or more wavelengths using a secondary modulation scheme which is different from a primary modulation used to modulate packet data; and (2) a controller responsive to a received read message for controlling a network connection at this router, and for generating a network control message to be written by the optical tag apparatus, the generated message controlling a network connection to said another router.

Abstract: A system is disclosed for overload control in a hybrid switching system that separately transports each monomedia stream, such as video, voice and data, of a composite multimedia signal. The overload control is based on the time delay for completion of call establishment of each multimedia session. When the average time delay for completion of call establishment of each multimedia session is below a predefined threshold, the system has sufficient capacity and overload corrective measures are not required. When the average time delay for completion of call establishment of each multimedia session, or a connection for any individual monomedia component within the multimedia session, exceeds a predefined threshold, the switching system is approaching an overload condition, and overload control must be implemented to reduce the number of calls accepted in the next time interval.

Abstract: An optical signal access apparatus responds to variations in network traffic by dynamically assigning the number of wavelengths at originating and terminating optical signal access apparatus. A controller of an optical signal access apparatus monitors network traffic by checking the occupancy level (or other parameters) of data buffers and determines therefrom the number of optical signals that should be allocated to handle the network traffic from those buffers. When the optical signal access apparatus is part of a router it can be used to control traffic at the router as well as on the links between the routers of an optical network.

Abstract: An optical router includes a capacity utilization unit which determines a packet capacity utilization level of each of a plurality of wavelengths being received at the optical router and a packet combiner unit which combines packets from the two or more wavelengths onto only one of those wavelengths for transmission from the optical router when the combined determined packet utilization level on the two or more wavelengths is less than a predetermined packet utilization level. According to one feature, the router also determines the destination of the packets on each of the wavelengths and only combines the packets of two or more wavelengths if their packets have the same next-hop router or the same termination router destination.

Abstract: A method and apparatus are disclosed for measuring the usage of a communications network, based on a two level sampling and measuring technique. A sampling interval, T, represents the intervals at which the network resource is observed. In addition, during each sampling interval, a measurement window of length, &tgr;, is utilized. Generally, while the values for the sampling interval, T, and the measurement window, &tgr;, are calibrated, actual measurements are only taken for the smaller measurement window, &tgr;, and the actual measurements are extrapolated to estimate the usage over the larger sampling interval, T. The sampling interval, T, and measurement window, &tgr;, values may be periodically recalibrated.

Abstract: A method and system for controlling overload at a network processor in a communications system. Messages relating to a plurality of types of calls, functions or processes (collectively, “calls”) received at a processor seeking access to processor resources are granted normal access when the delay in processing such messages does not exceed threshold values. When such delay exceeds a threshold, messages are blocked in numbers relating to, among other things, the number of messages allowed in a reference interval, message delay, the total number of blocked calls, the number of blocked calls of each type, the number of calls allowed in one or more preceding intervals and preferences between types of calls.

Abstract: A method and apparatus for separately transporting each monomedia stream of a composite multimedia signal across a network, such as an ATM network, is disclosed. The transport of monomedia traffic over different network segments, which may or may not support all multimedia components, is disclosed. Each monomedia component, n, such as video, voice and data, of the multimedia session is separately transmitted over a connection having a capacity, Cn. The capacity, Cn, is generally specified in number of units of information, such as the bandwidth that should be allocated to the respective monomedia component for the duration of the call, or the number of ATM cells per unit time for the duration of the call. In an illustrative ATM network implementation, individual connections can be established for each monomedia component by assigning separate VP/VC identifiers to each monomedia connection. Jitter, due to synchronization problems, is controlled by allocating appropriate bandwidth to each monomedia component.

Abstract: A method of responding to overload in a real time control system. Overload is measured through the use of a control parameter such as the occupancy of a control processor or the number of entries in a queue of a module of the system. The overload indication is reduced to one of a plurality of levels. The levels corresponding to a longer term more serious overload are based on control parameter measurements over a longer period of time than the less serious short term overload levels. With autonomous control, each module of the system determines its own overload level and performs overload control actions corresponding to that level. In integrated system overload control, a centralized processor receives overload indications from each of the modules of the system and requests an appropriate overload control action of each module. Advantageously, these arrangements allow the system and its modules to respond to overload more rapidly and to return to normal operation more rapidly.

Abstract: A method of responding to overload in a real time control system. Overload is measured through the use of a control parameter such as the occupancy of a control processor or the number of entries in a queue of a module of the system. The overload indication is reduced to one of a plurality of levels. The levels corresponding to a longer term more serious overload are based on control parameter measurements over a longer period of time than the less serious short term overload levels. With autonomous control, each module of the system determines its own overload level and performs overload control actions corresponding to that level. In integrated system overload control, a centralized processor receives overload indications from each of the modules of the system and requests an appropriate overload control action of each module. Advantageously, these arrangements allow the system and its modules to respond to overload more rapidly and to return to normal operation more rapidly.