Abstract: In Asynchronous Transfer Mode (ATM) communications networks, certain congestion control features, such as Partial Packet Discard (PPD) and Early Packet Discard (EPD), operate on ATM cells that have been segmented from ATM Adaptation Layer #5 (AAL5) frames (packets). AAL5 frames are automatically detected by observing transitions of an indicator in the ATM cell header unique to AAL5 traffic. Automatic detection of AAL5 traffic allows enablement of packet-aware cell discarding techniques such as PPD and EPD on a Virtual Channel Connection (VCC) basis, whether in a switch for a VCC or for a Virtual Path Connection (VPC) to which the VCC belongs.

Abstract: A circuit and special cable which allow a single DB9 connector to provide a standard RS-232 interface to a RAID controller in single RAID controller systems or to provide a controller-to-controller communication link for messaging, control and status signals when the special cable is used to interconnect two RAID controllers in a dual-active system.

Abstract: An application module, that is part of an electronic assembly including a controller module, is coupled to a backplane bus structure. The backplane comprises a differential bus(s) having a TX and RX data signal, a differential clock signal, and a single ended collision detection line. The application module comprises differential bus transceivers that are controlled by differential bus control logic on the application module. The control logic compares data bits received over a collision detection line with the data bits the application module originally transmitted. If the data is not the same, a collision has occurred and the control logic places the bus transceivers into a high impedance state. A data packet controller on the application module can only detect certain types of collisions that occur in the single ended environment. The control logic enables the data packet controller to recognize a collision that it normally would not.

Abstract: An automatic network topology identification technique is described herein. Each node in the network periodically or constantly transmits its unique address to its neighboring node. Once a node receives a different message from its neighbor, the node identifies a topology change in the network. In one embodiment, a current topology is associated with a session number. When a change in the topology is detected, the detecting node increments the session number and broadcasts the change in topology. The other nodes, detecting the changed session number, now know that there has been a change in the network. In response, the nodes in the network modify routing tables and other information stored at the node related to the topology. In one embodiment, the technique is used to reassign shortened addresses to each device on the network to support a dual-addressing mode of the network.

Abstract: A switch card for telecommunications node includes a shared memory operable to store traffic channels. A time slot interchanger (TSI) is coupled to a first bus and to the shared memory. The TSI is operable based on predefined switching instructions to access the shared memory to stored traffic channels received from the first bus and to retrieve traffic channels for transmission on the first bus. An asynchronous transfer mode (ATM) switch is operable to switch a traffic cell based on header information in the traffic cell. A traffic converter is operable to convert traffic channels retrieved from the shared memory to traffic cells for processing by a bus fuser and to convert traffic cells to traffic channels for storage in the shared memory. The bus fuser is coupled to the shared memory through the traffic converter, the ATM switch, and a second bus.

Abstract: An input of an OFDM signal containing known pilot carriers among given subcarriers is separated into subcarriers through Fourier transform in a fast Fourier transform unit. A data carrier phase error estimating unit obtains an amount of phase correction of each subcarrier on the basis of the pilot carriers in the separated subcarriers. A data carrier phase correcting unit corrects the phase of the separated subcarrier signal on the basis of the amount of phase correction. Thus, the phase errors of the subcarriers can be corrected and the OFDM symbols can be demodulated even if a frequency error and a timing error are occurring between the transmitter and receiver.

Abstract: In a butterfly network, a number of switches are set to provide two paths that are independent of each other, from a first switch to a second switch, and from the first switch to a third switch respectively. Identification of switches to be set from among all switches in the butterfly network depends on the locations of the first switch, the second switch and the third switch relative to one another. The to-be-set switches are determined by starting with the first switch as a preceding switch, identifying the next switch for a path by simply changing the level number (e.g. incrementing the level number) of a preceding switch in the path, and by changing a bit of the row number of the preceding switch (e.g. by replacing the &agr;-th bit with a corresponding bit from the destination switch's row number), and repeating such acts with the just-identified switch as a preceding switch. The direction of the path is reversed on reaching a last level or a last row of the network.

Abstract: ATM transmission equipment provided between existing exchange or terminals of carrier equipment that, for example, can emulate existing transmission paths, and also implement T point interfaces for an in-home unit. The ATM transmission equipment detects communication anomalies or extracts maintenance/operation information from data strings on STM lines, such as high-speed digital lines or ISDN lines, and replaces only the necessary information resulting from those extractions or detections with alarm signals. The alarm signals are then transmitted together with information channels to the ATM network via a cell assembler/dissembler. The information channels and alarm information that arrive from the ATM network are rearranged into STM line data strings and output to LT units, DSUs, or terminals.

Abstract: A method for detecting the mode of a telecommunications signal is provided. The method receives the telecommunications signal and contemporaneously evaluates the telecommunications signal for compliance with at least two signal modes. When the evaluation indicates that the signal conforms to a first mode, the signal is processed as a first mode signal. When the evaluation indicates that the signal conforms to a second mode, the signal is processed as a second mode signal.

Abstract: A method of performing flow control in a PNNI network wherein a node that becomes congested advertises this fact to the network thus eliminating additional call requests and other messages that it cannot handle due to the current load. The method utilizes the Maximum Cell Rate (MCR) and Available Cell Rate (ACR) parameters provided for in the PNNI standard. When the congestion level on a local node exceeds a predetermined threshold, a PTSE with MCR set to zero and ACR set to zero is advertised to the network. The PTSE causes nodes (originating nodes in particular) to not consider that node in route calculations. When the congestion level recedes on the local node, another PTSE is generated with the original MCR and ACR that existed before the congestion occurred causing the resumption of call request messages to be forwarded to the network.

Abstract: An ATM switching node has an ATM switch (30) to which at least one inter-node physical link (56) is connected. In addition, a cell handling unit (32) connected to the ATM switch has a centralized queuing resource (230) which queues ATM cells which are to be routed through the ATM switch for transmission from the node on the physical link. ATM cells destined for the physical link from the queuing resource are discharged from the queuing resource in accordance with a parameter of the physical link. The parameter is preferably the capacity (e.g., transmission rate) of the physical link. In the illustrated embodiment, the node is one of the following nodes of a cellular telecommunications network: a base station (42); a base station controller (44); a mobile switching center (46).

Abstract: Methods and system for controlling the processing of data packets comprising a plurality of routers and a plurality of virtual router instances with each virtual router instance storing received data packets in one or more ingress data queues located on each router in which the virtual router instance appears. Packet flow rates of ingress data queues associated with the first virtual router instance on each of a first and second router are periodically adjusted based on current operating conditions of the first router. Packet flow rates of one or more ingress data queues may be adjusted based on current operating conditions of the first router when at least a second virtual router instance is also located on the first and second routers. Packet flow rates of the first and second virtual router instances may also be adjusted independently of each other.

Abstract: An apparatus, a search tree structure, methods and computer devices for constructing and using the structure to efficiently accomplish policy based service differentiation in packet networks is presented. This invention reduces the number of steps performed to implement packet classification. It uses a method of preprocessing a given set of policy rules by modeling the conditions in the rules as multidimensional hyper-cubes, a simple and compact search tree is constructed. Using this search tree, packet classification is achieved determining all applicable policies for a packet with a few compare and branch instructions.

Abstract: A TSA circuit which receives as input upper side incoming transmission data from a super high speed ring network and lower side incoming transmission data from a high speed ring network and outputs upper side outgoing transmission data to the super high speed ring network and lower side outgoing transmission data to the high speed ring network, provided with a time slot assignment function block which has a time switch and a space switch and produces outgoing transmission data obtained by switching channels for the incoming transmission data in units of bits, whereby high speed and large volume incoming transmission data can be processed for time slot assignment (TSA), interchanged in channels, and sent out as outgoing transmission data by a relatively small sized circuit configuration.

Abstract: In one embodiment, in a switching system, an ASIC device on a card coupled to a backplane communicates switched data to an outgoing network interface for the card without using the backplane, and remaining ASIC devices on the card communicate switched data, to other cards using the backplane for communication to outgoing network interfaces for the other cards. In another embodiment, an ASIC device includes a RAM storing a code for each first slot to combine with corresponding data from a first bus to specify an operation, a RAM applying the operation to generate modified data for each first slot, a RAM communicating as an address information specifying a second slot to correspond to each first slot, and a RAM locating the modified data for each first slot of a previous frame according to the address and communicating this modified data to a second bus in the corresponding second slot while the modified data for a current frame is being stored.

Abstract: The present invention is directed toward data packet transmission scheduling. Scheduling values, such as priority or other scheduling criteria assigned to data packets, are placed in a scheduling heap data structure. Packets percolate up through the heap by comparing their assigned values in pairs. Operations in the heap may be pipelined so as to provide for high-speed sorting. Thus, a few relatively simple operations can be performed repeatedly to quickly percolate packets up through the heap. Another aspect of the invention provides for fast traversal of the scheduling heap data structure. The hierarchical heap may include a highest level having a single position and each succeeding lower level having twice the number of positions as the preceding level. A binary number may represent each position in the heap. To traverse the heap, the relative movements necessary to move from one position to another may be determined from the binary number. This is useful to quickly and efficiently traverse the heap.

Abstract: The invention relates to a switching network which operates in accordance with the asynchronous transfer mode and which comprises a switching unit (1), which is provided to change selected contents in the header field of a cell.

Abstract: A network switch configured for switching data packets across multiple ports uses an external memory to store data frames. When a data frame is transmitted to the external memory, a frame header portion of the data frame is stored on the switch for processing by decision making logic. The switch memory is configured to store a number of the frame headers corresponding to each port on the switch along with frame pointer information indicating the location in the external memory where the data frame is stored.

Abstract: The present invention relates to a method for monitoring data messages in a network element in a telecommunications network, particularly in the SCP network element of an intelligent network. In the network element, the messages are forwarded through a protocol stack. The messages of the various protocol levels are processed by useful program blocks (MDP, FMP, SLP) and the messages of the selected protocol level are monitored to verify their validity. To make it possible to monitor messages in a simpler and more reliable manner, a separate monitoring block (MPP) is created in the network element for monitoring purposes and a copy of the message of the selected protocol level is sent to the said monitoring program to effect monitoring.

Abstract: A method for recovering clock signals includes generating a media sync signal to synchronize processing of digital media, and generating a transmission reference clock signal to define a duration of a transaction through a packet-based data network. The media sync and transmission clock signals may have different frequency and phase. The media is sent to a slave node of the network. The media sync and transmission clock signals are correlated to generate phase correlation information, and the phase correlation information is also sent to the slave node. Accordingly, a relatively low cost and reliable clock recovery technique suitable for synchronizing media streams across a packet-based data network is disclosed.