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 transceiver comprises a communication line interface, memory, and logic. The memory stores predefined noise spectra, and the logic is configured to analyze an initialization signal received from the communication line coupled to the communication line interface during an initialization phase that precedes a data phase. The logic is configured to automatically select one of the predefined noise spectra based on the initialization signal and to combine the selected noise spectrum with the initialization signal to calculate a value. The logic is configured to perform a comparison between the value and a threshold and to make a determination, based on the comparison, whether a data signal to be communicated in the data phase will be spectrally compatible, if the data signal is transmitted at a data rate of the initialization signal. The logic is further configured to select a data rate for the data signal based on the determination thereby ensuring that the data signal is spectrally compatible.

Abstract: Methods and apparatuses enable generating an analog representation of an M-bit digital input. A DAC system receives the M-bit data word and generates a control signal to control the output elements of a DAC to output an analog representation of the input data word. The DAC includes two data weighted averaging (DWA) loops, each one having 2M bits to control corresponding groups of 2M output elements. The control signal includes a number of bits equal to the number of output elements, with a number of one bits equal to the number of output elements to activate to represent the input data word. Half of the number of ones are triggered by one of the DWA loops, and the other half are triggered by the other DWA loop. One of the loops may include a constant offset in addition to the variable number of ones that represents the input data word.

Abstract: An integrated processor-controlled router and switch fabric architecture provides connectivity between local area network (LAN) ports serving a plurality of local area network users and a wide area network (WAN) port that provides connectivity with the internet. IEEE 802.1Q virtual local area network (VLAN) trunks are automatically created by the processor in response to a reduced set of command inputs. No user-configurable physical link exists between the switch fabric and the router. Instead, a virtual IEEE 802.1Q trunk is created through software to provide connectivity between the switch fabric and the router's control processor.

Abstract: An integrated processor-controlled router and switch fabric architecture provides connectivity between local area network (LAN) ports of an Ethernet switch serving a plurality of local area network users and a wide area network (WAN) port that provides connectivity with the internet. The integrated switch fabric treats the processor interface back to the router as though it were a regular LAN port; as a result, all incoming (WAN-to-LAN) traffic and all outgoing (LAN-to-WAN) traffic relative to the processor interface can be mirrored to any LAN port of the Ethernet switch.

Abstract: A mechanism for implementing a single-interrupt-based voice playout buffer transfer operation. The contents of each respective channel of a multi-channel voice playout buffer are encapsulated so as to prepend a four byte ATM header, a HEC byte, and a four byte AAL2 header to a forty-four byte voice channel field to realize a standard fifty-three byte ATM cell. Within the AAL2 header, a channel identification byte (CID) provides selective mapping to timeslots of a TDM frame, to accommodate variations among different vendor equipments. The next to last bit of the last byte of the ATM header is used as an interrupt to the network processor. Only the highest voice channel asserts this next to last bit as an interrupt bit.

Abstract: A packet analysis-based mechanism ensures the transmission of critical (voice) frames distributed among a sequence of fragmented frames of data signals. Received fragmented frames are analyzed to derive fragmented frame size information representative of the fragmented frame size. The fragmented frames are then defragmented, to form non-fragmented packets, which are then processed to extract user requested information. The non-fragmented packets are then refragmented in accordance with fragmented frame size information, to derive refragmented frames of information signals, which are then retransmitted in an intermingled manner with non-fragmented voice frames.

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: The disclosed network includes two rings, wherein a first ring transmits data in a clockwise direction, and the other ring transmits data in a counterclockwise direction. The traffic is removed from the ring by the destination node. During normal operations (i.e., all spans operational), data between nodes can flow on either ring. Thus, both rings are fully utilized during normal operations. The nodes periodically test the bit error rate of the links (or the error rate is constantly calculated) to detect a fault in one of the links. The detection of such a fault sends a broadcast signal to all nodes to reconfigure a routing table within the node so as to identify the optimum routing of source traffic to the destination node after the fault.

Abstract: The disclosed network includes two rings, wherein a first ring transmits data in a clockwise direction, and the other ring transmits data in a counterclockwise direction. The traffic is removed from the ring by the destination node. During normal operations (i.e., all spans operational), data between nodes can flow on either ring. Thus, both rings are fully utilized during normal operations. The nodes periodically test the bit error rate of the links (or the error rate is constantly calculated) to detect a fault in one of the links. The detection of such a fault sends a broadcast signal to all nodes to reconfigure a routing table within the node so as to identify the optimum routing of source traffic to the destination node after the fault.

Abstract: A wireline termination arrangement bridges a telecommunication wireline pair of a telecommunication system equipment backplane with a termination resistor. The backplane adjoins a plurality of card slots. A first end of the termination resistor installed in the backplane is connected to one wire of the wireline pair, and a second end is connected to a plurality of first terminals on the backplane. The first terminals are engageable by associated first ends of jumper conductors installed on respective ones of a plurality of line cards, when the line cards are installed in the card slots. A plurality of second terminals are arranged adjacent to the first terminals, are connected to the other wire of the wireline pair, and are engageable by second ends of the jumper conductors, when the line cards are installed in the card slots, thereby bridging the wireline pair with the termination resistor.

Abstract: A differential time domain digital communication bridge module interfaces 100 Mbps Ethernet traffic with a T3 communication link, using a relatively small sized data buffer. To avoid dropping packets, the relatively large sized buffer in the Ethernet switch is used to temporarily store packets, in when an upper threshold of the storage capacity of the buffer is reached. The upper threshold leaves enough storage overhead in the buffer to allow the Ethernet switch to complete its current transmission of a maximum length packet. When a lower threshold is reached a ‘resume transmission’ packet is sent to the switch. The lower threshold provides sufficient buffer space to allow the T3 transmitter to read out the contents of the buffer without underflow.

Abstract: In order to configure and monitor the operation of a span-powered T1 radio, use is made of the out-of-band facility data link channel that is available within an extended superframe of the T1 digital data stream transported between an indoor carrier services unit and the T1 framer of the radio. The facility data link channel is employed to transport packetized configuration and status information between the indoor carrier service unit and the span-powered T1 radio.

Abstract: A system and method for selective flooding in a multicast network are disclosed. Some embodiments provide for a promiscuous mode device on a network to signal to one or more other devices on the network that the promiscuous mode device is operating in promiscuous mode. In response to such a signal, one or more devices on the network dynamically cease operating in non-broadcast mode and dynamically commence operating in broadcast mode to ensure that the promiscuous mode device sees all data transmissions on the network or sub-network.

Abstract: A data transmission scheduler subsystem for a multi-channel bank communication system architecture contains a plurality of ‘per port’ schedulers. Each per port scheduler is resident in the system's primary channel bank, and is operative to controllably cause customer-destined data, that has been buffered from a communication network into switch fabric storage circuitry of the primary channel bank, to be controllably read out for downlink transmission to associated destination data ports of the channel banks at the destination data ports' data rates.

Abstract: An alarm indication translation mechanism in a digital access and cross-connect system monitors all incoming tributary DS1 streams for the presence of an alarm indication. Whenever an alarm indication is detected in a fractional tributary DS1 data stream, all DS0 bytes within the T1 stream containing that tributary DS1 data stream include the detected alarm indication. For a Yellow alarm, this means that for the case of D4 superframe format (SF), the second most significant bit of each of the twenty-four bytes of a T1 frame containing at least one fractional DS1 carrying alarm information is set to a ‘0’, irrespective of whether the bytes are valid DS0s or idle bytes. For extended superframe format (ESF), Yellow alarm is transmitted by sending a repetitive sixteen bit pattern consisting of eight marks or ‘1’s, followed by eight spaces or ‘0’s in the data link.

Abstract: A method and apparatus detects a ground fault on a span-powered telecommunication wireline within a plurality of span-powered wireline segments, to respective ones of which DSL-Cs are coupled, so that a ground fault may be detected when power is delivered by the DSL-C over a respective wireline segment to a respective downstream functional RT. A respective DSL-C measures a first voltage across a first sense resistor representative of current flowing in a first portion of its wireline segment to the RT, and also measures a second voltage across a second sense resistor representative of current flowing in a second portion of the wireline segment from the RT. In response to a difference in the first and second voltages an output representative of a ground fault in that wireline segment is generated.

Abstract: A system and method provide transparent LAN services in a metro-WAN environment to extend enterprise LANs over metro and wide area networks. The transparent LAN services generally provide customers with a layer two Ethernet connectivity with MAC learning capabilities.

Abstract: A system for adaptively updating precoder taps comprises a first signal path, a second signal path, a delay mechanism, and logic. The first signal path is configured to receive encoded signals. The first signal path has a decoder that is configured to decode the encoded signals thereby recovering data originally transmitted from a remote transmitter. The delay mechanism is configured to receive and delay the encoded signals. The second signal path is connected in parallel with the first signal path and is configured to receive the encoded signals delayed by the delay mechanism. The second signal path has an adaptive filter configured to filter the encoded signals received by the second signal path based on a set of coefficients of the adaptive filter. The adaptive filter is configured to adaptively update the coefficients based on the data recovered by the first signal path.

Abstract: A cable simulator that comprises an input device configured to receive a communication signal. The cable simulator further comprises a circuit configured to simulate attenuation in both the differential mode and common mode components of a communication signal.