Abstract: The present disclosure generally pertains to systems and methods for enabling leaf isolation in a multi-node tree network. In one exemplary embodiment, an Ethernet virtual network (EVC) system has a multi-node E-Tree network comprising a plurality of nodes (e.g., switches), including at least one ingress node and at least one egress node. The ingress node is configured to receive a data packet to be communicated through the E-Tree network and to modify a field, such as the tag protocol identifier (TPID), in the packet's header to indicate whether the data packet is received by the ingress node via a leaf port. As the data packet is communicated through the E-Tree network, the nodes determine the leaf status of the packet based on the modified field thereby enabling the nodes to enforce leaf isolation rules. The egress node upon receiving the packet is configured to adjust the modified field as appropriate such that the field on egress matches the field on ingress.

Abstract: A system for dynamically learning virtual local area network (VLAN) tags comprises a switching element having a VLAN table and a media access control (MAC) table. For at least one VLAN, the switching element is configured to dynamically learn VLAN tags for packets carried by the VLAN in order to build the VLAN table and to then use mappings of the VLAN table, rather than mappings of the MAC table, to make forwarding decisions for all types of packets carried by the VLAN. The MAC table is not used for forwarding decisions for packets carried by the VLAN, but it can be used to help learn the VLAN tags. In particular, the switching element can use the MAC table to selectively trap packets when they are useful for learning VLAN tags and to prevent MAC learning traps for packets carrying VLAN tags previously learned by the switching element.

Abstract: Methods, systems, and apparatus for protecting electrical components are disclosed. In one aspect a system includes a first gas discharge tube connected to a first conductor of a first twisted wire pair; and a second gas discharge tube connected to a second conductor of the first twisted wire pair. The first gas discharge tube can also be connected to a third conductor of a second twisted wire pair, and the second gas discharge tube can be connected to a fourth conductor of the second twisted wire pair.

Abstract: The present disclosure generally pertains to systems and methods for provisioning nodes of a packet network. Rather than requiring a user to individually set the configuration parameters of each node to achieve a desired behavior, the user is presented with options of various predefined network behaviors and/or the option of customizing a network behavior, such as a queuing, scheduling, or shaping profile, and each node is configured to automatically provision its configuration parameters to implement the desired behavior. Information is passed from node-to-node so that each node can automatically provision its settings to implement such behavior. Thus, the network is automatically provisioned thereby facilitating the provisioning process. Automatic provisioning also helps to ensure a correct network configuration. Indeed, since the provisioning is automatic, at least some manual provisioning errors may be prevented.

Abstract: A small form factor pluggable (SFP) device has an embedded optical time domain reflectometer (OTDR) for detecting anomalies along an optical fiber. The SFP device has a plurality of optical subassemblies (OSAs) that are used to transmit an optical data signal at a first wavelength, transmit an optical OTDR signal at a second wavelength, and receive an optical data signal at a third wavelength. The OTDR signal is effectively isolated from the data signals based on wavelength, and samples of returns of the OTDR signal are analyzed to detect at least one anomaly along the optical fiber.

Abstract: A communication system has a trunk extending from a network facility, such as a central office, with a plurality of distribution points positioned along the trunk. Each leg of the trunk defines a shared channel that permits peak data rates much greater than what would be achievable without channel sharing. As an example, the connections of each respective trunk leg may be bonded. Further, the same modulation format and crosstalk vectoring are used for each leg of the trunk. The crosstalk vectoring cancels both far-end crosstalk (FEXT) that couples between connections of a given trunk leg and crossover crosstalk that couples between one trunk leg and another. In addition, logic determines an amount of excess capacity available for each leg of the trunk and controls error correction based on the determined excess capacity.

Abstract: A communications system includes at least one telecommunications access module coupled to a plurality of communications subscriber line pairs and comprising at least one bonding engine. A module is configured to receive a provisioning request and determine the total number of communications subscriber line pairs available to form a bonding group and select at least one bonding engine for the bonding group. A data processor is configured to determine a maximum packet fragment size for the data packets based on the total number of available subscriber line pairs forming the bonding group. A maximum packet fragment size is adapted to the number of communications line pairs within the bending group and the bonding engine fragments the data packets into the packet fragments. A transmitter receives the packet fragments and transmits the packet fragments over the communications subscriber line pairs forming the bonding group.

Abstract: An exemplary optical transmission system comprises an optical subassembly (OSA) coupled to an optical receiver via an optical fiber. The OSA comprises a laser diode configured to transmit optical signals across the optical fiber, and the OSA further comprises an avalanche photodiode (APD) configured to receive optical return signals from the optical fiber. The system further comprises a crosstalk canceller configured to estimate an amount of electrical crosstalk affecting measurements of the return signals in order to cancel such crosstalk from measurements of subsequent optical signals received by the APD.

Abstract: An optical communication module include a housing having a circuit element configured to provide an optical communication function, and a rotatable connector assembly coupled to the housing, the rotatable connector assembly configured to rotate between a first position and a second position, wherein when in the first position, the rotatable connector assembly allows the communication module to interface with a first form factor card cage and when in the second position, the rotatable connector assembly allows the communication module to interface with a second form factor card cage.

Abstract: A system and method transmits data and receives data packets within a bonding engine. The data packets are fragmented into a plurality of packet fragments for communication across a bonded group of subscriber lines. A Frame Check Sequence (FCS) in the data packet is inverted on one direction of the bonding group to prevent any data packets from propagating towards the network during a loopback condition.

Abstract: A midspan device for providing power and data from a one-pair power sourcing equipment to a two-pair powered device is described. The midspan device is connected to the one-pair power sourcing equipment and takes a portion of the power from the power sourcing equipment to power a converter. The converter converts one-pair data into a two-pair data and forwards the converted data to the two pairs of the powered device. Another portion of the power from the power sourcing equipment is on a DC path and coupled through center tap transformers to provide power to the powered device.

Abstract: A power sourcing equipment is connected to a powered device via a cable. The power sourcing equipment is configured to provide power to different types of devices and the powered device is configured to receive power from different types of power sourcing equipment. The power sourcing equipment has a control system for determining the type of powered device that is connected to the cable and furnishes power in response to the determination. The powered device has a detection resistance that is detectable by different types of power sourcing equipment. Also described is a powered device capable of establishing communication with PSEs of multiple types.

Abstract: A communication system comprises a plurality of line cards having transceivers coupled to a plurality of subscriber lines. Each line card has at least one active transceiver within the same vectoring group, and each line card also has vector logic capable of cancelling crosstalk induced by an active transceiver that is a member of the vectoring group. In the event of a vectoring fault that prevents a line card from receiving vectoring information from at least on other line card, the vector logic is configured to disable vectoring for the interferers affected by the error in order to prevent vectoring operations based on obsolete vectoring coefficients from adversely affecting the quality of the communicated signals. The transceivers communicating signals affected by the suspended vectoring operations are also configured to adjust their constellation density profiles, thereby reducing their data rates, to accommodate the increased noise level resulting from the loss of vectoring.

Abstract: A passive optical network (PON) has an optical line termination (OLT) that terminates an optical fiber servicing a plurality of optical network units (ONUs). Each ONU has one or more traffic containers (TCONTs) addressable by the OLT. The PON dynamic bandwidth allocation (DBA) implements a scheduling hierarchy, including several scheduling layers, such that disjoint sets of TCONTs can be grouped together, then disjoint sets of groups can be grouped, and so on. In such hierarchy, the residential traffic can be grouped separately from the business traffic. Further, within either the residential or business group, traffic may be grouped to define scheduling layers (“sub-groups”) within the residential or business group. Scheduling in one group or sub-group is performed independently of the scheduling in other groups or sub-groups, subject to the available bandwidth for each group.

Abstract: A discrete multi-tone (DMT) transceiver communicates tones across a subscriber line. Vectoring is employed in an effort to reduce the effects of crosstalk. However, for some tones, such as tones significantly affected by radio frequency interference (RFI) or other forms of alien noise, vectoring may actually introduce distortions such that the vectoring degrades rather than improves overall signal quality. Control logic of the DMT transceiver is configured to sense when tones are affected by significant levels of alien noise and to exclude such tones from vectoring, thereby improving signal quality for such tones. The control logic also may lower the constellation densities of such tones in order to accommodate the vectoring exclusions applied to such tones.

Abstract: The present disclosure generally pertains to systems and methods for wirelessly communicating multidrop packets via wireless networks. In one exemplary embodiment, communication devices of a multidrop system are respectively coupled to nodes of a wireless network. At least one of the nodes stores data for mapping multidrop addresses to network addresses. Upon receiving a multidrop packet, such node maps the multidrop address of the received packet to a network address identifying the packet's destination communication device within the multidrop system. The receiving node then inserts the multidrop packet into a unicast message and wirelessly transmits the unicast message through the wireless network to the remote node. The remote node depacketizes the unicast message to recover the multidrop packet and provides the multidrop packet to its destination.

Abstract: Embodiments of the present disclosure generally pertain to systems and methods for policing packet networks. A system in accordance with an exemplary embodiment of the present disclosure includes an enqueue policer positioned within an intermediate node of a packet network prior to at least one egress queue. The enqueue policer utilizes information related to destination end-point capacity limits for a given customer in order to police packets based on such information at a relatively early point in the packet network. Thus, a packet that would have been dropped by an egress node due to capacity limits is dropped by the intermediate node thereby preventing the packet from needlessly consuming bandwidth of the network beyond the intermediate node.

Abstract: A power sourcing equipment is connected to a powered device via a cable. The power sourcing equipment is configured to provide power to different types of devices. The power sourcing equipment has a control system for determining the type of powered device that is connected to the cable and furnishes power in response to the determination. Also described is a powered device capable of establishing communication with PSEs of multiple types.

Abstract: An optical network unit includes a central office interface configured to connect to a central office local loop and customer premises and provide a central office source service. A switch and a switch device is connected to the switch and has at least one service port to provide a local source service. A relay switch is connected to the at least one service port and the central office interface. A processor is connected to the switch and relay switch and configured to receive a command message and in response switch into either the central office interface and provide the central office source service or switch into the service port and provide the local source service.

Abstract: A knockout can be removed from a parent part in a sheet metal structure by removing one or more twistable tabs located on a perimeter of the knockout. A tab is defined by a region of sheet metal within a perimeter consisting of a first and a second cut. The first and second cuts extend through the sheet metal along first and second paths. A first neck extends between the first end of the first cut and the first end of the second cut and between the tab and the parent part. A second neck extends between the second end of the first cut and the second end of the second cut and extends between the tab and the knockout. To remove the tab, the tab is rotated such that the two necks twist about an axis between them, until torsional fatigue fractures the necks.