Abstract: In a transmission circuit used in a TDD scheme, a preset current is supplied from a current source to a detection diode via a switch that is made conductive during a reception period and made non-conductive during a transmission period. A determination is made if the output of the detection diode is within a predetermined specified range and, if the output is out of the specified range, a judgment is made that the detection diode is faulty.

Abstract: Recovery time upon the failure of a link or switching system in an asynchronous data network can be minimized if downstream data switches provide upstream messages indicating to upstream switching system that the downstream traffic arrived in tact and was properly handled. Upon this loss or failure of the upstream status message to an upstream switching system, an upstream switching system can reroute data traffic around a failed link or failed switch with a minimal amount of lost data. The upstream status message is conveyed from a downstream switching system to an upstream switching system via a reverse notification tree data pathway. The reverse notification pathway is established by using a messaging protocol between network switches by which the working and protection paths, among other things, are established.

Abstract: In a packet switch with databases (250, 404) used for packet forwarding, the database pieces are identified by version identifiers (410V) which are used by the packet switch's modules (LCx, RPM0, RPM1) in exchanging information on the databases and requesting updates to the databases. For example, if a primary management module fails and the management is transferred to a secondary management module, the secondary management module requests forwarding modules (e.g. line cards) to identify the database pieces stored on the forwarding modules, and to update the databases as needed. Use of version identifiers reduces the amount of data that has to be transferred in connection with such requests.

Abstract: The present invention is directed towards a method for using a listening policy for a virtual server on an intermediary device. An intermediary device establishes for a first virtual server a first listening policy with an expression for evaluating packets received by the intermediary device to determine whether the packet may access the first virtual server. The intermediary device listens for packets at a first internet protocol (IP) address and a first port specified for the first virtual server. Then, the intermediary device evaluates the expression of the first listening policy to a first packet received at the first IP address and first port and determines whether to provide the first packet to the first virtual server based on a result of the evaluation.

Abstract: A method for diagnosing performance of a network switch device includes a processor monitoring data generated by a sensor associated with a network switch device, the data related to states or attributes of the network switch device. The processor detects a determined condition in the operation of the network switch device related to the state or attribute. The processor generates an event trigger in response to detecting the determined condition and executes a forensic command in response to the event trigger. Executing the command includes sending information relevant to the determined condition for aggregation in computer storage and for analysis.

Abstract: A technique for protecting traffic in a Layer 2 (L2) communication network between a first and a second local nodes (CE1, CE2) interconnected via a redundant dual homed structure, the technique comprises a) distributing the traffic in the dual homed structure in a fault-free state, to form two traffic flows between the CE1 and CE2; b) providing Layer 2 (L2) fault indications for the dual homed structure, in the form of operation and maintenance (OAM) tools, c) in a faulty state of the dual homed structure, forwarding traffic packets at the provider edges of the structure, based only on conventional physical fault indications and L2 fault indications, by locally making forwarding decisions for selecting an active communication line via the redundant dual homed structure.

Abstract: A plurality of wireless interfaces and/or internal radios is utilized within a network switching device to enable wireless intra-connectivity within its switch fabric. The wireless intra-connectivity services switching operations in the network switching device, to prevent and/or reduce blocking in the network switching device. The wireless intra-connectivity is also used to enable management and control operations in the network switching device. Operations of the internal radios and/or wireless interfaces are managed to mitigate and/or limit interference among the internal radios and to optimize throughput available via the wireless intra-connectivity. Arbitration, channelization, time multiplexing, and/or directionality techniques, for example, are utilized in the internal radios. External radios are operable to enable cascading plurality of network switching devices.

Abstract: In some embodiments, an apparatus includes a validation engine configured to receive multiple validation packets from an edge device via multiple data paths from a set of data paths between the validation engine and the edge device. The validation engine is configured to compare a number of validation packets from the multiple validation packets received from the edge device to a number of data paths from the set of data paths to determine an error at a data path from the set of data paths. The validation engine is configured to send an indication of the error at the data path from the set of data paths to the edge device.

Abstract: Data services may be enhanced by mitigating the need for unplanned core network capacity expansion or network element upgrades and reconfiguration, by offloading data to an alternative network, such as Exchange Point (IXP) or other operator network. A method can include monitoring a status of a transit network. The method can also include offloading traffic to the transit network from a transport network when a predetermined condition is met. The predetermined condition includes the status of the transit network indicating that the transit network is operational.

Abstract: A first communication node communicates by multiple-input-multiple-output (MIMO) wireless communications with a second communication node of a wireless communication system. The method includes receiving a Sounding Reference Signal (SRS) over a plurality of subcarriers transmitted by the second communication node for MIMO communications. Channel quality is measured responsive to the sounding reference signal to output a first channel quality value. A demodulation reference signal is received over a plurality of subcarriers transmitted by the second communication node for MIMO communications. Channel quality is measured responsive to the demodulation reference signal to output a second channel quality value. Reliability of the measurements of the first channel quality value and the second channel quality value is determined. The first and second channel quality values are combined while compensating for the determined reliability difference between the measurements to generate a combined channel quality value.

Abstract: The present invention relates to a method and a device for assessing and indicating the quality of VoIP calls, comprising the steps of end-point reception of the VoIP packets over an IP network link, end-point determination of the VoIP quality (QRX) of the received VoIP packet sequence, the VoIP quality (QTX) of the transmitted VoIP packet sequence, exchange of the quality information (QRX and QTX) between the end points, calulation of the difference (QRX-QTX) between the received VoIP quality and the VoIP quality transmitted by the other side; supply of the determined VoIP quality information to a quality indication; and end-point indication of the quality information in optical and/or acoustic form.

Abstract: A method and apparatus for communication in a wireless sensor network. In one embodiment, one or more routers in a network may be available for communication with one or more star nodes at a randomized time and/or frequency. A connectivity assessment, which may be performed at several different frequencies and/or times, may be performed to evaluate the quality of communications between devices in the network. Primary and secondary communication relationships may be formed between devices to provide for system redundancy. One or more proxies may be maintained where each proxy includes a status of one or more devices in the network, e.g., one or more star nodes or routers. Proxies may be used to handle information requests and/or status change requests, e.g., a proxy may be requested to change a communication relationship between devices in the network and may generate command signals to cause the corresponding devices to make the change.

Abstract: A system and method for providing multimedia communication between a firewall protected, LAN based endpoint and an endpoint that is external to the LAN. A logical port of a multimedia communications control unit is attached to the LAN behind the firewall. Another logical port of the multimedia communications control unit is attached to the external endpoint. Multimedia communication data, consisting of call management data and media data, can be exchanged between the endpoints via the multimedia communications control unit. The multimedia communications control unit allows only multimedia communication data that strictly adheres to a particular communications protocol to pass through. Thus, the security afforded by the firewall is not compromised.

Abstract: A method, system and machine-readable storage medium for providing fault tolerance in a distributed mobile architecture (dMA) system. The method includes receiving a message or failing to receive the message within a predetermined time relating to a first dMA gateway (dMAG) at a second dMAG. It is determined whether the first dMAG is not operational or is otherwise offline based on the received message or the failure to receive the message. One or more dMA nodes associated with the first dMAG are notified in order to request connections to an external system via the second dMAG. The external system is also notified to request connections to one or more dMA nodes associated with the first dMAG via the second dMAG.

Abstract: Improved techniques are disclosed for detecting instability events in data communications systems that support inter-administrative domain (inter-domain) routing. For example, a technique for detecting an instability event in a communications system supporting inter-administrative domain routing includes the following steps. At an inter-domain router, one or more features are extracted from one or more messages obtained from at least another router in the communications system. The one or more extracted features include a path length feature, a path edit distance feature, or a combination thereof. Then, the inter-domain router detects whether an instability event has occurred in the communications system based on the one or more extracted features such that an action can be effectuated. By way of example, the one or more messages may include one or more border gateway protocol update messages and the inter-domain router may be a border gateway protocol router.

Abstract: A troubleshooting method and a troubleshooting apparatus are disclosed. The troubleshooting method includes: sending a forward detection message to at least one node on a path to be detected, where the forward detection message carries information about a forward path to be detected and information about a backward path to be detected; and detecting faults according to a backward detection message returned by the at least one node. With the troubleshooting method and the troubleshooting apparatus disclosed herein, troubleshooting operations such as fault detection and fault location can be performed for the forward path and the backward path that require bidirectional path detection.

Abstract: A traffic control apparatus is provided which includes an interface connector to transmit/receive an Internet Protocol (IP) packet to/from an external circuit, a frame generator to receive the IP packet through the interface connector and to generate a Media Access Control (MAC) frame, and a network processor to transmit/receive the IP packet to/from the frame generator, to execute at least one programmable application, and to identify and classify the at least one programmable application.

Abstract: A method and system for transmitting data corresponding to at least one endpoint device problem in a packet communications network is described. Specifically, an endpoint device detects at least one problem that pertains to the endpoint device. The endpoint device then generates data pertaining to the endpoint device problem. Lastly, the endpoint device then transmits the data detailing that endpoint device problem to the packet communications network.

Abstract: A wireless network printing system and method, the system including: a first wireless terminal to selectively connect to an ad-hoc network, where inter-device communication is directly performed between devices, and an infrastructure network, where inter-device communication is indirectly performed, via an access point (AP); a second wireless terminal to transmit data to the first wireless terminal, via the ad-hoc network; and an image forming device affiliated with the infrastructure network, to print the data, after the data has been relayed through the first wireless terminal.

Abstract: An Ethernet protection and loadsharing capability is provided. The Ethernet protection and loadsharing capability enables co-existence of both protection and loadsharing for an Ethernet tunnel, having a plurality of associated Ethernet paths, between first and second Ethernet switches. The first Ethernet switch receives configuration information associated with the Ethernet tunnel between the first and second Ethernet switches, and processes the configuration information for causing the first Ethernet switch to associate the Ethernet paths of the Ethernet tunnel with an Ethernet tunnel endpoint object associated with an Ethernet tunnel. The first Ethernet switch, upon receiving traffic intended for the second Ethernet switch, propagates the traffic from the first Ethernet switch toward the second Ethernet switch via at least a subset of the Ethernet paths of the Ethernet tunnel using protection and/or loadsharing.

Abstract: Aspects of the disclosure relate to routing of an emergency communication under fault conditions. Routing can be implemented in a packet-switching (PS) network that provides voice service. For a network node of the PS network, availability to route the emergency communication through a specific emergency service routing number (ESRN) can be determined and, in response to the network node being unavailable, administrative data associated with the ESRN can be accessed. In addition, an identifier associated with the administrative data can be updated (e.g., created or modified) with data indicative of the device that originated the emergency communication. The administrative data and the resulting identifier can be delivered to a second network node that can route the emergency communication to an emergency service network.

Abstract: A communication session between a first communication device and a second communication device is hosted in an Internet Protocol (IP) based packet data network. A contact server functions as a bridge service between the first communication device and the second communication device. A communication link between the first communication device and the contact server or the second communication device and the contact server is initially a voice-over IP (VoIP) communication link over a wireless data network comprised of a first packet data media stream. The contact server receives the first packet data media stream and at least one other packet data media stream from the first communication device and combines them into a single packet data media stream before transmitting the combined single packet data media stream to the second communication device.

Abstract: A method for operating a wireless mesh data network with multiple nodes, wherein data frames are transmitted from a source node via one or more intermediate nodes to a destination node, wherein the source node, the one or more intermediate nodes, and the destination node constitute network nodes of the data network, wherein during transmission of a data frame, at least some of the network nodes which receive the data frame, using a precursor list for the destination nodes which is assigned to the destination nodes of the data frame, check whether the network node sending the data frame is in the precursor list, and wherein in the case of a positive result, the data frame is transmitted to a further network node, and in the case of a negative result, the data frame is thrown out or processed by an error recovery routine.

Abstract: A VoIP-aware device generates data structures that include diagnostics data. The diagnostics data of each data structure identifies at least one of sender and network problems that degrade VoIP voice quality.

Abstract: One embodiment of the present invention provides a switch. The switch includes a management mechanism and a configuration mechanism. During operation, the management mechanism is configured to operate the switch in conjunction with the partner switch as a single logical switch. The configuration mechanism is configured to assign a virtual switch identifier to the logical switch.

Abstract: A system (including a processor, a host having a network multipath daemon, and multiple network interfaces) and method involving issuing, by an active interface, an Internet Protocol probe packet (IPPP) to a probe target, issuing, by an alternate interface, a transitive probe packet (TPP) to the active interface, where the alternate interface and the active interface belong to a broadcast domain. The system and method further involve awaiting, by the active interface, a responsive IPPP from the probe target, awaiting by the alternate interface, a responsive TPP from the active interface, and determining network conditions based upon receiving at least one of the responsive IPPP and the responsive TPP.

Abstract: The invention relates to a method of detecting an anomaly in traffic containing a plurality of flows. Each flow has a plurality of flow features. The method including the steps of: (i) dividing the traffic into a plurality of sets, on the basis a first flow feature, such that the flows in at least one of the sets have a common value for the first flow feature (ii) determining that the anomaly is present in one of the sets and, (iii) dividing the set in which the anomaly is present on the basis of a second flow feature, such that the flows in at least one of the resulting sets have a common value for the second flow feature.

Abstract: There is disclosed apparatus and processes for generating simulated network test traffic from a stored test traffic definition. A network test system or a user may select arbitrary ways to group flows of test traffic into streams, and to modify these streams before and during transmission of the test traffic by network test equipment.

Abstract: A method for determining location of a failure causing degradation of a service in a mobile communications network is disclosed. Service trajectories for the mobile terminals are determined (104) by correlating earlier obtained movement trajectories (102) of individual mobile terminals with service session records of the mobile terminals. In the next step distributions of the service trajectories of mobile terminals with degraded service are determined and then a network element around which the service trajectories converge is identified (108) as the location of the failure. An apparatus, a communications network and a computer program product are also disclosed.

Abstract: A method of providing security for network access radio systems and associated access radio security systems used with the systems. The method includes connecting an access radio having a radio link to a network; communicating between the access radio and a computer over the network using a ping application having ping commands and unique encrypted codes; and enabling operation of the access radio when the access radio is receiving ping commands. Typically, the access radio and the computer are nodes on the network and the network is a local area network (LAN). The ping application sends packets of information from the computer to the access radio and receives a response from the access radio. The ping application must be functioning (i.e., sending and receiving commands between the computer and the access radio) to enable the access radio to communicate via the radio link with a remote network.

Abstract: Cable communication systems and methods to provide voice and/or data services to subscriber premises via a cable plant that conveys upstream information over an upstream path bandwidth, and a cable modem system including one or more demodulation tuners to receive and demodulate one or more upstream radio frequency (RF) signals. An RF signal includes an encoded carrier wave having a carrier frequency of between approximately 5 MHz and at least approximately 42 MHz that is modulated using quadrature amplitude modulation (QAM) with voice and/or data information constituting at least some of the upstream information. A modulation order of the QAM for the first upstream RF signal is at least 256, and at least one demodulation tuner of the cable modem system is configured to receive and demodulate the first upstream RF signal.

Abstract: An inter-provider virtual provider network path is identified by identifying a provider network provider edge router having a provider edge interface serving, obtaining routing information from the provider edge router, identifying, from the routing information, a remote customer edge interface of a customer edge router connected to the provider edge router by an intermediate service provider, and identifying the path and associated links between the identified provider edge interface and the identified remote customer edge interface.

Abstract: In an example embodiment, a service that analyzes location information of a client as the client roams. For example, whenever a trigger event occurs, such as a change in the association state, a change in Internet Protocol (IP) address, etc., a determination is made whether the event was expected. If the event was not expected, the location of where the trigger event occurred can be determined enabling a network administrator to investigate roaming problems at a particular location.

Abstract: The fault diagnosis device is for a multiplexer having inner channels selectable by a selection signal. At least two of the inner channels are assigned with input channels. Two of the inner channels in a mutually exclusive relationship are assigned with first and second diagnostic channels. Input voltages of the first and second diagnostic channels are applied with first and second diagnostic voltages, respectively. The fault diagnostic device includes a voltage detection section configured to detect a first detection voltage appearing at the output channel when the first diagnostic channel is selected and a second detection voltage appearing at the output channel when the second diagnostic channel is selected, and a diagnosis section configured to determine that the multiplexer is faulty upon detecting that the first detection voltage is different from the first diagnostic voltage or the second detection voltage is different from the second diagnostic voltage.

Abstract: Systems and methods for implementing FlexRay communications between FlexRay nodes using Ethernet are provided. An Ethernet switch includes ports, each of which receives an Ethernet data packet (EDP) from a respective FlexRay node. Each EDP includes a FlexRay message, which includes at least one of a data frame and a frame identification (ID). A first EDP is received at a first port no later than a second EDP is received at a second port. The Ethernet switch also includes a controller module that determines whether the second EDP has higher priority than the first EDP based on the frame IDs associated with the first and second EDPs. The controller module is configured to route the second EDP to a second destination no later than routing the first EDP to a first destination and meet FlexRay transmission cycle times when it has been determined that the second EDP has higher priority.

Abstract: A method, apparatus, and machine readable storage medium is disclosed for establishing a test protocol processor which autonomously intercepts success path protocol messages at a network element port buffer and substitutes a corresponding failure path messages to simulate the introduction of unexpected protocol messages into the protocol message flow from an external source to the network element under test. Subsequent to intercepting messages, the test protocol processor may perform one or more of several actions according to the results of statistical calculations. These actions include allowing the message to drop, replacing the message after a delay, replacing the message after altering the payload of the message, and replacing the message after altering the message type. The disclosed autonomous self disrupting network element is particularly useful for providing a means to perform in situ field testing of network performance indicators under desired statistical conditions.

Abstract: A ring network with plural network relay devices connected in a ring shape includes first and second control ports to be transitioned into either a forwarding state that permits relaying information, or a blocking state that prohibits relaying information; and a ring protocol control unit for transmitting connection confirmation information indicative of communications being possible between the first and the second control port, from the first to the second control port, and from the second to the first control port at a predetermined time interval, or for, in the event that the first or the second control port does not receive the connection confirmation information from the second or the first control port, transmitting failure information indicative of communications being not possible between the first and the second control port, from the first to the second control port, or from the second to the first control port.

Abstract: Example methods, apparatus and articles of manufacture to respond to signaling protocol failures in traffic engineering (TE) tunnels are disclosed. A disclosed example apparatus includes a database to store a tunnel state for a first TE tunnel, a signaling engine to detect whether a signaling protocol failure associated with the first TE tunnel occurred, and to set the tunnel state to a first logic state when the signaling protocol failure is detected, and a label switching engine to route the data through a multiprotocol label switching (MPLS) based network via a second TE tunnel when the tunnel state is the first logic state, and to route the data through the MPLS-based network via the first TE tunnel when the tunnel state is a second logic state.

Abstract: Specially configured host bus adaptors (HBAs) are located in the switches in the fabric or added to a management server. The HBAs are programmed to perform higher level protocol analysis, such as monitoring exchanges, LUNs, and VM/LUN/LBA ranges and developing SCSI statistics on the flows. The HBA can detect protocol exceptions. When located in the switches, mirroring of the desired frames is simplified as all routing is handled internally to the switch, with the HBA/switch combination providing data over the management Ethernet port to a management server. To maintain performance, preferably only the protocol relevant frames are mirrored to the HBAs. With the data provided from the HBAs, in conjunction with the normal diagnostic and statistics data available from the switch itself, the management server can correlate events end-to-end, correlate I/O error statistics collected from the fabric with server statistics, and correlate performance statistics collected from the fabric with server statistics.

Abstract: The system and method get a packet trace for a failed communication and a packet trace for a successful communication. The two packet traces are generated with packets from a common protocol(s) shared by the two communications. The failed and successful communications have at least some network elements in common. A field(s) in the common protocol(s) is identified. The field(s) is updated to be the same in both packet traces. The two packet traces are then compared to produce a list of remaining differences that can be used to diagnose problems in the failed communication. The list can also be compared to bills of materials for the failed and successful communications to further enhance diagnosis of the failed communication.

Abstract: Methods and systems for implementing self-testing of packet processing devices are disclosed. For example, a packet-processing device can include a plurality of ports having a receive media access controller (RX MAC) and a transmit media access controller (TX MAC). The TX MAC of a first port is selectably configurable to loop back packets to its respective RX MAC during the self-testing. The packet-processing device can further include a switching engine configured to provide a test packet received from a packet generator to the TX MAC of the first port, and route to the TX MAC of one or more second ports at least the test packet received from the RX MAC of the first port, or a copy of the received test packet, after the received test packet or its copy has been looped-back one or more times between the TX MAC and the RX MAC of the first port.

Abstract: An apparatus comprising a node configured to transmit operation, administration, and maintenance (OAM) connectivity frames, wherein the node adds an impairment notification indication to some, but not all of OAM connectivity frames transmitted by the node, wherein the impairment notification indication indicates the node's desire to receive notification of an impairment condition along the path. A network component comprising a receiver unit configured to receive multiprotocol label switching (MPLS) Ping frames, a circuit logic configured to add a downstream link impairment indication to responses to the MPLS Ping frames, wherein the downstream link impairment indication comprises a type and a severity level for a path impairment condition, and a transmitter unit configured to transmit the responses to the transmitted MPLS Ping frames.

Abstract: Method and system for handling error events on a current path for processing an I/O request for reading information from and writing information to a storage space is provided. A system is able to communicate with the storage space via more than one path. If the current path reports an error event, then an alternate path quality is determined to ascertain whether the alternate path will generate an error similar to the current path. The alternate path quality is determined based on a plurality of factors which are assigned certain weights. The weights are determined based on a likely contribution of each factor to a repetition of the error reported by the current path. If the alternate path quality is equal to or exceeds a programmable threshold value, then the alternate path is selected.

Abstract: The present invention enables a method for following the state of a call and generating defects as function of call completion success as opposed to discrete events that happen at individual network elements during the call. In one embodiment, the invention uses Call Detail Records (CDR) to analyze the end-to-end completion status to measure per call basis defects instead of using defect codes generated by network elements on a per equipment basis. CDR is data associated with a telephone call, including the calling and the called numbers, the date and timestamp, the duration, the call setup delay, and the final handling code of the telephone call.

Abstract: Systems and methods of backup battery support for switches and access points in fire detection systems are provided. Methods can include identifying a communications time interval for a plurality of devices, detecting a power failure, identifying a start time for a next scheduled communications time interval for a respective one of the plurality of devices, placing a wireless access point in a low power mode, and, substantially immediately prior to the start time, removing the wireless access point from the low power mode.

Abstract: Disclosed are methods and system to dynamically monitor a number of switching ports of a networking device. In one embodiment, a system is disclosed to monitor network traffic comprising a switch port monitoring device comprising a real-time processor, a packet data processor, a packet queue and a storage device. The system also comprises one or more switches coupled to the switch port monitoring device, where at least one of the switches comprising a switch processor, a switch fabric, one or more ingress/egress ports coupled to the switch fabric, and one or more uplink ports coupling the switch packet to the packet queue of the switch port monitoring device.

Abstract: There are disclosed methods and apparatus for testing a network. One or more source port units may transmit packets, each packet including a packet group identifier (PGID) that identifies one or more of a plurality of destination port units as expected destinations of the packet. The plurality of destination port units may receive the packets from the network. Each destination port unit may extract the PGID from each received packet, accumulate receive statistics for at least a range of PGID values, and store accumulate receive statistics in a receive statistics memory. Misdirected packet statistics may be reported by retrieving, from the receive statistics memory of at least one destination port unit, receive statistics for at least some PGIDs for which the respective destination port unit is not an expected destination, and aggregating the retrieved receive statistics to generate the misdirected packet statistics.

Abstract: An mLDP failover using fast notification packets. In one embodiment of a process for mLDP failover using fast notification packets, a first network node detects a failure of a second network node or a communication link coupled to the second network node. In response to detecting the failure, the first network node sends a packet to a third network node, wherein the packet comprises a notification of link or node failure and information identifying a multipoint label switched path (MLSP) that is configured to transmit multicast data packets of a multicast data stream.

Abstract: Conventional network tomography techniques do not allow the location or cause of a failure to be specified, and false positives are common due to lack of information. Using aggregation flow mining (AFM) or a similar method, an IMF (102) acquires, from each router (105) to be tested, information in relation to each flow. The IMF, in relation to each of the routers, obtains distributions of statistical information such as throughput or difference for each flow; calculates, in relation to each of the distributions, a Mahalanobis distance in relation to the expected value of a reference distribution; and makes a comprehensive assessment of the distributions to perform a fault determination. When the fault determination is performed, a normal value of the distribution used for comparison is acquired from AFM and updated through feedback as needed.

Abstract: An apparatus and method for updating a network as to the link used by a protected network device when a first switch for the protected network device fails or is determined to be once again operational. The link protection device builds and transmits an update data packet on a second link for the protected network device that emulates a data packet sent from the protected network device on the second link.