Abstract: Accordingly, there is provided an IMS node, comprising a transmission module and a processor. The transmission module is arranged to send SIP messages to a plurality of other IMS nodes. The processor arranged to detect an error in a particular other IMS node, the error indicating that the particular other IMS node is not available to receive traffic. In response to detection of such an error, the processor causes the particular other IMS node not to be used for a period of time. The transmission module is further arranged to send at least one test message to the particular other IMS node when the period of time expires. The processor is further arranged to determine if the at least one test message is successfully processed by the particular other IMS node, and in response to a positive determination then returning the particular other IMS node to use.

Abstract: In a radio telecommunications network, a serving gateway support node controls connections between user equipment nodes and a packet-based network that pass through at least one serving gateway and at least one packet gateway. The serving gateway support node detects failure of communications to a first serving gateway. The serving gateway support node responds to the detected failure by initiating relocation of existing connections through the first serving gateway to instead pass through a second serving gateway. The serving gateway support node detects recovery of communications to the first serving gateway, and responds by ceasing relocation of at least some of the existing connections that have not yet been relocated to the second serving gateway. Related methods, serving gateways, and packet gateways are also disclosed.

Abstract: A node comprises a first communications interface to a customer network element, where the first communications interface is part of a group of communications interfaces to the customer network element to provide failover support. The node further includes a network interface to communicate over a trunk group to other nodes, where the trunk group includes a primary trunk and a secondary trunk. Just one of the primary and secondary trunks is active for communicating data units.

Abstract: A data processing apparatus includes multiple processing means that are connected in a ring shape via corresponding communication means respectively. Each communication means includes a reception means for receiving data from a previous communication means, and a transmission means for transmitting data to a next communication means. Connection information is assigned to each of the reception means and the transmission means. The communication means, when receiving a packet that has same connection information as one assigned to its reception means, causes the corresponding processing means to perform data processing on the packet, sets the connection information assigned to its transmission means to the packet, and transmits the packet to the next communication means, and when receiving a packet that has connection information that is not same as one assigned to its reception means, transmits the packet to the next communication means without changing the connection information of the packet.

Abstract: An access gateway node couples a control node to an external data network, where the control node and access gateway node are for use in a wireless communications network. The access gateway node comprises a data function to route packets containing traffic data between the control node and the external data network. An interface to the control node enables exchange of control messages between the data function and a control function in the control node.

Abstract: A system for PIM fast failover recovery includes a network of a plurality of switching devices. The plurality of switching devices includes a source switching device near a source communicatively connected to a receiver switching device near a receiver by a first interface and at least a third switching device that is communicatively connected to the receiver switching device by a second interface and further is communicatively connected to the source switching device by a third interface. The receiver switching device may discover that the first interface has failed and responds by sending the third switching device a PIM graft message prior to deleting an associated first interface route entry.

Abstract: An embodiment of the present invention discloses a method and device for managing a forwarding plane tunnel resource, wherein the method includes: sending a forwarding plane tunnel resource request message to a forwarding plane device, for enabling the forwarding plane device to allocate a forwarding plane tunnel resource according to the forwarding plane tunnel resource request message; acquiring the allocated forwarding plane tunnel resource from the forwarding plane device; and sending the acquired forwarding plane tunnel resource to a target network element, to establish a packet data network connection with the target network element. By adopting the present invention, the load balancing of the forwarding plane device is achieved, the signaling interaction between the control plane device and the forwarding plane device is reduced as much as possible, and meanwhile, efficient failure processing can also be achieved in the case of a failure occurred in a device.

Abstract: Provided is a linear protection switching method of a node, wherein the method includes selecting a local request based on a priority of at least one local request, determining a global request based on a priority between the selected local request and a remote message, and performing a state transition based on the global request.

Abstract: Embodiments of the invention include a method for maintaining an active-standby relationship between an active control card and a standby control card in a network element. The network element receives a data from a remote peer at the active control card. The network element communicates data from the active TCP module to an active application module in the active control card. The network element communicates synchronization data from the active application module to a standby application module on the standby control card. The network element communicates a single application synchronization acknowledgement from the standby application module to the active APP module. The network element communicates an application acknowledgment packet from the active application module to the active TCP module responsive to receiving the application synchronization acknowledgment. The network element then communicates an acknowledgement to the remote peer responsive to the application acknowledgement.

Abstract: Diagnosing connectivity in a network includes obtaining information from a network wherein the network is a hybrid network including software-defined networking (SDN) network components and other network components, querying a SDN controller for network metrics of the network, and diagnosing a connectivity issue in the network based on the information from the network and the network metrics.

Abstract: A transmission network is comprised of a network management system for collectively managing and controlling a plurality of transmission devices coupled mutually through transmission routes and the transmission network as well. The network management system includes a plane management table adapted to manage transmission planes defined as a set of paths in the transmission network, and the plane management table has the function to set and manage a transmission plane (working plane) applied during normal operation and besides, a single or a plurality of transmission planes (protection planes) applicable in the event of occurrence of a fault in the transmission network. Then, when a fault occurs in the transmission network, the network management system changes the applied plane to a suitable transmission plane.

Abstract: Layered third-party (enhanced) application software redundancy is provided in a non-homogeneous virtual chassis including two or more switches coupled via a virtual fabric link. A virtual chassis management module within at least one of the switches discovers the other switches within the virtual chassis, determines a base master switch from all of the switches in the virtual chassis, detects an enhanced application installed on at least one enhanced switch and determines an enhanced master switch from the enhanced switches.

Abstract: A method for protecting a bi-connected network against a dual link failure, the method comprising finding a plurality of cut-pairs for a data flow, finding a work path and a primary backup path for the data flow, determining the cut-pairs that overlap both the work path and the primary backup path, merging the cut-pairs that overlap the work path and the primary backup path into a plurality of cut-groups, wherein each cut-group comprises a first half and a second half, and constructing a plurality of partially disjoint backup paths based on the cut-groups, wherein one of the partially disjoint backup paths protects against the dual link failure that causes a failure on the second half of a first cut-group and a failure on the first half of a second cut-group.

Abstract: Provided is a protection end node located at an end of a protection path, wherein the protection end node includes a receiver to receive, from a working end node located at an end of a working path, path defect information indicating whether a defect occurs on the working path, a processor to perform protection switching in response to reception of the path defect information and generate path control information used for the working end node to control a connection of the working path based on the protection switching, and a transmitter to transmit the path control information to the working end node.

Abstract: An aspect of the subject disclosure may include, for example, receiving a communication request responsive to a telephone number mapping query failure, where the communication request is initiated by an originating communication device requesting a communication session with a terminating communication device, foregoing initiating the communication session as a circuit-switched communication session responsive to determining that the originating communication device and the terminating communication device are enabled to use packet-switched communications, and instructing a second network node to initiate the communication session as a packet-switched communication session between the originating communication device and the terminating communication device responsive to the determination. Other embodiments are disclosed.

Abstract: A computing network, including: a plurality of peer computing devices including code, which when executed by a peer computing device causes the executing peer computing device to cooperate with at least one other of the peer computing devices; at least one server including code, which when executed by the at least one server locates at least one of the peer computing devices; and at least one mediator including code, which when executed by the at least on mediator collects charging information from at least some of the peer computing devices; wherein, the peer computing devices, at least one sever and at least one mediator are communicatively coupled via an at least carrier-grade telecommunications network being suitable for enhancing cooperation among the cooperating ones of the peer computing devices relative to best-efforts communications among the cooperating ones of the peer computing devices.

Abstract: A control protocol is run in the interconnect region between network domains so that the interconnect region may be managed using a separate control plane. According to an embodiment of the invention, a spanning tree protocol is used to establish a separate spanning tree within the interconnect region. To avoid loop formation within the interconnect region, links interconnecting adjacent edge nodes that are part of the interconnect region and which belong to a given domain are allowed to pass control frames but not data frames. OAM may be used detect link failure of a link between adjacent nodes on a given domain.

Abstract: In some cases, it may be desirable to limit the number of routers in a mesh network. Various techniques to limit the number of routers, without affecting connectivity, are disclosed. In some embodiments, a node enables its router capability if there are less than a predetermined number of routers already in the network. In other embodiments, a node enables its routing capability only is it is necessary to resolve a connectivity issue or a biconnectivity issue. In some cases, a node, which previously enabled its router capability, may no longer be required to be a router. In some embodiments, this node, upon making this determination, disables its routing capability.

Abstract: The invention relates to a method for operating a telecommunications network and a telecommunications network for mobile telecommunication, having a network register in which identifier of mobile terminals and network-related user data of the terminals are stored. The network register is formed from a peer-to-peer network having a multiplicity of decentralized register nodes which are networked with one another and are each associated with a geographic region. Hash tables are held in the register nodes, in which hash tables the identifiers of the terminals are stored as hash values and the user data is stored associated with these hash values. The network has at least a first node associated with a geographic region at which a terminal can register, and a second node, which is permanently assigned to the terminal and is associated with a geographic region. The terminal registers with the first node by transmitting the identifier, when it is located in the first region.

Abstract: The embodiments of the present invention provide a paging processing method and system and also a serving gateway. The paging processing method includes: detecting, by a serving gateway, a fault of a mobility management element, determining a type of the fault, and reselecting a mobility management element according to the type of the fault; and sending, by the serving gateway, a downlink data notification message to the reselected mobility management element, whereupon the reselected mobility management element sends a paging message to a user equipment UE that is served by the faulty mobility management element before the fault occurs. With the method, system and serving gateway provided in the embodiments of the present invention, user experience is improved effectively.

Abstract: A computer program product comprising computer executable instructions stored on a non-transitory computer readable medium such that when executed by a processor cause a network element to protect a label switched network against egress node failure by receiving a primary service label and a backup service label from an upstream node in the network, receiving data traffic comprising the primary service label from the upstream node for transmitting to a downstream node in the network, determining a status of a primary egress node in the network, the primary egress node being associated with a primary label switching path, forwarding the data traffic according to a primary label switching path when the primary egress node is operating properly, and replacing the primary service label with the backup service label and forwarding the data traffic according to a backup label switching path when the primary egress node has failed.

Abstract: A method of performing protection switching in a network including a first node and a plurality of second nodes that are connected to the first node is provided. The first node counts the number of obstacles that have occurred in a plurality of paths that are connected between the plurality of second nodes, and if the counted number is smaller than a predetermined threshold value, the first node performs protection switching per leaf. Alternatively, if the counted number is equal to or larger than a predetermined threshold value, the first node performs protection switching per tree.

Abstract: An apparatus comprising an aggregation/core switch configure to couple to an edge switch and receive information about a plurality of end system facing ports of the edge switch, wherein the information about the end system facing ports is used to associate the end system facing ports with a plurality of corresponding queues at the aggregation/core switch. Also disclosed is a network component comprising a receiver configured to receive information about a plurality of end system facing ports of an edge switch, a processor configured to establish and associate the end system facing ports with a plurality of corresponding queues, and a transmitter configured to return information about the associated end system facing ports.

Abstract: Techniques are described for providing managed computer networks. In some situations, the techniques include managing communications for computing nodes of a managed computer network by using one or more particular computing nodes of the managed computer network that are configured to operate as intermediate destinations to handle at least some communications that are sent by and/or directed to one or more other computing nodes of the managed computer network. In addition, the techniques may include managing the communications in accordance with configured failure behavior specified for one or more computing nodes of the computer network, such as specified failure behavior for a computing node configured to operate as an intermediate destination that indicates how communications that would otherwise be routed via the intermediate destination computing node are to be handled if the intermediate destination computing node fails or is otherwise unavailable (e.g., to block or allow such communications).

Abstract: A method is described for operating a device in a wireless communication system. The device communicates with a base station using a subframe for the device only; detects, by the device, a problem with a connection between the device and the base station. The device starts a timer upon detecting the problem with the connection between the device and the base station. The device releases a restriction of using the subframe for the device only, if the timer expires. The problem with the connection between the device and the base station is associated with a radio link failure. The detection of a problem with the connection between the device and the base station comprises detecting consecutive out-of-sync indications.

Abstract: The present invention discloses a method, an apparatus, and a system for detecting connectivity. A node receives connectivity detection request information; determines, according to nicknames of target nodes, whether the is one of the target nodes; if the node is one of the target nodes, sends connectivity detection reply information to a source node; if the node is not one of the target nodes, performs corresponding processing according to a value of a hop count and whether the node is on a path that is in the multicast distribution tree and is from the source node to any one of the target nodes. With the present invention, a source node is capable of receiving only a feedback of a node on a true path, thereby making it easier to identify a path.

Abstract: A process for an implicit logout of links to a fiber channel over Ethernet switch includes receiving, at a second switch, a first message from a first switch. The first message indicates an implicit link logout event on one of two or more links between the first switch and a node. Also, the process includes transmitting a second message from the second switch. The second message indicates zoning information for all of the two or more links between the first switch and the node.

Abstract: This disclosure discloses a method for implementing protection group overlay and a method for implementing Ethernet protection switching based on the protection group overlay. The method for implementing Ethernet protection switching based on the protection group overlay comprises: when the fault of TESI is detected by multiple IPG which protect the same TESI, only one IPG of the multiple nested IPGs performs protection switching. This disclosure further discloses a system for implementing Ethernet protection switching based on the protection group overlay, comprising a protection switching performing unit, configured to when a fault of a TESI is detected by multiple IPGs which protect the TESI, only one IPG of the multiple nested IPGs performing protection switching. Application of the method and system of this disclosure implements protection for key protected path through protection group overlay, and can achieve effects of saving network resource and increasing utilization rate of network resource.

Abstract: A method for configuring a router is disclosed. The method comprises providing router configuration information. The router configuration information is sent to the router over a cellular data network.

Abstract: An event trigger and management system for providing automatic repeat requests (ARQs) by a single timer and a method thereof are provided. Various type timers for providing an ARQ are integrated into a single timer. Through a data structure of a timer node of automatic repeat requests time series, the automatic repeat request time series can be managed only by a single timer. Therefore, the efficiency of controlling and managing a timer associated with Worldwide Interoperability for Microwave Access (WiMAX) may be achieved.

Abstract: The invention relates to a method for determining a path between a first radio station and an access point of a radio communications system, whereby the radio communications system comprises additional radio stations. A frequency band subdivided into a number of subbands is used in order to communicate between, the radio stations. At least one subband for communicating is assigned to each radio station. The path extends over one or more of the additional radio stations so that information between the first radio station and the access point can be transmitted over the path. The path is at least partially determined by a radio installation apparatus on request of the first radio station. The radio installation additionally transmits, to at least a portion of the radio stations of the path, respective path identification information, subband information and radio station identification information.

Abstract: A dedicated control path architecture for systems of devices, such as stacking systems, is provided. In one embodiment, a network device for use in a system of devices can comprise a CPU complex; a first set of ports for establishing a data path between the network device and other network devices in the system of devices; and a second set of ports for establishing a control path between the network device and the other network devices in the system of devices. The control path can be separate from the data path and can allow the CPU complex to exchange control plane traffic with other CPU complexes resident in the other network devices.

Abstract: Systems and methods are disclosed for effectuating control-plane changes at increased speeds to protect a network in which switching operations are performed. Operations to effectuate control-plane changes in the network can be divided between software and more-rapid, dedicated hardware within a line card. Examples of operations reserved to hardware implementation can include blocking and unblocking of ports, flushing of learned entries from switch tables, and coordination of control-plane changes through the generation of messages sent between nodes, and also between line cards of a node. Determinations about the need for hardware-driven, control-plane changes may be made based on events occurring in the network in accordance with any of a number of different network protection protocols. The protocol may be implemented in a state machine and the software may determine the state of the hardware through a master/slave relationship.

Abstract: An example method for increasing multi-destination scale in a network environment is provided and includes receiving a packet at a pair of switches comprising a first switch and a second switch in a network environment, where the first switch is configured as an elected forwarder, and the second switch is configured as a standby forwarder. A fabric extender (FEX) is connected to the first switch and the second switch with a virtual PortChannel. The method further includes forwarding the packet to a host connected to the FEX. The elected forwarder is configured with substantially all multi-destination virtual interfaces (VIFs) on the FEX in a forwarding table. The standby forwarder forwards the packet to the elected forwarder. In specific embodiments, the elected forwarder programs the FEX with the VIFs.

Abstract: Various exemplary embodiments relate to a method performed by a network node, the method including: receiving a connection request from a peer network node including a peer identifier; determining that the received peer identifier matches an identifier of an existing peer; sending a verification message to the existing peer; setting a timer; when a response the verification message is received before the timer expires: cancelling the timer; and rejecting the received connection request; when the timer expires: closing a connection to the existing peer; and accepting the new connection from the new peer.

Abstract: A system for interfacing a client system in a first network domain with a Provider Link State Bridging (PLSB) domain includes at least two Backbone Edge Bridges (BEBs) of the PLSB domain. Each BEB is an end-point of a connection in the first network domain to the client system and an end-point of at least a unicast path in the PLSB domain. An inter-node trunk is provided in the PLSB domain for interconnecting the BEBs. A phantom node is defined in the PLSB domain and is notionally located on the inter-node trunk. Each of the BEBs is configured such that: an ingress packet received from the client system via the connection in the first network domain is forwarded through a path notionally rooted at the phantom node; and an egress packet destined for the client system is forwarded to the client system through the connection in the first network domain.

Abstract: For a network that includes several managed edge switching elements and several managed non-edge switching elements that are for implementing a logical switching element, some embodiments provide a method of distributing packet processing across the several managed non-edge switching elements. The method receives a packet for processing through the logical switching element. Based on a determination that the packet needs to be processed by a managed non-edge switching element, the method determines a particular managed non-edge switching element of the several managed non-edge switching elements to forward the packet. The method forwards the packet to the particular managed non-edge switching element for the particular managed non-edge switching element to process the packet.

Abstract: A network device determines whether the network device has a local link for a link aggregation group (LAG), and identifies, when the network device has a local link for the LAG, the network device as a designated forwarder for the LAG. The network device also identifies, when the network device does not have a local link for the LAG, a closest network device to the network device, with a local link for the LAG, as the designated forwarder for the LAG.

Abstract: A distributed switch may include a hierarchy with one or more levels of surrogate sub-switches (and surrogate bridge elements) that enable the distributed switch to scale bandwidth based on the size of the membership of a multicast group. Moreover, each surrogate may optimize the hierarchy according to one or more optimization criteria. For example, each surrogate in the hierarchy may have the necessary information to ensure that if the next surrogate in the hierarchy is unavailable, the data may be routed to a backup surrogate. The selected hierarchy may be further optimized by skipping surrogates (or a surrogate level) such that the data intended for a skipped surrogate is sent to a surrogate in a lower-level of the hierarchy. This may better utilize the connection interfaces in the transmitting sub-switches and eliminate any unnecessary surrogate-to-surrogate transfers.

Abstract: In some embodiments, an apparatus includes a gateway device configured to be operatively coupled to a Fiber Channel switch by a first data port and a second data port. The gateway device is configured to designate the first data port as a primary data port and the second data port as a secondary data port. The gateway device is configured to associate a set of virtual ports with the first data port and not the second data port when in the first configuration. The gateway device is configured to associate the set of virtual ports with the second data port when in the second configuration. The gateway device moves from the first configuration to the second configuration when an error associated with the first data port is detected.

Abstract: Various exemplary embodiments relate to a method and related network node including one or more of the following: performing an active gateway election to determine whether the provider edge device will be an active gateway for a connection; if the provider edge device will be the active gateway for the connection, indicating to a customer edge device that no fault is currently associated with a link between the customer edge device and the provider edge device; and if the provider edge device will not be the active gateway for the connection, indicating to the customer edge device that a fault is currently associated with the link between the customer edge device and the provider edge device.

Abstract: A device includes a master control card that performs control plane processing, a backup control card, where the backup control card takes over control plane processing if the master control card goes out of service, and a database card that connects to the master control card and the backup control card, where the database control card stores information relating to control plane processing. A method of achieving hitless failover in a network element includes detecting that a master control card of the network element has gone out of service, designating the backup control card as a new master control card of the network element, establishing communication with a database card of the network element, and retrieving protocol states information from the database card.

Abstract: A method and an apparatus for rapidly resuming, at times of failures, network traffic in a connection-oriented network by using an alternative route pre-computed and stored locally in nodes along an initial route without requiring signaling of upstream nodes or a master server.

Abstract: Techniques are described for separating control plane functions in a network device using virtual machines. The techniques include initializing multiple virtual machine instances in a control unit of a standalone router, and running different control processes for the router in each of the virtual machines. For example, in a root system domain (RSD)-protected system domain (PSD) system, a control unit of the standalone router may support a RSD virtual machine (VM) and one or more PSD VMs configured to form logical devices and execute logically separate control processes without requiring physically separate, hardware-independent routing engines to form the PSDs. Each of the RSD VM and PSD VMs includes a separate kernel, an operating system, and control processes for the logical device. When a software failure occurs in the PSD VM, the PSD VM may perform a software failover without affecting the operation of the RSD VM.

Abstract: A route determination device includes a memory to store a piece of route information of the route which is already calculated; and a processor to execute a process including: receiving a calculation request which requests route calculation; determining the route which conforms to the calculation request by performing the route calculation when the route information stored in the memory does not include the route which conforms to the calculation request; obtaining the route which conforms to the calculation request from the route information when the route information stored in the memory includes the route which conforms to the calculation request; storing the route information of the route determined by route determining processing in the memory; and sharing, with another route determination device which determines the route going through another node device among the plurality of node devices, the route information of the route determined by the route determining processing.

Abstract: In general, techniques are described for performing a graceful restart for a computing network utilizing downstream on demand (DOD) label distribution. In one example, a method is provided that includes establishing a communication session for Label Distribution Protocol (LDP) that uses a downstream on demand label distribution mechanism for distributing labels. A first label mapping message is exchanged between two routers that defines at least a first label to be applied by an upstream router when forwarding one or more of the data packets to a destination. When the communication session fails, a forwarding state comprising the first label is preserved, and one or more data packets are forwarded based on the first label. The communication session is gracefully restarted. Once the communication session is reestablished, a second label mapping message is exchanged between the routers.

Abstract: A distributed switch may include a hierarchy with one or more levels of surrogate sub-switches (and surrogate bridge elements) that enable the distributed switch to scale bandwidth based on the size of the membership of a multicast group. Moreover, each surrogate may optimize the hierarchy according to one or more optimization criteria. For example, each surrogate in the hierarchy may have the necessary information to ensure that if the next surrogate in the hierarchy is unavailable, the data may be routed to a backup surrogate. The selected hierarchy may be further optimized by skipping surrogates (or a surrogate level) such that the data intended for a skipped surrogate is sent to a surrogate in a lower-level of the hierarchy. This may better utilize the connection interfaces in the transmitting sub-switches and eliminate any unnecessary surrogate-to-surrogate transfers.

Abstract: Systems and methods for replacing a stack unit in a stack system include determining that a first and a second port that are located on opposite ends of the stack system are inactive when operating in a stack port mode after being connected to respective ports on a new stack unit that are operating in a Ethernet port mode. In response, the first and second port are converted from the stack port mode to the Ethernet port mode. A stack port probe packet is then sent from the first and second port to the new stack unit that cause the new stack unit to convert its connected ports from the Ethernet port mode to the stack port mode. A stack port probe reply is then received through the first and second port from the new stack unit and, in response, the first and second port are converted from the Ethernet port mode to the stack port mode.

Abstract: Techniques are described for detecting failure or degradation of a service enabling technology function independent from an operational state of a service node hosting the service enabling technology function. For example, a service node may provide one or more service enabling technology functions, and service engineered paths may be traffic-engineered through a network to service node network devices that host a service enabling technology function. A monitor component at the service layer of the service node can detect failure or degradation of one or more service enabling technology functions provided by the service node. The monitor component reports detection of failure or degradation to a fault detection network protocol in a forwarding plane of the service node. The fault detection network protocol communicates with an ingress router of a service engineered path to trigger fast reroute by the ingress of traffic flows to bypass the affected service enabling technology function.

Abstract: One embodiment relates to a method of providing dual-homing in a layer 2 switch. A determination is made as to whether a link is available to an upstream network on for a currently active port. If the link is unavailable, then the layer 2 switch a) performs a switchover such that the currently active port becomes a newly passive port, and a currently passive port becomes a newly active port, b) clears entries in an address table of the layer 2 switch, and c) spoofs MAC addresses out of the newly active link. Other embodiments are also disclosed.