Abstract: A method and a network for routing data packet in a unified wide area network (WAN) is provided. The method includes encapsulating a data packet by an ingress aggregation router and forwarding the encapsulated data packet to an ingress backbone router. The encapsulated data packet includes a first label. The ingress backbone router selects an optimized traffic engineered tunnel and replaces the first label with the optimized traffic engineered tunnel and forwards the encapsulated data packet along the optimized traffic engineered tunnel.

Abstract: A system manages network traffic in a distributed system comprising a plurality of network devices. The network devices are divided into a plurality of network slices, each of the network slices including a subset of the network devices such that there is no overlap of network devices between the network slices. Individual network slices are associated with individual slice controllers, and an individual slice controller is configured to manage network routing of an individual network slice. Each of the individual slice controllers route the network traffic within each respective individual network slice. The network traffic is independently routed based on expected network conditions for each respective individual network slice, and data defining routing decisions is contained within each network slice to limit fault effects between the network slices.

Abstract: A system manages network traffic in a distributed system comprising a plurality of network devices. The network devices are divided into a plurality of network slices, each of the network slices including a subset of the network devices such that there is no overlap of network devices between the network slices. Individual network slices are associated with individual slice controllers, and an individual slice controller is configured to manage network routing of an individual network slice. Each of the individual slice controllers route the network traffic within each respective individual network slice. The network traffic is independently routed based on expected network conditions for each respective individual network slice, and data defining routing decisions is contained within each network slice to limit fault effects between the network slices.

Abstract: A system manages network traffic in a distributed system comprising a plurality of network devices. The network devices are divided into a plurality of network slices, each of the network slices including a subset of the network devices such that there is no overlap of network devices between the network slices. Individual network slices are associated with individual slice controllers, and an individual slice controller is configured to manage network routing of an individual network slice. Each of the individual slice controllers route the network traffic within each respective individual network slice. The network traffic is independently routed based on expected network conditions for each respective individual network slice, and data defining routing decisions is contained within each network slice to limit fault effects between the network slices.

Abstract: The present technology is generally directed to updating a cloud network. This technology may include generating a set is inequalities based network topology information, shared risk link group information, demand information, and traffic solver parameters. The set of inequalities may also be based upon a model of traffic routing that is based on selection of routes based on dynamic and global traffic engineering. A capacity plan may also be generated based on the set of inequalities and at least one objective. The capacity plan may include a target capacity for each link of the plurality of links in the network.

Abstract: The present technology is generally directed to updating a cloud network. This technology may include generating a set is inequalities based network topology information, shared risk link group information, demand information, and traffic solver parameters. The set of inequalities may also be based upon a model of traffic routing that is based on selection of routes based on dynamic and global traffic engineering. A capacity plan may also be generated based on the set of inequalities and at least one objective. The capacity plan may include a target capacity for each link of the plurality of links in the network.

Abstract: Techniques are described for synchronizing state information between a plurality of control units. A router, for example, is described that includes a primary control unit and a standby control unit. The primary control unit maintains router resources to ensure operation of the router. To ensure operation, the primary control unit receives state information from the router resources and maintains the state information for consumers, i.e. router resources that require or “consume” state information. Prior to updating the consumers with the state information, the primary control unit synchronizes the state information with the standby control unit. In the event the primary control unit fails, the standby control unit assumes control of the router resources. Upon assuming control, the standby control unit resumes updating the consumers with state information without having to “relearn” state information, e.g., by way of power cycling the router resources to a known state.

Abstract: State information is synchronized between a plurality of routing engines in a multi-chassis router according to a synchronization gradient. An example multi-chassis router is described that includes a primary routing engine and a standby routing engine in each chassis. According to the synchronization gradient, the primary routing engine of a control node updates state information on the standby routing engine of the control node prior to updating the primary routing engines of the other chassis. The primary routing engines of the other chassis update state information in respective standby routing engines prior to updating state information in consumers. If a primary routing engine fails, the corresponding standby routing engine assumes control of the primary routing engine's duties. Upon assuming control, a standby routing engine resumes updating state information without having to resend state information or interrupt packet forwarding.

Abstract: Techniques are described for configuration of a multi-chassis router for managing periodic communications between the multi-chassis router and other network devices. The multi-chassis router selectively processes data received from a network by determine whether the data: (1) indicates an operational state of a network device in association with a routing protocol, or (2) conveys routing information for the routing protocol. Data conveying routing information are processed by a master routing component of the multi-chassis router, while data indicating an operational state of a network device are processed by one or more slave routing components of the multi-chassis router.

Abstract: A multi-chassis network device sends state information to internal consumers within the multi-chassis device via a hierarchical distribution. As one example, a primary master routing engine within a control node of a multi-chassis router forwards state information to local routing engines within other chassis, which in turn distribute the state information to consumers on each chassis. Each local routing engine defers sending acknowledgement to the master routing engine until acknowledgements have been received from all consumers serviced by the local routing engine. Embodiments of the invention may reduce control plane data traffic and convergence times associated with distribution of state updates in the multi-chassis network device.

Abstract: A standalone router is integrated into a multi-chassis router. Integrating the standalone router into a multi-chassis router requires replacing switch cards in the standalone router with multi-chassis switch cards. The multi-chassis switch cards forward packets to a central switch card chassis for routing within the multi-chassis router. By incrementally replacing standalone switch cards with multi-chassis switch cards in the standalone router, packet forwarding performance is maintained during the integration.

Abstract: State information is synchronized between a plurality of routing engines in a multi-chassis router according to a synchronization gradient. An example multi-chassis router is described that includes a primary routing engine and a standby routing engine in each chassis. According to the synchronization gradient, the primary routing engine of a control node updates state information on the standby routing engine of the control node prior to updating the primary routing engines of the other chassis. The primary routing engines of the other chassis update state information in respective standby routing engines prior to updating state information in consumers. If a primary routing engine fails, the corresponding standby routing engine assumes control of the primary routing engine's duties. Upon assuming control, a standby routing engine resumes updating state information without having to resend state information or interrupt packet forwarding.

Abstract: State information is synchronized between a plurality of routing engines in a multi-chassis router according to a synchronization gradient. An example multi-chassis router is described that includes a primary routing engine and a standby routing engine in each chassis. According to the synchronization gradient, the primary routing engine of a control node updates state information on the standby routing engine of the control node prior to updating the primary routing engines of the other chassis. The primary routing engines of the other chassis update state information in respective standby routing engines prior to updating state information in consumers. If a primary routing engine fails, the corresponding standby routing engine assumes control of the primary routing engine's duties. Upon assuming control, a standby routing engine resumes updating state information without having to resend state information or interrupt packet forwarding.

Abstract: Techniques are described for synchronizing state information between a plurality of control units. A router, for example, is described that includes a primary control unit and a standby control unit. The primary control unit maintains router resources to ensure operation of the router. To ensure operation, the primary control unit receives state information from the router resources and maintains the state information for consumers, i.e. router resources that require or “consume” state information. Prior to updating the consumers with the state information, the primary control unit synchronizes the state information with the standby control unit. In the event the primary control unit fails, the standby control unit assumes control of the router resources. Upon assuming control, the standby control unit resumes updating the consumers with state information without having to “relearn” state information, e.g., by way of power cycling the router resources to a known state.

Abstract: Techniques are described for configuration of a multi-chassis router for managing periodic communications between the multi-chassis router and other network devices. The multi-chassis router selectively processes data received from a network by determine whether the data: (1) indicates an operational state of a network device in association with a routing protocol, or (2) conveys routing information for the routing protocol. Data conveying routing information are processed by a master routing component of the multi-chassis router, while data indicating an operational state of a network device are processed by one or more slave routing components of the multi-chassis router.

Abstract: A standalone router is integrated into a multi-chassis router. Integrating the standalone router into a multi-chassis router requires replacing switch cards in the standalone router with multi-chassis switch cards. The multi-chassis switch cards forward packets to a central switch card chassis for routing within the multi-chassis router. By incrementally replacing standalone switch cards with multi-chassis switch cards in the standalone router, packet forwarding performance is maintained during the integration.

Abstract: A multi-chassis network device sends state information to internal consumers within the multi-chassis device via a hierarchical distribution. As one example, a primary master routing engine within a control node of a multi-chassis router forwards state information to local routing engines within other chassis, which in turn distribute the state information to consumers on each chassis. Each local routing engine defers sending acknowledgement to the master routing engine until acknowledgements have been received from all consumers serviced by the local routing engine. Embodiments of the invention may reduce control plane data traffic and convergence times associated with distribution of state updates in the multi-chassis network device.

Abstract: A router includes a detection module to detect a presence of the network attack, such as a denial of service (DOS) attack. The detection module may, for example, include counters indicating a number of packets processed for various network protocols supported by the router. The detection module enables a rate-limiting operating mode for the router when one or more of the counters exceed a protocol-specific threshold. Under normal traffic levels, the router receives inbound packets using interrupt-driven service routines. When a network attack is detected, however, the router dynamically switches modes and processes the patents using a finely controlled software process. This allows the software process to control the computing resources allocated to servicing packets during a network attack, thereby reserving sufficient resources for lower priority software processes to process the packets and service other tasks.

Abstract: A router includes a detection module to detect a presence of the network attack, such as a denial of service (DOS) attack. The detection module may, for example, include counters indicating a number of packets processed for various network protocols supported by the router. The detection module enables a rate-limiting operating mode for the router when one or more of the counters exceed a protocol-specific threshold. Under normal traffic levels, the router receives inbound packets using interrupt-driven service routines. When a network attack is detected, however, the router dynamically switches modes and processes the packets using a finely controlled software process. This allows the software process to control the computing resources allocated to servicing packets during a network attack, thereby reserving sufficient resources for lower priority software processes to process the packets and service other tasks.

Abstract: The present invention, in various embodiments, is directed to techniques for providing debugging capability for program code instrumentation. In one embodiment, an instrumentor inserts an instrumentation breakpoint at the beginning of a block of original code. When this breakpoint is reached during execution of the application program that includes the block of original code, the instrumenator, from the block of original code, generates a block of instrumented code. This block of instrumented code may include debugging breakpoints that are carried from the block of original code or are inserted into the block of instrumented code during debugging. After generating the instrumented code, the instrumentor executes the instrumented code until debugging breakpoints are reached that stop the program flow, thereby allowing a programmer to perform debugging functions at these debugging breakpoints.