Patent application number | Description | Published |
20120044940 | FLOODING-BASED ROUTING PROTOCOL HAVING AVERAGE-RATE AND BURST-RATE CONTROL - An enhanced, flooding-based routing protocol is described that provides burst-rate and average-rate flow control. A routing device comprises a network interfaces configured to send and receive packets over a layer-two (L2) communication medium. A flooding-based link state routing protocol executes on a processor of the routing device to maintain network topology information for a network and establish an adjacency with a peer router over the layer-two (L2) communication medium. A database of the routing device stores a minimum packet interval and a credit specified by the peer router for the adjacency. When sufficient credit has been allocated to the L2 communication medium, a scheduler of the router dequeues link state messages from an outbound packet queue and floods each of the link state messages to the L2 communication medium while maintaining at least the specified minimum packet interval between each of the plurality of link state messages. | 02-23-2012 |
20120044947 | FLOODING-BASED ROUTING PROTOCOL HAVING DATABASE PRUNING AND RATE-CONTROLLED STATE REFRESH - An enhanced, flooding-based link state routing protocol is described that provides pruning of link state data and, when needed, rate-controlled refresh of the pruned link state data from other routers of the flooding domain. A routing device comprises a network interface to send and receive packets over a layer-two (L2) communication medium. The routing device includes a control unit coupled to the network interface, and a flooding-based link state routing protocol executing on a processor of the control unit. The link-state routing protocol establishes an adjacency with a peer router. A database of the routing device includes entries that store a plurality of link state messages for a flooding domain of the link state routing protocol, wherein at least one of the entries in the database stores a partial link state message having a header portion and a payload having pruned link state data. | 02-23-2012 |
20120144066 | DYNAMICALLY GENERATING APPLICATION-LAYER TRAFFIC OPTIMIZATION PROTOCOL MAPS - In general, techniques are described for using routing information obtained by operation of network routing protocols to dynamically generate network and cost maps for an application-layer traffic optimization (ALTO) service. For example, an ALTO server of an autonomous system (AS) receives routing information from routers of the AS by listening for routing protocol updates outputted by the routers and uses the received topology information to dynamically generate a network map of PIDs that reflects a current topology of the AS and/or of the broader network that includes the AS. Additionally, the ALTO server dynamically calculates inter-PID costs using received routing information that reflects current link metrics. The ALTO server then assembles the inter-PID costs into a cost map that the ALTO server may provide, along with the network map, to clients of the ALTO service. | 06-07-2012 |
20120224506 | ADVERTISING TRAFFIC ENGINEERING INFORMATION WITH THE BORDER GATEWAY PROTOCOL - In general, techniques are described for distributing traffic engineering (TE) link information across network routing protocol domain boundaries using a routing protocol. In one example, a network device logically located within a first routing protocol domain includes a routing protocol module executing on a control unit to execute an exterior gateway routing protocol. The routing protocol module of the network device receives an exterior gateway routing protocol advertisement from a router logically located within a second routing protocol domain and decodes traffic engineering information for a traffic engineering link from the exterior gateway routing protocol advertisement. A path computation module of the network device computes a traffic engineered path by selecting the traffic engineering link for inclusion in the traffic engineered path based on the traffic engineering information. | 09-06-2012 |
20130121211 | FLOODING-BASED ROUTING PROTOCOL HAVING DATABASE PRUNING AND RATE-CONTROLLED STATE REFRESH - An enhanced, flooding-based link state routing protocol is described that provides pruning of link state data and, when needed, rate-controlled refresh of the pruned link state data from other routers of the flooding domain. A routing device comprises a network interface to send and receive packets over a layer-two (L2) communication medium. The routing device includes a control unit coupled to the network interface, and a flooding-based link state routing protocol executing on a processor of the control unit. The link-state routing protocol establishes an adjacency with a peer router. A database of the routing device includes entries that store a plurality of link state messages for a flooding domain of the link state routing protocol, wherein at least one of the entries in the database stores a partial link state message having a header portion and a payload having pruned link state data. | 05-16-2013 |
20130265894 | NETWORK AVAILABILITY ANALYTICS - In one embodiment, a method includes receiving at a network device, route convergence measurements and traffic demand measurements from a plurality of routers, and computing network availability based on the measurements at the network device. The route convergence measurements are associated with route computations at the routers and the traffic demand measurements include portions of a demand matrix associated with the routers. An apparatus and logic are also disclosed herein. | 10-10-2013 |
20130286846 | PATH WEIGHTED EQUAL-COST MULTIPATH - Routers balance network traffic among multiple paths through a network according to an amount of bandwidth that can be sent on an outgoing interface computed for each of the paths. For example, a router receives a link bandwidth for network links that are positioned between the first router and a second router of the network, and selects a plurality of forwarding paths from the first router to the second router. Upon determining that one of the network links is shared by multiple of the plurality of forwarding paths, the router computes a path bandwidth for each of the plurality of forwarding paths so as to account for splitting of link bandwidth of the shared network link across the multiple forwarding paths that share the network link. The router assigns packet flows to the forwarding paths based at least on the computed amount of bandwidth for each of the forwarding paths. | 10-31-2013 |
20130322236 | CONGESTION MANAGMENT FOR FIBRE CHANNEL OVER ETHERNET OVER WIDE AREA NETWORKS - In general, techniques are described for mapping WAN conditions to appropriate back-pressure mechanisms at the WAN edges to improve the performance of delay and/or loss-sensitive applications. In one example, a system includes a wide area network having a provider edge (PE) router to establish a Fibre Channel over Ethernet (FCoE) pseudowire over the wide area network. A Lossless Ethernet network attaches, by an attachment circuit, to the FCoE pseudowire at the PE router. A Fibre Channel Fabric connects to the Lossless Ethernet network and to a storage device that provides data for transmission over the wide area network by the FCoE pseudowire. The PE router detects a defect in the FCoE pseudowire and, in response to detecting the defect in FCoE pseudowire, injects an FCoE flow control extension into the Lossless Ethernet network by the attachment circuit. | 12-05-2013 |
20130336108 | GLOBAL STATE RESYNCHRONIZATION FOR PATH COMPUTATION ELEMENT FAILURE DURING A REOPTIMIZATION PROCESS - In one embodiment, a router initiates reroutes of one or more tunnels at the router as part of optimization of a plurality of tunnels in a computer network, and stores an original state of the one or more tunnels at the router prior to the optimization. By detecting whether path computation element (PCE) failure occurs prior to completion of the optimization, the router may revert to the original state of the one or more tunnels in response to PCE failure prior to completion of the optimization. | 12-19-2013 |
20130336109 | ORDERED FLOODING REQUESTS FOR PATH COMPUTATION ELEMENTS - In one embodiment, a stateful path computation element (PCE) in a computer network determines a need to route at least a threshold number of tunnels, and in response, triggers a routing update from a determined set of routers. Having updated the routing information and available network resources for the set of routers, the stateful PCE may then compute the tunnels based on the update. | 12-19-2013 |
20130336159 | DISTRIBUTED STATEFUL PATH COMPUTATION ELEMENT OVERLAY ARCHITECTURE - In one embodiment, a particular device in a computer network maintains a locally owned tunnel-state table, and joins a distributed hash table (DHT) ring. In addition, the locally owned tunnel-state table is shared with other devices of the DHT ring to establish a DHT-owned tunnel-state table. The particular device (and other devices) determines ownership of link-state advertisements (LSAs) for a specific portion of a traffic engineering database (TED) according to the DHT ring. As such, when the particular device (or any device) computes a path for a tunnel using a local TED, the particular device may request permission to use resources along the computed path that were advertised in particular LSAs from owners of those particular LSAs when not owned by the particular device. | 12-19-2013 |
20130336315 | ALLOCATING AND DISTRIBUTING LABELS FOR PACKET ENCAPSULATION - In one example, a network device receives a packet to be forwarded according to a label switching protocol, determines a service to be performed on the packet by a service network device, sends a label request message to the service network device, wherein the label request message indicates support for labels having a particular length, wherein the particular length is larger than twenty bits (e.g., forty bits), and wherein the label request message specifies the service to be performed on the packet, receives, in response to the label request message, a label mapping message defining a label of the particular length, appends the label to the packet to form a Multi-Protocol Label Switching (MPLS)-encapsulated packet, and forwards the MPLS-encapsulated packet according to the label switching protocol. | 12-19-2013 |
20130343174 | SERVICE PLANE TRIGGERED FAST REROUTE PROTECTION - 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. | 12-26-2013 |
20130346470 | DISTRIBUTED PROCESSING OF NETWORK DEVICE TASKS - Techniques are described for distributing network device tasks across virtual machines executing in a computing cloud. A network device includes a network interface to send and receive messages, a routing unit comprising one or more processors configured to execute a version of a network operating system, and a virtual machine agent. The virtual machine agent is configured to identify a virtual machine executing at a computing cloud communicatively coupled to the network device, wherein the identified virtual machine executes an instance of the version of the network operating system, to send, using the at least one network interface and to the virtual machine, a request to perform a task, and to receive, using the at least one network interface and from the virtual machine, a task response that includes a result of performing the task. The routing unit is configured to update the network device based on the result. | 12-26-2013 |
20140003232 | FEEDBACK LOOP FOR SERVICE ENGINEERED PATHS | 01-02-2014 |
20140334295 | Symmetric Service Chain Binding - A plurality of network nodes are deployed in a network, each network node configured to apply a service function to traffic that passes through the respective network nodes. A controller generates information for a service chain that involves application to traffic of one or more service functions at corresponding ones of the plurality of network nodes along a forward path through the one or more network nodes. The controller identifies one or more of the service functions within the service chain that is stateful. When one or more of the service functions of the service chain is stateful, the controller generates information for a reverse path through the one or more service nodes for the one or more stateful service functions. The controller binds a forward chain identifier for the forward path with a reverse chain identifier for the reverse path for the service chain. | 11-13-2014 |
20140334488 | Data Plane Learning of Bi-Directional Service Chains - Techniques are provided to decouple service chain structure from the underlying network forwarding state and allow for data plane learning of service chain forwarding requirements and any association between services function state requirements and the forward and reverse forwarding paths for a service chain. In a network comprising a plurality of network nodes each configured to apply a service function to traffic that passes through the respective network node, a packet is received at a network node. When the network node determines that the service function it applies is stateful, it updates context information in a network service header of the packet to indicate that the service function applied at the network node is stateful and that traffic for a reverse path matching the classification criteria is to be returned to the network node. | 11-13-2014 |
20140351452 | Chaining Service Zones by way of Route Re-Origination - Presented herein are techniques for use in a network environment that includes one or more service zones, each service zone including at least one instance of an in-line application service to be applied to network traffic and one or more routers to direct network traffic to the at least one service, and a route target being assigned to a unique service zone to serve as a community value for route import and export between routers of other service zones, destination networks or source networks via a control protocol. An edge router in each service zone or destination network advertises routes by its destination network prefix tagged with its route target. A service chain is created by importing and exporting of destination network prefixes by way of route targets at edge routers of the service zones or source networks. | 11-27-2014 |
20140362682 | Determining the Operations Performed Along a Service Path/Service Chain - Presented herein are techniques performed in a network comprising a plurality of network nodes each configured to apply one or more service functions to traffic that passes the respective network nodes in a service path. At a network node, an indication is received of a failure or degradation of one or more service functions or applications applied to traffic at the network node. Data descriptive of the failure or degradation is generated. A previous service hop network node at which a service function or application was applied to traffic in the service path is determined. The data descriptive of the failure or degradation is communicated to the previous service hop network node. | 12-11-2014 |
20140362857 | Stacking Metadata Contexts for Service Chains - Presented herein are techniques useful in a network comprising a plurality of network nodes each configured to apply one or more service functions to traffic that passes through the respective network nodes. A network node receives packets encapsulated in a service header that includes information defining a variable set of context headers stacked into an association of metadata that is relevant to one or more service functions within a service path comprised of one or more network nodes. The network node interprets a forwarding state and a next-hop network node for the service path from the service header, and determines a service action or associated metadata from the set of context headers. | 12-11-2014 |
20140365634 | Programmable Network Analytics Processing via an Inspect/Apply-Action Applied to Physical and Virtual Entities - Techniques are provided to programming network analytics processing in virtual and physical network devices, useful for software-defined networking (SDN). A controller, e.g., a so-called SDN controller, is configured to identify a control-plane or data-plane flow originating, terminating or transiting a physical or virtual network element. The controller generates one or more network analytics processing actions to be performed by the physical or virtual network element based on inspection of traffic by the physical or virtual network element. The controller forms or generates an inspect/apply-action message containing information identifying the control-plane or data-plane flow for inspection and the one or more network analytics processing actions to be performed. The inspect/apply-action message is sent to the physical or virtual network element. | 12-11-2014 |