H04L12/705

Ring protection network module

Examples herein involve establishing communication links between a first ring protection network in communication with a service network and a second ring protection network in communication with a service network, the communication links between the first ring protection network and the second ring protection network to form a management network ring; determining an owner of the management network ring; and establishing a single uplink between one network module of the management network ring and the service network.

Fast and loss-free local recovery by a RPL parent device

In one embodiment, a network device (e.g., a RPL router) executes fast local RPL recovery in a low power and lossy network (LLN). The network device, in response to becoming an orphan in a directed acyclic graph (DAG) topology, can utilize the data plane to maintain at least some data traffic by randomly forwarding the data traffic to identified neighbor devices, while eliminating children from the list of forwarders and by finding successors that can be used for re-parenting. Hence, when a RPL network device having lost its last feasible parent can avoid data loss and accelerate a re-parenting process using local repair in the data plane instead of the control plane of the routing protocol used to establish the DAG topology.

CONSTRAINED RELIABLE MULTICAST IN A DIRECTED ACYCLIC GRAPH BASED ON DEFERRED CONTENTION TO HIGHER DEVICES

A network device receives a data packet sourced from a root of a tree-based topology and including a data structure identifying transmitted data packets transmitted by the root; in response to determining one or more absent transmitted data packets based on the data structure, the network device starts a deferred transmission timer requiring the network device to wait a first half of a selected minimum contention interval before attempting transmission to a parent at a randomized position within a second half of the selected minimum contention interval, the selected minimum contention interval based on the distance to the root and at least twice that of the parent; the network device selectively transmits a control message to the parent to request the absent transmitted data packets only if, upon reaching the corresponding randomized position of the deferred transmission timer, the network device has not received the absent transmitted data packets.

Loop prevention for EVPN and PBB-EVPN

In general, techniques are described for reducing forwarding loops for layer (L2) traffic that traverses an EVPN or PBB-EVPN instance (EVI) by deterministically determining an access-facing logical interface to block from respective access-facing logical interfaces of PE devices that switch the L2 traffic using the EVI. A provider edge (PE) network device may detect an L2 forwarding loop on an L2 forwarding path that includes the access-facing logical interface. In response to detecting an L2 forwarding loop and based at least on comparing an identifier for the local PE device and an identifier for a remote PE device that implements the EVPN instance, the PE device may block the access-facing logical interface to block L2 traffic from the local customer network.

FRAMEWORK FOR UNIVERSALLY SPECIFIED AFFINITY TOPOLOGIES WITH PARTIAL PATH INVALIDATION AND GENERALIZED NETWORK FLOWS
20190327167 · 2019-10-24 ·

A method for setting up forwarding tables is described. A USAT part for a node is received. The USAT part includes glow definitions and a FGPL. Each glow describes network traffic flows and role instructions for the flows. Each FGP describes a role for the switching node; a validity rule; and relevant network topology. The method also includes determining a selected active FGP in the FGPL using the validity rule for the FGP, a network state and the ordering of the FGPs; initializing the glows, requesting a role identification to perform based on the selected FGP, determining the role instructions and instructing the TMS to update tables accordingly; and storing entries in software tables based on glows and the role instructions for the identified role, dynamically resolving conflicts among entries, and granting table updates to hardware tables. The tables include a software table for each hardware memory for forwarding packets.

TELECOMMUNICATIONS APPARATUS AND METHODS

A method of operating first and second terminal devices for transmitting data in a device-to-device communication mode in a wireless telecommunications system supporting communications on a first carrier operating over a first frequency band and a second carrier operating over a second frequency band. The first terminal device transmits control signalling on the first carrier and this is received by the second terminal device. The control signalling comprises an indication of an allocation of radio resource blocks on the second carrier to be used for transmitting user-plane data from the first terminal device to the second terminal device. The first terminal device then proceeds to transmit the user-plane data to the second terminal device on the second carrier using the radio resource blocks on the second carrier identified by the control signalling. The control signalling may also provide an indication of an allocation of radio resource blocks on the first carrier to be used for transmitting user-plane data to the second terminal device.

SYSTEM AND METHOD FOR USING INFINIBAND ROUTING ALGORITHMS FOR ETHERNET FABRICS IN A HIGH PERFORMANCE COMPUTING ENVIRONMENT
20190319848 · 2019-10-17 ·

Systems and methods for using InfiniBand routing algorithms for Ethernet fabrics in a high performance computing environment. The method can provide, at a computer comprising one or more microprocessors, a plurality of switches, a plurality of hosts, a topology provider (TP) module, a routing engine (RE) module, and a switch initializer (SI) module. The method can perform a discovery sweep, by the TP, of the plurality of hosts and the plurality of switches and assigns an address to each of the plurality of hosts and the plurality of switches. The method can calculate, by the routing engine, a routing map, based upon a routing scheme, for the plurality of hosts and the plurality of switches, the routing map comprising a plurality of forwarding tables. The method can configure, each of the plurality of switches with a forwarding table of the plurality of forwarding tables calculated by the routing engine.

Loop-free convergence in communication networks

In one embodiment, a method includes identifying a change in network topology at a network device, transmitting a test packet from the network device to determine if an adjacent network device located in a backup path has converged following the network topology change, and updating a forwarding information base at the network device in response to the network topology change if a response to the test packet indicates that the adjacent network device has converged. An apparatus and logic are also disclosed herein.

Methods, devices, and computer-readable media for preventing broadcast loops during a site merge

Methods, devices, and computer-readable medium for preventing broadcast looping during a site merge are described herein. An example method can include detecting a site merge between a plurality of layer 2 (L2) networks using a spanning tree protocol (STP), blocking a data traffic port connecting the L2 networks in response to detecting the site merge, and performing an STP-Ethernet virtual private network (EVPN) handshake. The STP-EVPN handshake can include changing a root bridge in one of the L2 networks. Thereafter, the method can include unblocking the data traffic port connecting the L2 networks. In other words, the data traffic port connecting the L2 networks can be unblocked after changing the root bridge in the one of the L2 networks.

Route Detection Method and Network Device
20190297001 · 2019-09-26 ·

A method includes: establishing, by a first network device, a first BMP session with a second network device, and establishing a second BMP session with a third network device; receiving a first BGP route set sent by the second network device, where the first BGP route set includes a BGP route sent by the second network device to the third network device; receiving a second BGP route set sent by the third network device, where the second BGP route set includes the BGP route received by the third network device from the second network device; and when detecting that the second BGP route set includes a first BGP route but the first BGP route set does not include the first BGP route, determining the first BGP route as an unavailable route.