Telefonaktiebolaget Lm Ericsson (publ)

Gabor Sandor Enyedi

András Császár

Gergely Pongrácz

Zoltan Lajos Kis

János Farkas

Sriganesh Kini

Geza Szabo

Balázs Peter Gerö

Evgeny Tantsura

Zoltán Turányi

Zoltan Kiss

Djamel Sadok

László Molnár

Stenio Fernandes

Wesley Davison Braga Melo

Zoltán Lajos Kis

András CSÁSZÁR

The present disclosure relates to forwarding of network traffic. In one of its aspects, the technology presented herein concerns a method for forwarding network traffic from multiple sources to multiple destinations on maximally disjoint paths by maximally redundant trees, MRTs. The method is implemented in a network element implementing multipoint-to-multipoint functionalities in a path computation element, PCE, of a network, wherein the network includes a plurality of network elements. According to the method, an almost directed acyclic graph, ADAG, is computed for the network. Next hops along MRTs are computed by using the ADAG. One or more valid path pair(s) of the computed MRTs that is/are disjoint is/are determined and then, the network traffic is forwarded by using the valid path pair(s) of the MRT(s).

Method and apparatus for forwarding network traffic on maximally disjoint paths

A method is implemented by a network device to dynamically optimize lookup speed in a packet processing table maintained at the network device while the network device is in operation. The method includes determining one or more runtime metrics of the packet processing table, selecting a lookup algorithm for the packet processing table from a set of lookup algorithms supported by the network device based on the one or more runtime metrics of the packet processing table, and configuring the network device to match incoming packets against rules in the packet processing table using the selected lookup algorithm for the packet processing table.

Dynamic lookup optimization for packet classification

A technique for ciphering source data () into target data () is described. As to a method aspect of the technique, a level () of ciphering is determined for the source data (). A key sequence () is generated depending on the determined level () of ciphering. The source data () and the key sequence () are combined resulting in the target data ().

Stream ciphering

The invention relates to a counting unit () configured to count an amount of traffic events of a data packet traffic. The counting unit comprises a counting element () configured to store a value representing the amount of traffic events. The counting unit further comprises a processing unit (-) configured to detect an arrival of each data packet of the data packet traffic at the processing unit, to process each data packet and to determine whether the value at counting element () should be increased each time the arrival of one data packet is detected at the processing unit, wherein the processing unit (-) is configured to store a probability value p&#x3c;1 indicating a probability that the processing unit increases the value at the counting element each time the arrival of one data packet is detected at the processing unit, wherein the processing unit is configured such that when it detects the arrival of one data packet at the processing unit, it increases the value at the counting element only with the probability p.

Counter with reduced memory access

Computer controlled method, network server () and system () for detecting data patterns in a data stream () received by a computer (). The data stream () comprising a plurality of data symbols. The computer () executes a finite automata () comprising a plurality of states () including a start state () and at least one accepting state (). State transitions () are triggered by a data symbol () according to a state transition register () and the method comprises the steps of determining (), by the computer (), from a data symbol register () whether a data symbol of the data stream () is comprised in a group of data symbols not resulting in an accepting state (), and triggering (), by the computer (), a transition () to the start state () for data symbols comprised in the group and a transition () to a state () according to the state transition register () for detecting the data pattern otherwise.

Method of and network server for detecting data patterns in an input data stream

A technique for informing nodes in a communications network about changes in a state of the communications network using notification packets is described. In that technique, the communications network is reconfigured using a fast reroute protocol responsive to the state change. A method aspect of the technique comprises generating, upon a network state change, a notification packet. Generating the notification packet includes adding a unique identifier to the notification packet. The method further includes propagating the notification packet through the communications network.

Notification technique for network reconfiguration

The invention refers to operating a first node of a communication network comprising a plurality of nodes which are interconnected by communication links and wherein data traffic is provided over the communication links to provide a data stream to the nodes, wherein the first node () performs the steps of: detecting a data traffic interruption with respect to a second node (), determining, if the data traffic is still received, and forwarding the data traffic to the second node () if the first node () receives the data traffic, and otherwise notifying a third node () of the plurality of network nodes about the data traffic interruption. The invention further refers to a corresponding node, a network and a computer program to be run in the node.

Reconnection in a transmission tree

A method is implemented by a network element or controller for determining a backup path for a fast reroute process to be utilized in response to a network event invalidating a primary path to a destination node. The method identifies at least one intermediate node that has a backup loop free alternative (LFA) path to a destination node in a network where no path meeting LFA conditions can be found for a point of local repair (PLR).

Extended remote LFA fast reroute

A technique of operating a network node of a multicast communication network comprising a plurality of network nodes which are interconnected with each other by communication links is provided, wherein the network node is associate with a common source network node. A method implementation of the technique comprises: determining a first path which connects the network node to the common source network node along a primary network tree, and determining a second path which connects the network node to the common source network node along a secondary network tree, wherein the first path and the second path show redundancy with respect to each other; receiving, at the network node, multicast data from the common source network node via the first path; triggering, by the network node, reception of multicast data from the common source network node via the second path if the network node detects a failure of the first path (e.g., determines that no multicast data is received via the first path).

Technique for operating a network node

There is provided a method for use by a router in a communications network. Forwarding information is maintained (S) which specifies the next hop node for each of a plurality of possible destination nodes. Update information is maintained (S) which specifies how, if at all, the next hop nodes specified in the forwarding information are to be updated for a plurality of possible network resource failures. Known failure information is maintained (S) which relates to a known network resource failure or which specifies that there is no known network resource failure. A failure notification is received (S) relating to a network resource failure. In response to receipt of the failure notification, it is determined (S) from the failure notification how, if at all, the known failure information is to be updated, and the known failure information is updated, if required, based on the determination (S). A communications packet is received (S). Various steps (Sto S) are carried out in response to receipt of the communications packet. The destination node for the received packet is determined (S). It is determined (S) whether the next hop node specified by the forwarding information for the determined destination node is potentially invalid in view of the known failure information. If so, then the next hop node for the determined destination node is updated if necessary in the forwarding information using the update information and the known failure information (S). The next hop node is determined for the received packet using the forwarding information and the determined destination node (S). The received packet is forwarded towards the determined next hop node (S).

Method and apparatus for handling network resource failures in a router

A method of routing packets across a packet switched network domain, comprising a multiplicity of nodes. Each node comprises an ingress interface and an egress interface. For each destination node a default and a detour branching are defined, each specifying a route to the destination node. For each two-edge connected node the default and detour branchings do not share a common ingress interface. Each node operates as an intermediate node receiving a packet at an ingress interface, identifying an egress interface based upon the ingress interface upon which the packet is received and the packet destination, forwarding the packet via that egress interface if the connected link is available and, if the connected link is not available, forwarding the packet via an alternative egress interface associated with said detour branching if the packet was received at an ingress interface associated with said default branching or dropping the packet if the packet was received at an ingress interface associated with said detour branching.

Link failure recovery method and apparatus

A system, method, and node for implementing lightweight Not-via Internet Protocol fast reroutes of a packet in a telecommunications network between a first node and a destination node. The method determines a shortest path between the first node and the destination node and two redundant trees between the first node and the destination node. Each redundant tree provides an alternate path from the first node and the destination node. When a failure in a link between the first node and the destination node is detected, the packet is forwarded to the destination node via a first redundant tree, and if not available, via a second redundant tree. If the second redundant tree is not available, the packet is dropped. If no failure in the link between the first node and the destination node is detected, the packet is sent via the determined shortest path to the destination node.

Growing community of inventors

Budapest, Hungary

Gabor Sandor Enyedi