Abstract: 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).

Abstract: 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.

Abstract: A technique for ciphering source data (306) into target data (308) is described. As to a method aspect of the technique, a level (302) of ciphering is determined for the source data (306). A key sequence (304) is generated depending on the determined level (302) of ciphering. The source data (306) and the key sequence (304) are combined resulting in the target data (308).

Abstract: 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).

Abstract: A technique for ciphering source data (306) into target data (308) is described. As to a method aspect of the technique, a level (302) of ciphering is determined for the source data (306). A key sequence (304) is generated depending on the determined level (302) of ciphering. The source data (306) and the key sequence (304) are combined resulting in the target data (308).

Abstract: 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.

Abstract: The invention relates to a counting unit (100) configured to count an amount of traffic events of a data packet traffic. The counting unit comprises a counting element (131) configured to store a value representing the amount of traffic events.

Abstract: 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.

Abstract: The invention relates to a counting unit (100) configured to count an amount of traffic events of a data packet traffic. The counting unit comprises a counting element (131) configured to store a value representing the amount of traffic events.

Abstract: 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.

Abstract: Computer controlled method, network server (42, 43, 44, 46, 48) and system (40) for detecting data patterns in a data stream (36) received by a computer (30). The data stream (36) comprising a plurality of data symbols. The computer (30) executes a finite automata (10) comprising a plurality of states (11, 12, 13, 14, 15) including a start state (11) and at least one accepting state (15). State transitions (16) are triggered by a data symbol (17a) according to a state transition register (17) and the method comprises the steps of determining (21), by the computer (30), from a data symbol register (18) whether a data symbol of the data stream (36) is comprised in a group of data symbols not resulting in an accepting state (15), and triggering (22), by the computer (30), a transition (16) to the start state (11) for data symbols comprised in the group and a transition (23) to a state (12, 13, 14, 15) according to the state transition register (17) for detecting the data pattern otherwise.

Abstract: A method performed by a network node. The method includes detecting a loss of connection at an incoming interface to an upstream neighbor of the network node, where the network node is in a multicast communication network that includes a multicast tree to provide connectivity from a common source node to one or more multicast recipient nodes. The multicast communication network further includes a set of one or more secondary paths to provide redundancy to the multicast tree, and sending a notification packet downstream toward the one or more multicast recipient nodes when the network node cannot re-route the multicast data traffic to allow the multicast data traffic to be received by the multicast recipient nodes, wherein the notification packet causes one or more downstream nodes to switch multicast reception to one or more of the set of one or more secondary paths to re-route the multicast data traffic.

Abstract: A method and system is disclosed to compute and distribute a generalized almost directed acyclic graph (GADAG). The method includes computing, by a network element, a GADAG for the network, where the GADAG is a graph abstraction of the network, where the plurality of network elements are the vertices of the GADAG and links connecting the plurality of network elements are the directed edges of the GADAG. The method continues with assembling a GADAG descriptor based on the computed GADAG, and distributing the GADAG descriptor to a plurality of network elements, where each of the plurality of network elements utilizes the GADAG descriptor to compute maximally redundant trees for forwarding traffic. The method also includes leveraging layer 2 attributes and features for layer 2 deployments and updating redundant trees upon topology change events such that traffic outage is avoided or minimized.

Abstract: 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.

Abstract: 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 (15) performs the steps of: detecting a data traffic interruption with respect to a second node (16), determining, if the data traffic is still received, and forwarding the data traffic to the second node (16) if the first node (15) receives the data traffic, and otherwise notifying a third node (17) 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.

Abstract: 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).

Abstract: The present disclosure relates to preparation of nodes in a packet-switched communication network for enabling packet rerouting upon a failure in the network. The rerouting occurs along a detour defined by a Multiple Redundant Tree (MRT). A method aspect of this disclosure comprises computing, by a node of a set of connected nodes, at least one first MRT pair for a first MRT area to which a node is assigned. The first MRT area comprises a first subset of connected nodes. The method further comprises computing, by the node, at least one second MRT pair for a second MRT area to which the node is assigned. The second MRT comprises a second subset of the connected nodes.

Abstract: 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).

Abstract: A technique for informing nodes in a communications net work 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.

Abstract: There is provided a method for use by a router in a communications network. Forwarding information is maintained (S1) which specifies the next hop node for each of a plurality of possible destination nodes. Update information is maintained (S1) 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 (S1) which relates to a known network resource failure or which specifies that there is no known network resource failure. A failure notification is received (S2) relating to a network resource failure. In response to receipt of the failure notification, it is determined (S3) 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 (S4). A communications packet is received (S5).