Abstract: In a multiple interface, low power and lossy network comprising a plurality of nodes, a sender node dynamically selects a data packet for setting a transmission parameter request in response to determining that an age value for a set of transmission parameters associated with a recipient device has expired or is expiring. The sender node selects an desired data packet for sending a transmission parameter request and transmits the selected data packet to the recipient device. The sender node receives a transmission parameter response from the recipient node comprising updated transmission parameters for that recipient node and then updates the current transmission parameters associated with the recipient node accordingly.

Abstract: For a network that includes several managed edge switching elements and several managed non-edge switching elements that are for implementing a logical switching element, some embodiments provide a method of distributing packet processing across the several managed non-edge switching elements. The method receives a packet for processing through the logical switching element. Based on a determination that the packet needs to be processed by a managed non-edge switching element, the method determines a particular managed non-edge switching element of the several managed non-edge switching elements to forward the packet. The method forwards the packet to the particular managed non-edge switching element for the particular managed non-edge switching element to process the packet.

Abstract: Some embodiments provide a network architecture that includes several lower level managed switching elements for forwarding network data to several of network hosts. The network architecture includes a set of higher level managed switching elements. The several lower level managed switching elements and the set of higher level managed switching elements implement several logical datapath sets. Communication channels are established among the several lower level managed switching elements and the set of higher level managed switching elements based on a mesh topology.

Abstract: A novel method for logically routing a packet between a source machine that is in a first logical domain and a destination machine that is in a second logical domain is described. The method configures a managed switching element as a second-level managed switching element. The method configures a router in a host that includes the second-level managed switching element. The method communicatively couples the second-level managed switching element with the router. The method causes the router to route a packet when the router receives a packet from the first logical domain that is addressed to the second logical domain.

Abstract: A distributed switch may include a hierarchy with one or more levels of surrogate sub-switches (and surrogate bridge elements) that enable the distributed switch to scale bandwidth based on the size of the membership of a multicast group. Moreover, each surrogate may optimize the hierarchy according to one or more optimization criteria. For example, each surrogate in the hierarchy may have the necessary information to ensure that if the next surrogate in the hierarchy is unavailable, the data may be routed to a backup surrogate. The selected hierarchy may be further optimized by skipping surrogates (or a surrogate level) such that the data intended for a skipped surrogate is sent to a surrogate in a lower-level of the hierarchy. This may better utilize the connection interfaces in the transmitting sub-switches and eliminate any unnecessary surrogate-to-surrogate transfers.

Abstract: A distributed switch may include a hierarchy with one or more levels of surrogate sub-switches (and surrogate bridge elements) that enable the distributed switch to scale bandwidth based on the size of the membership of a multicast group. Moreover, each surrogate may optimize the hierarchy according to one or more optimization criteria. For example, each surrogate in the hierarchy may have the necessary information to ensure that if the next surrogate in the hierarchy is unavailable, the data may be routed to a backup surrogate. The selected hierarchy may be further optimized by skipping surrogates (or a surrogate level) such that the data intended for a skipped surrogate is sent to a surrogate in a lower-level of the hierarchy. This may better utilize the connection interfaces in the transmitting sub-switches and eliminate any unnecessary surrogate-to-surrogate transfers.

Abstract: An apparatus comprising a path computation element (PCE) configured to communicate with a path computation client (PCC) and compute a point-to-multipoint (P2MP) path across an autonomous system (AS) domain. Also included is a network component comprising at least one processor configured to implement a method comprising obtaining a computation request for a P2MP path across a plurality of AS domains, attempting to calculate the P2MP path across the AS domains, thereby generating a computed path or a failure reason, and transmitting a reply comprising the computed path or an indication of the failure reason. Included is a method comprising exchanging a request message and a reply message about a P2MP path across an AS domain between a PCC and a PCE.

Abstract: A router maintains routing information including (i) route data representing destinations within a computer network, (ii) next hop data representing interfaces to neighboring network devices, and (iii) indirect next hop data that maps a subset of the routes represented by the route data to a common one of the next hop data elements. In this manner, routing information is structured such that routes having the same next hop use indirect next hop data structures to reference common next hop data. In particular, in response to a change in network topology, the router need not change all of the affected routes, but only the common next hop data referenced by the intermediate data structures. This provides for increased efficiency in updating routing information after a change in network topology, such as link failure.

Abstract: A scheduler in a network element may include a dequeuer to dequeue packets from a set of scheduling nodes using a deficit weighted round robin process, where the dequeuer is to determine whether a subset of the set of scheduling nodes is being backpressured. The dequeuer may set a root rich most negative credits (MNC) value, associated with a root node, to a root poor MNC value, associated with the root node, and set the root poor MNC value to zero, when the subset is not being backpressured, and may set the rich MNC value to a maximum of the root poor MNC value and a root backpressured rich MNC value, associated with the subset, and set the root poor MNC value to a root backpressured poor MNC value, associated with the subset, when the subset is being backpressured.

Abstract: The control node, on the basis of the connection information between the distribution nodes and the load information of the distribution nodes, determines a distribution node of the distribution destination to which one of a plurality of distribution nodes subsequently distributes the data, and the data type which is distributed to the distribution node of the distribution destination. The control node distributes node information which specifies the distribution node of the determined distribution destination and type information which specifies the determined data type. The distribution node receives the node information and the type information distributed from the control node. The distribution node, when it receives the data distributed from the other distribution nodes, selects the data of the type specified by the type information from the received data. The distribution node transmits the data of the selected type to the distribution node specified by the node information.

Abstract: A network system includes lower switches and upper switches connected to the lower switches. Each of the upper switches transmits a first notification frame containing a connected lower switch number information indicative of the number of the lower switches connected to each of the upper switches, to the lower switches connected to each of the upper switches. Each of the lower switches configures a link aggregation group for ports which received the first notification frames each of which contains a maximum value of the connected lower switch number information among the connected lower switch number informations contained in the received first notification frames.

Abstract: Systems and methods for hierarchical link aggregation are disclosed. A system for hierarchical link aggregation may include a network interface having a plurality of physical ports. A first plurality of the physical ports may be configured as member ports of a first link aggregation group (LAG). A second plurality of the physical ports may be configured as member ports of a second LAG. The first LAG and second LAG may be configured as member logical ports of a third LAG.

Abstract: In a multi-PHY, low power and lossy network comprising a plurality of nodes, a sender determines that a dwell time threshold limit for transmission of data will be exceeded by transmission of the data over a first network interface or that the recipient is unknown. The sender determines transmission parameters for the transmission of the data over the first network interface and transmits the transmission parameters to a receiver device over a second network interface that is different than the first network interface. The sender determines a channel on the first network interface for transmission of the data and transmits the determined channel with the transmission parameters to the receiver, or the receiver determines the channel on the first network interface for transmission of the data and transmits an indication of the determined channel to the sender in response to receiving the transmission parameters.

Abstract: Redundant, non-overlapping paths or routes for a sensor signal in a mesh network are selected based on predetermined metrics. In one embodiment, a wireless sensor transmits a signal that is received by two separate infrastructure nodes. The signal is retransmitted by the two intermediate nodes via the selected non-overlapping routes to a controller node. Routes are identified for at least two infrastructure nodes that receive signals from an added sensor. Performance metrics are calculated for each route. The two routes with the best performance metrics are selected in one embodiment.

Abstract: In a hierarchical switching architecture that includes at least one lower level managed switching element that connects to several higher level managed switching elements, some embodiments provide a method of identifying a higher level managed switching element to which the lower level managed switching element forwards a packet for further processing. The method computes a value based on a set of attributes of the packet. The method identifies a record from a hierarchy traversal table based on the computed value. The record specifies (1) a first higher level managed switching element as a primary higher level managed switching element and (2) a second higher level managed switching element as a secondary higher level managed switching element. The primary and secondary higher level managed switching elements are for forwarding the packet for further processing. The method forwards the packet to one of the higher level managed switching elements.

Abstract: An ad hoc network with distributed hierarchical scheduling is disclosed. In one aspect, stations in a network mesh detect interfering neighbor stations and form interference lists. Stations transmit their interference lists. Scheduling stations schedule allocations for child stations in response to interference lists, received remote allocations, or a combination thereof. Coordination messages are transmitted including frame structure, allocations, and interference lists, among others. In another aspect, an ad hoc mesh network may be organized into a tree topology. In an example wireless backhaul network, this matches traffic flow. Distributed, hierarchical scheduling is provided where parents schedule communication with children while respecting already scheduled transmissions to/from interferers and to/from interferers of their respective children.

Abstract: Communication between clusters of processing nodes is initiated by designating a link layer address and a target node name in a remote cluster. The link layer address is transmitted to the target node via a regular network transmission. The link layer address is stored locally in each cluster and the nodes in each cluster are signaled that a configuration change has been made, so that gateway nodes in the clusters can obtain the link layer address to use for subsequent communications with the other cluster, such as event notifications of node status changes.

Abstract: Various techniques for exchanging control messages in order to gracefully reroute multicast traffic are disclosed. For example, one method involves sending a join message for a multicast group towards a root of a new multicast tree and forwarding multicast traffic, addressed to the multicast group, on a current multicast tree until an acknowledgment corresponding to the join message is received. The new multicast tree can be identified in response to detection of a topology change within the network. Until the acknowledgment is received, multicast traffic that is received via the new multicast tree can be dropped.

Abstract: The present invention discloses a method for implementing an E-tree service and a provider edge device, and relates to the field of network communications technologies. A local PE device obtains leaf PE attribute information of a peer provider edge PE device; when the leaf PE attribute information of the peer PE device indicates that the peer PE device is a leaf PE device and the local PE device is a leaf PE device, the local PE device forbids a pseudo-wire connection between the local PE device and the peer PE device. The technical solution of the present invention implements effective isolation between leaf nodes supporting an E-Tree service and therefore implements the E-Tree service in a VPLS network.

Abstract: In accordance with a non-limiting example, a communications system includes a plurality of Virtual Local Area Networks (VLAN) enabled switches interconnected together and each having a plurality of ports and configured into a plurality of VLAN's in a single topology map. The switches each comprise a processor and transceiver and configured to process and transport data packets and further comprising forwarding tables and operating in accordance with a Spanning Tree Protocol in a single topology map, for example, operating with the Rapid Spanning Tree Protocol and not having multiple topologies. When a topology changes occurs to a specified VLAN, the switches are configured to flush the forwarding tables only for the specified VLAN associated with the port of the switch whose state change caused the topology change.

Abstract: To reduce the delivery delay of video data to a display device in which a control right for adjusting parameters of the video data is vested, a video delivery apparatus modifies a delivery tree for delivering the video data to multiple display devices, and delivers the video data to the multiple display device via a network in accordance with the delivery tree.

Abstract: Various embodiments provide a method and apparatus of providing a non-overlapping ring-mesh network topology which reduces costs (e.g., the number of network links) while providing resiliency to failure and meeting QoS requirements (e.g., network delay attributed to traversing the network architecture). In particular, a set of target nodes belonging to a cluster are connected through N rings. Each node is member of all N rings and no link between nodes in a ring is duplicated in another ring.

Abstract: In one embodiment, a source routing device (e.g., root device) pre-computes diverse source-routed paths to one or more nodes in a computer network. Upon receiving a particular packet, the device forwards the particular packet on a source-routed first path of the pre-computed diverse paths. In the event the device implicitly detects failure of the first path, then it forwards a copy of the particular packet on a source-routed second path of the pre-computed diverse paths in response. In one embodiment, implicit failure detection comprises seeing a second (repeated) packet with the same identification within a certain time since the first packet, and the second packet is forwarded on the second path. In another embodiment, implicit failure detection comprises not seeing a link-layer acknowledgment returned or receiving an error notification from a node along the broken path, and a stored copy of the particular packet is forwarded on the second path.

Abstract: Provided is a method and apparatus for avoiding an interference in a local area wireless communication system. The method includes (a) transmitting, by an interference device detecting a frequency interference, a channel update request signal to a channel manager, (b) broadcasting, by the channel manager, channel update information including new channel information in response to the channel update request and changing a channel, (c) rebroadcasting, by at least one device having received the broadcasted channel update information, the received channel update information and changing a channel after waiting for a maximum polling delay time of a child sleep device, and (d) transmitting, by the at least one device having changed the channel, a channel change confirmation packet to the channel manager.

Abstract: A network element coupled to a communication network is described. The network element includes multiple switching units. The switching units may be configured to independently implement a Spanning Tree Protocol (xSTP) processing in a completely distributed manner including each of the switching units independently calculating an external spanning tree for the network element in the communication network. The network element may act as a single bridge to other network elements in a bridging domain of the communication network.

Abstract: Methods and systems for determining shortest paths between a source node and a target node in a road network are disclosed. An example method includes determining a hierarchy of nodes with a number of levels of a first graph and calculating a first shortest path between the source node and the target node traversing a meeting node in the first graph. The number of levels in the first graph is reduced. One or more second shortest paths between the source node and the target node traversing one or more meeting nodes in the second reduced graph is determined. The first shortest path is assigned as a primary route and the one or more second shortest paths are assigned as alternate routes.

Abstract: The invention relates to a hierarchical radio network operations system (OS) and a method for controlling a mobile communications network by a hierarchical radio network OS, the hierarchical radio network OS comprising at least one radio network OS on a subordinate level and a radio network OS on a superior level, wherein after a controlling action is initiated a demand for data depending on the controlling action is forwarded from the superior level OS to at least one subordinate level OS. The latter in response to the call forwards the demanded data to the radio network OS on the superior level.

Abstract: An apparatus comprising a backup node coupled to an ingress node of a point-to-multipoint (P2MP) label switched path (LSP) and to a plurality of next-hop nodes of the ingress node of the P2MP LSP via a backup tree, wherein the backup node and the ingress node are both coupled to an external node, and wherein the backup node is configured to ensure data delivery in the P2MP LSP when the ingress node fails. Included is a network component comprising at least one processor configured to implement a method comprising detecting a failure in an ingress node of a P2MP LSP, receiving a data packet destined for the ingress node and to be transported by the P2MP LSP from a provider node when the ingress node fails, and transmitting the data packet on a backup tree that merges with the P2MP LSP prior to reaching an egress node.

Abstract: A disclosed switch includes: ports that include a first port to be connected to another switch included in a first domain that includes plural switches to be virtually integrated, and a second port that is other than the first port; a first processing unit configured to obtain data of a switch included in the first domain through the first port; and a second processing unit configured to obtain data of switches included in a second domain that is adjacent to the first domain through the second port and obtain data of switches included in the second domain from the another switch included in the first domain to identify, from among the ports, plural ports that are connected to the second domain, perform a setting for the identified plural ports, and perform a first processing to make plural domains that include the first and second domains a tree structure.

Abstract: Network topology codes are computed and used as keys to retrieve topology-specific information for isomorphic networks.

Abstract: Provided is an event delivery system where a bottleneck on the system can be eliminated by reducing load on a rendezvous node. The event delivery system includes publisher nodes, subscriber nodes, the rendezvous node, and broker nodes. The rendezvous node includes a traffic monitoring means that monitors the traffic volume of event information issued by the publisher node, and a specific event determination means that determines specific event information subject to load distribution from among the event information when the traffic volume exceeds a predetermined value. Each broker node includes a route defection means that detects whether its own node is an aggregation point node or a branch point node of the delivery route of the specific event information, and a route construction means that constructs a new delivery route of the specific event information going through the aggregation point node and the branch point node, bypassing the rendezvous node.

Abstract: A method and apparatus for coordinating communication in a wireless sensor network may include a plurality of nodes, such as routers, edge nodes, data accumulators and/or gateways. Time management functions, such as determining an elapsed time, may be controlled based on a detected temperature, e.g., a temperature detected at a node, and/or based on a detected clock skew between two or more clocks in two or more different devices. Accurate time management may allow for devices to more accurately coordinate communication instances, e.g., communication that occurs at periodic wake up times. A cluster head, such as a data accumulator, may be associated with a network after its initial formation and cause nodes in the network to alter their hierarchy in the network, thereby making the cluster head accumulator a parent to nodes in the network. Nodes having a relatively lower hop count may have a higher battery capacity than nodes having a higher hop count.

Abstract: A method and system provide in-band protection switch signaling in a communication system arranged as a point-to-multipoint tree. The point-to-multipoint tree includes a root node communicatively coupled to a plurality of leaf nodes through both a working link and a protection link. Data is transferred through a current link of the point-to-multipoint tree. The current link is either the working link or the protection link. A fault is detected in the current link in the point-to-multipoint tree. Each leaf node in the point-to-multipoint tree is notified of the fault using the current link. Upon receiving the notification, the root node and each leaf node switch to the other link of the working link and the protection link.

Abstract: Embodiments of the present invention relate to methods and arrangements for configuring the L2GPs in a first STP domain connected towards a second STP domain such that L2GPs in the first STP domain are assigned with the same Pseudo Root identity. Thus the Pseudo Root identity does not have to be changed if one of the L2GPs goes down, which implies that count-to-infinity loops may be avoided. It should be noted that only one L2GP is allowed to be open towards the second STP domain. The root path costs are assigned to the L2GPs towards the pseudo root and the value of the root path cost controls which of the L2GPs that should be open. The most preferred L2GP will be given a root path cost=0, the second best L2GP will have a path cost which is high enough so the two ports never will be open at the same time if there is connectivity between the Ethernet switches having the L2GPs.

Abstract: A mobile unit managing network is provided which is capable of supporting a communication area being wider than ever by one highest-layer router. A radio base station transfers a path updating notification fed from a mobile terminal to a lowest-layer router. The lowest-layer router establishes a path in which a network address to the mobile terminal exists in the radio base station and transfers path information to an intermediate-layer router serving as an upward router. The intermediate-layer router establishes a path in which the network address to the mobile terminal exists in the lowest-layer router and transfers path information to the highest-layer router. The highest-layer router, when having received path information notification from the intermediate-layer router, establishes a path in which the network address to the mobile terminal exists in the intermediate-layer router.

Abstract: A server creates a communication path table indicating a communication path for packet data, based on connection information reported by a parent device and a relay device, and distributes the created communication path table to the parent device, the relay device and a child device. The child device transmits the packet data to a relay device indicated in the communication path table, based on the distributed communication path table. The relay device transfers the packet data transmitted from the child device, to a relay device or a parent device indicated in the communication path table, based on the distributed communication path table.

Abstract: A method is provided for forwarding packets. Using a control plane state machine, addresses in a packet header are examined to derive a pointer value. The pointer value is used to access entries in a result database to identify routing information, a buffer pool ID associated with a location in memory, and a queue ID. A direct memory access (DMA) engine writes the packet into the memory location in response to the first message including the buffer pool ID. The QM prepares a second message associated with the packet, the second message including the routing information, the memory allocation in the buffer pool ID, and the queue ID. An operating system reads the second message, reads the packet from the memory allocation, modifies the packet header using the routing information, and writes the modified packet back into the memory allocation.

Abstract: A link state network comprising a plurality of interconnected nodes, and a multiprotocol label switching (MPLS) tree established amongst at least some of the interconnected nodes, wherein the MPLS tree is associated with an MPLS label, and wherein the interconnected nodes are configured to deterministically forward a plurality of link state update (LSU) packets comprising the MPLS label over the MPLS tree.

Abstract: The invention discloses a wireless network apparatus, wireless network system and wireless network node controlling method. The method applied in a wireless network including an aggregation node and a plurality of subnodes includes: randomly setting in advance sleeping time and working time for each subnode according to a predetermined strategy; judging a current state of each subnode, and recording monitor data of the subnode according to the current state of the subnode, wherein: when the subnode is currently in a working state, directly acquiring the monitor data currently reported by the subnode, and recording the acquired monitor data; when the subnode is currently in a sleeping state, estimating current monitor data of the subnode, and recording an estimate value of the monitor data. The embodiment of the invention can facilitate lowered energy consumption of a wireless ad hoc network and improve the robustness, reliability and real-time performance of the network.

Abstract: A trunk line topology network is configured with an electronic control units being communication apparatuses transmitting and receiving data, and gateway apparatuses and a distribution apparatus being a specific gateway apparatus that are connected to a communication line being a trunk line, for relaying, through the gateway apparatuses, data transmitted among the electronic control units. The distribution apparatus includes a storage region utilized for a database. The data transmitted from the electronic control units are relayed by the gateway apparatuses and then aggregated by the distribution apparatus. The relayed data are stored once on the database. When transmitting data to the electronic control units, the distribution apparatus reads out data from the database and transmits the data at the adjusted transmission timing. The gateway apparatuses relay the transmitted data.

Abstract: Methods and apparatus provide for a network device(s) employing tree tracer processing of a data packet(s) and/or a response(s) in order to discover and graphically represent all the paths within a hierarchical tree of network devices for multicast traffic flows. Specifically, a first network device receives a data packet. The data packet provides a multicast target MAC address. The first network device forwards the data packet to a plurality of network devices, where each of the plurality of the network devices belong to a multicast group identified according to the multicast target MAC address. Based on receipt of the data packet, the first network device generates and transmits a first response to a source of the data packet. The first response indicates a placement of the first network device with respect to a hierarchical tree of the plurality of network devices belonging to the multicast group.

Abstract: System and method for selling, configuring, installing, reconfiguring and servicing integrated voice/data communications systems are disclosed. An Internet/web based portal is provided to enable a high level of data to be easily collected. The portal guides the customer or sales persons in the collection of user requirements data indicative of the particular customer's hardware, telephony and network service requirements. Test of the data is performed, ensuring that all required data has been entered. The user requirements data is translated into configuration data in order to configure the system in a manner to satisfy the user requirements data. Configuration data resulting from a user requirements data entry and translation process is coupled with a hardware manufacturing process to produce an integrated system configured for the particular customer.

Abstract: A network apparatus comprising a trunk end point associated with an Ethernet-tree (E-Tree) service in a network domain and configured to forward a frame that comprises a tag according to the tag in the frame, wherein the tag in the frame is a root tag that indicates a root source of the frame or a leaf tag that indicates a leaf source of the frame, and wherein the trunk end point is coupled to a second end point associated with the E-tree service outside the network domain.

Abstract: In one embodiment, a mobile router receives a multicast-supported router advertisement message from an attachment mobile router in a mobile ad hoc network, the multicast-supported router advertisement message specifying an attachment prefix and a multicast-capable identifier. The mobile router attaches to the attachment mobile router in response to the multicast-supported router advertisement message and according to a protocol requiring establishment in the mobile ad hoc network of a tree topology having a single multicast clusterhead, and selects a default attachment address within an address space of the attachment prefix. The mobile router receives a multicast request, from an attached node, for receiving a multicast stream, and the mobile router outputs a neighbor advertisement message with multicast extension, to the attachment router, that specifies that access to the multicast stream is requested via the default attachment address.

Abstract: A plurality of modules interact to form an adaptive network in which each module transmits and receives data signals indicative of the proximity of objects. A central computer accumulates the data produced or received and relayed by each module. One of the modules is operable as a leaf node having a sleep mode to conserve energy and an interactive mode. The central computer can send a message to the leaf node commanding it to stay awake in order to receive subsequent communications.

Abstract: One embodiment relates to a method of automated multiple-instance spanning tree reconfiguration. Query packets are sent to switches within an multiple-instance spanning tree (MST) region, and response packets are received from the switches with traffic utilization data for ports of the switches. An MST reconfiguration is determined. The MST reconfiguration is propagated to the switches within the MST region. Other embodiments and features are also disclosed.

Abstract: Methods, system and apparatus for determining shortest path bridging (SPB) of multicast frames within a communications network.

Abstract: The invention relates to a telecommunication network having IP packet-supporting capabilities, which includes a load distribution processing function, either centralized or distributed, by means of which a load distribution function may be applied to sets of paths between network nodes or sets of links of network trunks. The load distribution processing function handles different load distribution functions. Each of the different load distribution functions is associated to a different network input unit involved in the load distribution for a set of paths between network nodes or a set of trunk links. The invention also relates to a method of load distribution in a telecommunication network as summarized above.

Abstract: A Hierarchical Cluster Tree (HCT) overlay network reflects underlying physical network topology including inter-node distances (e.g., hop count), and an HCT structure groups nodes based on distance measurements. Local area networks (LANs) are basic building blocks. The network includes first and second level-1 clusters of LANs, each LAN including computerized data processing and/or storage nodes. A distance between LANs in the level-1 clusters is less than or equal to a predefined level-1 maximum distance. The LANs of the first and second level-1 clusters form a level-2 cluster of LANs in which a distance between cluster medoid nodes of the level-1 clusters is less than or equal to a predefined level-2 maximum distance greater than the level-1 maximum distance. Clustering can be extended to higher levels having successively greater maximum distances.

Abstract: A method for operating a wireless mesh data network with multiple nodes, wherein data frames are transmitted from a source node via one or more intermediate nodes to a destination node, wherein the source node, the one or more intermediate nodes, and the destination node constitute network nodes of the data network, wherein during transmission of a data frame, at least some of the network nodes which receive the data frame, using a precursor list for the destination nodes which is assigned to the destination nodes of the data frame, check whether the network node sending the data frame is in the precursor list, and wherein in the case of a positive result, the data frame is transmitted to a further network node, and in the case of a negative result, the data frame is thrown out or processed by an error recovery routine.