摘要:
In one embodiment, a communication device in a frequency hopping communication network determines an intention to forward a first packet in a particular timeslot of a frequency hopping sequence. As such, the device scans in receive mode for an initial portion of the particular timeslot on a particular frequency known to neighbors of the communication device for reaching the communication device. In response to determining that the communication device is receiving a second packet during the initial portion, the device remains in receive mode to receive a remainder of the second packet. Conversely, in response to not receiving the second packet during the initial portion, the device proceeds to transmit the first packet during a remainder of the particular timeslot.
摘要:
In one embodiment, a node joins a communication network, and in response to joining the network, operates in a rapid startup mode, wherein the node in rapid startup mode establishes network configurations rapidly by deemphasizing quality (optimality) of the network configurations. Subsequent to operating in the rapid startup mode (e.g., after some timer or explicit command), the node then operates in a robust mode, wherein the node in robust mode iteratively refines the network configurations to increase the quality of the network configurations.
摘要:
In one embodiment, a node in a computer network detects a misbehaving node in the computer network based on the misbehaving node acting in violation of one or more rules. As such, the node communicates information regarding the misbehaving node to a network management system (NMS), and then may receive isolation instructions from the NMS regarding how to isolate the misbehaving node from the computer network. Accordingly, the node may perform the isolation instructions. In another embodiment, the NMS receives the communicated information regarding the misbehaving node, and determines whether the misbehaving node should be isolated based on the communicated information. If so, then the NMS determines isolation instructions regarding how to isolate the misbehaving node from the computer network, and transmits them to one or more nodes in the computer network, accordingly.
摘要:
In one embodiment, a device in a computer network monitors an alternating-current (AC) waveform of an electrical power source at the device, where the power source is part of a polyphase power source system. Once the device determines a particular phase of the polyphase power source system at the device, then the device joins a directed acyclic graph (DAG) specific to the particular phase. In another embodiment, a device detects a time of a zero crossing of the AC waveform, and may then determine a particular phase of the polyphase power source system at the device based on the time of the zero crossing relative to a corresponding location within a frequency hopping superframe of the computer network.
摘要:
In one embodiment, a particular node in a computer network receives an indication of a number of child nodes of one or more potential parent nodes to the particular node in a primary directed acyclic graph (DAG). From this, the particular node selects a particular potential parent node with the highest number of child nodes as a secondary DAG parent for the particular node, and joins the secondary DAG at the selected secondary DAG parent (e.g., for multicast and/or broadcast message distribution). This may recursively continue, such that nodes gravitate toward parents with more children, potentially allowing parents with fewer children to relinquish their parental responsibilities.
摘要:
In one embodiment, in response to a trigger condition being detected at a particular location in a primary directed acyclic graph (DAG) in a computer network, a particular node in the primary DAG at the particular location may be determined to act as a remote stitched (RS)-DAG root for an RS-DAG at the particular location. The determined RS-DAG root may then be instructed to initiate the RS-DAG, the instructing indicating one or more properties for the RS-DAG that are based on the trigger condition and that are different from properties of the primary DAG. In another embodiment, a particular node receives instructions to initiate an RS-DAG as its RS-DAG root, initiates the RS-DAG, and relays messages of the RS-DAG with a primary root of the primary DAG.
摘要:
In one embodiment, a probing technique allows a root node to determine whether to trigger reoptimization of a computer network represented by a directed acyclic graph (DAG) without injecting unnecessary traffic into the network. The root node may store and maintain information indicative of an ideal shape or topology of the DAG. During a normal DAG maintenance operation, the root node may transmit a DAG discovery request (probe request) that is configured to probe each node within the DAG for information used to determine a current topology of the DAG. In response, each node may record the information, e.g., routing and non-routing metrics, in a DAG discovery reply (probe reply) that is propagated to the root node. Upon receiving one or more replies, the root node may analyze the metrics to determine whether the current topology of the DAG deviates from the ideal DAG topology. The root node may thus determine DAG topology deviation upon probing at minimal cost. A number of algorithms may then be used to determine whether reoptimization, i.e., global repair, of the DAG is is required and, if so, the root node may dynamically trigger the global repair.
摘要:
In one embodiment, a parent node in a directed acyclic graph (DAG) in a computer network may detect congestion from its child nodes. In response, the parent node may determine particular child nodes to expel from the parent node based on the congestion, and notifies the expelled child nodes that they must detach from the parent node in response to dynamically detecting congestion (e.g., to find a new parent, excluding the parent node and optionally any nodes in the vicinity). In another embodiment, a child node receives a detach request packet from a current parent node that indicates that the child node is expelled from using the current parent node. In response, the child node triggers a new parent selection to select a new parent node that specifically excludes the current parent node (e.g., and optionally any nodes in the parent's vicinity).
摘要:
In one embodiment, a receiving node in a computer network may detect congestion, and also identifies a set (e.g., subset) of its neighbor nodes. In response to the congestion, the receiving node may assign a transmission timeslot to each neighbor node of the set based on the congestion, where each neighbor is allowed to transmit (synchronously) only during its respective timeslot. The assigned timeslots may then be transmitted to the set of neighbor nodes. In another embodiment, a transmitting node (e.g., a neighbor node of the receiving node) may receive a scheduling packet from the receiving node. Accordingly, the transmitting node may determine its assigned transmission timeslot during which the transmitting node is allowed to transmit. As such, the transmitting node may then transmit packets only during the assigned timeslot (e.g., for a given time). In this manner, congestion at the receiving node may be reduced.
摘要:
A node in a Low power and Lossy Network (LLN) is managed by monitoring a routing configuration on a node in a LLN. A triggering parameter that is used to invoke an address change on a child node is tracked and a threshold against which to compare the triggering parameter is accessed. The triggering parameter is compared to the threshold. Based on results of comparing the triggering parameter to the threshold, it is determined that an address change at the child node is appropriate. An address change of a child node appearing in the routing configuration is invoked based on the determination that an address change is appropriate.