A data sequence correction method for temporarily saving data with sequence information in a ring buffer and performing sequence correction is provided. The ring buffer includes a number of storage regions, a monitoring section having one or more continuous sequence numbers, and an acceptance section having a first or second sequence number of the monitoring section as a start sequence number and a sequence number immediately preceding the start sequence number of the monitoring section as an end sequence number. The method includes, when a value determined based on a remainder obtained by dividing a sequence number of received data by the number of storage regions is inside the acceptance section, writing the received data in a position of the storage region corresponding to the determined value, and when data are written in the entire monitoring section, reading out all the data in the monitoring section.

A port selection method applied to a first network device and a second network device includes determining that a port status of a first port that is in the first network device and that is used for dual-homing access can switch from a first state to an UP state; receiving a port status of a second port that is in the second network device and that is used for dual-homing access; and selecting, based on the port status of the first port and the port status of the second port, a port to be switched to the UP state from the first port and the second port.

A port selection method applied to a first network device and a second network device includes determining that a port status of a first port that is in the first network device and that is used for dual-homing access can switch from a first state to an UP state; receiving a port status of a second port that is in the second network device and that is used for dual-homing access; and selecting, based on the port status of the first port and the port status of the second port, a port to be switched to the UP state from the first port and the second port.

Examples disclosed herein relate to a method comprising detecting, by a bi-directional forwarding detection (BFD) protocol, a link failure of a link associated with a network device on a network. The method may include notifying, by the BFD protocol, a routing protocol and a hardware plugin about the link failure and identifying, by the routing protocol, an updated route for the network that does not include the network device. The method may also include deleting, by the hardware plugin, any routes programmed into a forwarding information base (FIB) including the first network device upon receiving the notification from the BFD protocol and installing, by the hardware plugin, the updated route into the FIB to be used for forwarding network traffic on the network.

Some embodiments provide a method for quantifying quality of several service classes provided by a link between first and second forwarding nodes in a wide area network (WAN). At a first forwarding node, the method computes and stores first and second path quality metric (PQM) values based on packets sent from the second forwarding node for the first and second service classes. The different service classes in some embodiments are associated with different quality of service (QoS) guarantees that the WAN offers to the packets. In some embodiments, the computed PQM value for each service class quantifies the QoS provided to packets processed through the service class. In some embodiments, the first forwarding node adjusts the first and second PQM values as it processes more packets associated with the first and second service classes. The first forwarding node also periodically forwards to the second forwarding node the first and second PQM values that it maintains for the first and second service classes. In some embodiments, the second forwarding node performs a similar set of operations to compute first and second PQM values for packets sent from the first forwarding node for the first and second service classes, and to provide these PQM values to the first forwarding node periodically.

A multi-logical port data traffic stream preservation system includes a networking device coupled to a computing device via its physical port, a first networking fabric via a first uplink, and a second networking fabric via a second uplink. The networking device receives communications from the computing device that identify first and second logical ports provided using the physical port on the computing device, a first data traffic type associated with the first networking fabric and transmitted on the first logical port, and a second data traffic type associated with the second networking fabric and transmitted on the second logical port. If the first uplink becomes unavailable, the networking device transmits a communication to the computing device that causes the computing device to stop transmitting the first data traffic type via the first logical port while continuing to transmit the second data traffic type via the second logical port.

Some embodiments provide a method for quantifying quality of several service classes provided by a link between first and second forwarding nodes in a wide area network (WAN). At a first forwarding node, the method computes and stores first and second path quality metric (PQM) values based on packets sent from the second forwarding node for the first and second service classes. The different service classes in some embodiments are associated with different quality of service (QoS) guarantees that the WAN offers to the packets. In some embodiments, the computed PQM value for each service class quantifies the QoS provided to packets processed through the service class. In some embodiments, the first forwarding node adjusts the first and second PQM values as it processes more packets associated with the first and second service classes. The first forwarding node also periodically forwards to the second forwarding node the first and second PQM values that it maintains for the first and second service classes. In some embodiments, the second forwarding node performs a similar set of operations to compute first and second PQM values for packets sent from the first forwarding node for the first and second service classes, and to provide these PQM values to the first forwarding node periodically.

A network switch and a network switch system thereof are provided. The network switch includes a plurality of connection ports and a processing circuit. When any of the connection ports receives a first abnormal message packet and one of the connection ports is in a disabled state, the processing circuit sets the connection port in the disabled state to switch to an enabled state, and the processing circuit does not forward the first abnormal message packet in the single loop network. When one of the connection ports is abnormal and each of the connection ports forming the single loop network is in the enabled state, the processing circuit sets the abnormal connection port to switch to the disabled state, and transmits a second abnormal message packet to other network switches in the single loop network through another connection port that is not abnormal.

A network communication system may include intelligent electronic devices (IEDs) in a ring communication network. A software-defined networking device may be programmed by a removable or disconnectable software-defined network (SDN) controller to control the flow path of data packets to the IEDs in the ring network. The software-defined networking device may inspect a data packet intended for a first IED to determine that the inspected data packet requests a responsive data packet from the first IED. A flow path failure may be identified based on a failure to detect a responsive data packet from the first IED within an expected response time.

An example operation may include a system, comprising one or more of receiving a heartbeat message from a peer virtualization network function component interface (VFCNI) indicating a current operational state of active when a VNFCI is in an active state, sending a first heartbeat message to the peer VNFCI indicating a current operational state as active, sending a next state request with an active state and split-brain condition to a virtual network function manager (VNFM), starting a response timer, sending a second heartbeat message to the peer VNFCI indicating the current operational state as active and a desired operational state as active when one or more of: the VNFCI is not a preferred standby instance, the response timer expires, stopping the response timer when a next state response message is received, sending a third heartbeat message to the peer VNFCI indicating the current operational state as active and a desired operational state as active when and an active state is contained in the next state response message, and transitioning a state of the VNFCI to a deactivating state when one or more of: the VCNFI is the preferred standby instance, and a standby state is contained in the next state response message.