A cascaded clock ring network includes a clock path that transmits a source clock through series-connected processing nodes, from a first processing node to a last processing node. A data path transmits data through the processing nodes in response to the transmitted source clock, from the first processing node to the last processing node. The last processing node provides the transmitted source clock as an end clock signal, and provides the transmitted data as end data values. The end data values are written into a FIFO memory in response to the end clock signal. The end data values are subsequently read from the FIFO memory using the source clock signal, and are provided to the first processing node. A synchronizing circuit ensures that a plurality of end data values are initially written into the FIFO memory before an end data value is read from the FIFO memory.

A ring network architecture includes multiple communication nodes configured in a ring. Wave pipelining is used to provide for high bandwidth and low latency on-chip communications. Each node implements a source-synchronized clocking scheme, such that there is no need to build an extensive low skew clock-tree across a large die area. A single reference clock signal is generated within a root node, and is routed through each of the nodes of the ring network in a unidirectional manner. Each node includes a timestamp counter and a color bit register, which store values that enable the node to resolve ordered transaction messages issued by the other nodes in a precise order, even though the nodes are operating independently, and receive the various transaction messages in totally different timing orders. Because the control logic is distributed among the nodes, no centralized controller is necessary.

A redundant communication network is provided. A first set of network interface controllers form at least a first ring communication loop. At least one of the network interface controllers provide a gateway to at least one first client unit. The first set of network interface controllers include a first master network interface controller and a first backup master interface controller. A second set of network interface controllers form at least a second communication loop. At least one of the network interface controllers provide a gateway to at least one second client unit. The second set of network interface controllers include a second master network interface controller and a second backup master interface controller. The first master network interface controller and the first backup master interface controller are in a cross-side linked commutation configuration with the second master network interface controller and the second backup master interface controller.

The disclosure provides a transmission method for an Optical Burst Transport Network (OBTN), a slave node and computer storage medium. The transmission method includes that: a slave node performs frame synchronization training and timeslot synchronization training according to a test data frame and test control frame transmitted by a master node, and transmits a result of the frame synchronization training and a result of the timeslot synchronization training to the master node; and the slave node controls reception and transmission of each timeslot in a data frame according to a bandwidth map transmitted by the master node as well as the result of the frame synchronization training and the result of the timeslot synchronization training, and transmits a request for bandwidth to the master node, wherein the test data frame and the data frame are transmitted through a data channel, the test control frame is transmitted through a control channel, and the control channel and the data channel are independent of each other.

A web handling system is described, including a plurality of web handling controllers and a web handling process logic controller networked to form a ring network. A processor of the web handling process logic controller being configured to determine whether a fault exists within the ring network, and responsive to determining that a fault exists within the ring network, to generate and send signals throughout the ring network to switch the configuration of the ring network to at least one linear network.

Loop prevention systems and methods implemented in a switch to prevent loops in a Layer 2 packet switched network based on Media Access Control (MAC) movement in a forwarding database include enabling class based MAC learning on one or more ports with all of the one or more ports initially in a higher priority learning class; disabling MAC movements from the higher priority learning class to a lower priority learning class and disabling MAC movements in the lower priority learning class such that the switch discards frames attempting to perform MAC movement to ports which are in the lower priority learning class; and managing a priority for specific Source MAC addresses between a source port belonging to the higher priority learning class and the lower priority learning class based on detected loops for the specific Source MAC addresses.

Disclosed are an optical burst transport network, a node, a transmission method and a computer storage medium. The method comprises: measuring, by a master node, the network ring length of an OBTN, and according to a measurement result, calculating the length of a data frame, the number of time slots in the data frame, the length of the time slots and the guard interval of the time slots; according to the calculated length of the data frame, the number of time slots in the data frame, the length of the time slots and the guard interval of the time slots, sending a testing data frame and a testing control frame to a slave node to conduct frame synchronization training and time slot synchronization training; according to a result of the frame synchronization training and a result of the time slot synchronization training, sending, by the master node, a data frame and a bandwidth map to the slave node; and according to a bandwidth request sent from the node, generating, by the master node, a new bandwidth map, and sending the new bandwidth map to the slave node.

Embodiments of the present disclosure disclose a method for transmitting a clock packet. The method includes: a first network element generates a first clock packet, where the first clock packet includes a first source identity and first clock information, and the first source identity is used to indicate a device that provides the first clock information. The first network element sends the first clock packet to a second network element forming a ring network with the first network element. The first network element receives a second clock packet sent by the second network element, where the second clock packet includes a second source identity and second clock information, and the second source identity is used to indicate a device that provides the second clock information. The first network element skips tracking the second clock information after determining that the second source identity is the same as the first source identity.

An object of the present invention is to provide a network system or the like in which the construction cost of a network for a plurality of control systems is suppressed which is excellent in resistance to a network failure. In order to solve the problems, according to the present invention, there is provided a network system including a plurality of communication devices that are disposed in a plurality of bases, and are grouped into predetermined control systems for each of the devices which transmit and receive packets to and from each other so as to monitor or control target equipment, and a plurality of relay devices each of which includes a plurality of communication ports and transmits a packet transmitted by the communication device to another communication device, in which a plurality of communication devices disposed in each base are connected in parallel between the two relay devices, the relay devices disposed in different bases are connected to each other in a ring shape via a network, and a plurality of communication devices disposed in at least one base include communication devices belonging to different control systems.

The present disclosure discloses a method for training time slot synchronization of nodes in an Optical Burst Transport Network (OBTN), a node device and a network. The method includes that: a node trains a reference time delay between receiving of a control frame and receiving of a data frame, wherein the data frame and the control frame are within one period; and the node trains a sending time slot between sending of adjacent data packets in the data frame.