In one embodiment, a processing apparatus includes processing circuitry to process an event, a timestamping unit to generate a timestamp for the event, at least one register to store at least one parameter describing a hardware state of the processing circuitry, and timestamp correction processing circuitry to compute a time value as a correction to the generated timestamp responsively to the at least one parameter.

Embodiments disclosed herein provide techniques to selectively distribute Precision Time Protocol (PTP) data in a network. The network can include multiple different network devices (e.g., switches) connected to form a network architecture (e.g., a spine/leaf architecture). Rather than distributing the PTP data (e.g., PTP timestamps) through all the network devices in order to synchronize local clocks to a global, master clock, the embodiments herein describe an out-of-band distribution network which selectively distributes the PTP data to select network devices in the network.

In certain aspects, the present disclosure is related to devices, methods, systems and/or computer-readable media for use in an isochronous media network in which media devices connected to a network employ one or more synchronization signal to regulate or facilitate the transmission of media signals through the network. In certain aspects, the present disclosure is also related to devices, methods, systems and/or computer-readable media for use in a larger unified, or substantially unified, isochronous network created from aggregating local isochronous media networks in which media devices connected to a network employ a one or more synchronisation signal distributed from a local master clock to regulate or facilitate the transmission of media signals.

A communication apparatus includes at least a processor and at least a memory. The at least memory contains instructions that, when executed by the at least processor, cause the at least processor to perform operations comprising performing a determination process and performing a setting process. The determination process determines whether the communication apparatus operates as a leader apparatus in communication or operates as a follower apparatus in the communication. The setting process, based on a result of the determination process, sets the communication apparatus to be a time master apparatus that is a provider of a reference clock for implementing time synchronization with one or more other communication apparatuses or to be a time slave apparatus that adjusts time in accordance with the reference clock.

The Digital Time Processing using Rational Number Filters (DTP RNF) disclosed herein is contributing methods, systems and circuits for using a Precision Time Protocol (PTP) such as IEEE 1588 for distributing a master time secured by a master unit to slave units by utilizing slave clocks, synchronous to referencing frames communicated with PTP messages or compatible with them data receiver clocks, for maintaining a local slave time which is increased to a local master time by adding to it an estimate of a transmission delay derived by processing PTP messages or by other means, wherein such distribution of the master time includes filtering out phase noise of the timing referencing signals with the Rational Number Filters in order to produce accurate and stable timing implementing signals such as the slave clock, local slave time and local master time.

A method of operation of a Multiprotocol Label Switching network involves, in an active node of the network, receiving a first data packet from a source node and forwarding the first data packet to a destination node. At the same time, the active node measures a residence time of the first data packet in the active node. The active node then sends a further data packet containing residence time information.

A bus system, a method for operating a bus system and a participant of a bus system are provided. The participant includes a timer and a transceiver circuit. The transceiver circuit is configured to receive a data packet having a time stamp value via a bus. The timer is configured for synchronization, based on the time stamp value. The timer is configured to change the time stamp value. The transceiver circuit is configured to transmit the data packet with the changed time stamp value via the bus.

The present technology improves synchronization of a slave node with a master node in a network using PTP packets in which the slave node is coupled to the working master node through at least one boundary node. The technology establishes a synchronization communication session between the boundary node and the slave node in which the synchronization communication session is configured to measure a first timing delay from the boundary node to the slave node, and establishes a transparent communication session between the master node and the slave node through the boundary timing node in which the transparent communication session configured to measure a second timing delay from the master node to the slave node. Using the sessions, the technology adjusts a timing delay correction factor according to the first timing delay and the second timing delay, and synchronizes the slave node with the master node according to the correction factor.

An object of the present invention is to provide a time synchronization device, a time synchronization method, and a program capable of maintaining PTP synchronization accuracy even in a network in which PTP incompatible devices are mixed. The time synchronization device according to the present invention focuses on a possibility of multiplexing a plurality of PTP domains on a transmission line with the same PTP and derives one time based on time information from a plurality of PTP domains. The time synchronization device 301 includes PTP slave units (11-1 to 3) belonging to corresponding PTP domains (20-1 to 3) different from each other and configured to synchronize with times of the corresponding PTP domains, and a time integration unit 12 configured to use time information that is a time after the PTP slave unit synchronizes with the time of a master device (GM or BC) belonging to the corresponding PTP domain and synchronization accuracy information that is an accuracy of synchronization of the PTP slave unit with the time of the master device to generate one integrated time.

A shared bus time interleaves 1 PPS signal and control and coordination information between a primary timing source and line cards that need to be synchronized using the 1 PPS signals. The shared bus utilizes 1 second frames divided into time slots. The 1 PPS signals are interleaved at predetermined locations in the frame so the delays introduced by interleaving the 1 PPS data in time can be precisely removed. While the bus is not being used for 1 PPS signals, the bus is available to send control and coordination information between the line cards and the primary timing source, avoiding the use of another system and increasing utilization of an available communication path.