An object is to provide a relay apparatus capable of detecting a failure that occurs in the relay apparatus. A relay apparatus (10) according to the present disclosure includes a data reception unit (11) configured to receive a synchronizing packet transmitted from a master apparatus (20), the synchronizing packet containing a time value and a time correction value for correcting the time value, an update unit (12) configured to update the time correction value based on a processing time for the synchronizing packet, and a determination unit (13) configured to determine whether or not a failure has occurred in a functional block related to a process for updating the time correction value by using a result of a comparison between a corrected time value and a reference time value, the corrected time value having been corrected by using the updated time correction value.

A synchronization information transmission method includes: receiving synchronization information sent by a preceding node; on the basis of synchronization accuracy information of a current node, updating intermediate node information in the synchronization information; and sending the updated synchronization information to a subsequent node.

An example method comprises receiving, by a first PHY of a first transceiver, a timing packet, timestamping, by the first transceiver, the timing packet and providing the timing packet to a first intermediate node, determining a first offset between the first intermediate node and the first transceiver, updating a first field within the timing packet with the first offset between the first intermediate node and the first transceiver, the offset being in the direction of the second transceiver, receiving the timing packet by a second transceiver, the timing packet including the first field, information within the first field being at least based on the first offset, determining a second offset between the second transceiver and an intermediate node that provided the timing packet to the second transceiver and correcting a time of the second transceiver based on the information within the first field and the second offset.

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.

Systems and methods for regaining synchronization between a CMTS core and an RPD, where both the core and the RPD are configured for individual synchronization in a slave configuration to a common grandmaster clock.

Synchronization of clocks among computing devices in a network includes determining master/slave relations among the computing devices. Some computing devices (e.g., switches) include trunk ports configured to carry traffic for several logical networks; e.g., virtual local area networks, VLANs. A trunk port can be associated with a master/slave setting for each logical network that it is configured for. Synchronization of clocks among the computing devices further includes running a synchronization sequence between a trunk port and each computing device on each of the logical networks configured on the trunk port.

Synchronization of clocks among computing devices in a network includes determining master/slave relations among the computing devices. Some computing devices (e.g., switches) include trunk ports configured to carry traffic for several logical networks; e.g., virtual local area networks, VLANs. A trunk port can be associated with a master/slave setting for each logical network that it is configured for. Synchronization of clocks among the computing devices further includes running a synchronization sequence between a trunk port and each computing device on each of the logical networks configured on the trunk port.

A method for providing a network tap supporting time sensitive network standards includes scanning, by an active network tap, received frames on a network port of the active network tap to identify timing synchronization messages of targeted message types. The method further includes identifying a timing synchronization message of the targeted message type. The method further includes modifying a timing value in the timing synchronization message to account for delay introduced by the active network tap. The method further includes forwarding the timing synchronization message with the modifying timing value to a destination time sensitive network node via an egress network port of the active network tap.

According to an embodiment, in a network system 1 in which at least one data of the audio data and the video data is transmitted from a first node to a second node through a network, the second node includes a processor configured to generate a clock signal for reproduction of the audio data and the like. The processor is configured to synchronize a current time in the second node with a current time in the first node, based on a transmission time that is based on the current time in the first node and is contained in a received extended CRF frame, a reception time that is based on the current time in the second node and at which the extended CRF frame is received, and a delay time period occurring while the extended CRF frame is transmitted from the first node to the second node.

A reference time determining method and apparatus are provided, to prevent aberrations in a control instruction execution time caused by inconsistency between a reference time of a terminal and a reference time of a control device in the conventional technology. In this application, the terminal may receive a plurality of pieces of time reference information sent by the network device. When the terminal receives indication information from the network device, the terminal may select, based on the indication information, one piece of time reference information from the plurality of pieces of time reference information as first time reference information. The indication information indicates the first time reference information. After determining the first time reference information, the terminal may determine the reference time of the terminal based on the first time reference information.