Clock transparent transmission device and method based on ieee 1588 standard

Abstract

The invention provides an IEEE-1588-standard-based clock transparent transmission apparatus and method. With the apparatus and method, problems of complicated connection relationship, single function, low message exchange rate, difficult upgrading realization of a protocol, and inconvenient extension of the port number due to usage of various special-purpose chips in the prior art can be solved. According to the technical scheme, the method comprises: whether an arriving ethernet frame is a PTP event frame is determined and a time stamp is stamped on the PTP event frame; a correction domain field content of the PTP event frame is extracted; the time stamp and the correction field content are stored temporarily; packet switching is carried out on all ethernet frames; a time stamp of leaving the node by the PTP event frame is recorded; a new correction domain field value is calculated and is written into a field corresponding to the PTP event frame; generation of verification fields of all ethernet frames is completed; and all ethernet frames are forwarded. According to the invention, problems in the prior art are solved. The apparatus and method have advantages of high transportability and extensibility of the port number of switching units and can be applied to a high-precision time synchronization system.

Description

technical field [0001] The invention belongs to the technical field of communication, and in particular relates to a clock calibration method used in the IEEE 1588 clock synchronization protocol standard. Background technique [0002] With the increasing development and wide application of communication technology, the demand for time synchronization function of network equipment is becoming increasingly urgent. The normal operation of many services requires network clock synchronization. The precision clock synchronization protocol standard for network measurement and control systems, that is, the IEEE 1588 standard, also known as the Precision Time Protocol, or PTP for short, is a time developed under the supervision of the IEEE Standardization Association. Synchronization protocols have been widely used for sub-microsecond synchronization of clocks in sensors, actuators, and other terminal devices in standard Ethernet or other distributed bus systems using multicast techn...

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Problems solved by technology

[0008] Existing transparent transmission devices based on the IEEE 1588 standard mainly use a dedicated Ethernet MAC chip and a dedicated Ethernet PHY chip that support this function, and also need a CPU to assist in calculating the dwell time. The connection relationship between each chip is complex and the function is single , the message exchange rate is not high and it is not convenient for protocol upgrade and function customization, and it is not convenient for expanding the number of ports

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