Research And Implement Of IEEE1588Network Delay Measurement

With the widely application of the distributed network and local area network(LAN), high precision time synchronization technology has become a keytechnology in a lot of application systems that have strict requirements on timesynchronization accuracy. Among various kinds of network clock synchronizationprotocol, IEEE1588protocol synchronization precision is highest, many experts andscholars are committed to the research and application of the agreement at home andabroad. Due to the transmission of IEEE1588protocol packets through the switch orhub, packet delay is asymmetric and jitter in it, which leads to the precision reduceand unstable. In order to solve the problem, the paper’s research focus on IEEE1588protocol of network delay measurement, mainly done the following several aspectsof research work:1.Summarized the IEEE1588protocol content and principle of timesynchronization, analysis for Peer delay mechanism that is put forward in the secondversion of IEEE1588. Study of IEEE1588protocol network time delay, work out themain components of network time delay, and proposed a method of measurementand correction based on End-to-End transparent clock for the delay caused by thenetwork switching equipment delay uncertainty and asymmetry.2.Implemented End-to-End transparent clock hardware and software design,basing on the study of End-to-End transparent clock model. In hardware, completedidentify PTP event messages, mark packets into and outside of the transparent clocktime stamp, designed the reference frequency of End-to-End transparent clock andrealized the ordinary function of switching. In software, achieved the measurementand correction of PTP event messages, dealing with PTP general message, directlyforward non-PTP packet.3.Designed an experimental setup that was analogous to the practical networkenvironment, validated the performance of End-to-End transparent clock. Themeasured results show that the transparent clock can measured and correct networkswitching equipment delay under different of network background traffic, efficientlysolved the message asymmetric delay and jitter in the network switching equipment,guarantee the clock synchronization precision of nanosecond order of magnitude. Itis a remarkable improvement achieve and anticipated target of the paper.