時間同步化是網際網路及分散式系統各種應用的重要課題。然而欲使網際網路內各個協同作業的電腦達成時間同步有數項限制需加以考慮：首先，應考慮參與節點的系統時鐘有不同的運作速率；接著，應考慮各節點交換時間訊息時有不同的網路延遲；此外，也應考慮廣域網路和區域網路等不同架構的差異，以及網路斷線、節點故障等問題。
本研究針對廣域網路（WAN）、區域網路（LAN）等不同的網際網路架構，來實作及分析時間同步化在通訊協定（包括網路時間協定（NTP）、簡易網路時間協定（SNTP））、作業系統（包括UNIX、LINUX、NT）、網路延遲、時間設定演算法與錯誤偵測等各方面做時間同步準確度的比較和分析。並提出在網際網路建置時間同步化作業的理想策略。以提供各界在建置分散式系統及網際網路服務時的重要參考。

Time synchronization is an important issue of many Internet and distributed system applications. There are many factors to be considered when the cooperating computers perform time synchronization services: first, the system clock of each node has its own operating rate; second, the transmission delay for time messages will affect the accuracy of time synchronization. Besides, other factors such as the different architectures between Wide Area Network (WAN) and Local Area Network (LAN), the communication link failure, and node failure are to be considered.
In this thesis, we implement and analyze time synchronization services on WAN and LAN. Our works considered different time protocols (including Network Time Protocol (NTP), Simple Network Time Protocol (SNTP)), different operating systems (including UNIX, LINUX, NT), transmission delays, time setting algorithms and failure detection schemes. According to our analytical results, a roll out strategy for time synchronization services on Internet and distributed system is proposed. We hope that our works can provide a good reference for the computer industry.

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