| 摘要: | 網路應用與服務已是生活中不可或缺的一環，網路故障將對使用者及網路提供者造成許多不便與損失，因此如何快速找出網路故障的所在及原因，並迅速恢復網路服務，對於網管人員來說是個挑戰。本論文利用Multihoming之觀念，利用多重網路介面互相備援，能夠更精確的診斷出故障的詳細位置及原因。此外，並針對TCP/IP的五個層級，分層逐步診斷，以縮小網路故障之範圍，幫助網管人員迅速釐清問題所在，提高網路故障診斷之效率。 網路管理系統的架構隨著網路複雜度的提升，由中央集權式的管理架構演變成階層式的網路管理架構，但仍然無法完全滿足網管系統的需求，因此有人提出應用軟體代理人於網路管理系統之構想。若以移動式代理人（mobile agent）技術應用在網路管理上，具有節省頻寬、縮短網路傳輸延遲、平衡負載及可以分散式與智慧型的方式管理網路等優點，且可在異質之網路環境下執行。因此，引用移動式代理人技術可建構更具有效率及彈性之網路管理系統。 本論文提出之應用多重移動式代理人之多介面與多層級網路故障診斷系統（Multihomed and Multilayered Network Fault Diagnoses Systems with Multiple Mobile Agent Support，簡稱MMNFDS），以Web-based介面，提供網路應用層服務狀況顯示、網路拓樸顯示、圖形化之頻寬顯示、網路故障可能原因顯示及各種代理人之派送等功能，讓網管人員可以在任何時候任何地點都能掌握網路之狀況，提高網路故障管理之效率。 The internet has become an indispensable part of life. Any network failure will be inconvenient and costly to end users and ISPs. It is therefore an challenge to the network managers that how to locate the network fault, find out the cause of it and restore the services quickly. The concept of multihoming is adopted in this thesis. It helps locating the network fault more precisely by using multiple network interfaces. In addition, the network faults are diagnosed by each layer in TCP/IP model. In this way, it will help the network manager to clarify the problems, and the efficiency of network fault diagnoses will be increased. As the complexity of the network increases, the architecture of the network management model is evolved from centralized architecture to hierarchical one, but still can not satisfy the requirement of modern network management systems. Therefore, it has been proposed applying software agent to network management. Mobile agent has the advantage of bandwidth saving, load balancing and distributed network managing, artificial intelligence, not mention to its ability to execute in heterogeneous environment. Therefore, it will be a flexible and efficient network management system with mobile agent technique. An Multihomed and Multilayered Network Fault Diagnoses Systems with Multiple Mobile Agent Support, called MMNFDS in short, is proposed in this thesis. The user interface of MMNFDS is web-based, provides functions as display of application services status, network topology, graphical network bandwidth display, possible root fault causes display and dispatching different mobile agents with various functions, etc. The network manager can handle the network status anytime and anywhere, therefore the efficiency of the network fault management will be increased |
