| 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，因此突顯出網路管理中之網路故障管理的重要性。隨著網路架構日趨龐大，傳統client/server主從式架構網路管理系統之client端與server端必須持續且穩定的連線方能互相傳遞訊息以完成工作，因此效率及擴充性有所限制。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、具容錯能力與環境適應性，及可以分散式與智慧型的方式管理網路等優點，因此以移動式代理人建構之網路故障管理系統將更具有效率及彈性。 本論文提出一應用多重移動式代理人之網路故障管理系統（Network Fault Management System with Multiple Mobile Agents Support），利用Internet Control Message Protocol （ICMP）協定所提供之網路狀態探測與回報機制為基礎，將各個網路故障管理功能整合至多個移動式代理人中。除引用Multihomed技術，利用多重網路介面相互備援外，並針對實體網路之分層逐步偵測，以縮小故障範圍，提昇網路故障管理之效率。 目前國家實驗網路上每一網接中心節點均已置放一台信賴主機（trusted host），並於其上建構 Mobile Agent System 以便執行移動代理人程式，因此本論文所提出之網路故障管理系統以國家實驗網路作為實作平台，研發出Ping網路節點監測代理人、Traceroute網路連線狀態查詢代理人、SNMP Trap接收代理人網路故障偵測代理人、網路故障鑑定代理人，以及網路故障通知代理人，以提供國家實驗網路一可靠且具有效率的網路故障管理環境。 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 important to have good network fault management. As the complexity of the network increases, traditional network management system, which has been based on the centralized client/server architecture, and must be connected permanently to serve, has limited efficiency and scalability. Mobile agent, on the other hand, has the advantage of bandwidth saving, delay shortening, load balancing and distributed network managing, not to mention its fault tolerance, adaptability and artificial intelligence. Therefore, the Network with Fault Management System(NFMS) based on the mobile agent system is very much robust. An NFMS with multiple Mobile Agents Support is proposed in this thesis. It is based on the mechanisms of network status probing and reporting, which are provided by the Internet Control Message Protocol (ICMP). This system is herein integrating fault management functions into multiple mobile agents and is developed in Java. Because of its object oriented nature, other agents of different functions can be developed in the future, assuring an expandable system. Currently, each GigaPOP of NBEN (National Broadband Experimental Network) has installed a trusted host and an established Mobile Agent System to provide an execution environment for mobile agent. This NFMS makes NBEN the platform on which the following agents have been developed: ping network monitoring agent, SNMP trap receiving agent, fault discovering agent, fault identifying agent, traceroute network querying agent, and fault notifying agent. This undoubtedly helps make NBEN management system more reliable and efficient. |
