臺灣博碩士論文加值系統

由於非同步傳輸模式(asynchronous transfer mode；ATM)網路中虛擬路徑(virtual path；VP)的使用，有效提供網路減少呼叫連接時的成本及簡化資源管理的複雜。虛擬路徑的建構方式、資源管理配置的策略更關係著系統運作的效能。
在如ATM般的高速光纖網路中，線路發生損害時，將比傳統網路更為嚴重。因此，自動回復系統對於網路運作及管理，是非常重要的。
本篇論文提出幾個以虛擬路徑為基礎(VP-based)的策略，包括路徑選擇，資源分配及故障回復，首先利用動態繞徑及動態資源分配的觀念來發展我們的策略，另外並設計一個預先規畫及二段備份路徑串接之回復策略，使中斷之服務可以繼續傳送，最後利用程式模擬取得結果，與分配固定頻寬虛擬路徑比較，並分析在不同保留頻寬及交通流量分佈下的資料回復情況。

Virtual path (VP) in asynchronous transfer mode (ATM) networks can provide a useful facility to the network resulting in reduction of connection setup cost and simplify resource management. VP constitution method and resources management allocation strategy greatly affect the efficiency of the system operation.
In a high-capacity optical fiber network, such as ATM network, the failure of a link will become much more serious than that in conventional networks. Automatic and rapid network service restoration (self-healing) when failures occur is therefore getting increasingly important for network operations and management.
This paper proposes several strategies, including VP routing rule, allocate resource and VP restoration, in VP-based ATM networks. We use the concepts of dynamic routing and dynamic resource allocation to develop our strategies. In addition to design a restoration strategies that activates alternate VPs for the failed VPs by the preplan and two backup VP connect method such that the interrupted services are recovered. In simulation experiment, we compare the results with fixed bandwidth VP’s and analyze the result of restoration in different spare capacity and traffic distribution.

圖表索引V
第1章 簡介1
1.1 非同步傳輸模式1
1.2 ATM網路的結構及特點2
1.3 研究動機與方向4
1.4 章節概要5
第2章 ATM網路特性6
2.1 ATM傳輸方法6
2.1.1 傳輸路徑、虛擬路徑、虛擬通道6
2.1.2 VP-Based的ATM網路9
2.2 故障管理10
第3章 網路模型及策略描述13
3.1 網路模型13
3.1.1 網路模型架構13
3.1.2 網路模型假設14
3.2 資源管理策略15
3.2.1 增加資源15
3.2.2 縮減資源17
3.3 虛擬路徑繞徑策略18
3.3.1 最小連接成本的計算19
3.3.2 重新繞徑策略21
3.3.3 虛擬路徑重整策略22
3.4 故障回復策略25
3.4.1 備份虛擬路徑的建置演算法26
3.4.2 回復演算法28
3.4.3 故障處理的資源管理30
第4章 模擬結果32
4.1 模擬系統的定義32
4.2 比較固定與動態頻寬分配法32
4.2.1 依平均要求頻寬變化比較33
4.2.2 依平均服務維持時間變化比較38
4.2.3 依平均交通流量密度變化比較43
4.3 回復策略的效能48
4.3.1 依平均要求頻寬變化比較48
4.3.2 依平均服務維持時間變化比較52
4.3.3 依平均交通流量密度變化比較56
第5章 分析與結論61
參考資料63

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