網路演進的趨勢已使我們可以不受到有線網路所限制住，不論在室內還是戶外皆可隨時隨地透過無線網路來瀏覽各種資訊，而在行動通訊裝置的普遍使用之下，無線網路的發展有了迫切的需求，所以漸漸的有越來越多種無線網路標準以及介面被設計了出來。

異質性網路 (Heterogeneous Network) 現在已融入我們所處的環境當中，也就是說有我們身邊有多種網路混合共存的情形，已經是一件非常稀鬆平常的事情，這讓使用者可以因應各種不同的情況來使用著不同的網路存取方式，而SCTP建立關聯 (Association) 時能夠同時配置一個以上的IP位址來使用，對於現在異質性網路的環境下，擺脫了TCP協定只得使用單一IP位址的連線限制，並利用了此多重定址的特性達到同步多路徑傳輸 (Concurrent Mulitpath Transfer) 的實現。

而由於在同步多路徑傳輸下，各路徑間存在傳輸速率的差距，封包常會有錯序抵達的情況出現，造成緩衝空間的飽和則整體效能下降，因此本論文提出路徑的速率調整機制，利用速率控制讓路徑間的傳輸速率差異可以減緩，使得兩條路徑的速率在成長過程中，路徑速率差異避免太大，以此來減緩接收端緩衝空間阻塞現象，藉此提升CMT-SCTP整體效能。

Nowadays, we can no longer be restricted by the wires due to the development of network technique. No matter we are indoor or outdoor, we can search any information via wireless network anytime. On the use of the mobile communication device, there is a high demand for the development of wireless network, so more and more wireless standards have been developed for this situation.

Therefore, it is very common that there are multiple ubiquitous networks around our world, so-called “Heterogeneous Network.” Users can choose any different network interfaces to fit what situation they are facing in. And the transport layer protocol –Stream Control Transmission Protocol (SCTP), can set up multiple IP addresses to use while creating the association. In the current situation with heterogeneous networks, SCTP with the multiple IP addresses can also implement the Concurrent Multipath Transfer (CMT), and is therefore more suitable than TCP which is restricted in using only single IP address.

Due to the transmission rate gap between each path under the CMT, our research proposes a rate control scheme using CMT .We can control the transmission rate between each path according to the receiver buffer size, and avoid large gap of transmission rate between the path. Therefore, it can avoid the receiver buffer blocking problem for the connection, and improve the performance of CMT-SCTP overall.

學位論文審定書 i
摘要 ii
Abstract iii
目錄 iv
圖目錄 vi
第一章 導論 1
1.1研究背景簡介 1
1.2研究動機 2
1.3論文架構 3
第二章 相關背景技術研究 4
2.1串流控制傳輸協定 (SCTP) 的介紹 4
2.1.1 SCTP基本簡介 4
2.1.2 SCTP封包格式 10
2.1.3 SCTP 壅塞控制機制 18
2.1.4 SCTP的路徑錯誤偵測 21
2.2相關文獻研究 23
2.2.1 多重定址 (Multihoming) 路徑選擇相關研究 23
2.2.2 同步多路徑傳輸 (CMT-SCTP) 25
2.2.3 接收端緩衝空間阻塞 (Receiver Buffer Blocking) 29
2.2.4 異質性網路 30
第三章 協定機制制定 33
3.1情境假設 33
3.2問題描述 34
3.2.1可能之解決策略 38
3.3 提出方法 40
3.3.1機制運行流程 40
3.3.2速率之定義 41
3.3.3速率差值取定積分之定義 43
3.3.4 CMT-SCTP速率差異大之定義 46
第四章 模擬實驗與結果分析 52
4.1模擬工具介紹 52
4.2模擬環境與參數設定 53
4.3模擬結果與分析 55
4.3.1 評測對象 55
4.3.2 數據分析 55
第五章 結論 61
參考文獻 62

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