無線網際網路語音協定應用程式的SIP行動管理

Abstract

網際網路電話亦稱為網際網路語音協定是利用網際網路協定在網路傳送即時的語音或多媒體串流和利用訊息交換以控制傳送。網際網路電話提供比傳統公眾交換電話網路許多的優點，如：有成本效益，更互動的即時服務，以及提供語音與數據的整合應用。使用網際網路為行動電話基礎架構，讓我們面臨許多針對無線存取和行動管理支援的設計問題，如：行動管理和網路位置轉譯機制等相關問題。當務之急就是提出這些解決這些問題的方法。 在此論文中，我們強調如何設計和實作以解決在無線環境網路語音協定應用程式的行動管理和網路位置轉譯機制問題。我們提出一個以SIP為基礎的方法。這個方法能在一個網域中支援快速的交遞和讓位於網路位址轉譯路由器的使用者可以打電話。在電話建立中，Integrated Call Agent (ICA) 經由和媒體轉送伺服器互動為行動節點產生兩個傳送階段的媒體路徑。如果行動節點在通話中從一個子網路跑到另一個子網路，在我們的方法中ICA 會重新建立由行動節點新的位置至媒體轉送伺服器的路徑以節省交遞的時間。

Internet telephony, also known as voice-voice-IP (VoIP), delivers a real-time voice or multimedia stream across networks using the Internet Protocol (IP), and exchanges messages to control the delivery. Internet telephony offers a number of advantages over the public switched telephony network (PSTN), such as lower cost, more interactive real-time services, and the integration of voice and data applications. To use the Internet as a basis for mobile telephony, we face design issues that are specific to the use of wireless access and mobility support, such as mobility management and NAT traversal. It is critical to provide solutions to the issues. In this thesis, we focus on the design and implementation to solve the problems of mobility management and NAT traversal for VoIP applications in a wireless environment. We present a SIP-based solution. That can support fast handoff in a domain and enable calls to be established for the endpoints behind NAT routers. During a call setup, the Integrated Call Agent (ICA) inter-works with a media forwarding server to create a two-stage media path for the mobile node. If the mobile node moves from one subnet to another during the call, the ICA re-establishes the path from the new address of the mobile node to the media forwarding server to save the time to handoff in the solution.