近年來，無線通訊網路結合不同的有線及無線網路，而行動裝置在各種不同網路中移動，因此，裝置必需由舊的網路切換到新的網路，這個過程就是交遞(Handover)。
而在傳統的TCP與UDP協定中，當某一個端點有數個網路介面時，UDP/TCP只能選擇其中一個使用，而且不能更改，當介面或網路失效時，就會造成網路連結中斷。因為有如此先天上的限制，所以，若要處理交遞的動作，有一些新的協定，例如IP層使用新的Mobile IP，但是，如此一來必需更新所有的網路設備來支援Mobile IP。為了改善UDP/TCP用於多重連結網路環境的效能，而使用IETF所提出的串流控制傳輸協定(Stream Control Transmission Protocol)提供了幾個很好的特性「多宿(Multi-homing)」，使得一個端點可以擁有多個網路IP，透過這一個特性，可以更容易的在不同的IP的切換。並且，可以動態的加入新的網路位址到連線中，也可以動態的由連線中移除某一個網路位址。透過這一個特性，使得我們很容易透過SCTP來完成多個網路之間移動，並不會讓使用者查覺資料傳送中的中斷。
本論文主要透過SCTP的多宿、多串流、不完全可靠性傳輸的特性，在Linux下實作一影像語音通話程式，並提出了在交遞時，必需要變更stream number來達到不會產生堵塞的機制。

In recent years, networks are composed by complex subnets. When a mobile device moves for a subnet to another, the network interface of the device must switch from original network IP address to the new one. The procedure is named “Handover”.
If TCP or UDP protocol is applied, the application program can choose only one network interface when the PC has multi-network interface. When the default network interface failed in the handover situation, the application program can’t change to the available one. Therefore, there is a new protocol, Mobile IP, used to solve the handover issue. However, the existing infrastructures have to be updated to support the Mobile IP. In order to improve the performance on multi-network interface environment, the IETF (Internet Engineering Task Force) standardized the new transport protocol Stream Control Transmission Protocol (SCTP). There are some good features of SCTP, “multi-homing”, “multi-streaming” and “PR-SCTP”.
The feature of multi-homing allows an SCTP node has multiple IP addresses. We apply one of the SCTP extensions: dynamic IP address reconfiguration to handler the handover problems. It can provide a graceful method to add/delete/change to the interface of an existing association when the node moves from subnet to another.
By using SCTP features, multi-homing, multi-streaming and PR-SCTP, we design and implement a video/audio SCTP-Based Seamless multimedia application on Linux operating system. We also propose a mechanism, which changes the stream number, to avoid blocking during handover procedure.

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