基于SIP协议的PDA软电话的设计与实现

近年来，随着VoIP技术的发展，PDA、手机等无线终端已经具备了软电话功能。本文以SIP协议为基础，在PDA平台上搭建了软电话系统模型，实现了PDA软电话与PsTN电话的通话功能，并对通话QoS进行了一系列测试。文中详细介绍了SIP软电话以及windowsMobile5．0开发的基本方法，提出了一种基于SIP协议的PDA软电话的具体实现方案，包括开发环境搭建、软电话结构、软电话信令、语音采集、编解码等。

Design and Implementation of the PDA Soft Phone Based on the SIP Protocol

With the development of the VoIP technology in recent years, wireless terminals such as PDAs, mobile phones gradually feature the soft phone functions. This paper constructs a soft phone system model based on the SIP protocol and the PDA platform, realizes the calling function between a PDA soft phone and a PSTN phone, and tests the QoS. In this paper, the basic design methods of the SIP Soft Phone and the Windows mobile 5.0 platform are introduced in detail, and the detailed realization scheme of a PDA soft phone based on the SIP protocol is presented. The scheme includes the development environment, soft phone structure, soft phone messages, speech collection, coder-decoder,and so on.