本文提出了一种基于SIP协议的软件电话的软件结构和设计实现方案。该方案以嵌入式Windows CE为平台，中间件采用开源的SIP协议栈oSIP/eXosip，通过协议栈的移植和在协议栈之上应用程序的开发，实现了SIP软件电话。测试结果表明，该软件电话在布置Windows CE的PDA上具有良好的语音通话质量。 -In this paper, a software-based SIP-phone software architecture and design to achieve the program. The program is embedded Windows CE as a platform, using open-source middleware SIP protocol stack oSIP/eXosip, through the protocol stack of transplantation and in the protocol stack on top of application development and achieving a SIP software phone. Test results show that the layout of the software phone in the PDA on Windows CE has a good voice call quality.