【作者】 陶慧明；

【导师】 覃中平；

【作者基本信息】 华中科技大学 ， 软件工程， 2008， 硕士

【摘要】 近几年,随IP语音通信技术和宽带业务的发展,VoIP电话技术已逐步取代传统PSTN(Public Switch Telephone Network公共电话交换网络)电话,成为语音通信技术发展的新的趋势,并且其形态也由最初的基与PC的应用软件发展为基于IP网络的嵌入式SoC(System on Chip片上系统)智能终端。SIP(Session Initiation Protocol会话初始协议)是由IETF(Internet Engineering Task Force英特网工程任务组)提出的一个应用层协议,用于创建、修改和终止一个或多个参与者参加的会话。该协议通过借鉴HTTP和SMTP协议风格及其成功经验,继承了HTTP协议的一些头域、编码规则、协议流程和认证机制,以其简单、开放、灵活、可扩展等显著优点,成为为业界所广泛接受,应用最为广泛的VoIP信令协议。在分析了IP语音通信技术的基本原理、关键技术和发展现状之后,着重讨论了语音通信通常用到的一些重要协议和技术,包括用于信令部分的SIP协议,用于媒体参数协商的SDP协议,用于语音数据实时传输的RTP协议等。然后从整体上介绍了本终端的系统结构和设计过程,最终选用Broadcom 1100系列语音通信专用SoC平台,基与VxWorks实时操作系统,采用消息队列机制控制系统事务状态机运作与转换予以实现。经过测试,终端实现了RFC3261所规定的基本要求,具有稳定、操作简单等优点,并有良好的互通性。更多还原

【Abstract】 With the development of IP-based telecommunication technology and Internet wideband service, VoIP telephone technology superseded the conventional PSTN technology step by step in recent years, and becoming the development trend of voice communication technology. On the other hand, the form of which developed from Applications based on personal computer to system-on-chip intelligent terminal embedded system based on IP networks.The Session Initiation Protocol is an application-layer signaling protocol distributed by IETF for creating, modifying, and terminating session with one or more participants. By learning lessons of HTTP and SMTP protocols, reusing many of the header field, encoding rule, protocol procedures and authentication mechanism of HTTP, as a result of its far lower complexity, rich extensibility and better scalability, it is accept by the industry and becoming the best wide-used protocol, also, it is the core protocol of the NGN project.This thesis decribes the principle, core technology and development trend of IP communication technology in the first part. After that, it analyses the wide-used protocols of IP phone technology, including SIP used for signaling control, SDP for media parameters negotiation, and RTP for voice data real-time transporting. In the following charpters, it details the architecture and processing of design and implementation this terminal. It is implemented on the Broadcom 1100 series voice communication dedicated SoC platform, based on VxWorks real time OS, and controlled the system state machine by message queue mechanism.At last, this terminal passed the performance and compatibility test, complying with the RFC3261. And it is considered as stable, easily used and high compatible.更多还原