【作者】 刘一闻；

【导师】 温向明；

【作者基本信息】 北京邮电大学 ， 通信与信息系统， 2008， 硕士

【摘要】 随着宽带网络技术日新月异的发展,IP网络中传输的信息已由单纯的文本数据演变到多媒体信息(如语音、视频等)。IP电话作为一种价格低廉的通信方式,凭借相对于传统的电路交换网络的独特优势,成为下一代网络(NGN)的发展目标之一。如何为普通家庭用户提供一种性价比高、使用方便的潜入式VoIP解决方案,正是本文研究的重点。本文设计的双协议栈语音网关提供RJ11、RJ45端口,通过ADSL或LAN,把普通电话机接入Internet,可以进行网关间直接通话,也可通过软交换平台实现通信。在IP网络上传输语音包括两个步骤,一是呼叫建立,二是媒体传输。本文围绕这两个方面的内容进行了对双协议栈语音网关的研究,首先说明了VoIP的基本原理,比较了不同的实现方式,从中选取H.323和SIP作为信令交互协议栈;然后介绍了基于ARM的系统硬件平台,分析并且设计了基于RTOS(实时操作系统)VxWorks的系统软件,包括软件架构的设计,核心控制模块FSM(有限状态机)的实现和改进,音频处理模块的设计,多路处理和以及一些其他辅助功能的实现。测试结果表明,本文所设计的双协议栈语音网关性能稳定,语音质量良好,达到了预期的目标。更多还原

【Abstract】 Due to the rapid development of computer and broadband network technology, the information transferred by Internet is converting from simple text to multimedia content, such as voice and video. Contributed to its low price and tremendous advantages compared with PSTN, VoIP has become one of the aims of NGN. What this thesis researches is how to provide ordinary families with high performing and convenient VoIP solutions. This dual stack VoIP Gateway designed by this thesis provides RJ11, used to connect POTs, and RJ45, used to connect ADSL or LAN, so, telephone calls can be conducted directly or through Gatekeeper.When voice data are carried on IP network, there are two steps; one is to set up the session, and the other is to transfer media across the network. Arround theses, following several explanations of the basis of VoIP, comparation of different solutions, and the choose of H.323 as well as SIP as the stacks, this thesis introduces hardware platform based on ARM, and illustrates software based on VxWorks, including software architecture, FSM, voice module, and other assistant functions.It is tested that the dual stack VoIP Gateway designed in this thesis performs well and has good voice quality.更多还原