【作者】 刘寒；

【导师】 刘知青；

【作者基本信息】 北京邮电大学 ， 软件工程， 2008， 硕士

【副题名】基于SIP协议的IP语音软终端的设计与实现

【摘要】 IMS(IP Multimedia Subsystem)是3GPP提出的支持IP多媒体业务的子系统。它的显著特点是采用了SIP体系,通信与接入方式无关,可以具备多种媒体业务控制功能和承载功能分离、呼叫与会话分离、应用与服务分离、业务与网络分离、以及移动网与因特网业务融合等多种能力。随着网络以及多媒体技术的不断发展,多媒体业务逐渐在Internet应用中占据主导地位,其中IP语音技术的应用尤为突出。信令技术是发展IP语音技术的关键之一,目前广泛应用的两种信令协议分别是H.323和SIP。SIP协议具有结构简洁、易于扩展和实现,以及适于Internet接入等良好特性,更符合未来网络发展的趋势。因此,研究基于SIP协议的IP语音软终端的设计与实现具有深远的意义和巨大的实用价值。本文介绍了开发IP语音软终端的关键技术以及SIP的网络体系,并对SIP和H.323标准在各方面进行了比较。本文重点论述了Windows平台上IP语音终端的结构设计,包括音频流的采集、编解码和网络传输方案以及SIP终端的工作流程等;并通过在局域网内进行软终端通信功能测试,验证了本课题所设计的软终端能够使用SIP信令建立连接,可以完成基于IP网络的实时通信功能,并且针对软终端及服务器所出现的bug进行了测试和分析。更多还原

【Abstract】 IMS (IP Multimedia Subsystem) is a subsystem which support to IP multimedia operation that is brought forward by 3GPP. Its marked characteristic is that it adopt SIP system, correspondence is not related to connecting mode, it has multimedia operation controlling function is separated from carrying capacity, calling is separated from conversation, application is separated from service, operation is separated from network, mobile network is syncretized with internet, etc.With the development of technology in the network and multimedia area, the business of multimedia communication, especially the Voice IP technology has become a leading element in the Internet applications. The key technology of the development of Voice IP technology is Signaling Technology. At the present time, the most widely used protocols are H.323 and SIP. The Session Initiation Protocol is very concise in the structure, easy to be extended and realized, especially more suitable to access the Internet. All these advantages show that SIP is better than H.323 for Voice IP technology and the future development of network. So, the design and realization of IP Voice Soft-terminal based on SIP will be meaningful practice usage.This paper introduces the key technologies of developing IP voice soft-terminal, the SIP network architecture and makes comparison between SIP and the H.323 standard. This paper emphasizes the structure design implementation of IP voice soft-terminal based on the Windows platform, including the capture and compression of audio steams, the working thread of IP voice soft-terminal, and so on. And it shows that this soft-terminal can create the connection by SIP Signaling and finish the real-time communication through IP network by a functional testing experiment in local area network. Also tested the function of the soft-terminal and the server.更多还原