【作者】 郑剑芳；

【导师】 孙大跃；

【作者基本信息】 长安大学 ， 交通信息工程及控制， 2007， 硕士

【摘要】 随着计算机网络的广泛应用以及计算机技术、通信技术的不断发展,VOIP领域迎来了其发展的一个良好的契机。基于VOIP技术的IP电话会议系统作为一种先进的语音传送手段,为远程语音会议的召开提供了一种全新的方法。随着VOIP技术的发展,电话会议系统已经越来越多地应用到了各行各业,得到越来越多人的认可。现行VOIP领域协议标准主要有由ITU提出的H.323协议和由IETF提出的SIP协议。由于H.323协议提出时间较早,发展较为成熟,所以是现行电话会议系统所遵循的主要标准。自从1999年IETF提出SIP协议之后,由于SIP协议的简单、开放、兼容以及可扩展性等优点而得到了快速的发展。但由于SIP协议提出时间较短,协议并不是很成熟,特别是SIP协议缺少会议控制的相关标准,所以,研究基于SIP协议的IP电话会议系统具有极大的价值。本文在研究SIP协议的基础上,结合电话会议系统在企事业内部应用的实际需求,提出了一种基于SIP协议的多级分布式IP电话会议系统的实现模型。该模型包括成员管理模块、点对点通话模块、会议控制模块、多级管理模块和录音检索模块五个模块,五个模块间采用消息通道的方式进行交互,模块间的设计符合高内聚、低耦合的标准。在会议实现方面,通过对集中式会议模型的改进,提出并实现了一种分层结构的分布式会议模型。在系统实现过程中,对SIP协议扩展技术、混音技术以及分布式会议的实现进行了理论研究和具体应用设计。在实现了系统模型后,对该系统进行了全面测试,在测试过程中与传统H323会议系统进行了对比。实验表明,本系统达到了系统设计的要求,在会议方面,与H323相比有了较大的提高,可以满足企事业单位对电话会议系统的应用要求。更多还原

【Abstract】 Along with widespread application of computer network and unceasingly develop of computer and communication technology, the VOIP field meets a good opportunity to develop. As an advanced communication technology, the IP teleconference system based on VOIP technology provide a new way for convoking remote conference. Together with the development of VOIP technology, the teleconference system has used in varieties of vocations, and obtain approvals of more and more people.Nowadays, VOIP protocol mainly have two protocols, one is H323 proposed by IT while the other is SIP Protocol proposed by IETF. The H.323 Protocol is main standard of teleconference system because of its mature function. But since the SIP Protocol was proposed by IETF on year 1999, due to its simplicity, opening, compatibility and extensibility, SIP Protocol has been developed rapidly. Being proposed for such a short time, it will be a great value to study and actualize the IP teleconference system based on SIP.Depending on analyzing SIP Protocol and considering of real needs of teleconference system in enterprise, this thesis put forward on a distributed IP teleconference system based on SIP Protocol. The system includes member management, point to point communication, conference controlling, multi-level, recording and searching modules. In conference actualizing, some improvement has been added into the Centralized Conference, proposing and actualizing a distributed conference model in many levels. During the actualizing of system, the thesis made a deeply theory study and application design in technology of SIP extension, technology of audio mixing and the actualizing of distributed conference.After the system model was implemented, a comprehensive test was preceded.. And during the test we also compared this system with H.323. Experiment result shows that the system has reached the demand of designing, and it can also meets the demands ofteleconference using in enterprise.更多还原