VOIP语音通信系统的设计与应用

电子通信论文编号:TX183  论文字数:14556,页数:44

目    录

第一章  绪 论 1
1.1　VoIP背景材料 1
1.1.1 VoIP基本概念和原理 1
1.1.2　VoIP的实现形式 2
1.2  VoIP 的研究现状 3
1.2.1 国外VoIP的发展现状 3
1.2.2  国内VoIP的发展现状 4
1.3  VoIP的技术优势 4
第二章  VoIP关键技术 6
2.1 会话初始协议（SIP） 6
2.1.1  基于SIP的VoIP协议结构 6
2.1.2  SIP网络元素 7
2.1.3  SIP消息 9
2.1.4  SIP信令过程 11
2.1.5  SIP系统的工作流程 12
2.2  会话描述协议（SDP） 14
2.3  实时传输协议（RTP）与实时传输控制协议（RTCP） 15
2.3.1  RTP协议 15
2.3.2   RTCP协议 15
第三章  VoIP语音通信系统功能设计与实现 16
3.1 VoIP解决方案背景简介 16
3.2 用户基本需求分析 16
3.3 VoIP网络电话的解决方案构成 16
3.4 解决方案说明 17
3.3.1 方案说明 17
3.3.2 基本功能 17
3.3.3 特色功能 18
3.5 VoIP网络电话在大学校园的实施方案 18
第四章 系统测试 19
4.1  测试环境 19
4.2  测试内容 20
4.2.1  软交换系统互联 20
4.2.2  VoIP流程分析 22
4.2.3  抓包分析工具的应用 24
4.2.4  软换系统高级功能应用 27
4.2.5  软件电话 30
4.3  语音质量测试 31
4.3.1  分类指标感受测试 31
4.3.2  综合感受测试 32
4.3.3  语音质量测试结果 33
4.4  系统综合测试 33
结论与展望 35
主要参考文献 37
附    录 37
致    谢 38

摘  要

随着计算机和网络技术的快速发展，多媒体通信网络已经成为人们关注的焦点。基于TCP/IP的计算机网络技术不但无可争辩的成为数据领域的主导技术，而且在语音通信这一传统电信业务领域也表现出了强大的竞争力。IP的最大优势是已经具有一个全球统一的网络，它所具有的统一的网络层和传输层协议，为未来三网（电信网、计算机网和有线电视网）的融合打下了基础。因此在IP网络上传送语音（即VoIP）将是下一代语音网络发展的主导方向。
近两年来，随着全球宽带接入用户的迅猛增长，又有来自政策、投入上的推动，加之VoIP技术本身在不断完善，VoIP这个沉寂多年的技术终于又成为人们关注的热点之一。而依据VoIP技术的发展趋势，SIP协议因其较低的复杂性、较好的扩展性将逐渐代替H.323协议，成为VoIP技术的核心协议。因此基于SIP的VoIP系统及其增值业务功能扩展将有巨大的研究潜力和较为实用的现实意义。
基于这一背景，本文首先阐述了设计题目的选题意义、背景、发展前景；其次对SIP协议原理和工作过程、VoIP系统相关技术做了深入的研讨和分析，并加以实验认证和测试。并在此基础之上，根据用户需求，结合调查情况，详细设计了一个安徽大学VoIP校园网络的全面的解决方案，不断论证和改进，直到形成一定的可行系统方案。该方案不仅能够实现简单的语音通信功能，而且在SIP扩展功能上有所突破，实现了诸如电话会议、呼叫转接、计费管理等高级功能，并可进行一定的功能扩展。
最后通过对该VoIP语音通信系统进行的全面测试展现了该系统方便实用、稳定可靠、业务丰富等特点，完全符合各层次人群的需求，能够为用户通信提供一个很好的交流沟通平台。该系统的运用不仅能够极大提高社会生产力、节省成本，而且有助于改善人们生活质量，构建高效、和谐社会。

关键词：VoIP；会话初始协议；实时传输协议；会话描述协议;IP电话

The Design and Application of VoIP Voice Communications System

Abstract

With the rapid development of computer and network technology, multimedia telecommunications network has become the focus of attention. Computer Network Technology has not only indisputably become a leading data communications technology , but also demonstrated a strong competitive edge in the field of Speech Communication which is the main traditional telecommunications business. The Internet has already become a unified global network.Its unified network layer and transport layer protocols lay a foundation for the integration of the telecommunication network, computer network and the cable television network. So VoIP will be the guiding principle in the development of next generation voice network.
In the last two years, along with the sudden growth of global users of broadband access,  the push of policy and investment, and its constantly improving , VoIP technology finally become one of the hottest topics again after many years of silence. According to the development trend of VoIP, SIP will gradually replace H.323 to be the core agreement of VoIP, because of the lower complexity and better extension. So the extension of the value-added business and the VoIP system based on SIP will has great research potential and useful practical significance.
Against such background, this paper firstly shows the significance, background,development potential of the selected topic. Second, it describes the principle and process of SIP, the correlation technology of VoIP system.Besides, we test it by experiment. On this basis, according to the requirement of user and the survey, this paper presents a comprehensive and practical solution to the VoIP system of Anhui University and continually corrected and improved the system until formed a satisfied and feasible system. This solution is not only to achieve a simple voice phone functions, but also make a breakthrough of the SIP-based extensions. It achieves conference call, call transfer, accounting management and so on. And its function can be extended.
Finally, though completely test of this VoIP system, it is found that function is easy and practical, operation is stable and reliable, service is rich, fully corresponding to the demands of all levels of users, and it can provide a wonderful communication platform for all users. The application of this VoIP system not only improves society productivity and saves costs, but also improves the quality of peoples' lives, builds a harmonious and efficient society.
    Key words: voip ; sip; rtp; sdp; ip telephone;