基于SIP协议系统的体系结构的研究

文章研究SIP系统的体系结构，并分析体系各组成部分的工作原理。     

基于SCTP和DCCP的SIP电话设计与实现

分析了TCP和UDP应用于SIP电话时在可靠性、拥塞控制以及安全性等方面存在的缺陷,鉴于SCTP和DCCP的良好特性,提出了一种基于SCTP和DCCP的SIP电话设计方案,分析了这种SIP电话的会话流程,最后给出了具体的实现方法。     

Reconfiguring the innovation policy portfolios for Taiwan's SIP Mall industry

Since the year 2000, silicon intellectual property (SIP), which can minimize the gap in ‘design productivity’ that exists with systems-on-chip (SOC), has become one of the most important factors in the development of integrated circuit (IC) products in the SOC era. Although SIP is very important for IC industry development, complicated business, technical as well as legal issues inside SIP transactions have hindered successful transactions and the integration of SIPs into SOCs. Thus, web-based SIP e-Commerce mechanisms, called SIP Malls, have emerged, aiming to resolve complex SIP issues. To maintain its leading position and competitiveness in the World's IC industry, as well as the value added by SOC products in Taiwanese IC firms, the Taiwanese government has developed SIP Malls, using innovation policy tools. However, the Taiwanese SIP Mall industry remains immature. No existing Taiwanese SIP Malls generate a profit or account for a significant share of worldwide SIP transactions. This research will develop an analytical framework for defining an innovation policy portfolio that aims to develop Taiwan's SIP Mall industry, so that it will enhance the value added of SIP Malls and, thus, the nation's competitiveness in the SIP and IC industries, something which already has become one of the Taiwanese government's major concerns. The industry innovation requirements (IIRs) are summarized using the Delphi method. Meanwhile, the major IIRs identified by Decision Making Trial and Evaluation Laboratory (DEMATEL) are introduced. After the IIRs are derived, the relationships between the IIRs and innovation policy tools are derived by Grey relational analysis (GRA). Then, the innovation policy tools are clustered, based upon the Grey grades derived by GRA. Finally, reconfigured innovation policy portfolios are presented for the Taiwanese government's policy definition. The results demonstrate that developing an innovative policy portfolio that includes scientific, technical, educational, public enterprise, information, legal and regulatory, financial, and taxation policy tools will be the most necessary step towards developing Taiwan's SIP Mall industry.     

SIP与H．323协议互通研究

在SIP网络出现之前,以IP网络为传输系统的H．323网络已得到广泛应用,因此,应用SIP网络时必须考虑SIP网络和H．323网络的互联问题。文章研究SIP网络与H．323网络互通的功能实体IWF（互通的功能实体称为IWF,即Inter Working Function互通功能体）,经测试此方案是合理可行的。     

基于SIP的呼叫控制模块设计

介绍了呼叫控制模块的设计.该模块采用会话初始协议(SIP),主要用于无线局域网多媒体通信,支持局域网子网间无缝切换.通过编程对整个设计流程进行了验证,并利用IP呼叫生成器模拟电话终端进行测试,充分证明所设计的呼叫控制模块具有较高的性能参数.     

基于SIP和Windows的软电话设讣与实现

首先介绍了SIP协议,包括其功能、系统基本组成、消息格式,然后设计了软件的三大模块:用户界面模块、SIP UA模块、语音通信模块,并使用编程工具V isual C 6.0、SIP协议栈OSIP、EXOSIP及RTP协议栈W inRTP实现了该软电话。测试结果表明,该SIP软电话在局域网环境下具有良好的通话质量。     

网络多媒体应用的SIP和QoS网络叠加模型

SIP和IP服务质量是为解决IP网络多媒体应用的需要而提出的,SIP和IP服务质量的融合为多媒体应用提供了更好的解决方法,文章在对SIP及其扩展的简要介绍的基础上,分析了增强特性SIP代理服务器在各种IP服务质量模型下,是如何与QoS网络的交互,从而引出了SIP的IP网络服务质量的叠加模型。     

基于Service Broker的IMS业务特征冲突解决算法与方案

3GPP在UMTS R5中提出IMS作为下一代网络(NGN)技术在移动通信中的实现,但IMS业务触发机制的缺陷给交互管理带来挑战.把IMS中业务特征冲突分为SCFI(Single Component Fea-ture Interaction)和MCFI(Multi-component Feature Interaction)两类,利用SIP协议的可扩展性携带业务触发信息,提出解决MCFI类业务冲突的算法及方案.此方案为3GPP Service Broker标准制定提供了参考.     

海事卫星通信系统VoIP技术的应用分析

随着VoIP技术的发展，VoIP技术结合卫星通信网络的应用越来越广泛。Inmarsat卫星系统是地球同步轨道系统，网络传播时延大，卫星VoIP电话的语音通信是否可行值得研究。结合VoIP关键技术和海事卫星通信语音通信应用场景，探讨了基于Inmarsat卫星网络实现VoIP技术的方案，并分析出此方案下VoIP系统通话过程的单向时延为350 ms，低于ITU G.114的400 ms的要求。在实际使用环境中进行了测试和验证，结果表明，基于Inmarsat网络下实现VoIP的方案是可行的。该方案实现复杂度低，可以方便地实现Inmarsat网络与地面电话网之间的互联互通，也可以为我国自主研制的宽带卫星通信系统实现VoIP技术提供参考。     

软交换网络集中监测系统SIP监测方案

结合对SIP(Session Initiation Protocol)协议的深入分析,采 用正则表达式匹配方式进行消息解码,着重分析SIP呼叫合成的算法,使用Hash技 术有效解决了CDR合成效率低下等关键难题。该方案在已商用的软交换集中监测系统中进行 了 测试和验证,效果良好。