摘要
SIP ( Session Initiation Protocol,会话初始协议)是由IETF( Internet工程任务组)提出的IP电话信令协议,发挥着越来越重要的作用,其应用领域从最初的VOIP扩展到软交换、NGN和3G中。
SIP (Session Initiation Protocol)协议是由一个应用层信令控制协议,用于创建,修改以及终结由一个或多个参与者参加的会话。它能更好的将电信级应用与Internet应用融合在一起,打破传统的电信业务的传输模式,采用基于Internet的准则,提供基于IP的多媒体业务,具有广泛的应用前景,因此在IP电话中采用SIP协议作为信令协议成为越来越多开发者的选择。
本文将SIP协议引入到嵌入式环境中,实现了基于MIPS平台的嵌入式电话终端,本课题研究的主要内容如下:
1.深入分析了SIP协议体系结构如协议栈原理、消息机制、信令流程和SIP的一些关键技术如注册过程、可靠性机制等。重点探讨和分析了SIP在嵌入式环境下的应用优势和特点;
2.分析了基于SIP协议的嵌入式系统设计的关键问题;设计和实现了以MIPS为硬件平台的局域网内的嵌入式SIP电话终端,并针对此终端给出了应该如何从硬件和软件两方面对嵌入式SIP应用系统进行设计和开发的方案;
3.针对嵌入式网络通信系统的特点,从几个方面对嵌入式Nucleus系统和应用程序进行了优化,提高了系统的运行效率和响应速度。
SIP, Session Initiation Protocol, was initially proposed by IETF as an IP phone signaling protocol. It has been playing an important role in many fields including Voip, soft switch, NGN and 3G.
SIP (Session Initiation Protocol) is an application-layer control(signaling) protocol for creating,modifying, and terminating sessions with one or more participants. It can amalgamate traditional telecommunication network application into Internet application and break the traditional telecommunication service model,it provide muti-media service based on IP with Internet rules, so IP Phone which use SIP as signaling protocol become a choice by more and more developers.
Therefore, the paper presents the thought that applying SIP to the embedded system, and conducts the study of SIP and the design of an embedded IP Phone based on MIPS. This task of the paper is as follows:
1. Deeply research on SIP architecture including SIP Protocol, message mechanism, signaling flow and some other critical technique, such as registering process and reliability. SIP Discussing and analyzing the superiority and the characteristic of SIP when it is applied to embedded environment.
2. Analyzing the key questions when designing the embedded application system based on SIP. Designing and realizing the embedded SIP telephone terminal based on MIPS in LAN. Aiming at this telephone terminal, presenting the program of how to design and develop embedded SIP application system from hardware and software.
3. The paper also optimizes embedded Nucleus system and application according to the system hardware and software platform in various ways, which greatly improves its speed and efficiency.
引文
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