In the data transfer part of the project , we advanced the dynamic configuring vlan method to implement multicast data transfer , which solved the router bottleneck problem of ip - multicast in the campus network , and improved the data transfer capability 在数据传输方面，提出了用动态配置vlan的方法实现一对多数据传送的方案，解决了用传统ip多播方法在校园网传送数据造成的路由器瓶颈，提高了传输的性能。
At last , it design and come true the remote video surveillance system on ip network . the technology of ip multicast is implemented in the system , a scheme is bring forword to insure the qos . a method of image intelligence searches is firstly introduced for accident " s precision orientation 论文的最后部分，在ip网络上完成了远程图像监控系统的设计和实现，针对系统的具体情况采用了ip多播技术（ multicast ） ，对qos提出了实现方案，并首次提出了图像智能检索的方法，对事故的精确定位提供了有力的保证。
And the image information was disposed with jpeg arithmetic method to compress the data on the server , decompress the data to display it on the client . to video and audio data , we take the method of microsoft directx . in the part of transmission control , we implemented the transmission of multimedia data by ip - multicast method and udp protocol . moreover to assure the integrality and synchronization of the multimedia data , we designed and implemented application layer transfer control protocol above the connectionless lower network protocol 在传输控制方面，多媒体信息传输采用ip多播udp传输协议，设计并实现了在无连接的网络协议上的应用层传输控制协议，保证多媒体信息的完整性和同步性，建立了控制命令通道，控制命令信息传输采用tcp协议，从而既保证了控制命令的可靠传输，又提高了多媒体信息的传输性能。
Second , some techniques in the digital surveillance system , including audio and video codec . tcp / ip protocol and ip multicasting , are introduced in the paper . at the same time , the trimedia are referred to , which is a powerful media signal processor and used in the system largely , and the programming api is specified , too 其次，论文介绍了数字监控系统中所涉及的部分技术，包括音视频编解码、 tcp ip协议和ip多播，并简要概述了用于数字监控系统中的多媒体处理芯片trimedia的特点和编程api 。
As a part of the national 863 planned project - " 2001aa411320 regional modern integrated manufacture system development and application oriented city chengdu , deyang and mianyang " and the science and technology key project of sichuan province - " the engineering configuration intelligent cad technology oriented the process of design " , this thesis proposes a modified scheme , which restrains efficiently the " feedback implosion " question , and is able to realize the reliable multicast . this scheme has considerably academic and practical significance 作为国家863计划项目： “ 2001aa411320以成德绵为核心的区域现代集成制造系统开发及应用”与四川省重大科技攻关项目： “ 01gg010 - 01区域制造业信息化关键技术与应用研究”的一部分，本文提出的方法可以有效抑制“反馈内陷”问题，能够实现ip多播的可靠传输，为协同设计系统提供可靠的多点通信支持，具有一定的理论和实用价值。
This thesis discusses detailedly the flow process of ip multicast , error discovery method and error recovery method , and also proposes a new error control method to implement reliable multicast in computer supported cooperative design system : serial integrates with timer are used to discover error , arq mechanism based on nak feedback is modified to correct error , " sliding window " mechanism is imported to make up the drawbacks of traditional nak , and " slotting and damping " technique is used to resolve the question of " feedback implosion " which results from multicast reliability control 详细研究了ip多播传输的流程、数据传输的差错检测方法及差错恢复方法，提出在协同设计系统中实现可靠多播的控制方法：利用序列号和计时器相结合的方法进行传输数据的差错检测，改进了基于nak反馈信息的arq重传机制来实现差错恢复，并引入了滑动窗口机制来解决传统nak方法的不足，采用“时间分槽?抑制”技术来解决由于进行多播可靠控制而产生的“反馈内陷”问题。
