校园网VOD视频点播服务器的结构、配置、运转说明

产品型号 ZRI2216230S

采用处理器 Intel Xeon 5110

处理器主频/外频/缓存 1.6GHz/1066MHz/4M

内存类型/速度/标准/最大 FB-DIMM DDR2 ECC/667/4G/16G

可选内存配置 256M、512M、1G、2G、4G

硬盘大小/类型/控制器

>500G/ SATAII/ SATAII

芯片组 S5000V

图形子系统 显示芯片：ATI.ES1000

显存标准/类型：16M/ DDR

图形总线接口：PCI

最大分辨率：1024×768

最大色彩：16777216 colors

网卡/光驱

双千兆网卡/一个1/2英寸DVD-ROM

音频 声道控制芯片

机构 类型：2U机架式；最大支持硬盘位：8；光驱位：1 ；软驱位：1；热插拔盘位：8个热插拔盘位

外设 键盘/鼠标PS/2

重量及尺寸 35KGL×W×H650mm×430mm×87mm

扩展选件 插槽总数及类型：PCI-E×2,PCI-X×2,PCI×1

接口：2*USB（前置）；2*USB(后置) ；VIDEO；COM ；并口；PS/2

支持的操作系统 win2003/win2000sever/winxp/Linux/NT/Novell等

环境参数 工作温度及湿度(℃)：10℃-35℃,20%-80%

存储温度及湿度(℃)：-40℃-65℃,5%-95%

工作高度(米)：-16米至3,048米

电源管理 电源额定功率/最大功率：550W/600W

电源供应类型：EPS12V

VOD是Video On Demand的缩写，即视频点播的意思。顾名思义，它是一种可以按用户需要点播节目的交互式视频系统，或者更广义一点讲，它可以为用户提供各种交互式信息服务。交互式视频点播系统一般由VOD前端处理系统、传输网络、用户机顶盒三个部分组成。 而VOD前端处理系统是提供用户节目、进行管理及计费等用的，故包括视频服务器、磁盘阵列、节目播放及控制设备、节目数据库、网络管理和计费等系统。前端处理系统可以说是VOD的核心，决定了VOD系统的服务能力。VOD系统的传输网络大体可分为骨干传输网和用户接入网两部分。用户端的机顶盒是从网络获取多媒体信息的桥梁，是一种智能型数字信号转换器，现正向微型电脑方向发展，逐渐集成电视与电脑的功能，用户通过机顶盒实现视频节目点播、数字电视广播、电子商务等多媒体信息服务。 VOD (Video On Demand)即视频点播技术的简称,也称为交互式电视点播系统。视频点播是计算机技术、网络技术、多媒体技术发展的产物,是一项全新的信息服务。它摆脱了传统电视受时空限制的束缚,解决了一个想看什么节目就看什么,想何时看就何时看的问题。 有线电视视频点播,是指利用有线电视网络,采用多媒体技术,将声音、图像、图形、文字、数据等集成为一体,向特定用户播放其指定的视听节目的业务活动。包括按次付费、轮播、按需实时点播等服务形式。 视频点播的工作过程为：用户在客户端启动播放请求,这个请求通过网络发出,到达并由服务器的网卡接收,传送给服务器。经过请求验证后,服务器把存储子系统中可访问的节目名准备好,使用户可以浏览到所喜爱的节目单。用户选择节目后,服务器从存储子系统中取出节目内容,并传送到客户端播放。通常,一个“回放连接”定义为一个“流”。采用先进的“带有控制的流”技术,支持将上百个高质量的多媒体“流”传送到网络客户机。客户端可以在任何时间播放存在服务器视频存储器中的任何多媒体资料。客户端在接收到一小部分数据时,便可以观看所选择的多媒体资料。这种技术改进了“下载”或简单的“流”技术的缺陷,能够动态调整系统工作状态,以适应变化的网络流量,保证恒定的播放质量。 视频点播分为互动点播和预约点播两种。互动点播即用户通过拨打电话,电脑自动安排其所需节目。预定点播即用户通过打电话到点播台,然后由人工操作,按其要求定时播出节目。 VOD的最初出现是为了更好的满足用户对自主收看视频节目的需求，但是随着VOD技术的不断进步，其广泛的应用对大众文化和商业运作模式都将产生强烈的影响。 VOD不仅可以为终端用户提供多样化的媒体信息流，来扩大人们的信息渠道，丰富人们的精神生活；而且在医院、宾馆、飞机等场所的娱乐，公司的职员培训、远距离市场调查、公司的广告业务等领域将逐渐充斥着VOD技术的全新应用麻烦采纳，谢谢!

3) the ATM backbone network adds the ADSL way.This selection and broadcast way uses the ADSL line bearing capacity is limited. The video on demand learning environment research and the development mainly is based on wide band, the high speed network, the development cost is also high, but regarding relatively low band width, low gear rate network like in campus network typical exchange type fast ethernet development and research then few.Meanwhile speaking of the majority schools, rests on some companies and the manufacturer plan under the limited resources condition constructs the campus video on demand learning environment is completely impractical.“Because only then the school takes suitable measures”, carries on the school existing software and hardware resources the promotion transformation, is one kind cuts the feasible choice. The interactive VOD system by the front end processing system, the wide band exchange network, with records the access network, the user terminal equipment (set-top box adds television or adds computer) and so on several parts to be composed.The VOD system already may use the centralized processing structure, also may use the centralized processing structure, also may use the centralized management, the distribution processing way, and may select HFC, FTTP, FTTCADSL, VDSL nimbly and so on many kinds of turning on way. 1st, front end front end the processing system the processing system by the video frequency server, the floppy disk array, the program database, broadcasts generally controls constitutions and so on system.Video frequency server high speed data through-put capacity has guaranteed the user to the massive movies, the video frequency program, the game, the educational administration information as well as other service near immediate visit.Its prominent merit is certain users may from the different time beginning onlooking identical program, avoided the splendid program monopolizing by a user, this could especially suit regarding the user selection and broadcast request relative centralism field. The VOD video frequency server is preserving massively after the compression image program and can through the network the program copy which provides for the user needs, also may contain the real-time MFEG encoder to turn on the live broadcast.The program database is an archive system, is preserving the massive compression form movie program, may download in groups gives the video frequency server.The VOD video frequency server through with the user between direct, real-time bidirectional controls the program alternately the broadcast, including program choice, broadcast process start and termination, between broadcast speed control as well as different program dynamic cut and so on.In order to the video frequency server can adapt real-time, continuously the stable video frequency class, its reserves must be big, the data rate must be high, and should have the admission control, request processing, the data retrieval, according to spreads delivers and so on many kinds of functions, guarantees the user request under the system resources effective service.The storage device should use the SCSI connection, guarantees high speed, parallel, the multiple I /O line ability.Based on the ATM VOD system, the video frequency server which uses is take multi-channel free choice switch (MPSR) as the central wide band video frequency server.This kind of structure server may provide the immediate interactive video on demand and the time delay interactive video on demand two service ways.When massive users selection and broadcast, the server transmission speed is very highSimultaneously requests other correlation equipment also to be able to support this kind of high transmission speed, but this very difficult to realize.May (for example front end the ATM network switch place) establish the video frequency buffer pool for this in the network edge, duplicates the selection and broadcast rate high program in the buffer pool, causes the partial users only to have to visit the buffer pool then, in the buffer pool has not wanted the selection and broadcast the program, may visit the server again, this lightened the server burden, and may increase along with the user increases the buffer pool.Loading buffer pool available 150Mb/s speed, but from the buffer pool to the user transmission program is with the 2Mb/s speed, therefore a server may support many users

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