[Getting] the broadcasting industry, DNS, DHCP solution Detailed (a) - history and current situation papers

The history of radio and television

  Radio and television is broadcast television, radio and television development can be divided into three stages: one-way network, two-way networks, intelligent networks. It will be described below one by one.

 

 

 

Individual network

  The earliest use of radio and television is a pure one-way HFC network, it simply is a single terminal, generally composed of pure coaxial cable, is to look at, is the most simple architecture of early live television use. Business platform is relatively simple, pure business networks within the network structure, service terminal for the individual set-top boxes, and TVs without an IP address assigned.

Two-way network

  And then further development, it developed into a two-way terminal and HTTF HFC network. HTTF also relates to the CMTS, the figure is not drawn. Two-way network set-top boxes in addition to the live broadcast, you can play back, but also can see some of the other content, such as there will be some Tencent or other video resources are available through the Internet set-top boxes. Can also be an additional set-top box in a business, it will have the equivalent of a specialized interface to connect PC, which at the same time with Internet services and interactive TV services, and later developed into a two-way set-top boxes, then only the IP network.
With the IP network in the future, because the Internet requires DNS, DHCP set-top boxes also need to assign addresses, so after the development of two-way network, there is a need for DHCP with DNS, which is why the development of radio and television will DNS service, which is equivalent with the introduction of two-way after the network, DNS demand will increase, equal and they have a broadband user, then the equivalent of a radio and television network operators.

Intelligent Network

  Radio and television industry developed to form a diverse variety of internal and external network terminals and converged network architecture with the business integration platform, with HFC and a variety of access technologies and high bandwidth, intelligent, two-way network structure. After the radio and television to get the latest 5G license, is likely to develop its network 5G, 5G network operators to re-take a 5G Internet access business, which is DNS, there has been a new demand, equivalent to the same mobile operators to provides the user card, you need to DNS, radio and television next year or two there will be demand for 5G of DNS.

 This is an overview of the development of the entire network radio and television.

Radio and television network status

 

 

  我们先简单看一下广电行业的终端情况,分为双向终端、单向机终端和智能终端三种。上图是2017年的一个广电行业发展报告。我们可以看到双向机顶盒已经在市场上占比达60%到70%,说明双向网络占据大部分市场,单向机顶盒也有但也不多了,智能化的网络部分仅统计了“公客”业务部分,实际智能网络占比应远高于5%。


  我们可以分析出,整个广电网络发展正处于一个双向的网络化、宽带化还有智能化改进的过程当中,这便需要更智能的DDI(DNS、DHCP以及IPAM)来支撑网络建设。这是现在广电网络的现状。

 

 

广电网络典型特征

  广电网络典型特征可以概括为:接入技术混杂、承载业务多样化、业务终端错综复杂等。

· 接入技术混杂

  广电网络相对于运营商来说是一个比较特殊也比较复杂的网络情况,因为它的接入技术比较混乱,首先,刚才说到了早期HFC就是单纯的同轴做直播业务播放的,以及后期在同轴基础上增加了CMTS,你可以简单理解为CMTS就是在同轴的通路电缆上面加入了IP网络,相当于它通过CMTS形成了双向网络。

  同时,在CMTS往下又产生了一种新的接入方式,叫EoC的方式,EoC有两种方式,一种是通过同轴接EoC的终端,EoC下面再接PC或者机顶盒;还有一种就是在同轴下面是CMTS网络,下面加一个CM,所谓的CM就是一个类似于调制解调器,它其实连的也是PC跟机顶盒。

  再往下发展,在接入这一块因为CMTS网络包括同轴网络毕竟有些弊端:带宽限制,所以现在有些网络发展成了光纤,叫FTTH,通过ORT或者接ONU的方式,也就是跟现在的运营商模型类似,直接光纤入户。

  最后,是PON+LAN的方式,其实就是CMTS网络的一个延伸。CMTS网络有带宽限制,现在通过PON的技术,比如JPON和EPON,EPON就是百兆,可以达到百兆的带宽,JPON就可以达到万兆的带宽。

  总结起来其实是两个发展方向:一个是在CMTS网络基础上做延伸,一种是纯光纤接入的FTTH方式。现在广电接入最普遍的方式是CMTS同轴方式,同时逐渐往新的光纤接入的方式转变。

· 承载业务多样化

  现在广电不仅承载的DVB数字电视和IMS宽带业务,像VOIP语音、VOD交互电视、OTT多媒体、VPN专线等也会涉及。

· 业务终端错综复杂

  接下来就是业务终端,相当于刚才讲的接入方式就是网是怎么接入的,接下来介绍就是终端有哪些。宽带业务涉及到PC、电话上网,电视直播或者互动电视这一块就是它的机顶盒。其他的像CM同轴,CM跟CMTS是成套的,CM同轴终端是挂在CMTS下面,是提供PC跟机顶盒接入的。

· 其他

  终端数量太大;网络安全要求高但协议标准性较差、网络管理手段老旧且无专业的DHCP服务。

网络现状模型

 

 

  通过这张图能够看到整个广电网络的一个现状模型。

  1. 双向网络分为:总前端、分前端、接入层、入户侧。
    总前端部署主备核心路由,向上连接业务数据中心、Internet出口、支持系统及网络中心。

  2. 业务中心主要存储网内业务资源,如视频平台、多媒体平台等。
    支持系统及网管中心包含网络支撑和运营的系统,DDI核心网络服务系统、NMS网络管理系统。

  3. 分前端接入层有多种接入技术,如DOCSIS、PON、PON+EoC等,一般分为两种,一种是用同轴接入CMTS网络接入,CMTS下面挂的是CM,CM下面挂的是机顶盒或者PC上网业务;一种是通过OLT(光线路终端,用于连接光纤干线终端设备分出ONU和EoC两种接入方式。

  4. 公客入户业务终端:家庭网络的机顶盒、电脑等。 集客入户业务终端:大客户网络包括摄像头、POS终端、VoIP终端等。

  5. 通过这张图大家能够看到在整个模型当中DHCP或者DNS应用在哪一块。因为DNS提供PC上网或者机顶盒上网,PC跟机顶盒可能会应用DNS进行互联网的域名解析或本地域名的解析。然后DHCP就负责给这些终端分配地址。

总结

  目前广电网络的DNS跟DHCP的现状,可以总结为以下三点。

  1. 网络设备功能单一
    性能无法满足大用户场景并发要求;架构单一,冗余能力差;管理不便捷,需要较强的专业能力,且无法集中管理。

  2. 自建系统安全较差
    安全性较差,系统本身存在漏洞,容易被攻击;配置复杂,用户量大时维护成本较高;功能不足,无法满足复杂的业务要求。

  3. 商用DHCP成本较高
    成本较高,缺少专业的服务支持;IPv6架构简单,与现网实际需求存在一定差异;报表能力弱,缺少体现业务的报表展示。

DNS基本现状是大部分都使用了一些专业设备,80%到90%是用了DNS设备提供的DNS解析,可能部分广电还保留着通过linux或者其他品牌的DNS做的DNS解析。
DHCP基本现状是EoC的方式或者ONU的方式,光纤接入的方式,可能通过base分配地址。
网络设备功能单一。

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Origin www.cnblogs.com/zdns/p/11430911.html