Research And Design On The Framework Structure Of Cable TV IP MAN

With its spread, Internet becomes increasingly important in our daily life. But the Information Networks are up against many troubles, such as, vicious attacks,computer virus bursting-out,network congestion etc.In other words , the present Information Networks have vulnerabilities in manageability controllability and robustibility.Cable TV network is one of important City Information Infrastructures(CII). Comparing with other MAN,the Cable TV MAN(Metropolitan Area Network) has inborn advantages in content edit and transfer video programs ; the Access Network of Cable TV MAN—HFC(Hybrid Fiber/Coax) Network is with high bandwidth,big capacity and high customer-possession-rate. But present Cable TV network has great vulnerabilities in subscriber control,authentication and management. So we cry for further research on the framework structure of Cable TV MAN . Using Structured Design (SD) method, this article elicits prime principles to which the research on the framework structure of Cable TV MAN should comply and the characteristics of System Design Model . Aiming the System Design Model ,we have done function model analyse,information flow analyse and Internet TCP/IP protocol analyse.These analyses deepen our understand of the Information Network. In the end of the article, we put forward a set of feasible system design model of Cable TV MAN Framework.During the course of design Cable TV MAN system design ,this article has gotten these technology productions .1,It has made certain a subscriber authentication mechanism fit for Cable MAN Internet users.2,It has researched how to use Cisco 7114 CMTS equipments ,which are widely used in Cable TV MAN, to be Broadband Access Server (BAS).And it gives a method of realization .3,It has improved system reliability by skillful network routing design.This article puts forward some new thoughts and projects on the Cable TV network construction, and puts into practice in the author's own company. And it makes beneficial foundation for our Broadcast & TV department's informationization practice.