Research On Broadband Content Delivery Network For Jilin Communication

With the development of broadband access in the past two years, largenumbers of broadband access users need more and more network video services,which have made video-on-demand, living broadcast and othertelecommunications services grow exponentially nationwide. Meanwhile,following the sharp rise of penetration rate of broadband access among thecomputer-owned customers, telecommunications operators turn to expand theirbroadband access and broadband content services further by means of supplyingstreaming media service. As Internet can not expand illimitably, when networktraffic increases, its will become overburdensome and unstable, which makesplaying video programs on-line difficult and means Internet can not meet thedemand for the development of video services by itself.Along with the advance of network technology,CDN (Content DeliveryNetwork),which is a key technology for the purpose of enhancing the servicequality of the content, transported by network and sparing the bandwidth of thebackbone network, has been applied widely. By drive of business, CNC JilinBranch is planning and building CDN. CDN, which is a virtual network,established with servers at different nodes, can deliver the content of the websiteefficiently and stably to the nearest site where the net citizens could visit.CDN is supported by IP backbone network. CDN, which has multilevelstructure and uniform plan, make resources distributed efficiently and reasonably,and shared. The basic principle of CDN is to put the servers of streaming medianext to the networks of network operators, which means providing services fromthe nearest place, so as to improve efficiency of the system and offer finalcustomers colorful content services. By CDN providing content delivery services,such as video-on-demand, living broadcast, inserting broadcast, etc, operators canmeet various and customized need. If CDN, based on IP network, is connectedwith PSTN/ISDN, IN, NTERNET and other networks, it can provide newintegrative services of voice, data and picture.Broadband content distribution platform of Jilin province includes thetraditional CDN push network platform, storage network platform, servicecapability platform, service control platform and API open interface.intellectualized software-control platform, which can harmonize the traditionalCDN network, main storage network platform and the services that we want todeliver, is able to set up connection with platforms in the province to distributeservices between two levels and integrate and assign all the service resources.As for content management, on one hand, CDN capitalizes on many contentdistribution means and strategies, which make content distributionintellectualizedly. On the other hand, in order to manage content distributioncentralizedly, the Push pattern, which is active, and the Pull pattern, which is usedwhen there is no content on brim servers. When it comes to content distribution,the system has excellent content-based visit distribution principle and strategies,which optimizes the distribution of request of the users, so as to avoid congestionof the backbone network and keep the high quality service for users. As far ascontent storage is concerned, the whole network storage can be divided into twolevels. One is central storage, and the other is ES storage. The project of centralstorage content is SAN's, which is not only efficient and stable, but also has highcapability and can be enlarged smoothly. On content route, it adopts a completeload equilibrium and local equilibrium technology. Also, CDN is a good solutionthat can support massive application of streaming media, which is proved byIPTV in Changchun and the realization of streaming media service based onbroadband multimedia platform. As a content fold network over IP network, CDN,which uses distributing content service, owing the ability to provide distributingedge service, plays an important role in enhancing the quality of application ofstreaming media.When we look at the whole value chain, content providers are on one end,and customers are on the other end. They are connected by network serviceproviders. As Internet industry grows up and business pattern changes, the marketis fractionized and there are more roles connected by the value chain, such ascontent/application operators, trusteeship service providers, backbone networkservice providers, access service providers, etc. In order to provide good servicefor customers each provider must take its responsibility and cooperate with oneanother, so as to play a win-win game. From content and pattern, content has notbeen delivered by content servers or IDC any more. the upsurge of IDC madetrusteeship service providers appear. But IDC can not solve the problem how todelivered content efficiently. It is impossible to decrease the occupation ofbackbone network and make the traffic of backbone network more regular byputting content in the middle of the network. Therefore pushing content to theedge of network to provide convenient services is an obvious choice, which helpsto maintain a high standard service quality and keep the whole network visit order.This is just the service pattern of CDN. CDN create a way for content operators tofind balance between centralization and decentralization. Undoubtedly, it isvaluable and necessary for a good value chain.Following the advance of 3G and NGN, as a mainstream service among allthe services that 3G and NGN can provide, streaming media service is attachedmuch importance by main fixed-line telecommunications operators, who areconcerned about if they can provide mobile streaming media services quickly atan easy rate. If they can make it by investing little in fixed-line network, this willsave them a lot of money.It is quite certain that with the development of the networktechnology, CDN will be improved unceasingly and become one of theindispensable parts of the Internet, 3G and NGN.