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DVM/VBR Extends Reach of Internet Broadcasts As the Internet broadcasting business expands, it faces the problem of providing Internet users with high-quality multimedia content. Currently high-cost servers and the establishment of a network are required to provide stable live broadcasting with good quality images.Infobada, a domestic Internet broadcasting solution developer, has recently launched a transmission protocol -- DVM/VBR (dynamic virtual multicast/variable bit rate) -- which is claimed to be reliable, and can be used in an application multicast environment. The company will include the protocol in its IB Caster X series solution, targeted at the application multicast Internet broadcasting market, which includes remote virtual education, multipoint file transmission, and remote multimedia conferencing. The multicast, one of a number of streaming technology methods, transmits one data packet simultaneously to several receivers on the network. It is limited to intranets, as there are not many routers that support multicast. The data packet is encapsulated and passes through a unicast router in application multicast method. Many products based on this technology are currently adopted in Webcasting of Internet broadcasting. "Our QoS technology supports VBR, the next-generation Internet broadcasting digitalization, on the GRID-type of peer network for the first time," said In-muk Choi, co-CEO of Infobada. "I expect this to activate distribution of multimedia information more in the next high-speed Internet market." Multicast Technology Currently the unicast method is widely used in the data transmission of streaming media over the Internet. But it has some limitations, such as with the number of simultaneous viewers and the high-cost network establishment since it is a 1:1 connection between a server and a user. Also with the unicast method, an increase in the network size is necessary, due to the increased number of simultaneous users. Compared to this, the multicast has 1:N connections between a server and users (Fig). It transmits data to one PC, which also transfers the data to other connected PCs on the same network. The first PC that receives the data plays the role of a server. Thus it can reduce the network cost of servers with 1:N connections, but this is only possible when all routers support multicast. It is different from CDN (contents delivery network) in terms of expanding data capacity using the existing hardware without incurring additional costs. CDN needs a temporary server between the main server and the user. Infobada exploited the good points of both technologies to develop its proprietary DVM technology, which uses 1:N:N connections in a way that can dramatically increase the number of Internet users simultaneously using the computer resources. The IB Caster X series is based on this technology. It has various applications related to streaming media through the Internet, such as Internet broadcasting, chat, remote lectures, and video conferencing, etc. Multicast can save money, as it can be used "without changing the infrastructure or installing additional servers and networks," Choi added. IB Caster X Series The IB Caster X series, Infobada's Internet broadcasting solution, comprises Cast Control Center (CCC), Virtual Multicast Server (VMS), IB Cast Distributor (IBCD), and IB Admin. The CCC establishes the optimal connection for distributors, and forms the virtual multicast network. The multithread operates in a large-scale environment. Packet filtering and encapsulating, and virtual multicast streaming, are included in the VMS. The IBCD takes care of the tunneling and streaming, while the IB Admin provides integrated management for IB Caster administration and other media servers. The IB Caster X series supports various operating systems, including Windows 98, Windows Me and Windows 2000. An intelligent routing function allows each client to obtain streaming services directly from their respective ISP clients or servers. "This minimizes packet loss or delay, since the streaming packet only passes two or three routers," explained Jung-chul Lee, co-CEO. The solution also provides client viewing information and historical analyses. "The IP client switching function allows the other connected clients to continue viewing even when the first client terminates viewing," Lee said. "IB Caster X series also supports whether the network is composed of a security server or private IP." A client cannot watch a broadcast without multicast authorization. by Luz Park, Seoul (April 2002 Issue, Nikkei Electronics Asia) |
Copyright (c) 1996-2002 Nikkei Business Publications, Inc. All Rights Reserved. |
