MPLS 기반 IPTV 전송 고성능화를 위한 멀티캐스트 프로토콜 연구

Abstract

Unlike the Broadcast Method, IP multicasting is a very useful technology for the processing of large amounts of data on the network; such as the image data used for a particular group, because it reduces the load of the entire traffic and minimizes the influences on other networks and data transmissions when the network is formed by transmitting to a specific group using the same application. The existing research on multicasting mainly consists of studies of: bandwidth efficiency and the guarantee of real time video quality by improving the transmission method, the multicast algorism supplement and adding functions to supplement the shortcomings of each multicast protocol, improving the shortcomings such as the tree formation of the flooding and prune method, and channel diversion routing technology for solving the problems of the channel diversion time when the channel is diverted for guaranteeing the maximum service quality. The multicast protocol is largely divided into the transmitter based tree method and the group share based tree method, and they are used differently according to each situation, thus different multicast protocols have diverse advantages and disadvantages and usages at the L3 section. However, when real-time data is transmitted to the LAN environment of the L2 formation, problems occur where all the unwanted devices with VLAN information at the given bandwidth receive the real-time data. In the case of this occurring at the STP loop at the given VLAN, problems which have fatal influences on the entire network will occur. To solve the problems facing diverse multicast protocols, the PIM-SM method was the optimal protocol, which is the very RP selection method. This method consists of setting the RP at the core router of the router and the IGMP snooping function at the L2 section of the router. By setting it in this way, it is able to prevent the problem of all devices receiving the real-time data unnecessarily. With the selective operation of the multicast protocol at the L3-L2 section, the real-time server can transmit the wanted real-time data to the wanted terminal or group address through the LAN of the existing L2 section and reduce the load when transmitting to the router. The network load is reduced with maximum efficiency, because only the related group can be managed and transmitted and the whole network load can be minimized. Also, the investment cost reduction was achieved by using fewer circuits due to the reduction of bandwidth use.