In everyday network changing field, permanent service is being an issue. Network disconnection phenomenon is directed to financial damage to service providers. Some companies guarantee on network maintenance, but there is a permitted limit according to their company regulations. If customers overuse the limitation, extra pay will be placed. Moreover, network disconnection affects critical in some fields with using network. Permanent service becomes indispensable in stock, finance, online game, and other fields. Additionally, it should be possible to pre-detect and block abnormal traffic area, improve network infrastructure secureness and optimization, and reduce damage recovery cost. MCS(Multi Connection System) can provide permanent service even if a connection is cut because it provides multi-connection. It can also isolate the attacker when it detects DDoS attack, so it provides smooth service. Also, the benefit from this structure is that the real server can be hidden so the service can be provided continuously. It prevents damages from network cutting, reduces management cost, maintains the best performance, and increases convenient on management and maintenance. Stable and continuous service can be provided with managing network through MCS.