The Analysis On Alteration And The Capacitance Enlargement In The Customs Network System

The customs network system has already been constructed for more than ten years. Now, it became to a large network system with more than 800 nodes that lay over the customs'spots throughout China. Some application items have already circulated on the network for many years such as: The conveyance system through different customs, The network system for checking the customs declarations and The license network system etc.. They exert great effect on improve the efficiency of entering the customs and strengthen the supervising power of the customs'. But in recent years, a lot of accidents about the viruses invading took place on the customs'network. These cause the build up on the letter way in the network system and sometimes even cause the paralysis of the network system. The H2000 system will soon be carried out on the customs'network system, and some application items keep increasing continuously. All of these had put forward higher and higher requests for the customs'network system. So these had became the biggest challenge to strengthen the safety and credibility of the customs network system, set up a circulating network backup system, promise the customs key application data on the network of deliver. In order to suit for an information-based development of customs, especially suit for the demands of the H2000 customs clearance systems, it is necessary to expand the content of the original customs'network. As one of the first experimental units of this network reformation engineering, Chang Chun Customs take the lead in carrying out this engineering. Based on the file"The project for expanding the content and reconstructing the customs'network system"that was publicized by GAC. According to the actual situations of the Chang Chun Customs, the technicians of the Changchun customs engineering team draw up "The project for expanding the content and reconstructing the customs'network system in the Changchun Customs ". The aim of this project is to adapting the demand of the H2000 system, satisfy the various high requests of the customs. This engineering is authorized by the GAC, and is designed and carry out by the Changchun Customs. 1. The function of the Chang Chun Customs network system after expanding the content. According to the objectives of this engineering, the network system will possess the following functions: (1)to realize to carry out the "three nets separately" (2)to realize the high usability of the network (3)to realize the high expansibility of the network (4)to realize the credibility of the network (5)to improve the supervising of the network (6)to improve the security of the network (7)to realize VOIP in the Changchun customs area. 2. The main technical contents of the engineering (1).The theory background for the technique application â—‹1 The core LAN of Chang Chun Customs area The core LAN of the Chang Chun Customs area can be divided into three parts the "Run Net"and the "Manage Net"and the "Governmental Affairs Information net". The "Governmental Affairs Information net"possesses a set of completely independent network system. The "Run Net"and the "Manage Net"access each other through the fire wall.â—‹2 The LAN of Chang Chun Customs subjection units The LAN of Chang Chun Customs subjection units includes the "Run Net"and the "Manage Net"two parts. â—‹3 The WAN of Chang Chun Customs area The WAN of the Chang Chun Customs area can be divided into the "Run Net"and the "Manage Net". The users of the "Manage Net"connect with the Changchun Customs with the GRE tunnel technique. At the same time raise the speed of all the WAN (2).The key skills and the innovation â—‹1 The application of the VRRP â—‹2 The application of the Trunk â—‹3 ResilientLink â—‹4 The GRE techniques â—‹5 The QoS â—‹6 The application of the CHAP 3. The comparison and contrast of techniques in this engineering and the advanced techniques of the foreign countries'This engineering adopts a series of the techniques and methods such as: the CBWFQ technique, GRE-VPN technique, CA NMS and the 3com 3NS. They make the network system become safe, scientific, credible, reasonable, useful. The network system has already reached the level of the advanced techniques in the foreign countries, it can suit for the demands of the development of the network in the future. 4. The item application and the generalizationSince this enginerring was carried out, it has already improved well its standard and credibility, and permit wrong function. The network system is easy to be used, easy to be managed and protected. The credibility and safety of the network all had an obvious exaltation. The network system satisfied current various business needs, and laid good network hardware foundation for the development of aftertime. The completion of the Chang Chun Customs network experimental unit engineering, expanded provide good experiences for the other customs in China to use for reference, it is worth being generalized in all the customs in China. 5. The Production of this engineering Chang Chun Customs network system provided the guarantee for the business system of customs. On the aspect of the economical efficiency, it saves the time for delivering and save the budget for official affairs and raise work efficiency. On the aspect of the social efficiency, this system supplies the supports and pushed the generalization of the H2000, to make the development of the information-based construction of the customs. It also realize the carry out of some items on the network system. It embodies the work policy of the customs. The application of the VOIP, save the budget of the customs'official affaires, it has great economy benefit.