Research And Development Of Charge System Based On Gateway

Along with reform of educate system, increase in recruit of each university or college, scale of most campuses' net also extends immediately, intranet user is certainly rising doubly, so need a charge system that runs efficiently and in realtime, manages users conveniently;And aim at network charge's characters of high school itself, such as different charge price in different intranet area, different charge price in different target IP Range.The former traditional charge system is difficult to need such requirement, believe a charge system like this, running efficiently, multi-mode charge, convenient user management, would have a very vast applied foreground in high school of our country.According to the requirement of system, the paper analyzes and researches current charge technique in detail. The traditional router charge technique is based on IP address, not based on user, can't keep IP from peculating availably , and the router's memory is so limit that result in losing data package easily;The proxy server charge technique is based on applied layer.Because of its slow responding speed, proxy server becomes network bottleneck possibly, and it can't support new applied layer application so well;So in this paper, chooses gateway charge technique, it can provide good solution aimed at the problems above mentioned.The target of the project: implements a charge system based on gateway technique, captures network data package at network layer by special data-captured module, charges in realtime according to charge rule by special charge module. This kind of charge mode can provide the high-quality network charge management service, offer different network management charge solution oriented to different network circumstance.Three greatest characteristicses of the system:1. The user can choose time/flow charge mode and different user type (normal, prepay and month);2. The system can establish time rule, time/flow threshold rule and network access rule (includes protocol type, port and target IP), and provide special discount for the special user;3. The system can set different charge price according to different target IP address or IPaddresses range.This paper introduces the whole key technique used in system at first, gateway technique (foundation technique of system), Netfilter/iptables frame (realizes connection and data forward between user and Internet), tcpdump (realizes realtime capturing of network data package), Socket (realizes communication of Web page and charge system).Followed, illustrates design, realization and test of system in detail;Finally gives summary of system .System is designed to based on B/S construction on the whole, user or administrator only needs to login website, they can use or manage this charge system. The system service is composed of charge gateway, database and Web service.On the foundation, puts forward the mind of system expand and research scheme. In order to resolve the problem that single one gateway can't satisfy with the circumstance of large members of users in actual application, we can set multi-gateway, separating network flow. That improves network accessing speed, at the same time needs to consider problems of load equilibrium and mistake handling.