Research And Development Of Campus Network Accounting System Based On .NET

The paper analyzes accounting policy and methods currently adopted in the campus network. According to the current condition of network and actual requirements,the writer developed a network-accounting system that can be applied to this college and can be expand to other campus network also. Accounting policy defines principia and method of account. According to the condition of college and the account of CERNET based on IP flow, The accounting method adapted in this system is flow accounting .The fee-rate constitute of base fee, normal fee, spill fee. Because accounting standard of CERNET is base on the size of traffic , fee-rate is often changed with time moving,at the same time there is a different fee-rate to different destination. When instituting fee-rate , we must be in view of this . We are also considering equilibrium of network traffic and provide some discount .So we created different standard according to day and night .Thus accounting policy can adjust by the actual change of accounting standard in CERNET and meet the actual requirement flexibly. Contrasting the accounting method based on IP and user, we adopt the technique of flow-accounting based on IP. Analyzing popular technique of flow collected,through comprehensive research, we choose the technique of NETFLOW . The paper analyzes and contrasts difference of format between version 1 and version 5 of NETFlOW . AS a high performance switch-technique of Cisco, it collects statistics of flow through the ROUTER or SWITCH .In router, the network traffic is processed and recorded as "flow".After configured edge router , records of flow in router will be sent to the host which received data at every interval, so the information of NETFLOW in actual record will be collected ,at the same time the influence on network communication will be analyzed. The host opens the specified port to collect data with program, set time to gather and process the related data in files, save into the database of MYSQL . Then the database interface program FREETDS which support to connect SQL SERVER was installed and the program developed with PERL transports information of flow to accounting database based on SQL SERVER 2000,so that provides data to the account management system and self-help system. The administrators can export the traffic records and save periodically as historical data for using in future. Two databases: current database and historical database were created to prevent the disturber when writing current data and searching historical data .they can provide such functions as record saving ,traffic searching ,fee counting and historical flow saving. Account management system and self-help system based on .NET ( MICROSOFT Development Environment) .They respectively adopt the architecture of C/S and B/S .With the thinking of Object-oriented design and analysis, we draws use case diagram ,class diagram ,sequence diagram and state diagram to describe system with the tools of Microsoft visio in account management system. According to requirement, the paper divide the system into four subsystems or use cases .They are user managing , system setting , compositive search and fee managing. The central part of developtment is design of classes. We define different classes according to the system function and the layer thinking. A complicated system is divided into several subsystems, thus it has well encapsulated, highly cohesive, loosely coupled, and is easy to maintain, extend, divide, and improve. In account management system, namespaces, including base classes namespaces and business namespaces, are created. The base classes namespaces are composed of UI-related base classes, data access base classes,System-Control base classes,common layer base classes. The ralated classes about business are located in the namespace "account"and are used to implement actual business rule. UI base classes bring a face unified style to system. Data access base classes provide some methods of database access. Common base classes and System-Control base classes encapsulate functions that include control of program, exception processing and printing. The technique of ADO.NET is adopted in period of coding. It includes "DataAdapter", "DataSet", "DataReader"which used to operate database. Data access base classes implements some major database access methods, including stored procedure call, data...