Design and Implementation of Virtual Internet Pricing System in Campus Network

• Main Authors: Yi-Ting Chou, 周怡廷
• Other Authors: Shi-Chung Chang
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/79246094468481611618

碩士 === 國立臺灣大學 === 電機工程學研究所 === 89 === There exists unreasonable and unfair usage of campus network because of almost free usage and lack of effective usage control mechanism, which leads to poor network performance and service quality. Take the example of dormitory network in National Taiwan University (NTU). A small number of heavy-loading users occupy a big portion of the bandwidth most of the time. The majority of users have to tolerate long delay and high packet loss caused by congestion. How to exploit the advancements of network technology for effective management of congestion and fairness in campus network is an important and challenging research problem. The focus of the thesis is on developing a network experiment environment to support the following network management research topics: the introduction of prioritized services, the study of user demands, priority control, peak-load pricing policy, and bandwidth allocation. We integrate current campus network environment of NTU into a simple experimental platform, named virtual Internet pricing system, which offers a prioritized service of two or three classes. In our design of this virtual Internet pricing system, no changes are needed on existing dormitory network protocols and applications. In our design, we evaluated and selected a QoS router for achieving prioritized service and bandwidth allocation, and determined the method of network flow metering and information item of accounting for studying user-demands and responses to management policy. We also determined the user interface and accounting/charging operations for usage-based pricing policy. Users can learn about the objectives of experiment and related information through a well-designed user interface. Based on the design rules, the system proposed by this thesis consists of five parts: a metering router, a meter reading server, an accounting/charging and traffic control server, a quality of service router and an user interface server. In the implementation over multiple operation systems, the metering router is built on a Cisco router with a NetflowTM metering tool installed on it. The meter reading server operates on a FreeBSD operating system, which reads individual flow information from NetflowTM. The accounting/charging and traffic control server operates on a Linux operating system with MysqlTM database system, which stores all accounting and pricing record tables. This server controls the QoS router remotely. The QoS router is designed over the FreeBSD operating system by Prof. Yea-Li Sun and her students. It supports prioritized service and bandwidth allocation function. The user interface server is built on Window2000TM with IIS5.0TM installed and ASP supported. It dynamically generates web pages that reveal network information and setup pages to users. We tested this virtual Internet pricing system and analyzed its performance and the correctness in collecting statistics. In system performance evaluation, results meet our design requirements. In collecting user statistics, we found that user usage may exceed the volume quota allocated because of the low sampling frequency in metering. We also analyzed system scalability. Experiment data show that accounting/charging processing time linearly increases with the number of users. We also discussed about how the sampling frequency should be adjusted in a campus network. Finally, we assessed the CPU loading for a QoS router CPU load and the memory requirement.