隨著網路使用量的劇增以及網路使用人口的快速成長, 如何更有效地利用有限的頻寬資源以及對網路服務品質的保證 (The guarantee of Quality of Service) 成為現今一門重要的課題。現今被網路服務提供者 (Internet Service Provider, ISP) 所廣泛採用的兩種頻寬計費方式為單一速率計費 (flat-rate pricing) 和 使用時間計費 (Duration-based pricing), 而這兩種計費方式都無法應用在提供多種不同服務等級的網路架構上。因此, 網路服務提供者急需一個適當的計費機制, 而這個機制必須可以依據提供給各個使用者的服務等級和型態做出合理的收費, 並且透過這個計費機制可以讓使用者更有效率地使用網路資源, 以減少服務提供者不必要的軟硬體支出。這篇論文提出一個新的計費系統: 政策性頻寬計費系統 (Policy-based Bandwidth Billing System ) , 這個系統不但能有效地解決上述的頻寬計費問題, 同時可以事先或即時地控管使用者的頻寬和傳輸量, 提供對網路服務品質的保證。政策性頻寬計費系統採用的新的計費機制: 政策性頻寬計費機制 (Policy-based Billing Scheme), 該機制不但支援傳統的計費方式, 更包含了使用量計費 (volume-based pricing), 服務導向式計費 (service-based pricing), 時段式計費 (schedule-based pricing), 以及線上即時頻寬計費 (online-bandwidth-based pricing)。政策性頻寬計費系統是架構於政策性頻寬管理系統 (Policy-based Network Bandwidth Management System) 之上, 並根據管理者和使用者所訂定之頻寬計費政策 (Policy) 來控管網路頻寬和計費。此系統在安裝時不需要更動既有的網路架構和協定, 並且可以同時對多個網域做計費和控管。在這篇論文中也實作了這個系統, 並做了一個簡單的計費模擬。

The guarantee of Quality of Service (QoS) on the IP network is becoming an important issue in recent years. The pricing schemes currently used by the Internet Service Providers (ISPs) are flat rate pricing and duration-based pricing, and both cannot be applied to the network with multiple service levels. The service providers have an urgent demand for a proper billing system that can charge the users for different service levels provide by the service providers. This paper presents a Policy-based bandwidth billing system (PBBS), which not only bills users for their consumed services and bandwidth resources but also controls and guarantees the QoS classes required by the users over IP networks. The Policy-based pricing scheme adopted by PBBS can be molded into all kinds of pricing schemes such as flat rate pricing, duration-based pricing, volume-based pricing, service-based pricing, schedule-based pricing, or online-bandwidth-based pricing. The PBBS is based on the Policy-based bandwidth management system and achieves the billing and bandwidth controlling according to the Policies made by the network providers and users. The system requires no changes to the existing protocols and applications and can be used to bill and manage multiple domains simultaneously. An implementation of PBBS based on the BandKeeper system is described and indicates that the system is practical.

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