Summary: | 碩士 === 國立成功大學 === 電機工程研究所 === 82 === ATM 是 B-ISDN 的主要發展平台,其與傳統網路最大的不同乃在於可針對
於不同服務的品質(QOS) 需求提供一保證,為達到此一功能,我們需要設計
一有效的頻寬管理.而在頻寬管理中,一重要的課題就是基於不同的服務需
求如何做有效的頻寬分配.在此論文中,我們將進入網路的連接根據它的服
務需求,區分為預留頻寬連接,例如,音訊和視訊的服務;和非預留頻寬連
接,例如,資料的服務.一般而言,音訊和視訊對於延遲時間有較嚴格的要
求,故預留峰值或一等效頻寬.而在資料方面,因可容忍延遲時間,在網路使
用者界面發生擁塞時,可以緩衝器調節輸入網路的速率,降低界面上的擁
塞.本論文是在 VP的架構下,將VP中的頻寬分隔成預留頻寬連接使用區和
非預留頻寬連接專用區.當預留頻寬連接要求,系統需在預留頻寬使用區預
留其峰值頻寬,若無足夠空間則拒絕進入.而非預留連接除可充份利用非預
留頻寬連接專用區,當預留頻寬連接使用區有空閒時,可利用其資源.我們
將固定頻寬分配方法比較.並顯示所提的動態頻寬分配,將提高頻寬使用率
和降低cell遺失機率.
One of the most crucial features of ATM is to provide guarantee
quality of service for various service demands. To achieve
this, a bandwidth management and congestion control are
essential. One of bandwidth management function is bandwidth
allocation, which assign a amount of bandwidth to provide the
guarantee quality of service based on traffic characteristic
and service demand. In this thesis, we propose a dynamic
bandwidth allocation scheme based on ATM-VP architecture. By
distinguished traffic into reserved traffic,(audio and video),
and non-reserved traffic ,(data).In general,reserved traffic
needs to be reserved a peak-rate bandwidth on an equivallent
bandwidth due to real time service requirement.While non-
reserved traffic can be buffered at the network interface to
releive the congestion status.We partition a link bandwidth
into reserved bandwidth section and non-reserved bandwidth
section. In this thesis, we propose a dynamic bandwidth
allocation scheme and compare with a fixed bandwidth allocation
scheme. We show that the performance of our proposed scheme is
significantly improved the performance of link utilization and
cell-loss probability.In this scheme,non-reserved traffic is
allowed to utilize the idle resource in reserved bandwidth
section.
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