對稱式虛擬私有網路在軟管模式下頻寬預留模式之研究

Bandwidth Reservation for Symmetric VPNs in Hose-Model with Hybrid Routing

邱子哲(Tzu-Che Chiu)

指導教授 ： 陳彥文

國立中央大學/資訊電機學院/通訊工程學系/碩士(2007年)

摘要

虛擬私有網路(Virtual Private Network, VPN)提供使用者於公用網路中建置安全可靠的私有網路。而軟管模式是較具彈性的服務模式，因為它允許虛擬私有網路的進出流量，可由一個端點任意地到另一個端點。為滿足用戶端所提出的需求頻寬且兼具節省建置成本的考量，虛擬私有網路服務提供者需採用更佳的預留頻寬模式，於建置VPN拓樸時預留適當的頻寬。在早期的預留頻寬模式研究中，建置軟管模式虛擬私有網路拓樸的方法有樹狀架構和多條路徑架構，此二種方法各有其優缺點。
本篇論文中，結合二種架構形成適用於對稱式虛擬私有網路複合式架構，可兼具兩者的優點，而降低兩者的缺點。複合架構根據樹狀架構的建置結果發展出新的預留頻寬模式，改成選定一個可行的節點當root，並將端點的需求頻寬預留於其與root的所有最短跳躍數路徑上。模擬結果顯示，相較於樹狀架構，所提出之方法具有較低的建置失敗率和總預留頻寬量。

關鍵字

樹 ； 多條路徑 ； 虛擬私有網路 ； 頻寛管理 ； 服務品質 ； 軟管模式

並列摘要

Virtual Private Networks (VPN) provides customers with reliable and secure network connections over shared public network. In VPN service models, hose model has greater flexibility because the permitted traffic to and from a hose endpoint can be arbitrarily selected from other network nodes. In order to satisfy endpoint''s required bandwidth and save reserved bandwidth, VPN service provider must build VPN topology by more effective scheme of bandwidth reservation. Traditionally, schemes of bandwidth reservation in hose model can be divided into tree approach and multipath approach. These two approaches have their individual benefits and drawbacks.
In this thesis, a hybrid approach, which considers the effective route selection and bandwidth reservation, is proposed for the construction of symmetric VPNs in hose model. To generate hybrid topology that satisfies all endpoints, we need to find all of the minimum hop paths between each endpoint node and the root node, and allocate the required bandwidth to them. Our simulation results show that the proposed scheme can reduce the reserved bandwidth and the blocking ratio when comparing to the tree routing approach.

並列關鍵字

Tree ； Bandwidth reservation ； Hose model ； QoS ； Multipath ； VPN

參考文獻

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