用於 IPsec 叢集效能最佳化之模型

Abstract

近年來，網路傳輸的安全性越來越受到重視，許多研究提出能加強安全度的機制。其中 IPsec 能提供有效的解決方案。IPsec 的一項應用是 VPN，可提供兩個私密網域在公眾網域傳輸資訊的安全性。但是隨著網路速度的快速發展，IPsec VPN 的處理速度越顯侷限。為了解決這個問題，叢集式 IPsec架構被提出以增進效能。 這篇論文主要探討如何用數學分析叢集式 IPsec架構。藉由這樣的分析，我們可以很容易地找出系統效能與各種特性之間的關係，致力改善影響效能最多的特性，而調整系統到最佳狀態。

Nowadays, security issues are more and more important in the field of internet and IPsec protocol suites provides an effective secure solution over IP networks. We could apply IPsec into Virtual Private Network (VPN). However, in high speed network environment, IPsec VPN gateway might become the bottleneck due to their encryption or decryption overhead. Thus various approaches are proposed and a typical soulution is IPsec cluster to share and reduce the overhead. In order to verify the advantages and disadvantages of this scheme and promote performance, how to model IPsec cluster is necessary and critical. In this thesis, we propose a novel model to analyze IPsec cluster. Markov chain of this model is finite quasi birth-death process (QBD) and emulation result is based on the stationary analysis. It is showed to obtain the relation between system factors and performance flexiablely and easily. Based on above data, we could optimize system by tuning influential parameters.