現今的基礎網路架構與運行方式因需求的上升已漸漸不敷使用，因此開始有新的網路架構被提出，希望能符合未來網路的需求。目前最具代表性的未來網路架構是軟體定義是網路(Software Defined Network, SDN)。而且目前已有許多的研究人員從事SDN相關的研究。但是在單一實驗室中，想進行大規模的網路實驗是件困難的事情，而網路實驗平台則可以解決這個問題。於是本論文設計並實作一個SDN網路實驗平台。SDN網路實驗平台提供虛擬的OpenFlow Switch與OpenFlow Controller供研究人員進行OpenFlow相關之實驗。 為提升網路實驗的方便性，於是SDN網路實驗平台加入了網路功能虛擬化(Network Functions Virtualization，NFV)的概念。網路功能虛擬化可以將防火牆(Firewall)、Network address translation、深度封包檢測(Deep Packet Inspection)、閘道器(Gateway)等網路功能利用虛擬化技術變成虛擬網路功能(Virtual Network Function)。將虛擬網路功能加入網路實驗平台後，研究人員可以直接在實驗拓撲中新增虛擬網路功能。簡化自行建立虛擬網路功能的複雜程序。但是這些網路服務可能會在SDN網路實驗平台中產生大量的網路流量，若又發生網路功能和客戶端被分隔在距離遙遠的兩個計算機中心內，則會增加服務的延遲、有限的網路頻寬被嚴重的消耗等問題，為改善這個問題，本論文提出Shortest Path Algorithm-based Sliced Network Weighted Graph機制，藉由這個機制來搬移虛擬網路功能到客戶端附近的資料中心內，來減少網路服務的延遲與降低網路頻寬的消耗。在實驗中，使用本機制可以將傳出延遲從原本的平均3.21ms下降到0.46ms，改善幅度為85.5%的成效。;The basic network devices are not enough to use, so there are some new network architectures are proposed. New architectures can support the demands of future networks. Software Defined Network (SDN) is the most popular future network architecture.more and more scholars dedicate to SDN researchs. But doing large-scale network experiment is difficult in single laboratory, and the network testbed can solve this problem. It designs and implements an SDN-based network testbed in this paper. SDN-based netwrok testbed provides virtual OpenFlow Switch and OpenFlow Controller. Scholars can use those resources to do OpenFlow experiments. The SDN-baded Network Testbed has the concept of Network Functions Virtualization(NFV) to enhance the convenience of the Internet experiments. NFV use virtualization technologies to create Virtual Network Functions(VNF). Such as Firewall, Network address translation, Deep Packet Inspection, Gateway. In the SDN-based Network Testbed, scholars have the ability to deploy VNF in their experiment topologies.But VNF may create large network traffic between Data Centers. So this paper, provide Shortest Path Algorithm-based Sliced Network Weighted Graph(SPA-SNWG) mchanism to reduce network traffic and latency. SPA-SNWG reduce network traffic and latency by migration VNF close to clients. In the experimenet, using SPA-SNWG mechanism can reduce network latency from 3.21ms to 0.46ms, improving the margin of 85.5% of the results.
