網路功能虛擬化技術改變了原本網路功能傳統在硬體上使用的方法，而使其能以軟體的方式進行。虛擬網路功能的放置就成為網路功能虛擬化技術裡主要的問題。在本篇論文中，虛擬網路功能之間的關係，包含其之間的關聯性與流量的變化，都成為放置虛擬網路功能在虛擬機器時重要考慮的因素。度量嵌入結合了虛擬網路功能間的關係與網路伺服器上的虛擬機器這兩者。嵌入演算法掌握了服務鏈裡虛擬網路功能組成的結構並且反映在虛擬網路功能的布置上。在實驗的章節，本篇論文所提出的演算法在試驗的例子比起其他的方法也有不錯的結果。

Network function virtualization (NFV) has changed the traditional usage of network functions from hardware appliances to software implementation. Placement of virtual network functions (VNFs) has become a fundamental problem in NFV. In this study, relation in VNFs, including dependency and changes of flow size, would be important factors in placement of VNFs onto virtual machines on servers. Metric embedding is adopted to combine the relation of VNFs and virtual machines on network servers. The structures shown in service chains are seized by embedding algorithm and thus reflect the result on placement of VNFs on the network. In the simulation section, the proposed technique is evaluated and performs well in test cases, showing that the proposed technique gives a fine solution to VNF placement problem.

Abstract ii
Table of Contents iii
List of Figures iv
List of Tables v
1 Introduction 1
2 Related Works 3
3 Method 4
3.1 Problem definition and notation 4
3.2 Observation from service chain 5
3.3 Metric embedding 7
4 Simulation Setting and Result 13
4.1 Network topology 14
4.2 Naïve algorithm 15
4.3 Routing algorithm for service chain 15
4.4 VNFs in service chains 17
4.5 Simulation result 18
5 Conclusion 20
Bibliography 21

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