Studies on Construction Methods of Large-Scale Virtual Networks
暢 間野 · Institutional Repositories DataBase (IRDB) · 2020
Communication networks are vital infrastructure in our information society because they realize a large amount of communication between a vast number of hosts.The demand for communication networks, that is, the number of connected devices and the total bandwidth, has been increasing year by year.To meet this demand, the research community has been studying the network virtualization technology that allows logically separated virtual networks (VNs) to coexist on shared physical infrastructure.This network virtualization provides network operators with flexibility, diversity, and manageability.This thesis studies construction methods of large-scale VNs.In network virtualization, the role of traditional ISPs is divided into those of service providers (SPs) and infrastructure providers (InPs): an SP makes a request to an InP for building a VN; the InP embeds the VN onto its physical network.Virtual network embedding is an optimization problem, in which the InP attempts to find a minimum cost mapping between the desired VN and its physical network.To adequately provide flexibility, diversity, and manageability through network virtualization, there are still three issues.First, it is difficult to embed VNs across multiple infrastructure providers since they are competing with each other.Second, it takes a long time to embed a large VN because there is a vast number of mapping between virtual resources and physical resources.Third, we need a physical network in which we can embed various types of VN.Chapter 2 addresses the problem of embedding VNs across multiple infrastructure providers.This problem is hard because no entity knows the entirety of the physical network, CONTENTS 5.6