agazine. 49(7): 88-97. Spurgeon, C. E. and Zimmerman, J. 2000. Ethernet: The Definitive Guide: Designing and Managing Local Area Networks, 2nd Edition. Sebastopol, California: O'Reily Media. ISBN: 978-1449361846. VMWare. n.d. Introduction to VMware DRS and VMware HA Clusters. Retrieved from VMWare vSphere 5 Documentation Center: https://pubs.vmware.com/vsphere-55/index.jsp VMWare. n.d. VMWare NSX. http://www.vmware.com/products/nsx.html Network Functions Virtualization Infrastructure Greg Stiegler and John DeCastra CONTENTS Network Functions Virtualization Infrastructure Components of NFVI 4.2.1 Physical Components 4.2.1.1 Compute: Server, Computer Processing Unit, Graphical Processing Unit, Network Interface Controller, I/O 4.2.1.2 Network 4.2.1.3 Storage 4.2.2 Virtual Infrastructure Manager 4.2.3 VIM Solutions 4.2.3.1 Commercial 4.2.3.2 Commercial Open Source 4.2.3.3 Pure Open Source 4.2.4 VIM Components 4.2.4.1 Virtualization 4.2.4.2 Virtual Machine 4.2.4.3 Containers 4.2.4.4 Hypervisor 4.2.4.5 Storage Virtualization 4.2.5 Orchestrator Building an NFVI Solution 4.3.1 Operational Changes 4.3.1.1 Agile 4.3.1.2 DevOps 4.3.1.3 Continuous Integration/Continuous Delivery 4.3.2 Innovation and Integration 4.3.2.1 Design 4.3.2.2 Build 4.3.2.3 Manage 4.3.2.4 Integrate 4.3.2.5 Operate 4.4 NFVI Deployment 4.4.1 Meeting Zone Demand 4.4.2 Fault Tolerance 4.4.3 Infrastructure Resiliency 4.4.4 Application Resiliency Leveraging NFVI for VNFs 4.5.1 VNF Performance Profiles 4.5.2 Scalability 4.5.3 VNF Management Building the Network of the Future 4.6 Summary References 4.1 NETWORK FUNCTIONS VIRTUALIZATION INFRASTRUCTURE The use of network functions virtualization (NFV) for the design and implementation of a telecom network requires a distributed cloud infrastructure on which the various virtualized network func- tions (VNFs) run. Chapter 3 described the design and operating constraints of VNFs. As a refresher, a VNF is a virtualized task formerly carried out by proprietary, dedicated hardware. VNFs move network functions out of 