What is the best solution for deploying an optimal network function distribution?

The best solution for optimal network function distribution involves using a centralized management and orchestration (MANO) framework. This framework intelligently places, scales, and manages Virtual Network Functions (VNFs) across a distributed infrastructure, which typically consists of various cloud data centers (central, regional, and edge). This orchestrated approach allows network operators to balance performance, latency, cost, and resilience by deploying functions precisely where they are most needed. Orchestration across multiple data centers is the core principle for achieving a flexible, efficient, and scalable virtualized network.

A. Using duplicated Virtual Network Functions: Duplication is a technique for achieving high availability and redundancy, not a comprehensive strategy for optimal distribution of all network functions.
B. Using Virtual Network Functions to control the routing: This describes a specific application of a VNF (e.g., a virtual router), not the overarching strategy for deploying and distributing all network functions optimally.
D. Using Virtual Network Functions in Access: Placing VNFs in the access network (edge computing) is one part of a distributed strategy but is not the complete "best solution" for the entire network.

1. ETSI GS NFV 002 V1.2.1 (2014-12), "Network Functions Virtualisation (NFV); Architectural Framework."

Section 5.2, "NFV Management and Orchestration," and specifically Figure 4, illustrates the NFV Orchestrator (NFVO) having a network-wide view. It is responsible for the orchestration of NFVI resources across multiple Virtualised Infrastructure Managers (VIMs), which can represent different physical data centers, thus enabling optimal, distributed placement of VNFs.

2. Nokia, "CloudBand Application Manager Datasheet," (2020).

Page 2, "Benefits" section, describes how the platform provides "end-to-end service orchestration" and "automated deployment and lifecycle management of VNFs across distributed cloud infrastructure." This directly supports the concept of using orchestration across various data centers as the optimal solution.

3. Mijumbi, R., Serrat, J., Gorricho, J. L., Bouten, N., De Turck, F., & Wauters, T. (2016). "A Survey on Network Functions Virtualization." IEEE Communications Surveys & Tutorials, 18(1), 237-261.

Section IV.A, "NFV Orchestrator," explains that the NFVO has a global view of the network and is responsible for "deciding the optimal placement of VNFs on the available physical resources," which are often distributed across multiple locations. (https://doi.org/10.1109/COMST.2015.2477048)