The Core or Central Cloud covers a very large area, as it is the most centralized part of the Distributed Cloud architecture. It provides high-performance computing and storage resources for applications that do not require low latency or high bandwidth. It also hosts the management and orchestration functions for the entire Distributed Cloud network.The Core or Central Cloud is typically located in a data center or a cloud service provider's facility12.Reference:

Nokia Bell Labs 5G Professional Certification - Distributed Cloud Networks

Nokia Bell Labs 5G Certification Program - Courses

Security as a Service and Software as a Service are two examples of SaaS in a cloud deployment. Security as a Service is a model where security services such as firewall, antivirus, encryption, etc.are delivered over the Internet by a cloud provider1. Software as a Service is a model where software applications such as email, CRM, ERP, etc.are hosted and managed by a cloud provider and accessed by users over the Internet2. Stack as a Service and Service as a Service are not valid terms for SaaS in a cloud deployment.Stack as a Service is a typo for Stack Overflow, a popular online platform for developers3.Service as a Service is a redundant and meaningless term that does not describe any cloud service model4.Reference:1: Nokia Bell Labs Distributed Cloud Networks, Unit 1: Cloud Ecosystem, Section 1.3: Cloud Service Models2: Nokia Bell Labs Distributed Cloud Networks, Unit 1: Cloud Ecosystem, Section 1.3: Cloud Service Models3:Stack Overflow4:What is Service as a Service (SaaS)?

SaaS within cloud computing primarily stands for Software as a Service, which delivers software applications over the internet on a subscription basis. It allows users to connect to and use cloud-based apps over the Internet, such as email, calendaring, and office tools (like Microsoft Office 365). Security as a Service (SECaaS) is an outsourcing model for security management. Typically, businesses utilize this service for functions like anti-virus software, intrusion detection, and authentication. SECaaS is also considered a type of SaaS where security services are delivered remotely via the internet. Therefore, both Software as a Service and Security as a Service are correct answers, emphasizing the diversity of services provided through the SaaS model beyond just software applications.

The properties related to a public cloud arefor users, there is no cloud infrastructure operationandeasy scaling.A public cloud is a cloud service that is offered by a third-party provider over the public internet, and is available to anyone who wants to use or purchase it1.Users of public cloud do not need to operate or maintain the cloud infrastructure, as it is the responsibility of the cloud provider2.Public cloud also offers easy scaling, as users can quickly and dynamically provision or release resources according to their needs2.Public cloud is suitable for applications that have unpredictable or variable demand, or that do not require a high level of security or customization3.Reference:1:Nokia Bell Labs Distributed Cloud Networks, Unit 1: Cloud Ecosystem, Section 1.1: Cloud Types2:Nokia Bell Labs Distributed Cloud Networks, Unit 2: Cloud Technologies and Features, Section 2.1: Cloud Computing3:Nokia and DISH to deploy first 5G standalone core network in the public cloud with AWS, Press Release

The best option to complete the sentence isVNF Forwarding Graph.A VNF Forwarding Graph (VNF-FG) is a logical representation of a network service that consists of a set of interconnected Virtual Network Functions (VNFs) and the traffic flows between them1.The VNF-FG is used to orchestrate and manage traffic through VNFs by specifying the order and the requirements of the VNFs that need to be traversed by the traffic2.The VNF-FG also defines the connection points, virtual links, and network forwarding paths that are involved in the service delivery3.Reference:1:VNF Forwarding Graph and Network Service-Beginner's Guide, Introduction2:A survey of VNF forwarding graph embedding in B5G/6G networks - Springer, Section 13:A Deep Reinforcement Learning Approach for VNF Forwarding Graph Embedding, Section I

The standardization of network functions provides well defined interfaces and defined functional elements. Well defined interfaces are the specifications that describe how network functions communicate and interact with each other and with other network components. Defined functional elements are the components that perform specific tasks or functions within the network. By standardizing these aspects, network functions can achieve interoperability, compatibility, and modularity, which are essential for building and deploying network services.

Nokia Bell Labs 5G Professional Certification - Distributed Cloud Networks, Unit 3: Cloud Resource Planning, slide 13

Module by Module - Self Study Note Guide, DC3.2-- Network Function, page 13