BL0-220 Practice Exam Questions with Answers Nokia Bell Labs Distributed Cloud Networks Certification

The ETSI MANO Model operational stack is defined as Orchestration above Network Function Management above Infrastructure Management. The ETSI MANO Model is a framework that defines the architecture and interfaces for the management and orchestration of network functions virtualization (NFV) in cloud networks1. The ETSI MANO Model consists of three main components: Infrastructure Management, Network Function Management, and Orchestration2. Infrastructure Management is responsible for managing the physical and virtual resources that host the network functions, such as servers, storage, switches, hypervisors, andvirtual machines2. Network Function Management is responsible for managing the configuration, monitoring, and optimization of the network functions, such as scaling, healing, and updating2. Orchestration is responsible for coordinating the allocation and release of resources for network services and network slices, such as instantiation, termination, and modification2. The ETSI MANO Model operational stack is defined as Orchestration above Network Function Management above Infrastructure Management, meaning that Orchestration is the highest level of abstraction and control, Network Function Management is the intermediate level, and Infrastructure Management is the lowest level2. References: 1: Nokia Bell Labs Distributed Cloud Networks, Unit 5: New Services Automation, Section 5.3: Orchestration 2: Module by Module - Self Study Note Guide - training2

Adaptability is the most critical benefit a cloud native deployment provides when deploying applications in complex and very low predictive environments. Cloud native applications are designed to be modular, scalable, resilient, and portable across different cloud platforms1. They can leverage the cloud features such as automation, orchestration, and service discovery to dynamically adjust to changing conditions and demands2. This enables them to cope with the complexity and unpredictability of the environments they operate in, such as edge computing, industrial automation, and smart cities3. Capability and reliability are also important benefits of cloud native deployment, but they are not the most critical ones. Capability refers to the ability to deliver high-performance and feature-rich applications that meet the user and businessneeds1. Reliability refers to the ability to ensure the availability and consistency of the applications despite failures or errors1. However, these benefits are not sufficient if the applications cannot adapt to the evolving and diverse scenarios they face in the real world. References: 1: Nokia Bell Labs Distributed Cloud Networks, Unit 2: Cloud Technologies and Features, Section 2.3: Cloud Native applications design 2: Nokia Bell Labs Distributed Cloud Networks, Unit 2: Cloud Technologies and Features, Section 2.5: Microservices and Containerization 3: Google Cloud, Nokia partner to accelerate cloud-native 5G3

A Policy Database is a key component in Closed Loop Automation. It stores the policies that govern the automated decision-making processes within a system. These policies define the actions to be taken in response to specific events or conditions, enabling the system to automatically adjust its operations without human intervention, thus increasing efficiency and responsiveness.

The networking concept of “Underlay” refers to the physical network layer that provides the connectivity and transport for the overlay network, which is the virtual network layer that runs on top of the underlay network1. The underlay network is composed of routers, switches, links, and protocols that enable the data transmission between different locations2. The underlay network is independent of the overlay network, meaning that it does not need to be aware of the network configuration, policies, or services of the overlay network3. Therefore, option A best describes the underlay network, while options B, C, and D are incorrect. References: 1: Nokia Bell Labs Distributed Cloud Networks, Unit 2: Cloud Technologies and Features, Topic: Underlay and Overlay Networks 2: Module by Module - Self Study Note Guide, DC2.2– Cloud Options 3: Underlay Network - an overview | ScienceDirect Topics, Overview

The most appropriate word to complete the sentence is benefits. The public cloud ecosystem offers many benefits to users, such as scalability, flexibility, cost-efficiency, and innovation12. Constraints, problems, and operability are not suitable words to describe the advantages of the public cloud ecosystem over the simple consumption of resources. References: 1: Nokia Bell Labs Distributed Cloud Networks, Unit 1: Cloud Ecosystem, slide 7 2: Nokia Bell Labs 5G Certification Program - Blended Learning, Section 2: Distributed Cloud Networks, slide 9

It is not possible to run a cloud solution in a Single Node. A cloud solution requires a minimum of three nodes to provide high availability, scalability, and fault tolerance1. A Single Node is a standalone server that does not have any redundancy or load balancing features2. A Single Node can be used for testing or development purposes, but not for production or deployment of cloud applications.

References: 1: Nokia Bell Labs Distributed Cloud Networks, Unit 3: Cloud Resource Planning, slide 5 2: Nokia Bell Labs Distributed Cloud Networks, Unit 3: Cloud Resource Planning, slide 6

 The characteristics of Cloud Native services are very light weight application and very fast deployment. Cloud Native services are applications that are built using cloud-native design principles, such as microservices, containers, and orchestration. Cloud Native services are very light weight because they are composed of small, independent, and loosely coupled components that can run on any platform and environment. Cloud Native services are very fast to deploy because they can leverage the automation, scalability, and elasticity of the cloud infrastructure, and can be updated or rolled back without affecting the whole application. References: Cloud and Network Services: Leading cloud-native and as-a-service delivery models, Nokia Mobile Networks and Bell Labs 5G Cloud Native RAN Professional Certification

Cloud resource management provides management of the resources quota and the ability to scale resources up and down. Resource quota is the limit on the amount of resources that atenant can use in a cloud environment, such as CPU, memory, storage, network, etc. Resource quota helps to prevent overconsumption of resources by a single tenant and to ensure fair allocation of resources among multiple tenants. The ability to scale resources up and down means that the cloud can dynamically adjust the amount of resources allocated to a tenant based on the demand and availability. Scaling resources up and down helps to optimize the performance and efficiency of the cloud, as well as to reduce the cost and waste of resources. References: Nokia Bell Labs Distributed Cloud Networks, Cloud Resource Planning

The technology layer function supports automated service delivery by providing the necessary tools and mechanisms to orchestrate, monitor, and optimize the cloud resources and services. The technology layer function consists of four sub-functions: cloud management, cloud orchestration, cloud automation, and cloud analytics. These sub-functions work together to enable the efficient and flexible operation of the cloud ecosystem.

References:

• Nokia Bell Labs 5G Professional Certification - Distributed Cloud Networks | Nokia Distributed Cloud Networks, Unit 2: Cloud Technologies and Features, slide 11
• Nokia Bell Labs 5G Certification Program - Courses | Nokia, Distributed Cloud Networks, Unit 2: Cloud Technologies and Features

 The 5G Core control plane is responsible for managing the network functions, services, and resources, such as authentication, authorization, session management, policy control, mobility management, etc.1. The 5G Core control plane can be deployed in a distributed cloud architecture, which consists of different cloud layers that have different characteristics and roles2. The Metro Edge Cloud is a cloud layer that is located near the access network, and provides low latency, high bandwidth, and local processing for the control plane functions3. The Core/Central Cloud is a cloud layer that is located in the core network, and provides high availability, scalability, and security for the control plane functions4. The distributed cloud architecture enables the 5G Core control plane to optimize the network performance, efficiency, and flexibility, and to support various use cases and applications. References: 1: Nokia Bell Labs Distributed Cloud Networks, Unit 1: Cloud Ecosystem, Section 1.2: Cloud Architecture 2: Nokia Bell Labs Distributed Cloud Networks, Unit 1: Cloud Ecosystem, Section 1.3: Distributed Cloud 3: Nokia Bell Labs Distributed Cloud Networks, Unit 3: Cloud Resource Planning, Section 3.2: Cloud Resource Planning for Distributed Cloud 4: Nokia Bell Labs Distributed Cloud Networks, Unit 3: Cloud Resource Planning, Section 3.3: Cloud Resource Planning for Central Cloud : Nokia Bell Labs Distributed Cloud Networks, Unit 5: New Services Automation, Section 5.1: Distributed Cloud Services Automation

Multi-tenancy network connectivity provides dedicated resources through network slicing. Network slicing is a technique that allows operators to create multiple logical networks over a shared physical infrastructure. Each network slice can have its own characteristics, such as bandwidth, latency, security, and quality of service, to meet the specific requirements of different applications and customers. Network slicing enables operators to offer customized and differentiated services to various tenants, such as enterprises, industries, and public sector organizations, while optimizing the utilization of network resources. Network slicing is one of the key features of 5G networks, as it supports the diverse and dynamic use cases of 5G, such as enhanced mobile broadband, massive machine-type communications, and ultra-reliable low-latency communications. References: Nokia Bell Labs 5G Professional Certification - Distributed Cloud Networks, Unit 4: Operating Your Cloud, Section 4.2: Network Slicing.

The statement that best describes the scaling stage of the application life cycle is the application adjusts its capacity. Scaling is the process of increasing or decreasing the number of resources allocated to an application based on the demand and performance1. Scaling can be done manually or automatically using policies and metrics1. The other statements do not describe the scaling stage, but rather other stages of the application life cycle. The periodic upgrade of the service is part of the maintenance stage, which ensures the reliability and security of the application2. The deployment of the application over the infrastructure is part of the installation stage, which involves the configuration and activation of the application2. The termination and freeing of associated resources is part of the decommissioning stage, which removes the application from the network2. References: 1: Nokia Bell Labs Distributed Cloud Networks, Unit 4: Operating Your Cloud, slide 23 2: Nokia Bell Labs Distributed Cloud Networks, Unit 4: Operating Your Cloud, slide 10

 The best option to complete the sentence is VNF 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. References: 1: VNF Forwarding Graph and Network Service-Beginner’s Guide, Introduction 2: A survey of VNF forwarding graph embedding in B5G/6G networks - Springer, Section 1 3: A Deep Reinforcement Learning Approach for VNF Forwarding Graph Embedding, Section I