BL0-220 Nokia Bell Labs Distributed Cloud Networks Exam Questions and Answers

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 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

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. References: 1: Nokia Bell Labs Distributed Cloud Networks, Unit 1: Cloud Ecosystem, Section 1.3: Cloud Service Models 2: Nokia Bell Labs Distributed Cloud Networks, Unit 1: Cloud Ecosystem, Section 1.3: Cloud Service Models 3: Stack Overflow 4: 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.

 A logical space in the host’s operating system and B. Is in an isolated environment. A container is a software package that bundles an application and its dependencies, and runs as an isolated process in the host’s operating system1. Containers are lightweight, portable, and scalable, and can be deployed on any cloud infrastructure2. Unlike virtual machines (VMs), containers do not need a separate operating system or hypervisor, and share the kernel of the host3. However, containers have limited access to resources, as they are restricted by the host’s capabilities and the container runtime4. References: 1: Nokia Bell Labs Distributed Cloud Networks, Unit 2: Cloud Technologies and Features, Section 2.2: Cloud Virtualization 2: Nokia Container Services, Overview 3: Nokia Cloud Platform, Overview 4: Containers vs. virtual machines: What’s the difference?, Comparison

The “Stateless” service concept is indeed the most efficient for resource usage. In a stateless architecture, each request is treated as an independent transaction, unconnected to any previous request. This means that no state information is stored between transactions, which simplifies the design and scalability of systems. It allows for better resource utilization because there is no need to maintain state information over time, which can be resource-intensive. This approach aligns with the principles of RESTful services and is widely adopted in scalable web applications.

References: The concept of stateless services is a fundamental principle in distributed systems design, as discussed in the Nokia Bell Labs Distributed Cloud Networks learning resources. It is emphasized for its benefits in scalability and resource optimization.

All life cycle stages are clearly identified. Comprehensive Explanation and References of Correct Answer: Life cycle management is the process of managing the development, deployment, operation, and decommissioning of cloud applications and services. It involves defining the requirements, design, testing, deployment, monitoring, scaling, updating, and retiring of cloud resources. One of the benefits of life cycle management is that it provides clarity and visibility into the different stages of the cloud service, from inception to termination. This helps to ensure quality, efficiency, security, and reliability of the cloud service, as well as to optimize the use of resources and reduce costs.

References:

• Nokia Bell Labs 5G Professional Certification - Distributed Cloud Networks, Unit 4: Operating Your Cloud, slide 3
• Module by Module - Self Study Note Guide, DC4.1– Industry Trends in Data Center Hardware, page 16

 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 networkcomponents. 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.

References:

• 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

Multitenancy in cloud computing defines a set of cloud resources shared by several customers. Multitenancy is a feature of cloud computing that allows multiple customers, or tenants, to use the same cloud infrastructure and services, such as servers, storage, network, and applications, while maintaining their own data and configuration. Multitenancy enables cloud providers to optimize the utilization and allocation of cloud resources, reduce the cost and complexity of cloud operations, and offer scalable and flexible services to different customers. Multitenancy also benefits customers by providing them with on-demand access to cloud resources, pay-per-use pricing models, and enhanced security and isolation. The other options are not correct definitions of multitenancy in cloud computing. A set of cloud resources isolated from each other is a single-tenant model, where each customer has its own dedicated cloud infrastructure and services. A set of cloud resources located in different data centers is a distributed cloud model, where cloud resources are spread across multiple physical locations to provide low latency, high availability, and local compliance. A set of cloud resources assigned to the same network slice is a network slicing model, where a logical network is created over a sharedphysical network to support specific applications and customers with customized performance, quality, and security. References: Nokia Bell Labs 5G Professional Certification - Distributed Cloud Networks, Unit 2: Cloud Technologies and Features, Section 2.2: Cloud Characteristics.

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

 Physical Network Functions (PNFs) are the traditional network functions that run on dedicated hardware appliances, such as routers, switches, firewalls, etc1. Virtual Network Functions (VNFs) are the network functions that run on virtual machines (VMs) on top of a common hardware platform, such as servers, storage, and network1. Cloud-Native Network Functions (CNFs) are thenetwork functions that run on containers orchestrated by Kubernetes on a cloud infrastructure1. The evolution of Network Functions reflects the trend of moving from hardware-centric to software-centric and cloud-based solutions, which offer more flexibility, scalability, and efficiency12. References: 1: Nokia Bell Labs Distributed Cloud Networks, Unit 2: Cloud Technologies and Features, slide 18 2: Nokia Bell Labs 5G Certification Program - Blended Learning, Section 2: Distributed Cloud Networks, slide 11

 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

Kubernetes is an orchestrator, which is a software system that automates the deployment, scaling, and management of containerized applications1. Kubernetes allows users to define the desired state and configuration of their applications, and then ensures that the actual state matches the desired state2. Kubernetes also provides features such as service discovery, loadbalancing, storage management, and self-healing3. Therefore, option B best describes Kubernetes, while options A, C, and D are incorrect. References: 1: Nokia Bell Labs Distributed Cloud Networks, Unit 2: Cloud Technologies and Features, Topic: Microservices and Containerization 2: What is Kubernetes? | Kubernetes, Overview 3: Kubernetes - an overview | ScienceDirect Topics, Overview

Service automation and network automation are two techniques that provide the benefit of faster deployment. Service automation is the process of using software tools and predefined workflows to create, configure, and manage cloud services without human intervention1. Network automation is the process of using software tools and predefined policies to orchestrate, monitor, and optimize network resources and functions without human intervention2. Both techniques can reduce the time, cost, and errors associated with manual service deployment and configuration, and enable faster and more agile service delivery and network operations3. Manual service deployment and manual configuration are not techniques that provide the benefit of faster deployment, as they require human intervention and are prone to human errors, delays, and inefficiencies4. References: 1: Nokia Bell Labs Distributed Cloud Networks, Unit 5: New Services Automation, Section 5.2: Service Automation 2: Nokia Bell Labs Distributed Cloud Networks, Unit 4: Operating Your Cloud, Section 4.2: Network Automation 3: Nokia, A1 and Microsoft deploy industry’s first 5G edge cloud network slicing solution for enterprises 4: Nokia Bell Labs Distributed Cloud Networks, Unit 5: New Services Automation, Section 5.3: Service Automation Benefits and Challenges

Different paths for a NF providing Cloud Resilience are defined in a Network Service Descriptor. A Network Service Descriptor (NSD) is a document that describes the topology, configuration, and requirements of a network service. It specifies the network functions (NFs) that compose the service, the virtual links that connect them, and the forwarding graphs that define the traffic flows between them1. A NSD also defines the resilience policies for each NF, such as the number of instances, the scaling triggers, the fault management actions, and the alternative paths in case of failures2. A Network Function template, an NS Orchestrator configuration, and an NFV Orchestrator configuration are not the correct options to complete the sentence. A Network Function template is a document that describes the characteristics and requirements of a single network function, such as the virtualization environment, the resources, the interfaces, and the dependencies1. An NS Orchestrator configuration is a set of parameters that control the behavior and operation of the NS Orchestrator, which is a component that manages the lifecycle of network services3. An NFV Orchestrator configuration is a set of parameters that control the behavior and operation of the NFV Orchestrator, which is a component that coordinates the allocation and release of resources for network services3. References: 1: Nokia Bell Labs Distributed Cloud Networks, Unit 3: Cloud Resource Planning, Section 3.2: Network Function 2: Nokia Bell Labs Distributed Cloud Networks, Unit 3: Cloud Resource Planning, Section 3.3: Network Service Descriptor Role 3: Nokia Bell Labs Distributed Cloud Networks, Unit 4: Operating Your Cloud, Section 4.1: Industry Trends in Data Center Hardware

Low latency is the mandatory key driver to consider for Cloud RAN/vRAN deployment. Cloud RAN stands for Cloud Radio Access Network, which is a network architecture that centralizes the baseband processing of multiple radio sites in a cloud platform. vRAN stands for virtualized RAN, which is a network architecture that implements the baseband processing as software functions running on virtual machines or containers in a cloud platform. Both Cloud RAN and vRAN aim to improve the performance, efficiency, and flexibility of the radio access network by leveraging cloud technologies. Low latency refers to the minimal delay between the source and the destination of a data transmission, which affects the quality of service and user experience for various applications. Low latency is a critical requirement for Cloud RAN/vRAN deployment, as it ensures the timely and reliable delivery of radio signals between the centralized cloud platform and the distributed radio sites. Low latency also enables Cloud RAN/vRAN to support new 5G use cases that demand ultra-reliable and low-latency communications, such as autonomous driving, remote surgery, and industrial automation. References: Nokia Bell Labs 5G Professional Certification - Distributed Cloud Networks, Unit 3: Cloud Resource Planning, Section 3.2: Cloud RAN/vRAN.

Low latency is a mandatory key driver for Cloud RAN/vRAN deployment due to the stringent requirements of real-time communication and processing in radio access networks. Low latency ensures that data transmission and processing occur with minimal delay, which is crucial for supporting high-speed, reliable communication necessary in modern wireless networks, especially with the advent of 5G technologies.