BL0-220 Questions and Answers

The available options to interconnect private Datacenters are VPN and Backbone. VPN stands for Virtual Private Network, which is a secure and encrypted connection between two or more networks over the public internet. Backbone is a high-capacity network that connects different data centers across regions or countries. Both VPN and Backbone provide reliable, scalable, and secure data center interconnect (DCI) solutions for private/hybrid clouds. References: Nokia Cloud DCI offers a more scalable, reliable and secure way to connect data centers in private/hybrid clouds, Nokia business-critical cloud DCI solutions support multiple DCI applications, from real-time business continuity and disaster recovery, to synchronous data replication and cloud backup, Nokia partners with IP Telecom to deliver quantum-safe data center connectivity

The characteristics of traditional monolithic services are low scalability and fixed capacity. Monolithic services are applications that are built as a single unit, where all the components are tightly coupled and run in the same process. This makes them hard to scale, as they require more resources and coordination to handle increased demand. Monolithic services also have fixed capacity, as they are designed for a specific workload and cannot adapt to changing requirements or traffic patterns. Monolithic services are often slow to deploy, as they require updating the entire application for any change or improvement. References: [Cloud Native applications design], [Microservices and Containerization]

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

A YAML XML template file contains the configuration of a VNF or CNF. A VNF stands for Virtual Network Function, which is a software-based network function that runs on a virtual machine or a container. A CNF stands for Cloud-native Network Function, which is a network function that is designed and implemented using cloud-native principles and technologies, such as microservices, containers, and Kubernetes. A YAML XML template file is a file that defines the structure, parameters, and dependencies of a VNF or CNF, as well as the resources and policies required to deploy and manage it. A YAML XML template file is based on the TOSCA (Topology and Orchestration Specification for Cloud Applications) standard, which is a language for describing the components and relationships of complex cloud applications. A YAML XML template file is used by the MANO (Management and Orchestration) system to instantiate, configure, and operate a VNF or CNF on the cloud infrastructure. References: Nokia Bell Labs 5G Professional Certification - Distributed Cloud Networks, Unit 2: Cloud Technologies and Features, Section 2.4: Cloud Software and Hardware Resources.

A Network Service Descriptor (NSD) is a template that defines the characteristics and requirements of a network service, such as the number and type of virtual network functions (VNFs), the connectivity and topology between them, the scaling policies, and the service level agreements1. A NSD is defined in a catalog that is managed by the cloud orchestration layer, which is responsible for deploying, monitoring, and controlling the network services across the distributed cloud2. Therefore, cloud orchestration requires a NSD defined in a catalog, while the other options do not. References: 1: Nokia Bell Labs Distributed Cloud Networks, Unit 3: Cloud Resource Planning, Topic: Network Service Descriptor Role 2: Nokia Bell Labs Distributed Cloud Networks, Unit 4: Operating Your Cloud, Topic: Cloud Orchestration

A Network Service Descriptor (NSD) is an integral part of network function virtualization (NFV) architecture. It describes the composition of network services, including how different network functions are chained or combined to provide a specific service. Cloud orchestration involves the automated management of various cloud computing services and resources, including networking services. It requires a comprehensive description of these services (i.e., NSD) to automate their deployment, scaling, and management effectively. NSD in a catalog would be used to define the parameters and configurations needed for the orchestrated service to be deployed in a cloud environment, making cloud orchestration the most likely context for requiring an NSD.

Network Service Orchestration is the process of managing the lifecycle of network services across multiple domains and technologies. It automates NFV service bydeploying, configuring, and scaling virtual network functions (VNFs) on demand. It is part of the 5G key enablers because it supports the dynamic and flexible provisioning of network slices and edge cloud applications. It does not increase operational complexity, but rather simplifies and optimizes it by using AI/ML and closed loop automation.

References:

• Nokia Bell Labs 5G Professional Certification - Distributed Cloud Networks | Nokia Distributed Cloud Networks, Unit 4: Operating Your Cloud, slide 8
• Nokia Bell Labs 5G Certification Program - Courses | Nokia, Distributed Cloud Networks, Unit 4: Operating Your Cloud

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

 Hyperscale computing relies on scalable server architecture. This is true because hyperscale computing is a type of cloud computing that aims to provide massive scalability, performance, and efficiency for large-scale applications and data processing1. Hyperscale computing requires a scalable server architecture that can support thousands or millions of servers that are interconnected by high-speed networks2. Scalable server architecture enables hyperscale computing to handle increasing workloads, optimize resource utilization, and reduce operational costs3. References: 1: Nokia Bell Labs Distributed Cloud Networks, Unit 4: Operating Your Cloud, Section 4.1: Industry Trends in Data Center Hardware 2: How Nokia Bell Labs’ new serverless computing design will take cloud computing to the next level4 3: Nokia Bell Labs 5G Professional Certification - Distributed Cloud Networks1

The approximate maximum distance of an Edge Cloud from the end-user is 300KM. Edge Cloud is a type of cloud deployment that brings cloud resources closer to the end-user, reducing latency and improving performance1. Edge Cloud can be located at various distances from the end-user, depending on the use case and the network topology2. However, the general range of distance for Edge Cloud is between 10KM and 300KM3. 10000KM, 5000KM, and 10Q0KM are too far to be considered as Edge Cloud, as they would introduce significant delays and inefficiencies in the network.

References: 1: Nokia Bell Labs Distributed Cloud Networks, Unit 1: Cloud Ecosystem, slide 4 2: Nokia Bell Labs Distributed Cloud Networks, Unit 1: Cloud Ecosystem, slide 15 3: Nokia Bell Labs Distributed Cloud Networks, Unit 1: Cloud Ecosystem, slide 16

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.

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. References:

• Nokia Bell Labs 5G Professional Certification - Distributed Cloud Networks
• Nokia Bell Labs 5G Certification Program - Courses

 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

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