Question 28 - BL0-220 discussion

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.Reference:1:Nokia Bell Labs Distributed Cloud Networks, Unit 3: Cloud Resource Planning, Topic: Network Service Descriptor Role2: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.