Page 683 - Cloud computing: From paradigm to operation

XaaS 3

From the perspective of the management layers described in [ITU-T Y.3521], the OSS functionalities described
in this clause cover the service management layer and resource management layer aspects (see Figure 8-3 of
[ITU-T Y.3521]). The service management layer takes care of the management of NaaS services offered to
NaaS CSCs, i.e., OSS-NaaS services functionalities described in clause 7.8.1. Regarding resource management
layer aspects, they cover the management of the different NaaS resources (see clause 6.3) that are involved
in the support of NaaS services, i.e., network services, network functions, cloud compute and storage
resources, network connectivity resources and physical resources. These management functionalities are
described in more detail in clause 7.8.2.

7.8.1 Service management layer functionalities
The OSS-NaaS services (OSS-NaaS) functionalities are responsible for the management of NaaS services
(covering their deployment and operation), i.e., including service fulfilment, service assurance and service
repositories [ITU-T Y.3521].
In accordance with clause 10.3 of [ITU-T Y.3521], these functionalities include:
– Catalogue management of NaaS services (e.g., connectivity as a service, network function as a
service, network service as a service), with their relevant descriptions in terms of required network
functions and their interconnectivity;
– NaaS service order management functionalities including NaaS service order orchestration and
distribution decomposing the NaaS service order into resource order requests towards the relevant
OSS functionalities described in clause 7.8.2;
– NaaS service assurance functionalities such as performance management, problem management
and quality management of NaaS services instances;
– Inventory management of NaaS services instances;
– Usage management of NaaS services instances.

7.8.2 Resource management layer functionalities
This clause describes the resource management layer functionalities (see clause 10.4 of [ITU-T Y.3521]) for
the support of NaaS services. These functionalities cover the management functionalities related to NaaS
resources, i.e., network services, network functions, cloud compute and storage resources, network
connectivity resources and physical resources.
7.8.2.1 OSS-network services
The OSS-network services (OSS-NS) functionalities are responsible for the management (including the
deployment and operation) of network services.

In accordance with clause 10.4 of [ITU-T Y.3521], these functionalities include:
– Catalogue management of network services with their relevant descriptions in terms of required
network functions and their interconnectivity;

– Network services' order management functionalities including the automated creation,
modification and termination of network services instances (following NaaS service order requests
received from OSS-NaaS);
– Network services' assurance functions such as performance monitoring, fault management of
network services' instances; These functions include monitoring of network services' instances,
calculating and performing restoration activities when monitoring detects one or more faulty
network service instances as well as reporting status of network services' instances to clients of OSS-
NS, e.g., OSS-NaaS functionalities;
– Inventory management of network services' instances (including availability and performance of
network services' instances and the resources used to support the network services' instances);
– Usage collection and distribution of network services' instances.

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