Page 151 - 5G Basics - Core Network Aspects

Core network aspects 1

service delivery and operation procedures, from service parameter negotiation to fulfilment and
assurance;
– Customization of network resources including service-aware networking
SDN allows network customization for the network services which have different requirements,
through the programming of network resource operations, including the dynamic enforcement of a
set of policies (e.g., resource planning as a function of the number of customers' orders to be
processed over time, forwarding and routing, quality of service (QoS) and traffic engineering,
security).

9 High-level capabilities
SDN provides the following high-level capabilities:

– Programmability
The behaviour of network resources can be customized by SDN applications through a standardized
programming interface for network control and management functionality. The user of the interface
may be network providers, service providers, and customers including end-users. This enables the
SDN applications to automate the operations of network resources according to their needs.
– Resource abstraction
The property and behaviour of underlying network resources can be appropriately abstracted and
understood, orchestrated, controlled and/or managed by those who program them, thanks to
relevant, standard information and data models. These models provide a detailed, abstracted view
of physical or virtualized network resources.

Programmability contributes to the introduction of a high level of automation in the overall service delivery
procedure, to achieve business agility, such as dynamic service creation and provisioning. A standardized
interface providing a channel for interactions between SDN applications and SDN controllers is used to access
network information and to program application-specific network behaviors. This programmability provides
the ability to control or configure the network elements by a logically centralized SDN controller through
another standardized interface.
NOTE – The delivery of some network services assumes the combination of a variety of functionalities for optimized
packet processing and traffic forwarding purposes. Programmability will, in this case, allow to smartly combine these
various functionalities into an ordered set of function chains. See [b-IETF SFC]. To support programmability, resource
abstraction is a desirable capability. Information and data models are means to provide an abstracted view of the
underlying network resources to the SDN applications, so that the application developers can simplify their program
logic without the need for detailed knowledge of the underlying network resources and technologies.

10 Requirements
SDN provides programmability of network control and abstraction of underlying network resources, among
other SDN features. As described in clause 6, network resources as used in this context of requirements refer
to network elements including switches and routers.

In order to support these capabilities, the requirements for SDN are described as follows:
– SDN is required to support programmability of network resources;
– SDN is required to support orchestration of network resources and SDN applications;
– SDN is required to provide an application-control interface for customizing the behaviour of network
resources;
– SDN is required to provide a resource-control interface for control of network resources;
– SDN is required to provide logically centralized control of network resources;

– SDN is required to separate SDN control from the network resources;
– SDN is required to support the abstraction of underlying network resources, by means of standard
information and data models;

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