Page 153 - 5G Basics - Core Network Aspects

Core network aspects 1

– Abstraction

The abstraction function interacts with network resources, and provides an abstraction of the
network resources, including network capabilities and characteristics, in order to support
management and orchestration of physical and virtual network resources. Such abstraction relies
upon standard information and data models and is independent of the underlying transport
infrastructure.
NOTE – The SDN control layer, instead of the application layer, may execute control for the resource layer for the sake
of performance (e.g., for traffic engineering).

11.3 Resource layer

The resource layer is where the network elements perform the transport and the processing of data packets
according to the decisions made by the SDN control layer, and which have been forwarded to the resource
layer via a resource-control interface.
– Control support
The control support function interacts with the SDN control layer and supports programmability via
resource-control interfaces.
– Data transport and processing
The data transport and processing function provides data forwarding and data routing
functionalities.
The data forwarding functionality handles the incoming data flows to forward them along the data
forwarding paths that have been computed and established according to the requirements defined
by the SDN applications. The control of the data forwarding functionality is provided by the SDN
control layer so that the data forwarding functionality in the resource layer may be minimized.
The data routing functionality provides network control and services in the resource layer according
to the routing rules which can be customized by the SDN control layer for SDN applications. The data
forwarding paths are determined by distributed routing control of the resource layer.
Note that the resource layer may provide either data forwarding functionality or data routing
functionality, or both.
Additional functionalities including media transcoding and data compression can be added,
removed, or reconfigured for customization of data packets as specified by SDN applications.

NOTE – Additional functionalities including media transcoding and data compression can be invoked for the
delivery of a service. From an SDN perspective, the ability to solicit a variety of functions to dynamically
structure a service and allocate resources accordingly is a promising opportunity to enforce differentiated
traffic forwarding policies within the network, thereby contributing to the improvement of customer’s quality
of experience.

11.4 Multi-layer management functions
The multi-layer management functions exist as cross-layer functions providing functionalities for managing,
as appropriate, the functionalities of the other layers, i.e., the application layer, the SDN control layer and
the resource layer.

The multi-layer management functions include functionalities for supporting fault, configuration, accounting,
performance and security (FCAPS) management as described in [ITU-T M.3400]. Examples of such
functionalities are equipment inventory, software upgrade, fault isolation, performance optimization, energy
efficient operations, and initial configuration of the network resources, SDN controllers, and SDN
applications. Specifically, autonomic management, i.e., continuous adaptation to the network status, may be
performed by the SDN control layer.

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