Page 173 - 5G Basics - Core Network Aspects

Core network aspects 1

– Scalability.

In order to cope with appropriate control and application layers (ALs) performance in SDN networks
potentially involving a huge number of customers, providing various types of services and covering
vast geographical areas, the SDN architecture provides independent control and management
capabilities, which enables performance monitoring of available resources in all layers, and enables
dynamic adaptation of resources, e.g., scaling up and scaling down. The SDN architecture also allows
for implementation of functions in a distributed manner, and enables distribution of fault,
configuration, accounting, performance and security (FCAPS) management in each of the SDN
layers;

– Reliability.
The possibility of decomposition of the SDN architecture and their functionalities enabled by this
Recommendation, with the important role of management, contribute to the increased overall SDN
reliability. Some reliability-related mechanisms are implementation dependent;
– Covering multiple resource layer (RL) technologies.
The SDN architecture is designed to cover multiple resource layer technologies including basic data
forwarding and more complex data processing, which makes it easier for future expansion towards
software-defined infrastructure;
– Efficiency of resource usage.
The decomposition of the control and management architectures and their functionalities
contributes to overall efficiency of SDN resource usage. It is realized by monitoring and analytics of
all layers' resource usage together with dynamic resource provisioning in order to reach the required
system performance but at the same time to maintain optimal resource usage, taking into account
energy consumption reduction.

7 Functional architecture
Figure 7-1 presents an overview of the SDN functional architecture organized by means of the SDN layering
framework shown in Figure 6-1.

Figure 7-1 – SDN functional architecture

The functionalities that reside at the SDN application layer (SDN-AL), the SDN control layer (SDN-CL), the SDN
resource layer (SDN-RL) and the multi-layer management functions (MMF) are described in subsequent
clauses.

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