Page 178 - 5G Basics - Core Network Aspects

1 Core network aspects

Figure 7-4 – SDN-RL functional components

7.3.1 Resource layer control support functional component

The RL-CS functional component interacts with the SDN-CL via the RCI reference point. It provides data
models, or optionally information models, of the network resources, which are abstracted in the SDN-CL.

The RL-CS functional component may itself realize resource abstraction instead of the SDN-CL, in case
resource abstraction is supported by the underlying resource technology.
The RL-CS functional component is programmable. The RL-CS functional component enables to update
and/or modify the data transport and/or the data processing functional components. For example, a new
protocol or a new set of interface specifications may be added for the purpose of enhancing functionalities
of the data transport and/or the data processing functional components. The programmability of the RL-CS
functional component is supported by the MMF.
7.3.2 Resource layer data transport functional component

The resource layer data transport (RL-DT) functional component provides data forwarding and data routing
functionalities.

NOTE – Though mentioned as being an SDN-RL functionality, data routing functionality (including route computation,
selection and establishment) can also be provided by the SDN-CL, e.g., in a scenario where data forwarding
functionalities in the SDN-RL is performed according to the routes computed, selected and instructed by the SDN-CL.
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-CL.

SDN-RL routing policies can be configured by the SDN-CL for SDN applications needs.
Data forwarding and data routing functionalities are extensible. Examples of functional extension include
enhancing the existing data transport capabilities and incorporating new data transport capabilities, e.g., for
the handling a new data frame format or a new data packet format.

7.3.3 Resource layer data processing functional component

The resource layer data processing (RL-DP) functional component provides functionalities to examine and
manipulate data. Data processing functionalities enable to alter format and/or payload of data
packets/frames and to adjust sending of data packets/frames as specified by SDN applications.
Data processing functionalities are extensible. Examples of functional extension include enhancing the
existing data processing capabilities and incorporating new data processing capabilities, e.g., new
transcoding algorithms.
7.3.4 Resource layer management support functional component

The resource layer management support (RL-MS) functional component provides resource description, i.e.,
vendor, software version, and their status (e.g., CPU load, used RAM memory or storage). It may include a
management agent that performs some local management operations if delegated by MMF. This agent can
be used to support technology-dependent resource discovery, for programmable, local monitoring of the
SND-RL entity (in order to limit the amount of exchanged data between the SDN-CL and the SDN-RL or to
focus on a specific issue) or to implement so-called autonomic behaviour [b-GANA-arch].

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