Page 1349 - 5G Basics - Core Network Aspects

Signalling aspects 3

6.1.9 Content service application functions (CSAFs)

The CSAF is an application function (AF) responsible in the DSN functional architecture for the provision of
content-related services to the EF.
The functions are described in detail in [ITU-T Y.2080].

6.2 Reference points

6.2.1 Reference point C1
The C1 reference point is between NEF and RLF.

C1 is used by RLF to request the enrolment of a DSN node in which the RLF resides in the DHT-based DSN
network.

C1 is used by NEF to provide configuration and bootstrap information to the RLF regarding a DSN node that
newly joins the DHT based overlay in DSN network.

6.2.2 Reference point C2

The C2 reference point is between RLFs.
C2 is used to exchange the information that constructs and maintains the DHT based overlay in a DSN
network.
C2 is also used to forward resource location requests or resource location update requests to RLFs.

6.2.3 Reference point C3
The C3 reference point is between RLF and CDF.

C3 is used by CDF:
• to register content to RLFs;
• to request RLF for content location information;
• to report to RLF the status of a node in which the CDF resides. The status information includes: CPU
usage, memory usage, disk usage, network interface usage, etc.;
• to report event related information to RLF, for instance, the event may be that the load of the node
in which CDF resides reached threshold;
• to report content related information to RLF, for instance, the content availability or content
popularity, etc.
6.2.4 Reference point C4

The C4 reference point is between RF and RLF.
C4 is used by RF to register the relay node in which it resides to RLF.

C4 is used by RF to report the status of the node in which it resides to RLF, the status information includes:
CPU usage, memory usage, disk usage, network interface usage, etc.

C4 is used by RF to report event related information to RLF, for instance, the event may be that the load of
the node in which RF resides reached threshold.

C4 is used by RF to report the QoS measurement message to RLF.
C4 is used by RLF to reserve resources on RF.

6.2.5 Reference point C5
The C5 reference point is between TOCF and RLF.

C5 is used by RLF to enquire TOCF about network information and to request traffic optimization results from
TOCF.

1339