F.3 STa interface

29.2733GPP3GPP EPS AAA interfacesEvolved Packet System (EPS)Release 18TS

F.3.1 General

The Diameter load control mechanism is an optional feature over the STa interface.

It is recommended to make use of the IETF RFC 8583 [54] over the STa interface where, when applied, the trusted non 3GPP access network shall behave as a reacting node and the 3GPP AAA server as a reporting node.

F.3.2 3GPP AAA server behaviour

The 3GPP AAA server may report its current load by including a Load AVP of type HOST in answer commands as described in IETF RFC 8583 [54].

The 3GPP AAA server calculates its current load by implementation specific means. For example, the 3GPP AAA server may take into account the traffic over the STa interface or other interfaces, the level of usage of internal resources (e.g. CPU, memory), the access to external resources, etc.

The 3GPP AAA server determines when to send Load AVPs of type HOST by implementation specific means.

F.3.3 Trusted non 3GPP access network behaviour

When performing next hop Diameter Agent selection for requests that are routed based on realm, the Trusted non 3GPP access network may take into account load values from Load AVPs of type PEER received from candidate next hop Diameter nodes, as per IETF RFC 8583 [54].