F.2 SWx interface

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

F.2.1 General

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

It is recommended to make use of IETF RFC 8583 [54] on the SWx interface where, when applied, the 3GPP AAA server shall behave as a reacting node and the HSS as a reporting node.

F.2.2 HSS behaviour

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

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

The HSS determines when to send Load AVPs of type HOST by implementation specific means.

F.2.3 3GPP AAA server behaviour

When performing next hop Diameter Agent selection for requests that are routed based on realm, the 3GPP AAA server 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].