B.1 DOIC (Diameter Overload Indication Conveyance)

32.2993GPPCharging managementDiameter charging applicationsRelease 17Telecommunication managementTS

B.1.0 General

The Diameter Base Protocol, IETF RFC 6733 [401], uses the Protocol Error "DIAMETER_TOO_BUSY", in the Result_Code AVP of the answer to a related request, as a mean for overload control. This is further enhanced using generic DOIC (Diameter Overload Indication Conveyance) mechanism specified in IETF RFC 7683 [403], which makes it possible for a server to indicate overload situations to the clients before the server starts rejecting requests due to overload and thus prevents retransmission of the requests.

This clause specifies the DOIC (Diameter Overload Indication Conveyance) mechanism for Diameter charging applications.

B.1.1 Reporting node

When the OCS needs to request a reduction in the traffic it is handling due to an overload condition, it shall include the OC-OLR AVP in answer messages, as defined in clause B.3. The OCS should include the OC-OLR AVP in the answer messages for as long as the overload condition applies. This shall be based on the OC-Supported-Features AVP, defined in clause B3, exchanged earlier.

How OCS determines that it is in an overload situation and the severity of the overload is implementation dependent and based on operator policy.

B.1.2 Reacting node

A CTF acting as a reacting node reports its supported overload capabilities in the OC-Supported-Features AVP and applies the requested traffic reduction received in OC-OLR AVPs in answer messages to corresponding applicable requests, as per IETF RFC 7683 [33].

How it achieves the requested traffic reduction is implementation dependent.