2.6.15.10 Diameter Overload Indication Conveyance

Diameter Overload Indication Conveyance (DOIC) is a new IETF standard for supporting dynamic overload controls between Diameter servers and Diameter clients. It allows for Diameter servers to send overload reports requesting that Diameter clients reduce the traffic that they are sending to the server. It also allows for Diameter Agents such as the DSR to act as a proxy for any clients, by reducing traffic as requested by the servers, or as a proxy for the servers by requesting that traffic be reduced by the client.

There are two major interactions defined between the DOIC Reporting Node and the DOIC Reacting Node:

• The DOIC Capabilities Announcement (DCA) function allows the DOIC Reacting Node to send a list of its supported DOIC capabilities to the DOIC Reporting Node, and the DOIC Reporting Node to respond with its selected options if the DOIC Reacting Node gave it multiple options.
• The DOIC Reporting Node sends DOIC Overload Reports (OLR) to the DOIC Reacting Node requesting a reduction in traffic. The defined loss algorithm is an “abatement algorithm” which tells the DOIC Reacting Node to reduce the amount of traffic being sent by a given percentage.

DOIC layers on top of existing congestion controls in the DSR. Therefore, all of the current static controls such as ETLs/ETGs and the connection level congestion controls work as previously described.

The DSR supports the Reacting Node role in DOIC.

Figure 2-26 Reacting Node Role for DOIC