1. Feature Guide
  2. DSR Features and Functions
  3. Routing and Transaction Related Parameters in the DSR
  4. Congestion Control
  5. Diameter Overload Indication Conveyance
  6. DOIC Capabilities Announcement

2.6.15.10.1 DOIC Capabilities Announcement

The DOIC solution supports the ability for Diameter nodes to determine if other nodes in the path of a request support the DOIC solution. The DOIC Capabilities Announcement (DCA) mechanism uses the OC-Supported-Features AVPs to indicate the Diameter overload features supported. This AVP is added by the DSR to all requests that are routed to a HostID/AppID defined in a Traffic Throttling Point (TTP).

The figure below shows the basic flow of DCA. This example assumes that a TTP has been created for a combination of HostID/AppID.

  • A request is received by the DSR that AFTER ROUTING contains a HostID/AppID combination that matches the key of a TTP indicating that the DSR is functioning as a Reacting Node for that HostID/AppID. The evaluation has to be after routing in the DSR, since the request might have been Realm routed to DSR, or the HostID might have been changed by routing in the DSR (for instance from a Pseudo HostID to a real HostID).
  • The DSR inserts the OC-Supported-Features AVP into every request message sent to that HostID/AppID. This AVP includes the list of all of the supported Abatement Algorithms on the DSR.
  • The host returns in every answer message an OC-Supported-Features AVP indicating which of the abatement algorithms the DSR said it supported that the Host wants to use. While the DSR can include multiple supported abatement algorithms, the Reporting Node can only return one, the one it wants to use. The Host sends back the OC-Supported-Features AVP and optionally includes the OC-Feature-Vector that specifies the abatement algorithm. If the answer doesn’t include the OC-Supported-Features AVP then the abatement algorithm defaults to the Loss algorithm.
  • At this point the Host can start sending requests (Overload Reports) that causes the DSR to reduce the request traffic sent to the Host. The lifetime of an OC-Supported-Features exchange lasts for a single request and answer and so these steps are repeated for each request.

Figure 2-27 DOIC Capabilities Announcement


DOIC Capabilities Announcement