You can configure load shedding rules to determine how a device reacts to a processing backlog. This state is called busyness. Levels of busyness can be configured to accept, reject, or drop select messages at each level. An MPE has four busyness levels. With each successive level, the device becomes more aggressive in rejecting or discarding messages in an attempt to prevent the main queue from becoming full. At any level of busyness, requests that have been queued longer than a configurable time are discarded without further processing, since the originator would have abandoned that request.
On the MPE Advanced Configuration page, there is a default action for each Busyness Level. The default level action for levels 1, 2, and 3 is Accept, which means to process the message by bypassing load shedding rules. Level actions are configurable.
The following tables show the default load-shedding rules for an MPE. For configuration information, see the task Configuring MPE and MRA Load Shedding Rules.
Note: The default rules shown in your system may differ than those listed here depending on how your system is configured.
MPE Busyness Level 1. The default action for Level 1 is Accept.| Rule Name |
Actions |
|---|
| DefaultRule1 |
Reject Gx CCR messages with DIAMETER_TOO_BUSY |
| DefaultRule4 |
Reject Gxx CCR messages with DIAMETER_TOO_BUSY |
| DefaultRule14 |
Accept Gx CCR messages with DRMP priority 0 |
MPE Busyness Level 2. The default action for Level 2 is Accept.| Rule Name |
Actions |
|---|
| DefaultRule2 |
Reject Gx CCR messages with DIAMETER_TOO_BUSY |
| DefaultRule5 |
Reject Gxx CCR messages with DIAMETER_TOO_BUSY |
| DefaultRule7 |
Reject Rx AAR messages with DIAMETER_TOO_BUSY |
| DefaultRule15 |
Accept Gx CCR messages with a DRMP value of 0 |
| DefaultRule17 |
Accept Rx AAR messages with both the MPS-Identifier and Reservation-Priority AVPs present |
MPE Busyness Level 3. The default action for Level 3 is Accept.| Rule Name |
Actions |
|---|
| DefaultRule3 |
Reject Gx CCR messages with DIAMETER_TOO_BUSY |
| DefaultRule6 |
Reject Gxx CCR messages with DIAMETER_TOO_BUSY |
| DefaultRule8 |
Reject Rx AAR messages with DIAMETER_TOO_BUSY |
| DefaultRule9 |
Reject Sh PNR messages with DIAMETER_TOO_BUSY |
| DefaultRule10 |
Reject Sy SNR messages with DIAMETER_TOO_BUSY |
| DefaultRule16 |
Accept Gx CCR messages with a DRMP value of 0 |
| DefaultRule18 |
Accept RX AAR messages with both the MPS-Identifier and Reservation-Priority AVPs present |
MPE Busyness Level 4. The default action for Level 4 is Drop, which applies to all messages other than the DRMA messages that are accepted by default.Note: The DRMA rule configuration is only displayed in Diameter 3GPP mode as the functionality requires DRMA messaging which is a Diameter-based protocol.
| Rule Name |
Actions |
|---|
| DefaultRule11 |
Accept Drma LNR with ACCEPT |
| DefaultRule12 |
Accept Drma LSR with ACCEPT |
| DefaultRule13 |
Accept Drma RUR with ACCEPT |