1. User Guide
  2. Configuration
  3. DRMP configuration

3.2 DRMP configuration

The DRMP page controls the Diameter Internet Engineering Task Force (IETF) specification called Diameter Routing Message Priority (DRMP). DRMP allows Diameter nodes to embed the relative priority of the message into a Diameter message used for routing decisions, resource allocation, and overload abatement decisions. The priorities are based on a scale of 0 to 15, where priority value 0 is specified as the highest priority and priority value 15 is the lowest priority. DRMP performs congestion control and message throttling decisions based on DRMP-based relative priority of the Diameter message.

Note:

DRMP priority value of 0 is treated as highest priority and 15 as lowest priority, which is in reverse order of DSR priority values.

When making routing and resource allocation decisions, Diameter nodes currently have no generic mechanism to determine the relative priority of Diameter messages. IETF DRMP addresses this by defining a mechanism to allow diameter endpoints to indicate the relative priority of Diameter transactions. With this information, Diameter nodes can factor that priority into routing, resource allocation, and overload abatement decisions. For example, this includes first responder related signaling, emergency call related signaling, differentiated services, Application specific priorities, and so on. This allows SDS to support a custom policer mode based on tracker/shaper algorithm for managing congestion for all internal congestion points.

The custom policer mode tracks the offered traffic to each congestion point and arranges them by priority and color segments and stacks it according to the Site MO Discard Policy:
  • Discard by Priority Only
  • Discard by Color within Priority
  • Discard by Priority within Color
If any of the congestion point's (Task Queue, Task Thread Pool, and so on) congestion level is above normal, the custom policer discards a fixed percentage of messages depending on Discard Policy (of that site) starting from messages lowest in stacking order. The percentage of messages discarded are configured as:
  • CL1 Discard %: 15%
  • CL2 Discard %: 30%
  • CL3 Discard %: 45%

For information about DRMP APV and IETF, see Diameter User's Guide.