Routing Message Priority [RFC7944] AVPs

Diameter Routing Message Priority (RFC7944)

This interface defines a mechanism that allows Diameter nodes to indicate the relative priority of Diameter transactions. Designed to complement overload control solutions like DOIC [RFC7683], the Diameter Routing Message Priority (DRMP) mechanism enables nodes to factor the priority of requests into their routing and throttling decisions. This ensures that, during periods of overload, critical transactions—such as those involving first responders—are less likely to be throttled compared to lower-priority traffic.

Purpose of the Diameter Routing Message Priority Interface

• Differentiated Request Handling: The DRMP mechanism provides a means to differentiate among Diameter requests by indicating their relative priority. With this information, overloaded nodes can make more informed decisions, selectively throttling lower-priority messages while preserving higher-priority traffic.
• Enhanced Overload Management: By integrating message priorities into the overload control process, Diameter nodes can reduce the probability of critical transactions being delayed or dropped during high-load conditions. This is particularly important in scenarios where uniform treatment of all messages could lead to adverse effects during network congestion.

Key Elements:

• DRMP Attribute Value Pair (AVP): The mechanism introduces a new DRMP AVP that is inserted into Diameter messages by trusted nodes. This AVP carries the priority value, allowing both Diameter endpoints and agents to adjust their handling of requests based on the indicated priority.
• Priority Coordination Across Applications: In environments where multiple Diameter applications coexist within an administrative domain, the priorities for all messages must be defined in a consistent and coordinated fashion. This ensures that one application's messages do not inadvertently receive preferential treatment over another's unless explicitly intended.
• Throttling and Routing Decisions: When a Diameter node becomes overloaded, it can use the DRMP values to determine which messages should be subjected to overload abatement measures (such as throttling or diversion) and which should be routed normally. This decision-making process relies on the agreed-upon priority definitions within the Diameter administrative domain.
• Inter-Domain Considerations: Care must be taken when messages cross Diameter administrative boundaries. If the DRMP values are not standardized between domains, the priority information may need to be stripped or modified to prevent messages from a foreign domain from gaining unwarranted preferential treatment.

For complete technical specification of Diameter Routing Message Priority please refer to: [RFC7944]

package com.mobius.software.telco.protocols.diameter.primitives.rfc7944