P4-REQ-21-9-008

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Each QoS profile mapping SHALL identify the expected ordering behavior.

Part 4, Section 21.9: QoS Profile Requirements.

Ordering behavior determines whether communication sequence must be preserved when downstream processing or lifecycle progression depends on event order.

Explicitly identifying ordering expectations allows Phase 0 participants to implement compatible sequencing behavior for applicable exchanges.

This requirement applies to:

• QoS profile mappings;
• DDS Topic exchanges;
• publishers;
• subscribers; and
• sequence-dependent implementation flows.

Verification SHALL confirm that each QoS profile mapping identifies its expected ordering behavior.

Verification activities should include review checks confirming that:

• ordering expectations are stated;
• sequence-dependent exchanges preserve required ordering;
• publisher and subscriber behavior is compatible; and
• the selected ordering behavior supports the interaction purpose.

This requirement establishes the ordering expectation associated with each Phase 0 QoS profile mapping.

Related requirement identifiers:

• P4-REQ-21-9-007
• P4-REQ-21-9-010

Related source section:

• 21.9 QoS Profile Requirements

Draft