QoS Translation Matrix

Reference for translating QoS policies between HDDS and other DDS implementations.

Reliability

HDDS	FastDDS	CycloneDDS	RTI Connext
Reliability::BestEffort	BEST_EFFORT_RELIABILITY_QOS	DDS_RELIABILITY_BEST_EFFORT	DDS_BEST_EFFORT_RELIABILITY_QOS
Reliability::Reliable	RELIABLE_RELIABILITY_QOS	DDS_RELIABILITY_RELIABLE	DDS_RELIABLE_RELIABILITY_QOS

Configuration Examples

HDDS:

DataWriterQos::default()
    .reliability(Reliability::Reliable {
        max_blocking_time: Duration::from_millis(100),
    })

FastDDS (XML):

<reliability>
    <kind>RELIABLE_RELIABILITY_QOS</kind>
    <max_blocking_time><sec>0</sec><nanosec>100000000</nanosec></max_blocking_time>
</reliability>

CycloneDDS (XML):

<Reliability><Kind>reliable</Kind><MaxBlockingTime>100ms</MaxBlockingTime></Reliability>

RTI Connext:

<reliability><kind>RELIABLE_RELIABILITY_QOS</kind>
    <max_blocking_time><sec>0</sec><nanosec>100000000</nanosec></max_blocking_time>
</reliability>

Durability

HDDS	FastDDS	CycloneDDS	RTI Connext
Durability::Volatile	VOLATILE_DURABILITY_QOS	volatile	DDS_VOLATILE_DURABILITY_QOS
Durability::TransientLocal	TRANSIENT_LOCAL_DURABILITY_QOS	transient_local	DDS_TRANSIENT_LOCAL_DURABILITY_QOS
Durability::Transient	TRANSIENT_DURABILITY_QOS	transient	DDS_TRANSIENT_DURABILITY_QOS
Durability::Persistent	PERSISTENT_DURABILITY_QOS	persistent	DDS_PERSISTENT_DURABILITY_QOS

History

HDDS	FastDDS	CycloneDDS	RTI Connext
History::KeepLast { depth: N }	KEEP_LAST_HISTORY_QOS, depth=N	keep_last, depth=N	DDS_KEEP_LAST_HISTORY_QOS
History::KeepAll	KEEP_ALL_HISTORY_QOS	keep_all	DDS_KEEP_ALL_HISTORY_QOS

Configuration Examples

HDDS:

DataWriterQos::default().history(History::KeepLast { depth: 10 })

FastDDS:

<history><kind>KEEP_LAST_HISTORY_QOS</kind><depth>10</depth></history>

CycloneDDS:

<History><Kind>keep_last</Kind><Depth>10</Depth></History>

RTI Connext:

<history><kind>KEEP_LAST_HISTORY_QOS</kind><depth>10</depth></history>

Deadline

HDDS	FastDDS	CycloneDDS	RTI Connext
Deadline::from_millis(N)	<period><sec/><nanosec/></period>	<Deadline>Nms</Deadline>	<period><sec/><nanosec/></period>

Configuration Examples

HDDS:

DataWriterQos::default().deadline(Duration::from_millis(100))

FastDDS:

<deadline><period><sec>0</sec><nanosec>100000000</nanosec></period></deadline>

CycloneDDS:

<Deadline>100ms</Deadline>

RTI Connext:

<deadline><period><sec>0</sec><nanosec>100000000</nanosec></period></deadline>

Liveliness

HDDS	FastDDS	CycloneDDS	RTI Connext
Liveliness::Automatic	AUTOMATIC_LIVELINESS_QOS	automatic	DDS_AUTOMATIC_LIVELINESS_QOS
Liveliness::ManualByParticipant	MANUAL_BY_PARTICIPANT_LIVELINESS_QOS	manual_by_participant	DDS_MANUAL_BY_PARTICIPANT_LIVELINESS_QOS
Liveliness::ManualByTopic	MANUAL_BY_TOPIC_LIVELINESS_QOS	manual_by_topic	DDS_MANUAL_BY_TOPIC_LIVELINESS_QOS

Ownership

HDDS	FastDDS	CycloneDDS	RTI Connext
Ownership::Shared	SHARED_OWNERSHIP_QOS	shared	DDS_SHARED_OWNERSHIP_QOS
Ownership::Exclusive	EXCLUSIVE_OWNERSHIP_QOS	exclusive	DDS_EXCLUSIVE_OWNERSHIP_QOS

Presentation

HDDS	FastDDS	CycloneDDS	RTI Connext
Presentation::Instance	INSTANCE_PRESENTATION_QOS	instance	DDS_INSTANCE_PRESENTATION_QOS
Presentation::Topic	TOPIC_PRESENTATION_QOS	topic	DDS_TOPIC_PRESENTATION_QOS
Presentation::Group	GROUP_PRESENTATION_QOS	group	DDS_GROUP_PRESENTATION_QOS

Destination Order

HDDS	FastDDS	CycloneDDS	RTI Connext
DestinationOrder::ByReception	BY_RECEPTION_TIMESTAMP	by_reception_timestamp	DDS_BY_RECEPTION_TIMESTAMP
DestinationOrder::BySource	BY_SOURCE_TIMESTAMP	by_source_timestamp	DDS_BY_SOURCE_TIMESTAMP

Resource Limits

HDDS	FastDDS	CycloneDDS	RTI Connext
max_samples	max_samples	MaxSamples	max_samples
max_instances	max_instances	MaxInstances	max_instances
max_samples_per_instance	max_samples_per_instance	MaxSamplesPerInstance	max_samples_per_instance

Configuration Examples

HDDS:

DataReaderQos::default()
    .resource_limits(ResourceLimits {
        max_samples: 1000,
        max_instances: 100,
        max_samples_per_instance: 10,
    })

FastDDS:

<resource_limits>
    <max_samples>1000</max_samples>
    <max_instances>100</max_instances>
    <max_samples_per_instance>10</max_samples_per_instance>
</resource_limits>

CycloneDDS:

<ResourceLimits>
    <MaxSamples>1000</MaxSamples>
    <MaxInstances>100</MaxInstances>
    <MaxSamplesPerInstance>10</MaxSamplesPerInstance>
</ResourceLimits>

Partition

HDDS	FastDDS	CycloneDDS	RTI Connext
Partition::new(["a", "b"])	<name>a</name><name>b</name>	Partition("a,b")	<name>a</name><name>b</name>

Time-Based Filter

HDDS	FastDDS	CycloneDDS	RTI Connext
TimeBasedFilter::from_millis(N)	minimum_separation	MinimumSeparation	minimum_separation

Transport Priority

HDDS	FastDDS	CycloneDDS	RTI Connext
TransportPriority::new(N)	<value>N</value>	N/A	<value>N</value>

Compatibility Rules

Matching Requirements

QoS Policy	Requirement for Match
Reliability	Writer ≥ Reader
Durability	Writer ≥ Reader
Deadline	Writer period ≤ Reader period
Ownership	Writer = Reader
Liveliness	Writer kind ≥ Reader kind
Presentation	Access scope compatible
Partition	At least one overlap

Default Values Comparison

Policy	HDDS Default	FastDDS Default	CycloneDDS Default	RTI Default
Reliability	BestEffort	BestEffort	BestEffort	BestEffort
Durability	Volatile	Volatile	Volatile	Volatile
History	KeepLast(1)	KeepLast(1)	KeepLast(1)	KeepLast(1)
Deadline	Infinite	Infinite	Infinite	Infinite
Liveliness	Automatic	Automatic	Automatic	Automatic

Wire Compatibility Notes

All DDS implementations use the same RTPS wire protocol, so QoS policies are communicated during discovery. However:

1. Vendor extensions: Some vendors have proprietary QoS extensions not compatible with others
2. Defaults may differ: Explicit configuration recommended for interoperability
3. Type consistency: XTypes support varies; use @appendable for safety

Next Steps

• FastDDS QoS Mapping - FastDDS details
• CycloneDDS QoS Mapping - CycloneDDS details
• RTI Connext QoS Mapping - RTI details