QoS Translation Matrix

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

Reliability

HDDS	FastDDS	CycloneDDS	RTI Connext
QoS::best_effort()	BEST_EFFORT_RELIABILITY_QOS	DDS_RELIABILITY_BEST_EFFORT	DDS_BEST_EFFORT_RELIABILITY_QOS
QoS::reliable()	RELIABLE_RELIABILITY_QOS	DDS_RELIABILITY_RELIABLE	DDS_RELIABLE_RELIABILITY_QOS

Configuration Examples

HDDS:

use hdds::QoS;

let qos = QoS::reliable();

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
volatile()	VOLATILE_DURABILITY_QOS	volatile	DDS_VOLATILE_DURABILITY_QOS
transient_local()	TRANSIENT_LOCAL_DURABILITY_QOS	transient_local	DDS_TRANSIENT_LOCAL_DURABILITY_QOS
transient()	TRANSIENT_DURABILITY_QOS	transient	DDS_TRANSIENT_DURABILITY_QOS
persistent()	PERSISTENT_DURABILITY_QOS	persistent	DDS_PERSISTENT_DURABILITY_QOS

History

HDDS	FastDDS	CycloneDDS	RTI Connext
.keep_last(N)	KEEP_LAST_HISTORY_QOS, depth=N	keep_last, depth=N	DDS_KEEP_LAST_HISTORY_QOS
.keep_all()	KEEP_ALL_HISTORY_QOS	keep_all	DDS_KEEP_ALL_HISTORY_QOS

Configuration Examples

HDDS:

use hdds::QoS;

let qos = QoS::reliable().keep_last(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(Duration)	<period><sec/><nanosec/></period>	<Deadline>Nms</Deadline>	<period><sec/><nanosec/></period>

Configuration Examples

HDDS:

use hdds::QoS;
use std::time::Duration;

let qos = QoS::reliable().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_manual_by_participant()	MANUAL_BY_PARTICIPANT_LIVELINESS_QOS	manual_by_participant	DDS_MANUAL_BY_PARTICIPANT_LIVELINESS_QOS
liveliness_manual_by_topic()	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(N)	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
destination_order_by_reception()	BY_RECEPTION_TIMESTAMP	by_reception_timestamp	DDS_BY_RECEPTION_TIMESTAMP
destination_order_by_source()	BY_SOURCE_TIMESTAMP	by_source_timestamp	DDS_BY_SOURCE_TIMESTAMP

Resource Limits

HDDS	FastDDS	CycloneDDS	RTI Connext
max_samples(N)	max_samples	MaxSamples	max_samples
max_instances(N)	max_instances	MaxInstances	max_instances
max_samples_per_instance(N)	max_samples_per_instance	MaxSamplesPerInstance	max_samples_per_instance

Configuration Examples

HDDS:

use hdds::QoS;

let qos = QoS::reliable()
    .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(&["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
time_based_filter(Duration)	minimum_separation	MinimumSeparation	minimum_separation

Transport Priority

HDDS	FastDDS	CycloneDDS	RTI Connext
transport_priority(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