Using Transport Plugins
[Pluggable Transports]

Configuring transports used by RTI Data Distribution Service. More... There is more than one way to install a transport plugin for use with RTI Data Distribution Service:

• If it is a builtin transport plugin, by specifying a bitmask in DDS::TransportBuiltinQosPolicy (see Built-in Transport Plugins)
• For all other non-builtin transport plugins, by dynamically loading the plugin through PROPERTY QoS policy settings of DDS::DomainParticipant (on UNIX, Solaris and Windows systems only) (see Loading Transport Plugins through Property QoS Policy of Domain Participant)

The lifecycle of the transport plugin is automatically managed by RTI Data Distribution Service. See Transport Lifecycle for details.

Loading Transport Plugins through Property QoS Policy of Domain Participant

On UNIX, Solaris and Windows operating systems, a non-builtin transport plugin written in C/C++ and built as a dynamic-link library (*.dll/*.so) can be loaded by RTI Data Distribution Service through the PROPERTY QoS policy settings of the DDS::DomainParticipant. The dynamic-link library (and all the dependent libraries) need to be in the path during runtime (in LD_LIBRARY_PATH environment variable on Linux/Solaris systems,and in PATH environment variable for Windows systems).

To allow dynamic loading of the transport plugin, the transport plugin must implement the RTI Data Distribution Service abstract transport API and must provide a function with the signature DDS::Transport_create_plugin that can be called by RTI Data Distribution Service to create an instance of the transport plugin. The name of the dynamic library that contains the transport plugin implementation, the name of the function and properties that can be used to create the plugin, and the aliases and network address that are used to register the plugin can all be specified through the PROPERTY QoS policy of the DDS::DomainParticipant.

The following table lists the property names that are used to load the transport plugins dynamically:

Properties for dynamically loading and registering transport plugins

Property Name	Description	Required?
dds.transport.load_plugins	Comma-separated strings indicating the prefix names of all plugins that will be loaded by RTI Data Distribution Service. Up to 8 plugins may be specified. For example, "dds.transport.WAN.wan1, dds.transport.DTLS.dtls1", In the following examples, <TRANSPORT_PREFIX> is used to indicate one element of this string that is used as a prefix in the property names for all the settings that are related to the plugin. <TRANSPORT_PREFIX> must begin with "dds.transport." (such as "dds.transport.mytransport").	YES
<TRANSPORT_PREFIX>.library	Should be set to the name of the dynamic library (*.so for Unix/Solaris, and *.dll for Windows) that contains the transport plugin implementation. This library (and all the other dependent dynamic libraries) needs to be in the path during run time for used by RTI Data Distribution Service (in the LD_LIBRARY_PATH environment variable on UNIX/Solaris systems, in PATH for Windows systems).	YES
<TRANSPORT_PREFIX>.create_function	Should be set to the name of the function with the prototype of DDS::Transport_create_plugin that can be called by RTI Data Distribution Service to create an instance of the plugin. The resulting transport plugin will then be registered by RTI Data Distribution Service through DDS::Transport_Support::register_transport	YES
<TRANSPORT_PREFIX>.aliases	Used to register the transport plugin returned by DDS::Transport_create_plugin (as specified by <TRANSPORT_PREFIX>.create_function) to the DDS::DomainParticipant. Refer to aliases_in parameter in DDS::Transport_Support::register_transport for details. Aliases should be specified as comma separated string, with each comma delimiting an alias. If it is not specified, <TRANSPORT_PREFIX> is used as the default alias for the plugin	NO
<TRANSPORT_PREFIX>.network_address	Used to register the transport plugin returned by DDS::Transport_create_plugin (as specified by <TRANSPORT_PREFIX>.create_function) to the DDS::DomainParticipant. Refer to network_address_in parameter in DDS::Transport_Support::register_transport for details. If it is not specified, the network_address_out output parameter from DDS::Transport_create_plugin is used. The default value is a zeroed out network address.	NO
<TRANSPORT_PREFIX>.<property_name>	Property that is passed into DDS::Transport_create_plugin (as specified by <TRANSPORT_PREFIX>.create_function) for creating the transport plugin. This property name-value pair will be passed to DDS::Transport_create_plugin after stripping out <TRANSPORT_PREFIX> from the property name. The parsing of this property and configuring the transport using this property should be handled by the implementation of each transport plugin. Multiple <TRANSPORT_PREFIX>.<property_name> can be specified. Note: "library", "create_function", "aliases" and "network_address" cannot be used as the <property_name> due to conflicts with other builtin property names.	NO

A transport plugin is dynamically created and registered to the DDS::DomainParticipant by RTI Data Distribution Service when:

• the DDS::DomainParticipant is enabled,
• the first DataWriter/DataReader is created, or
• you lookup a builtin DataReader (DDS::Subscriber::lookup_datareader),

whichever happens first.

Any changes to the transport plugin related properties in PROPERTY QoS policy after the transport plugin has been registered with the DDS::DomainParticipant will have no effect.