.. _DiscoveryQos: ../../../api_c/html/structDDS__DiscoveryQosPolicy.html
.. _UserTrafficQos: ../../../api_c/html/structDDS__UserTrafficQosPolicy.html
.. _TransportQoS: ../../../api_c/html/structDDS__TransportQosPolicy.html

Transport Registration
----------------------

|rti_me| supports different transports and transports must be registered with
|rti_me| before they can be used. A transport must be given a name when it is
registered and this name is later used when configuring discovery and
user-traffic. A transport name cannot exceed 7 UTF-8 characters.

The following example registers the UDP transport with |rti_me| and makes
it available to all DDS applications within the same memory space. Please
note that each DDS applications creates its *own* instance of a transport.
Resources are *not* shared between instances of a transport unless stated.

For example, to register two UDP transports with the names myudp1 and myudp2, 
the following code is required:

::

    DDS_DomainParticipantFactory *factory;
    RT_Registry_T *registry;
    struct UDP_InterfaceFactoryProperty udp_property;

    factory = DDS_DomainParticipantFactory_get_instance();
    registry = DDS_DomainParticipantFactory_get_registry(factory);

    /* Set UDP properties */
    if (!RT_Registry_register(registry,"myudp1",
                              UDP_InterfaceFactory_get_interface(),
                              &udp_property._parent._parent,NULL))
    {
        return error;
    }

    /* Set UDP properties */
    if (!RT_Registry_register(registry,"myudp2",
                              UDP_InterfaceFactory_get_interface(),
                              &udp_property._parent._parent,NULL))
    {
        return error;
    }

Before a DomainParticipant can make use of a registered transport, it must 
enable it for use within the DomainParticipant. This is done by setting
the TransportQoS_. For example, to enable only myudp1, the following
code is required (error checking is not shown for clarity):

::

    DDS_StringSeq_set_maximum(&dp_qos.transports.enabled_transports,1);
    DDS_StringSeq_set_length(&dp_qos.transports.enabled_transports,1);
    *DDS_StringSeq_get_reference(&dp_qos.transports.enabled_transports,0) =
                                                     REDA_String_dup("myudp1");


To enable both transports:

::

    DDS_StringSeq_set_maximum(&dp_qos.transports.enabled_transports,2);
    DDS_StringSeq_set_length(&dp_qos.transports.enabled_transports,2);
    *DDS_StringSeq_get_reference(&dp_qos.transports.enabled_transports,0) =
                                                     REDA_String_dup("myudp1");
    *DDS_StringSeq_get_reference(&dp_qos.transports.enabled_transports,0) =
                                                     REDA_String_dup("myudp2");

Before enabled transports may be used for communication in |me|, they must be
registered and added to the DiscoveryQos_ and UserTrafficQos_ policies. 
Please see the section on :doc:`../discovery` for details.