Refs #21120. Improve test sample_lost_be_dw_be_dr_fragments.

Signed-off-by: Miguel Company <[email protected]>

test/blackbox/common/DDSBlackboxTestsListeners.cpp

@@ -22,6 +22,7 @@
 #include <fastdds/dds/domain/DomainParticipantFactory.hpp>
 #include <fastdds/LibrarySettings.hpp>
 #include <fastdds/rtps/transport/test_UDPv4TransportDescriptor.h>
+#include <fastdds/rtps/transport/UDPv4TransportDescriptor.h>
 #include <rtps/messages/CDRMessage.hpp>
 
 #include "BlackboxTests.hpp"
@@ -777,7 +778,13 @@ void sample_lost_test_dr_init(
         PubSubReader<T>& reader,
         std::function<void(const eprosima::fastdds::dds::SampleLostStatus& status)> functor)
 {
-    reader.sample_lost_status_functor(functor)
+    auto udp_transport = std::make_shared<UDPv4TransportDescriptor>();
+    udp_transport->sendBufferSize = SAMPLE_LOST_TEST_BUFFER_SIZE;
+    udp_transport->receiveBufferSize = SAMPLE_LOST_TEST_BUFFER_SIZE;
+
+    reader.disable_builtin_transport()
+            .add_user_transport_to_pparams(udp_transport)
+            .sample_lost_status_functor(functor)
             .init();
 
     ASSERT_TRUE(reader.isInitialized());