diff --git a/ecal/core/src/readwrite/ecal_reader.cpp b/ecal/core/src/readwrite/ecal_reader.cpp
index a2a450206d..ff0ae7fb8d 100644
--- a/ecal/core/src/readwrite/ecal_reader.cpp
+++ b/ecal/core/src/readwrite/ecal_reader.cpp
@@ -98,9 +98,6 @@ namespace eCAL
 
     // mark as created
     m_created = true;
-
-    // register
-    Register(false);
   }
 
   CDataReader::~CDataReader()
@@ -256,9 +253,6 @@ namespace eCAL
 
   bool CDataReader::SetAttribute(const std::string& attr_name_, const std::string& attr_value_)
   {
-    auto current_val = m_attr.find(attr_name_);
-
-    const bool force = current_val == m_attr.end() || current_val->second != attr_value_;
     m_attr[attr_name_] = attr_value_;
 
 #ifndef NDEBUG
@@ -266,16 +260,11 @@ namespace eCAL
     Logging::Log(log_level_debug2, m_topic_name + "::CDataReader::SetAttribute");
 #endif
 
-    // register it
-    Register(force);
-
     return(true);
   }
 
   bool CDataReader::ClearAttribute(const std::string& attr_name_)
   {
-    auto force = m_attr.find(attr_name_) != m_attr.end();
-
     m_attr.erase(attr_name_);
 
 #ifndef NDEBUG
@@ -283,9 +272,6 @@ namespace eCAL
     Logging::Log(log_level_debug2, m_topic_name + "::CDataReader::ClearAttribute");
 #endif
 
-    // register it
-    Register(force);
-
     return(true);
   }
 
@@ -533,10 +519,10 @@ namespace eCAL
     return(out.str());
   }
 
-  void CDataReader::Register(bool force_)
+  void CDataReader::Register()
   {
 #if ECAL_CORE_REGISTRATION
-    if (g_registration_provider() != nullptr) g_registration_provider()->ApplySample(GetRegistrationSample(), force_);
+    if (g_registration_provider() != nullptr) g_registration_provider()->RegisterSample(GetRegistrationSample());
 
 #ifndef NDEBUG
     // log it
@@ -548,7 +534,7 @@ namespace eCAL
   void CDataReader::Unregister()
   {
 #if ECAL_CORE_REGISTRATION
-    if (g_registration_provider() != nullptr) g_registration_provider()->ApplySample(GetUnregistrationSample(), false);
+    if (g_registration_provider() != nullptr) g_registration_provider()->UnregisterSample(GetUnregistrationSample());
 
 #ifndef NDEBUG
     // log it
diff --git a/ecal/core/src/readwrite/ecal_reader.h b/ecal/core/src/readwrite/ecal_reader.h
index 5716610dd6..eebff4d34c 100644
--- a/ecal/core/src/readwrite/ecal_reader.h
+++ b/ecal/core/src/readwrite/ecal_reader.h
@@ -125,7 +125,7 @@ namespace eCAL
     std::string Dump(const std::string& indent_ = "");
 
   protected:
-    void Register(bool force_);
+    void Register();
     void Unregister();
 
     void CheckConnections();
diff --git a/ecal/core/src/readwrite/ecal_writer.cpp b/ecal/core/src/readwrite/ecal_writer.cpp
index 5f00b7f33f..6f4164c1b4 100644
--- a/ecal/core/src/readwrite/ecal_writer.cpp
+++ b/ecal/core/src/readwrite/ecal_writer.cpp
@@ -120,9 +120,6 @@ namespace eCAL
 
     // mark as created
     m_created = true;
-
-    // register
-    Register(false);
   }
 
   CDataWriter::~CDataWriter()
@@ -227,7 +224,7 @@ namespace eCAL
         if (m_writer_shm->PrepareWrite(wattr))
         {
           // register new to update listening subscribers and rematch
-          Register(true);
+          Register();
           Process::SleepMS(5);
         }
 
@@ -291,7 +288,7 @@ namespace eCAL
         if (m_writer_udp->PrepareWrite(wattr))
         {
           // register new to update listening subscribers and rematch
-          Register(true);
+          Register();
           Process::SleepMS(5);
         }
 
@@ -364,8 +361,6 @@ namespace eCAL
 
   bool CDataWriter::SetDataTypeInformation(const SDataTypeInformation& topic_info_)
   {
-    // Does it even make sense to register if the info is the same???
-    const bool force = m_topic_info != topic_info_;
     m_topic_info = topic_info_;
 
 #ifndef NDEBUG
@@ -373,17 +368,11 @@ namespace eCAL
     Logging::Log(log_level_debug2, m_topic_name + "::CDataWriter::SetDescription");
 #endif
 
-    // register it
-    Register(force);
-
     return(true);
   }
 
   bool CDataWriter::SetAttribute(const std::string& attr_name_, const std::string& attr_value_)
   {
-    auto current_val = m_attr.find(attr_name_);
-
-    const bool force = current_val == m_attr.end() || current_val->second != attr_value_;
     m_attr[attr_name_] = attr_value_;
 
 #ifndef NDEBUG
@@ -391,16 +380,11 @@ namespace eCAL
     Logging::Log(log_level_debug2, m_topic_name + "::CDataWriter::SetAttribute");
 #endif
 
-    // register it
-    Register(force);
-
     return(true);
   }
 
   bool CDataWriter::ClearAttribute(const std::string& attr_name_)
   {
-    auto force = m_attr.find(attr_name_) != m_attr.end();
-
     m_attr.erase(attr_name_);
 
 #ifndef NDEBUG
@@ -408,9 +392,6 @@ namespace eCAL
     Logging::Log(log_level_debug2, m_topic_name + "::CDataWriter::ClearAttribute");
 #endif
 
-    // register it
-    Register(force);
-
     return(true);
   }
 
@@ -484,10 +465,10 @@ namespace eCAL
       StartUdpLayer();
       break;
     case tl_ecal_shm:
-      if (StartShmLayer()) Register(true);
+      StartShmLayer();
       break;
     case tl_ecal_tcp:
-      if (StartTcpLayer()) Register(true);
+      StartTcpLayer();
       break;
     default:
       break;
@@ -585,10 +566,10 @@ namespace eCAL
     return(out.str());
   }
 
-  void CDataWriter::Register(bool force_)
+  void CDataWriter::Register()
   {
 #if ECAL_CORE_REGISTRATION
-    if (g_registration_provider() != nullptr) g_registration_provider()->ApplySample(GetRegistrationSample(), force_);
+    if (g_registration_provider() != nullptr) g_registration_provider()->RegisterSample(GetRegistrationSample());
 
 #ifndef NDEBUG
     // log it
@@ -600,7 +581,7 @@ namespace eCAL
   void CDataWriter::Unregister()
   {
 #if ECAL_CORE_REGISTRATION
-    if (g_registration_provider() != nullptr) g_registration_provider()->ApplySample(GetUnregistrationSample(), false);
+    if (g_registration_provider() != nullptr) g_registration_provider()->UnregisterSample(GetUnregistrationSample());
 
 #ifndef NDEBUG
     // log it
@@ -625,8 +606,7 @@ namespace eCAL
     // check connection timeouts
     CheckConnections();
 
-    if (m_created) return GetRegistrationSample();
-    else           return GetUnregistrationSample();
+    return GetRegistrationSample();
   }
 
   Registration::Sample CDataWriter::GetRegistrationSample()
@@ -816,6 +796,9 @@ namespace eCAL
     // create writer
     m_writer_udp = std::make_unique<CDataWriterUdpMC>(m_host_name, m_topic_name, m_topic_id, m_config.layer.udp);
 
+    // register activated layer
+    Register();
+
 #ifndef NDEBUG
     Logging::Log(log_level_debug2, m_topic_name + "::CDataWriter::ActivateUdpLayer::WRITER_CREATED");
 #endif
@@ -839,6 +822,9 @@ namespace eCAL
     // create writer
     m_writer_shm = std::make_unique<CDataWriterSHM>(m_host_name, m_topic_name, m_topic_id, m_config.layer.shm);
 
+    // register activated layer
+    Register();
+
 #ifndef NDEBUG
     Logging::Log(log_level_debug2, m_topic_name + "::CDataWriter::ActivateShmLayer::WRITER_CREATED");
 #endif
@@ -862,6 +848,9 @@ namespace eCAL
     // create writer
     m_writer_tcp = std::make_unique<CDataWriterTCP>(m_host_name, m_topic_name, m_topic_id, m_config.layer.tcp);
 
+    // register activated layer
+    Register();
+
 #ifndef NDEBUG
     Logging::Log(log_level_debug2, m_topic_name + "::CDataWriter::ActivateTcpLayer::WRITER_CREATED");
 #endif
diff --git a/ecal/core/src/readwrite/ecal_writer.h b/ecal/core/src/readwrite/ecal_writer.h
index c1108de17e..1ea35da0d0 100644
--- a/ecal/core/src/readwrite/ecal_writer.h
+++ b/ecal/core/src/readwrite/ecal_writer.h
@@ -128,7 +128,7 @@ namespace eCAL
     std::string Dump(const std::string& indent_ = "");
 
   protected:
-    void Register(bool force_);
+    void Register();
     void Unregister();
 
     void CheckConnections();
diff --git a/ecal/core/src/registration/ecal_registration_provider.cpp b/ecal/core/src/registration/ecal_registration_provider.cpp
index 49f75c6041..f920848e5c 100644
--- a/ecal/core/src/registration/ecal_registration_provider.cpp
+++ b/ecal/core/src/registration/ecal_registration_provider.cpp
@@ -22,7 +22,7 @@
  * 
  * All process internal publisher/subscriber, server/clients register here with all their attributes.
  * 
- * These information will be send cyclic (registration refresh) via UDP to external eCAL processes.
+ * These information will be send cyclic (registration refresh) via UDP or SHM to external eCAL processes.
  * 
 **/
 #include "ecal_registration_provider.h"
@@ -84,7 +84,7 @@ namespace eCAL
 
     // start cyclic registration thread
     m_reg_sample_snd_thread = std::make_shared<CCallbackThread>(std::bind(&CRegistrationProvider::RegisterSendThread, this));
-    m_reg_sample_snd_thread->start(std::chrono::milliseconds(Config::GetRegistrationRefreshMs()));
+    m_reg_sample_snd_thread->start(std::chrono::milliseconds(0));
 
     m_created = true;
   }
@@ -97,37 +97,27 @@ namespace eCAL
     m_reg_sample_snd_thread->stop();
 
     // send process unregistration sample
-    SendSample(Registration::GetProcessUnregisterSample());
+    //m_reg_sender->SendSample(Registration::GetProcessUnregisterSample());
 
+    // delete registration sender
     m_reg_sender.reset();
 
     m_created = false;
   }
 
-  bool CRegistrationProvider::ApplySample(const Registration::Sample& sample_, const bool force_)
+  // register single sample (currently we do not differ between registration/unregistration)
+  bool CRegistrationProvider::RegisterSample(const Registration::Sample& sample_)
   {
     if (!m_created) return(false);
+    ProcessSingleSample(sample_);
+    return(true);
+  }
 
-    // forward all registration samples to outside "customer" (e.g. monitoring, descgate)
-    {
-      const std::lock_guard<std::mutex> lock(m_callback_custom_apply_sample_map_mtx);
-      for (const auto& iter : m_callback_custom_apply_sample_map)
-      {
-        iter.second(sample_);
-      }
-    }
-
-    if (force_)
-    {
-      // send sample
-      SendSample(sample_);
-    }
-    else
-    {
-      // add sample to sample list and send it later
-      AddSample2SampleList(sample_);
-    }
-
+  // unregister single sample (currently we do not differ between registration/unregistration)
+  bool CRegistrationProvider::UnregisterSample(const Registration::Sample& sample_)
+  {
+    if (!m_created) return(false);
+    ProcessSingleSample(sample_);
     return(true);
   }
 
@@ -147,55 +137,70 @@ namespace eCAL
     }
   }
 
-  void CRegistrationProvider::AddSample2SampleList(const Registration::Sample& sample_)
+  void CRegistrationProvider::ForwardSample(const Registration::Sample& sample_)
+  {
+    const std::lock_guard<std::mutex> lock(m_callback_custom_apply_sample_map_mtx);
+    for (const auto& iter : m_callback_custom_apply_sample_map)
+    {
+      iter.second(sample_);
+    }
+  }
+
+  void CRegistrationProvider::ProcessSingleSample(const Registration::Sample& sample_)
   {
-    const std::lock_guard<std::mutex> lock(m_sample_list_mtx);
-    m_sample_list.samples.push_back(sample_);
+    // forward registration sample to outside "customer" (currently monitoring and descgate)
+    ForwardSample(sample_);
+
+    // force rgistration thread to send
+    TriggerRegisterSendThread();
   }
 
-  void CRegistrationProvider::SendSample(const Registration::Sample& sample_)
+  void CRegistrationProvider::TriggerRegisterSendThread()
   {
-    Registration::SampleList sample_list;
-    sample_list.samples.push_back(sample_);
-    m_reg_sender->SendSampleList(sample_list);
+    {
+      std::lock_guard<std::mutex> lock(m_reg_sample_snd_thread_cv_mtx);
+      m_reg_sample_snd_thread_trigger = true;
+    }
+    m_reg_sample_snd_thread_cv.notify_one();
   }
 
   void CRegistrationProvider::RegisterSendThread()
   {
-    // collect all registrations and send them out
-    // the internal list already contain elements here:
-    //   one process registration sample
-    //   one or more registration/unregistration samples added by AddSample2SampleList
+    // collect all registrations and send them out cyclic
     {
-      // lock sample list
-      std::lock_guard<std::mutex> lock(m_sample_list_mtx);
+      // create sample list
+      Registration::SampleList sample_list;
+
+      // and add process registration sample
+      sample_list.samples.push_back(Registration::GetProcessRegisterSample());
 
 #if ECAL_CORE_SUBSCRIBER
       // add subscriber registrations
-      if (g_subgate() != nullptr) g_subgate()->GetRegistrations(m_sample_list);
+      if (g_subgate() != nullptr) g_subgate()->GetRegistrations(sample_list);
 #endif
 
 #if ECAL_CORE_PUBLISHER
       // add publisher registrations
-      if (g_pubgate() != nullptr) g_pubgate()->GetRegistrations(m_sample_list);
+      if (g_pubgate() != nullptr) g_pubgate()->GetRegistrations(sample_list);
 #endif
 
 #if ECAL_CORE_SERVICE
       // add server registrations
-      if (g_servicegate() != nullptr) g_servicegate()->GetRegistrations(m_sample_list);
+      if (g_servicegate() != nullptr) g_servicegate()->GetRegistrations(sample_list);
 
       // add client registrations
-      if (g_clientgate() != nullptr) g_clientgate()->GetRegistrations(m_sample_list);
+      if (g_clientgate() != nullptr) g_clientgate()->GetRegistrations(sample_list);
 #endif
 
       // send registration sample list
-      m_reg_sender->SendSampleList(m_sample_list);
+      m_reg_sender->SendSampleList(sample_list);
 
-      // clear it
-      m_sample_list.samples.clear();
-
-      // and add process registration sample to internal sample list as first sample (for next registration loop)
-      m_sample_list.samples.push_back(Registration::GetProcessRegisterSample());
+      // wait for trigger or registration refresh timeout
+      {
+        std::unique_lock<std::mutex> lock(m_reg_sample_snd_thread_cv_mtx);
+        m_reg_sample_snd_thread_cv.wait_for(lock, std::chrono::milliseconds(Config::GetRegistrationRefreshMs()), [this] { return m_reg_sample_snd_thread_trigger; });
+        m_reg_sample_snd_thread_trigger = false;
+      }
     }
   }
 }
diff --git a/ecal/core/src/registration/ecal_registration_provider.h b/ecal/core/src/registration/ecal_registration_provider.h
index 587be88dec..85bdccd708 100644
--- a/ecal/core/src/registration/ecal_registration_provider.h
+++ b/ecal/core/src/registration/ecal_registration_provider.h
@@ -31,6 +31,7 @@
 #include "io/udp/ecal_udp_sample_sender.h"
 
 #include <atomic>
+#include <condition_variable>
 #include <memory>
 #include <mutex>
 #include <string>
@@ -50,26 +51,28 @@ namespace eCAL
     void Start();
     void Stop();
 
-    bool ApplySample(const Registration::Sample& sample_, bool force_);
+    bool RegisterSample(const Registration::Sample& sample_);
+    bool UnregisterSample(const Registration::Sample& sample_);
 
     using ApplySampleCallbackT = std::function<void(const Registration::Sample&)>;
     void SetCustomApplySampleCallback(const std::string& customer_, const ApplySampleCallbackT& callback_);
     void RemCustomApplySampleCallback(const std::string& customer_);
 
   protected:
-    void AddSample2SampleList(const Registration::Sample& sample_);
-    void SendSample(const Registration::Sample& sample_);
+    void ForwardSample(const Registration::Sample& sample_);
+    void ProcessSingleSample(const Registration::Sample& sample_);
 
+    void TriggerRegisterSendThread();
     void RegisterSendThread();
 
     static std::atomic<bool>                    m_created;
 
     std::unique_ptr<CRegistrationSender>        m_reg_sender;
-
     std::shared_ptr<CCallbackThread>            m_reg_sample_snd_thread;
 
-    std::mutex                                  m_sample_list_mtx;
-    Registration::SampleList                    m_sample_list;
+    std::condition_variable                     m_reg_sample_snd_thread_cv;
+    std::mutex                                  m_reg_sample_snd_thread_cv_mtx;
+    bool                                        m_reg_sample_snd_thread_trigger;
 
     bool                                        m_use_registration_udp;
     bool                                        m_use_registration_shm;
diff --git a/ecal/core/src/registration/ecal_registration_sample_applier.cpp b/ecal/core/src/registration/ecal_registration_sample_applier.cpp
index 41b7a4aa17..4f3b65282f 100644
--- a/ecal/core/src/registration/ecal_registration_sample_applier.cpp
+++ b/ecal/core/src/registration/ecal_registration_sample_applier.cpp
@@ -96,6 +96,36 @@ namespace eCAL
       return true;
     }
 
+    bool CSampleApplier::IsSameProcess(const Registration::Sample& sample_)
+    {
+      int32_t pid(0);
+      switch (sample_.cmd_type)
+      {
+      case bct_reg_process:
+      case bct_unreg_process:
+        pid = sample_.process.pid;
+        break;
+      case bct_reg_publisher:
+      case bct_unreg_publisher:
+      case bct_reg_subscriber:
+      case bct_unreg_subscriber:
+        pid = sample_.topic.pid;
+        break;
+      case bct_reg_service:
+      case bct_unreg_service:
+        pid = sample_.service.pid;
+        break;
+      case bct_reg_client:
+      case bct_unreg_client:
+        pid = sample_.client.pid;
+        break;
+      default:
+        break;
+      }
+
+      return pid == m_pid;
+    }
+
     bool CSampleApplier::AcceptRegistrationSample(const Registration::Sample& sample_)
     {
       // check if the sample is from the same host group
@@ -103,7 +133,7 @@ namespace eCAL
       {
         // register if the sample is from another process
         // or if loopback mode is enabled
-        return m_loopback || (sample_.topic.pid != m_pid);
+        return !IsSameProcess(sample_) || m_loopback;
       }
       else
       {
diff --git a/ecal/core/src/registration/ecal_registration_sample_applier.h b/ecal/core/src/registration/ecal_registration_sample_applier.h
index 354f9c982c..401fdf4820 100644
--- a/ecal/core/src/registration/ecal_registration_sample_applier.h
+++ b/ecal/core/src/registration/ecal_registration_sample_applier.h
@@ -54,6 +54,7 @@ namespace eCAL
       void RemCustomApplySampleCallback(const std::string& customer_);
 
     private:
+      bool IsSameProcess(const Registration::Sample& sample_);
       bool IsHostGroupMember(const eCAL::Registration::Sample& sample_);
       bool AcceptRegistrationSample(const Registration::Sample& sample_);
 
diff --git a/ecal/core/src/service/ecal_service_client_impl.cpp b/ecal/core/src/service/ecal_service_client_impl.cpp
index 96f48f280d..abce7327eb 100644
--- a/ecal/core/src/service/ecal_service_client_impl.cpp
+++ b/ecal/core/src/service/ecal_service_client_impl.cpp
@@ -89,7 +89,7 @@ namespace eCAL
     m_created = true;
 
     // register this client
-    Register(true);
+    Register();
 
     return(true);
   }
@@ -687,13 +687,13 @@ namespace eCAL
     return ecal_reg_sample;
   }
 
-  void CServiceClientImpl::Register(const bool force_)
+  void CServiceClientImpl::Register()
   {
     if (!m_created)             return;
     if (m_service_name.empty()) return;
 
     // register entity
-    if (g_registration_provider() != nullptr) g_registration_provider()->ApplySample(GetRegistrationSample(), force_);
+    if (g_registration_provider() != nullptr) g_registration_provider()->RegisterSample(GetRegistrationSample());
   }
 
   void CServiceClientImpl::Unregister()
@@ -701,7 +701,7 @@ namespace eCAL
     if (m_service_name.empty()) return;
 
     // unregister entity
-    if (g_registration_provider() != nullptr) g_registration_provider()->ApplySample(GetUnregistrationSample(), false);
+    if (g_registration_provider() != nullptr) g_registration_provider()->UnregisterSample(GetUnregistrationSample());
   }
 
   void CServiceClientImpl::CheckForNewServices()
diff --git a/ecal/core/src/service/ecal_service_client_impl.h b/ecal/core/src/service/ecal_service_client_impl.h
index 1c75b75ab3..cb9059d124 100644
--- a/ecal/core/src/service/ecal_service_client_impl.h
+++ b/ecal/core/src/service/ecal_service_client_impl.h
@@ -99,7 +99,7 @@ namespace eCAL
     Registration::Sample GetRegistrationSample();
     Registration::Sample GetUnregistrationSample();
     
-    void Register(bool force_);
+    void Register();
     void Unregister();
 
     void CheckForNewServices();
diff --git a/ecal/core/src/service/ecal_service_server_impl.cpp b/ecal/core/src/service/ecal_service_server_impl.cpp
index 7aab9c31f4..10d2ff6450 100644
--- a/ecal/core/src/service/ecal_service_server_impl.cpp
+++ b/ecal/core/src/service/ecal_service_server_impl.cpp
@@ -128,9 +128,6 @@ namespace eCAL
     // mark as created
     m_created = true;
 
-    // register this service
-    Register(false);
-
     return(true);
   }
 
@@ -200,9 +197,6 @@ namespace eCAL
       }
     }
 
-    // register this service
-    Register(false);
-
     return true;
   }
 
@@ -238,9 +232,6 @@ namespace eCAL
       }
     }
 
-    // register this service
-    Register(false);
-
     return true;
   }
 
@@ -377,10 +368,10 @@ namespace eCAL
     return ecal_reg_sample;
   }
 
-  void CServiceServerImpl::Register(bool force_)
+  void CServiceServerImpl::Register()
   {
 #if ECAL_CORE_REGISTRATION
-    if (g_registration_provider() != nullptr) g_registration_provider()->ApplySample(GetRegistrationSample(), force_);
+    if (g_registration_provider() != nullptr) g_registration_provider()->RegisterSample(GetRegistrationSample());
 
 #ifndef NDEBUG
     // log it
@@ -392,7 +383,7 @@ namespace eCAL
   void CServiceServerImpl::Unregister()
   {
 #if ECAL_CORE_REGISTRATION
-    if (g_registration_provider() != nullptr) g_registration_provider()->ApplySample(GetUnregistrationSample(), false);
+    if (g_registration_provider() != nullptr) g_registration_provider()->UnregisterSample(GetUnregistrationSample());
 
 #ifndef NDEBUG
     // log it
diff --git a/ecal/core/src/service/ecal_service_server_impl.h b/ecal/core/src/service/ecal_service_server_impl.h
index 22eef8a9ec..ccf741bef2 100644
--- a/ecal/core/src/service/ecal_service_server_impl.h
+++ b/ecal/core/src/service/ecal_service_server_impl.h
@@ -85,7 +85,7 @@ namespace eCAL
     std::string GetServiceName() { return m_service_name; };
 
   protected:
-    void Register(bool force_);
+    void Register();
     void Unregister();
 
     Registration::Sample GetRegistrationSample();
diff --git a/ecal/tests/cpp/util_test/src/util_getclients.cpp b/ecal/tests/cpp/util_test/src/util_getclients.cpp
index bd70c9dbe0..8a938cf16e 100644
--- a/ecal/tests/cpp/util_test/src/util_getclients.cpp
+++ b/ecal/tests/cpp/util_test/src/util_getclients.cpp
@@ -22,8 +22,8 @@
 #include <gtest/gtest.h>
 
 enum {
-  CMN_MONITORING_TIMEOUT_MS   = (5000),
-  CMN_REGISTRATION_REFRESH_MS = (1000 * 2)
+  CMN_MONITORING_TIMEOUT_MS   = (5000 + 100),
+  CMN_REGISTRATION_REFRESH_MS = (1000)
 };
 
 TEST(core_cpp_util, ClientExpiration)
@@ -31,6 +31,9 @@ TEST(core_cpp_util, ClientExpiration)
   // initialize eCAL API
   eCAL::Initialize(0, nullptr, "core_cpp_util");
 
+  // enable loop back communication in the same process
+  eCAL::Util::EnableLoopback(true);
+
   std::map<eCAL::Util::SServiceMethod, eCAL::SServiceMethodInformation> client_info_map;
 
   // create simple client and let it expire
@@ -43,6 +46,9 @@ TEST(core_cpp_util, ClientExpiration)
     service_method_info.response_type.descriptor = "foo::resp_desc";
     const eCAL::CServiceClient client("foo::service", { {"foo::method", service_method_info} });
 
+    // let's register
+    eCAL::Process::SleepMS(2 * CMN_REGISTRATION_REFRESH_MS);
+
     // get all clients
     eCAL::Util::GetClients(client_info_map);
 
@@ -70,7 +76,7 @@ TEST(core_cpp_util, ClientExpiration)
   }
 
   // let's unregister
-  eCAL::Process::SleepMS(CMN_REGISTRATION_REFRESH_MS);
+  eCAL::Process::SleepMS(2 * CMN_REGISTRATION_REFRESH_MS);
 
   // get all clients again, all clients 
   // should be removed from the map
@@ -88,6 +94,9 @@ TEST(core_cpp_util, ClientEqualQualities)
   // initialize eCAL API
   eCAL::Initialize(0, nullptr, "core_cpp_util");
 
+  // enable loop back communication in the same process
+  eCAL::Util::EnableLoopback(true);
+
   std::map<eCAL::Util::SServiceMethod, eCAL::SServiceMethodInformation> client_info_map;
 
   // create 2 clients with the same quality of data type information
@@ -100,6 +109,9 @@ TEST(core_cpp_util, ClientEqualQualities)
     service_method_info1.response_type.descriptor = "foo::resp_desc1";
     eCAL::CServiceClient client1("foo::service", { {"foo::method", service_method_info1} });
 
+    // let's register
+    eCAL::Process::SleepMS(2 * CMN_REGISTRATION_REFRESH_MS);
+
     // get all clients
     eCAL::Util::GetClients(client_info_map);
 
@@ -159,7 +171,7 @@ TEST(core_cpp_util, ClientEqualQualities)
   }
 
   // let's unregister
-  eCAL::Process::SleepMS(CMN_REGISTRATION_REFRESH_MS);
+  eCAL::Process::SleepMS(2 * CMN_REGISTRATION_REFRESH_MS);
 
   // get all clients again, all clients 
   // should be removed from the map
@@ -177,6 +189,9 @@ TEST(core_cpp_util, ClientDifferentQualities)
   // initialize eCAL API
   eCAL::Initialize(0, nullptr, "core_cpp_util");
 
+  // enable loop back communication in the same process
+  eCAL::Util::EnableLoopback(true);
+
   std::map<eCAL::Util::SServiceMethod, eCAL::SServiceMethodInformation> client_info_map;
 
   // create 2 clients with different qualities of data type information
@@ -189,6 +204,9 @@ TEST(core_cpp_util, ClientDifferentQualities)
     service_method_info1.response_type.descriptor = "";
     eCAL::CServiceClient client1("foo::service", { {"foo::method", service_method_info1} });
 
+    // let's register
+    eCAL::Process::SleepMS(2 * CMN_REGISTRATION_REFRESH_MS);
+
     // get all clients
     eCAL::Util::GetClients(client_info_map);
 
@@ -214,6 +232,9 @@ TEST(core_cpp_util, ClientDifferentQualities)
     service_method_info2.response_type.descriptor = "foo::resp_desc2";
     eCAL::CServiceClient client2("foo::service", { {"foo::method", service_method_info2} });
 
+    // let's register
+    eCAL::Process::SleepMS(2 * CMN_REGISTRATION_REFRESH_MS);
+
     // check attributes, we expect attributes from client 2 here
     eCAL::Util::GetClientTypeNames("foo::service", "foo::method", req_type, resp_type);
     EXPECT_EQ(req_type,  "foo::req_type2");
@@ -227,7 +248,7 @@ TEST(core_cpp_util, ClientDifferentQualities)
   }
 
   // let's unregister
-  eCAL::Process::SleepMS(CMN_REGISTRATION_REFRESH_MS);
+  eCAL::Process::SleepMS(2 * CMN_REGISTRATION_REFRESH_MS);
 
   // get all clients again, all clients
   // should be removed from the map
diff --git a/ecal/tests/cpp/util_test/src/util_getservices.cpp b/ecal/tests/cpp/util_test/src/util_getservices.cpp
index fbf2239d43..7ad633d5c1 100644
--- a/ecal/tests/cpp/util_test/src/util_getservices.cpp
+++ b/ecal/tests/cpp/util_test/src/util_getservices.cpp
@@ -1,6 +1,6 @@
 /* ========================= eCAL LICENSE =================================
  *
- * Copyright (C) 2016 - 2019 Continental Corporation
+ * Copyright (C) 2016 - 2024 Continental Corporation
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,7 +23,7 @@
 
 enum {
   CMN_MONITORING_TIMEOUT_MS   = (5000 + 100),
-  CMN_REGISTRATION_REFRESH_MS = (1000 + 100)
+  CMN_REGISTRATION_REFRESH_MS = (1000)
 };
 
 TEST(core_cpp_util, ServiceExpiration)
@@ -31,6 +31,9 @@ TEST(core_cpp_util, ServiceExpiration)
   // initialize eCAL API
   eCAL::Initialize(0, nullptr, "core_cpp_util");
 
+  // enable loop back communication in the same process
+  eCAL::Util::EnableLoopback(true);
+
   std::map<eCAL::Util::SServiceMethod, eCAL::SServiceMethodInformation> service_info_map;
 
   // create simple service and let it expire
@@ -39,6 +42,9 @@ TEST(core_cpp_util, ServiceExpiration)
     eCAL::CServiceServer service("foo::service");
     service.AddDescription("foo::method", "foo::req_type", "foo::req_desc", "foo::resp_type", "foo::resp_desc");
 
+    // let's register
+    eCAL::Process::SleepMS(2 * CMN_REGISTRATION_REFRESH_MS);
+
     // get all services
     eCAL::Util::GetServices(service_info_map);
 
@@ -66,7 +72,7 @@ TEST(core_cpp_util, ServiceExpiration)
   }
 
   // let's unregister
-  eCAL::Process::SleepMS(CMN_REGISTRATION_REFRESH_MS);
+  eCAL::Process::SleepMS(2 * CMN_REGISTRATION_REFRESH_MS);
 
   // get all services again, all services
   // should be removed from the map
@@ -84,6 +90,9 @@ TEST(core_cpp_util, ServiceEqualQualities)
   // initialize eCAL API
   eCAL::Initialize(0, nullptr, "core_cpp_util");
 
+  // enable loop back communication in the same process
+  eCAL::Util::EnableLoopback(true);
+
   std::map<eCAL::Util::SServiceMethod, eCAL::SServiceMethodInformation> service_info_map;
 
   // create 2 services with the same quality of data type information
@@ -92,6 +101,9 @@ TEST(core_cpp_util, ServiceEqualQualities)
     eCAL::CServiceServer service1("foo::service");
     service1.AddDescription("foo::method", "foo::req_type1", "foo::req_desc1", "foo::resp_type1", "foo::resp_desc1");
 
+    // let's register
+    eCAL::Process::SleepMS(2 * CMN_REGISTRATION_REFRESH_MS);
+
     // get all services
     eCAL::Util::GetServices(service_info_map);
 
@@ -147,7 +159,7 @@ TEST(core_cpp_util, ServiceEqualQualities)
   }
 
   // let's unregister
-  eCAL::Process::SleepMS(CMN_REGISTRATION_REFRESH_MS);
+  eCAL::Process::SleepMS(2 * CMN_REGISTRATION_REFRESH_MS);
 
   // get all services again, all services 
   // should be removed from the map
@@ -165,6 +177,9 @@ TEST(core_cpp_util, ServiceDifferentQualities)
   // initialize eCAL API
   eCAL::Initialize(0, nullptr, "core_cpp_util");
 
+  // enable loop back communication in the same process
+  eCAL::Util::EnableLoopback(true);
+
   std::map<eCAL::Util::SServiceMethod, eCAL::SServiceMethodInformation> service_info_map;
 
   // create 2 services with different qualities of data type information
@@ -173,6 +188,9 @@ TEST(core_cpp_util, ServiceDifferentQualities)
     eCAL::CServiceServer service1("foo::service");
     service1.AddDescription("foo::method", "foo::req_type1", "foo::req_desc1", "", "");
 
+    // let's register
+    eCAL::Process::SleepMS(2 * CMN_REGISTRATION_REFRESH_MS);
+
     // get all services
     eCAL::Util::GetServices(service_info_map);
 
@@ -194,6 +212,9 @@ TEST(core_cpp_util, ServiceDifferentQualities)
     eCAL::CServiceServer service2("foo::service");
     service2.AddDescription("foo::method", "foo::req_type2", "foo::req_desc2", "foo::resp_type2", "foo::resp_desc2");
 
+    // let's register
+    eCAL::Process::SleepMS(2 * CMN_REGISTRATION_REFRESH_MS);
+
     // check attributes, we expect attributes from service 2 here
     eCAL::Util::GetServiceTypeNames("foo::service", "foo::method", req_type, resp_type);
     EXPECT_EQ(req_type,  "foo::req_type2");
@@ -207,7 +228,7 @@ TEST(core_cpp_util, ServiceDifferentQualities)
   }
 
   // let's unregister
-  eCAL::Process::SleepMS(CMN_REGISTRATION_REFRESH_MS);
+  eCAL::Process::SleepMS(2 * CMN_REGISTRATION_REFRESH_MS);
 
   // get all services again, all services
   // should be removed from the map
diff --git a/ecal/tests/cpp/util_test/src/util_gettopics.cpp b/ecal/tests/cpp/util_test/src/util_gettopics.cpp
index 495a9dcfea..19b27429da 100644
--- a/ecal/tests/cpp/util_test/src/util_gettopics.cpp
+++ b/ecal/tests/cpp/util_test/src/util_gettopics.cpp
@@ -27,8 +27,8 @@
 #include <thread>
 
 enum {
-  CMN_MONITORING_TIMEOUT_MS   = (5000),
-  CMN_REGISTRATION_REFRESH_MS = (1000 * 2)
+  CMN_MONITORING_TIMEOUT_MS   = (5000 + 100),
+  CMN_REGISTRATION_REFRESH_MS = (1000)
 };
 
 TEST(core_cpp_util, GetTopics)
@@ -69,6 +69,9 @@ TEST(core_cpp_util, GetTopics)
     // this should trigger a warning but not increase map size
     eCAL::CSubscriber sub12("B1", info_B1_2);
 
+    // let's register
+    eCAL::Process::SleepMS(2 * CMN_REGISTRATION_REFRESH_MS);
+
     // get all topics
     eCAL::Util::GetTopics(topic_info_map);
 
@@ -116,7 +119,7 @@ TEST(core_cpp_util, GetTopics)
   }
 
   // let's unregister
-  eCAL::Process::SleepMS(CMN_REGISTRATION_REFRESH_MS);
+  eCAL::Process::SleepMS(2 * CMN_REGISTRATION_REFRESH_MS);
 
   // get all topics again, now all topics 
   // should be removed from the map
@@ -132,7 +135,7 @@ TEST(core_cpp_util, GetTopics)
 TEST(core_cpp_util, GetTopicsParallel)
 {
   constexpr const int max_publisher_count(2000);
-  constexpr const int waiting_time_thread(1000);
+  constexpr const int waiting_time_thread(4000);
   constexpr const int parallel_threads(1);
 
   // initialize eCAL API