diff --git a/fairmq/sdk/DDSSession.cxx b/fairmq/sdk/DDSSession.cxx
index bf6a88df..4d02c6a8 100644
--- a/fairmq/sdk/DDSSession.cxx
+++ b/fairmq/sdk/DDSSession.cxx
@@ -65,8 +65,6 @@ struct DDSSession::Impl
         , fId(to_string(fSession->create()))
         , fStopOnDestruction(false)
     {
-        setenv("DDS_SESSION_ID", fId.c_str(), 1);
-
         fDDSService.subscribeOnError([](const dds::intercom_api::EErrorCode errorCode, const std::string& msg) {
             std::cerr << "DDS error, error code: " << errorCode << ", error message: " << msg << std::endl;
         });
@@ -81,10 +79,6 @@ struct DDSSession::Impl
         , fStopOnDestruction(false)
     {
         fSession->attach(fId);
-        auto envId(std::getenv("DDS_SESSION_ID"));
-        if (envId != nullptr && std::string(envId) != fId) {
-            setenv("DDS_SESSION_ID", fId.c_str(), 1);
-        }
 
         fDDSService.subscribeOnError([](const dds::intercom_api::EErrorCode errorCode, const std::string& msg) {
             std::cerr << "DDS error, error code: " << errorCode << ", error message: " << msg << std::endl;
@@ -99,11 +93,6 @@ struct DDSSession::Impl
         , fId(to_string(fSession->getSessionID()))
         , fStopOnDestruction(false)
     {
-        auto envId(std::getenv("DDS_SESSION_ID"));
-        if (envId != nullptr && std::string(envId) != fId) {
-            setenv("DDS_SESSION_ID", fId.c_str(), 1);
-        }
-
         // Sanity check
         if (!fSession->IsRunning()) {
             throw std::runtime_error("Given CSession must be running");
@@ -123,10 +112,6 @@ struct DDSSession::Impl
     Impl(Impl&&) = delete;
     Impl& operator=(Impl&&) = delete;
 
-    struct Tag {};
-    friend auto operator<<(std::ostream& os, Tag) -> std::ostream& { return os << "DDSSession"; }
-    tools::InstanceLimiter<Tag, 1> fCount;
-
     DDSEnvironment fEnv;
     DDSRMSPlugin fRMSPlugin;
     Path fRMSConfig;
diff --git a/test/sdk/Fixtures.h b/test/sdk/Fixtures.h
index 5c8893db..c92ffcfc 100644
--- a/test/sdk/Fixtures.h
+++ b/test/sdk/Fixtures.h
@@ -11,13 +11,18 @@
 
 #include "TestEnvironment.h"
 
-#include <asio/io_context.hpp>
-#include <chrono>
-#include <cstdlib>
-#include <fairlogger/Logger.h>
 #include <fairmq/SDK.h>
 #include <fairmq/tools/Strings.h>
+
+#include <fairlogger/Logger.h>
+
+#include <asio/io_context.hpp>
 #include <gtest/gtest.h>
+
+#include <algorithm> // for_each
+#include <array>
+#include <chrono>
+#include <cstdlib>
 #include <thread>
 
 namespace fair {
@@ -82,8 +87,7 @@ struct TopologyFixture : ::testing::Test
         }
     }
 
-    auto TearDown() -> void override {
-    }
+    auto TearDown() -> void override {}
 
     LoggerConfig mLoggerConfig;
     std::string mDDSTopoFile;
@@ -93,14 +97,70 @@ struct TopologyFixture : ::testing::Test
     asio::io_context mIoContext;
 };
 
-struct AsyncOpFixture : ::testing::Test
+struct MultipleTopologiesFixture : ::testing::Test
 {
-    auto SetUp() -> void override {
+    MultipleTopologiesFixture()
+        : mDDSTopoFile(tools::ToString(SDK_TESTSUITE_SOURCE_DIR, "/test_topo.xml"))
+        , mDDSEnv(CMAKE_CURRENT_BINARY_DIR)
+        , mDDSSessions{ sdk::DDSSession(mDDSEnv),
+                        sdk::DDSSession(mDDSEnv) }
+        , mDDSTopologies{ sdk::DDSTopology(sdk::DDSTopology::Path(mDDSTopoFile), mDDSEnv),
+                          sdk::DDSTopology(sdk::DDSTopology::Path(mDDSTopoFile), mDDSEnv) }
+    {
+        std::for_each(mDDSSessions.begin(), mDDSSessions.end(), [](sdk::DDSSession& s) {
+            s.StopOnDestruction();
+        });
     }
 
-    auto TearDown() -> void override {
+    auto SetUp() -> void override
+    {
+        LOG(info) << mDDSEnv;
+        for (int i = 0; i < mNumSessions; ++i) {
+            LOG(info) << "##### SESSION " << i << " #####";
+            LOG(info) << mDDSSessions[i];
+            LOG(info) << mDDSTopologies[i];
+            auto n(mDDSTopologies[i].GetNumRequiredAgents());
+            mDDSSessions[i].SubmitAgents(n);
+            mDDSSessions[i].ActivateTopology(mDDSTopologies[i]);
+
+            std::vector<sdk::DDSAgent> agents = mDDSSessions[i].RequestAgentInfo();
+            LOG(info) << "##### AgentInfo:";
+            LOG(info) << "size: " << agents.size();
+            for (const auto& a : agents) {
+                LOG(info) << a;
+            }
+
+            std::vector<sdk::DDSTask> tasks = mDDSSessions[i].RequestTaskInfo();
+            LOG(info) << "##### TaskInfo:";
+            LOG(info) << "size: " << tasks.size();
+            for (const auto& t : tasks) {
+                LOG(info) << t;
+            }
+
+            std::vector<sdk::DDSCollection> collections = mDDSTopologies[i].GetCollections();
+            LOG(info) << "##### CollectionInfo:";
+            LOG(info) << "size: " << collections.size();
+            for (const auto& c : collections) {
+                LOG(info) << c;
+            }
+        }
     }
 
+    auto TearDown() -> void override {}
+
+    static constexpr int mNumSessions = 2;
+    LoggerConfig mLoggerConfig;
+    std::string mDDSTopoFile;
+    sdk::DDSEnvironment mDDSEnv;
+    std::array<sdk::DDSSession, mNumSessions> mDDSSessions;
+    std::array<sdk::DDSTopology, mNumSessions> mDDSTopologies;
+};
+
+struct AsyncOpFixture : ::testing::Test
+{
+    auto SetUp() -> void override {}
+    auto TearDown() -> void override {}
+
     LoggerConfig mLoggerConfig;
     asio::io_context mIoContext;
 };
diff --git a/test/sdk/_topology.cxx b/test/sdk/_topology.cxx
index 183da18c..25b1f5c1 100644
--- a/test/sdk/_topology.cxx
+++ b/test/sdk/_topology.cxx
@@ -13,9 +13,30 @@
 #include <fairmq/sdk/Topology.h>
 #include <fairmq/Tools.h>
 
+#include <thread>
+
 namespace {
 
 using Topology = fair::mq::test::TopologyFixture;
+using MultipleTopologies = fair::mq::test::MultipleTopologiesFixture;
+
+void control(fair::mq::sdk::Topology& topo)
+{
+    using fair::mq::sdk::TopologyTransition;
+
+    for (auto transition : {TopologyTransition::InitDevice,
+                            TopologyTransition::CompleteInit,
+                            TopologyTransition::Bind,
+                            TopologyTransition::Connect,
+                            TopologyTransition::InitTask,
+                            TopologyTransition::Run,
+                            TopologyTransition::Stop,
+                            TopologyTransition::ResetTask,
+                            TopologyTransition::ResetDevice,
+                            TopologyTransition::End}) {
+        ASSERT_EQ(topo.ChangeState(transition).first, std::error_code());
+    }
+}
 
 TEST(TopologyHelper, MakeTopology)
 {
@@ -24,7 +45,6 @@ TEST(TopologyHelper, MakeTopology)
     // This is only needed for this unit test
     test::LoggerConfig cfg;
     sdk::DDSEnv env(CMAKE_CURRENT_BINARY_DIR);
-    /////////////////////////////////////
 
     std::string topoFile(tools::ToString(SDK_TESTSUITE_SOURCE_DIR, "/test_topo.xml"));
     dds::topology_api::CTopology nativeTopo(topoFile);
@@ -34,6 +54,59 @@ TEST(TopologyHelper, MakeTopology)
     nativeSession->shutdown();
 }
 
+TEST_F(MultipleTopologies, Construction)
+{
+    using namespace fair::mq;
+
+    std::array<sdk::Topology, mNumSessions> topos{
+        sdk::Topology(mDDSTopologies[0], mDDSSessions[0]),
+        sdk::Topology(mDDSTopologies[1], mDDSSessions[1])
+    };
+}
+
+TEST_F(MultipleTopologies, ChangeStateFullDeviceLifecycle)
+{
+    using namespace fair::mq;
+
+    std::array<sdk::Topology, mNumSessions> topos{
+        sdk::Topology(mDDSTopologies[0], mDDSSessions[0]),
+        sdk::Topology(mDDSTopologies[1], mDDSSessions[1])
+    };
+
+    for (int i = 0; i < mNumSessions; ++i) {
+        using fair::mq::sdk::TopologyTransition;
+
+        for (auto transition : {TopologyTransition::InitDevice,
+                                TopologyTransition::CompleteInit,
+                                TopologyTransition::Bind,
+                                TopologyTransition::Connect,
+                                TopologyTransition::InitTask,
+                                TopologyTransition::Run,
+                                TopologyTransition::Stop,
+                                TopologyTransition::ResetTask,
+                                TopologyTransition::ResetDevice,
+                                TopologyTransition::End}) {
+            ASSERT_EQ(topos[i].ChangeState(transition).first, std::error_code());
+        }
+    }
+}
+
+TEST_F(MultipleTopologies, ChangeStateFullDeviceLifecycleConcurrent)
+{
+    using namespace fair::mq;
+
+    std::array<sdk::Topology, mNumSessions> topos{
+        sdk::Topology(mDDSTopologies[0], mDDSSessions[0]),
+        sdk::Topology(mDDSTopologies[1], mDDSSessions[1])
+    };
+
+    std::thread t0(control, std::ref(topos[0]));
+    std::thread t1(control, std::ref(topos[1]));
+    t0.join();
+    t1.join();
+}
+
+
 TEST_F(Topology, Construction)
 {
     fair::mq::sdk::Topology topo(mDDSTopo, mDDSSession);