diff --git a/examples/dds/Sampler.cxx b/examples/dds/Sampler.cxx
index 7e0a8a02..bc4e39b2 100644
--- a/examples/dds/Sampler.cxx
+++ b/examples/dds/Sampler.cxx
@@ -46,6 +46,8 @@ bool Sampler::ConditionalRun()
         return false;
     }
 
+    this_thread::sleep_for(chrono::seconds(5));
+
     if (fIterations > 0) {
         ++fCounter;
         if (fCounter >= fIterations) {
diff --git a/fairmq/CMakeLists.txt b/fairmq/CMakeLists.txt
index 3d2f20bb..e775bfeb 100644
--- a/fairmq/CMakeLists.txt
+++ b/fairmq/CMakeLists.txt
@@ -413,6 +413,7 @@ if(BUILD_FAIRMQ)
   target_link_libraries(fairmq-splitter FairMQ)
 
   add_executable(fairmq-shmmonitor shmem/Monitor.cxx shmem/Monitor.h shmem/runMonitor.cxx)
+  target_compile_definitions(fairmq-shmmonitor PUBLIC BOOST_ERROR_CODE_HEADER_ONLY)
   target_link_libraries(fairmq-shmmonitor PUBLIC
     Threads::Threads
     $<$<PLATFORM_ID:Linux>:rt>
diff --git a/fairmq/sdk/CMakeLists.txt b/fairmq/sdk/CMakeLists.txt
index 0cc31cd3..01037cb8 100644
--- a/fairmq/sdk/CMakeLists.txt
+++ b/fairmq/sdk/CMakeLists.txt
@@ -17,6 +17,7 @@ set(SDK_PUBLIC_HEADER_FILES
   ../SDK.h
   DDSEnvironment.h
   DDSSession.h
+  DDSTopology.h
   Topology.h
 )
 
@@ -27,6 +28,7 @@ set(SDK_PRIVATE_HEADER_FILES
 set(SDK_SOURCE_FILES
   DDSEnvironment.cxx
   DDSSession.cxx
+  DDSTopology.cxx
   Topology.cxx
 )
 
diff --git a/fairmq/sdk/DDSEnvironment.cxx b/fairmq/sdk/DDSEnvironment.cxx
index a1ac2131..2d383ebd 100644
--- a/fairmq/sdk/DDSEnvironment.cxx
+++ b/fairmq/sdk/DDSEnvironment.cxx
@@ -8,73 +8,119 @@
 
 #include "DDSEnvironment.h"
 
-#include <DDS/Tools.h>
-#include <cstdlib>
 #include <fairmq/Tools.h>
+#include <fairmq/sdk/DDSInfo.h>
+
+#include <fairlogger/Logger.h>
+
+#include <DDS/Tools.h>
+#include <DDS/dds_intercom.h>
+
+#include <cstdlib>
 #include <sstream>
-#include <stdlib.h>
 #include <utility>
 
 namespace fair {
 namespace mq {
 namespace sdk {
 
-// TODO https://github.com/FairRootGroup/DDS/issues/224
-auto LoadDDSEnv(const boost::filesystem::path& config_home)
-    -> void
-{
-    setenv("DDS_LOCATION", DDSInstallPrefix.c_str(), 1);
-    if (!config_home.empty()) {
-        setenv("HOME", config_home.c_str(), 1);
-    }
-    std::string path(std::getenv("PATH"));
-    path = DDSExecutableDir + std::string(":") + path;
-    setenv("PATH", path.c_str(), 1);
-
-#ifndef __APPLE__
-    std::string ldVar("LD_LIBRARY_PATH");
-    std::string ld(std::getenv(ldVar.c_str()));
-    ld = DDSLibraryDir + std::string(":") + ld;
-    setenv(ldVar.c_str(), ld.c_str(), 1);
-#endif
-
-    std::istringstream cmd;
-    cmd.str("DDS_CFG=`dds-user-defaults --ignore-default-sid -p`\n"
-            "if [ -z \"$DDS_CFG\" ]; then\n"
-            "  mkdir -p \"$HOME/.DDS\"\n"
-            "  dds-user-defaults --ignore-default-sid -d -c \"$HOME/.DDS/DDS.cfg\"\n"
-            "fi");
-    std::system(cmd.str().c_str());
-}
-
 struct DDSEnvironment::Impl
 {
-    explicit Impl(Path config_home)
-        : fCount()
-        , fConfigHome(std::move(config_home))
+    explicit Impl(Path configHome)
+        : fLocation(DDSInstallPrefix)
+        , fConfigHome(std::move(configHome))
     {
-        LoadDDSEnv(fConfigHome);
-        if (fConfigHome.empty()) {
-            fConfigHome = std::getenv("HOME");
+        SetupLocation();
+        SetupDynamicLoader();
+        SetupPath();
+        SetupConfigHome();
+    }
+
+    auto SetupLocation() -> void
+    {
+        std::string location(GetEnv("DDS_LOCATION"));
+        if (location != DDSInstallPrefix) {
+            if (location.empty()) {
+                setenv("DDS_LOCATION", DDSInstallPrefix.c_str(), 1);
+            } else {
+                LOG(debug) << "$DDS_LOCATION appears to point to a different installation than this"
+                           << "program was linked against. Things might still work out, so not"
+                           << "touching it.";
+                fLocation = location;
+            }
         }
     }
 
+    auto SetupConfigHome() -> void
+    {
+        if (fConfigHome.empty()) {
+            fConfigHome = GetEnv("HOME");
+        } else {
+            setenv("HOME", fConfigHome.c_str(), 1);
+        }
+
+        std::istringstream cmd;
+        cmd.str("DDS_CFG=`dds-user-defaults --ignore-default-sid -p`\n"
+                "if [ -z \"$DDS_CFG\" ]; then\n"
+                "  mkdir -p \"$HOME/.DDS\"\n"
+                "  dds-user-defaults --ignore-default-sid -d -c \"$HOME/.DDS/DDS.cfg\"\n"
+                "fi");
+        std::system(cmd.str().c_str());
+    }
+
+    auto SetupPath() -> void
+    {
+        std::string path(GetEnv("PATH"));
+        Path ddsExecDir = (fLocation == DDSInstallPrefix) ? DDSExecutableDir : fLocation / Path("bin");
+        path = ddsExecDir.string() + std::string(":") + path;
+        setenv("PATH", path.c_str(), 1);
+    }
+
+    auto SetupDynamicLoader() -> void
+    {
+#ifdef __APPLE__
+        std::string ldVar("DYLD_LIBRARY_PATH");
+#else
+        std::string ldVar("LD_LIBRARY_PATH");
+#endif
+        std::string ld(GetEnv(ldVar));
+        Path ddsLibDir = (fLocation == DDSInstallPrefix) ? DDSLibraryDir : fLocation / Path("lib");
+        ld = ddsLibDir.string() + std::string(":") + ld;
+        setenv(ldVar.c_str(), ld.c_str(), 1);
+    }
+
+    auto GetEnv(const std::string& key) -> std::string
+    {
+        auto value = std::getenv(key.c_str());
+        if (value) {
+            return {value};
+        }
+        return {};
+    }
+
     struct Tag {};
     friend auto operator<<(std::ostream& os, Tag) -> std::ostream& { return os << "DDSEnvironment"; }
     tools::InstanceLimiter<Tag, 1> fCount;
 
+    Path fLocation;
     Path fConfigHome;
 };
 
-DDSEnvironment::DDSEnvironment(Path config_home)
-    : fImpl(std::make_shared<Impl>(std::move(config_home)))
+DDSEnvironment::DDSEnvironment()
+    : DDSEnvironment(Path())
 {}
 
+DDSEnvironment::DDSEnvironment(Path configHome)
+    : fImpl(std::make_shared<Impl>(std::move(configHome)))
+{}
+
+auto DDSEnvironment::GetLocation() const -> Path { return fImpl->fLocation; }
+
 auto DDSEnvironment::GetConfigHome() const -> Path { return fImpl->fConfigHome; }
 
 auto operator<<(std::ostream& os, DDSEnvironment env) -> std::ostream&
 {
-    return os << "$DDS_LOCATION: " << DDSInstallPrefix << ", "
+    return os << "$DDS_LOCATION: " << env.GetLocation() << ", "
               << "$DDS_CONFIG_HOME: " << env.GetConfigHome() / DDSEnvironment::Path(".DDS");
 }
 
diff --git a/fairmq/sdk/DDSEnvironment.h b/fairmq/sdk/DDSEnvironment.h
index 96faa7aa..2ba72eca 100644
--- a/fairmq/sdk/DDSEnvironment.h
+++ b/fairmq/sdk/DDSEnvironment.h
@@ -10,7 +10,6 @@
 #define FAIR_MQ_SDK_DDSENVIRONMENT_H
 
 #include <boost/filesystem.hpp>
-#include <fairmq/sdk/DDSInfo.h>
 #include <memory>
 #include <ostream>
 
@@ -27,9 +26,10 @@ class DDSEnvironment
   public:
     using Path = boost::filesystem::path;
 
-    /// @brief See fair::mq::sdk::LoadDDSEnv
-    explicit DDSEnvironment(Path config_home = "");
+    DDSEnvironment();
+    explicit DDSEnvironment(Path);
 
+    auto GetLocation() const -> Path;
     auto GetConfigHome() const -> Path;
 
     friend auto operator<<(std::ostream& os, DDSEnvironment env) -> std::ostream&;
@@ -38,6 +38,8 @@ class DDSEnvironment
     std::shared_ptr<Impl> fImpl;
 };
 
+using DDSEnv = DDSEnvironment;
+
 }   // namespace sdk
 }   // namespace mq
 }   // namespace fair
diff --git a/fairmq/sdk/DDSInfo.h.in b/fairmq/sdk/DDSInfo.h.in
index 357d9f7d..156d219c 100644
--- a/fairmq/sdk/DDSInfo.h.in
+++ b/fairmq/sdk/DDSInfo.h.in
@@ -11,6 +11,20 @@
 
 #include <string>
 
+namespace dds {
+namespace tools_api {
+
+class CSession;
+
+}   // namespace tools_api
+
+namespace topology_api {
+
+class CTopology;
+
+}   // namespace topology_api
+}   // namespace dds
+
 namespace fair {
 namespace mq {
 namespace sdk {
diff --git a/fairmq/sdk/DDSSession.cxx b/fairmq/sdk/DDSSession.cxx
index e533d6b5..2e2f4154 100644
--- a/fairmq/sdk/DDSSession.cxx
+++ b/fairmq/sdk/DDSSession.cxx
@@ -7,16 +7,19 @@
  ********************************************************************************/
 
 #include "DDSSession.h"
-#include "DDSEnvironment.h"
+
+#include <fairmq/sdk/DDSEnvironment.h>
+#include <fairmq/Tools.h>
+
+#include <fairlogger/Logger.h>
 
 #include <DDS/Tools.h>
+
 #include <boost/uuid/uuid_io.hpp>
+
 #include <cassert>
 #include <cstdlib>
-#include <fairlogger/Logger.h>
-#include <fairmq/Tools.h>
 #include <sstream>
-#include <stdlib.h>
 #include <utility>
 
 namespace fair {
@@ -52,48 +55,76 @@ auto operator>>(std::istream& is, DDSRMSPlugin& plugin) -> std::istream&
 
 struct DDSSession::Impl
 {
-    Impl(DDSEnvironment env, DDSRMSPlugin plugin)
-        : fCount()
-        , fEnv(std::move(env))
-        , fDefaultPlugin(std::move(plugin))
-        , fSession()
+    explicit Impl(DDSEnvironment env)
+        : fEnv(std::move(env))
+        , fRMSPlugin(DDSRMSPlugin::localhost)
+        , fDDSService()
+        , fDDSCustomCmd(fDDSService)
         , 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;
+        });
     }
 
-    Impl(DDSEnvironment env, DDSRMSPlugin plugin, Id existing_id)
-        : fCount()
-        , fEnv(std::move(env))
-        , fDefaultPlugin(std::move(plugin))
-        , fSession()
-        , fId(std::move(existing_id))
+    explicit Impl(Id existing, DDSEnvironment env)
+        : fEnv(std::move(env))
+        , fRMSPlugin(DDSRMSPlugin::localhost)
+        , fDDSService()
+        , fDDSCustomCmd(fDDSService)
+        , fId(std::move(existing))
+        , fStopOnDestruction(false)
     {
         fSession.attach(fId);
         std::string envId(std::getenv("DDS_SESSION_ID"));
         if (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;
+        });
     }
 
+    ~Impl()
+    {
+        if (fStopOnDestruction) {
+            fSession.shutdown();
+        }
+    }
+
+    Impl() = delete;
+    Impl(const Impl&) = delete;
+    Impl& operator=(const Impl&) = delete;
+    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;
 
-    const DDSEnvironment fEnv;
-    const DDSRMSPlugin fDefaultPlugin;
+    DDSEnvironment fEnv;
+    DDSRMSPlugin fRMSPlugin;
+    Path fRMSConfig;
     dds::tools_api::CSession fSession;
-    const Id fId;
+    dds::intercom_api::CIntercomService fDDSService;
+    dds::intercom_api::CCustomCmd fDDSCustomCmd;
+    Id fId;
+    bool fStopOnDestruction;
 };
 
-DDSSession::DDSSession(DDSEnvironment env, DDSRMSPlugin default_plugin)
-: fImpl(std::make_shared<Impl>(std::move(env), std::move(default_plugin))) {}
+DDSSession::DDSSession(DDSEnvironment env)
+    : fImpl(std::make_shared<Impl>(env))
+{}
 
-DDSSession::DDSSession(DDSEnvironment env, Id existing_id)
-: fImpl(std::make_shared<Impl>(std::move(env), DDSRMSPlugin::localhost, std::move(existing_id))) {}
+DDSSession::DDSSession(Id existing, DDSEnvironment env)
+    : fImpl(std::make_shared<Impl>(std::move(existing), env))
+{}
 
-DDSSession::DDSSession(DDSEnvironment env, DDSRMSPlugin default_plugin, Id existing_id)
-: fImpl(std::make_shared<Impl>(std::move(env), std::move(default_plugin), std::move(existing_id))) {}
+auto DDSSession::GetEnv() const -> DDSEnvironment { return fImpl->fEnv; }
 
 auto DDSSession::IsRunning() const -> bool { return fImpl->fSession.IsRunning(); }
 
@@ -101,36 +132,30 @@ auto DDSSession::GetId() const -> Id { return fImpl->fId; }
 
 auto DDSSession::Stop() -> void { return fImpl->fSession.shutdown(); }
 
-auto DDSSession::GetDefaultPlugin() const -> DDSRMSPlugin { return fImpl->fDefaultPlugin; }
+auto DDSSession::GetRMSPlugin() const -> DDSRMSPlugin { return fImpl->fRMSPlugin; }
+
+auto DDSSession::SetRMSPlugin(DDSRMSPlugin plugin) -> void { fImpl->fRMSPlugin = plugin; }
+
+auto DDSSession::GetRMSConfig() const -> Path { return fImpl->fRMSConfig; }
+
+auto DDSSession::SetRMSConfig(Path configFile) const -> void
+{
+    fImpl->fRMSConfig = std::move(configFile);
+}
+
+auto DDSSession::IsStoppedOnDestruction() const -> bool { return fImpl->fStopOnDestruction; }
+
+auto DDSSession::StopOnDestruction(bool stop) -> void { fImpl->fStopOnDestruction = stop; }
 
 auto DDSSession::SubmitAgents(Quantity agents) -> void
-{
-    SubmitAgents(agents, GetDefaultPlugin(), Path());
-}
-
-auto DDSSession::SubmitAgents(Quantity agents, DDSRMSPlugin plugin) -> void
-{
-    SubmitAgents(agents, plugin, Path());
-}
-
-auto DDSSession::SubmitAgents(Quantity agents, const Path& config) -> void
-{
-    SubmitAgents(agents, GetDefaultPlugin(), std::move(config));
-}
-
-auto DDSSession::SubmitAgents(Quantity agents, DDSRMSPlugin plugin, const Path& config) -> void
 {
     // Requesting to submit 0 agents is not meaningful
     assert(agents > 0);
-    // The config argument is required with all plugins except localhost
-    if (plugin != DDSRMSPlugin::localhost) {
-        assert(exists(config));
-    }
 
     dds::tools_api::SSubmitRequestData submitInfo;
-    submitInfo.m_rms = tools::ToString(plugin);
+    submitInfo.m_rms = tools::ToString(GetRMSPlugin());
     submitInfo.m_instances = agents;
-    submitInfo.m_config = config.string();
+    submitInfo.m_config = GetRMSConfig().string();
 
     tools::Semaphore blocker;
     auto submitRequest = dds::tools_api::SSubmitRequest::makeRequest(submitInfo);
@@ -162,7 +187,28 @@ auto DDSSession::RequestAgentInfo() -> void
     blocker.Wait();
 }
 
-auto DDSSession::ActivateTopology(Path topologyFile) -> void
+auto DDSSession::RequestCommanderInfo() -> void
+{
+    dds::tools_api::SCommanderInfoRequestData commanderInfoInfo;
+    tools::Semaphore blocker;
+    auto commanderInfoRequest =
+        dds::tools_api::SCommanderInfoRequest::makeRequest(commanderInfoInfo);
+    commanderInfoRequest->setResponseCallback(
+        [&](const dds::tools_api::SCommanderInfoResponseData& _response) {
+            LOG(debug) << "pid: " << _response.m_pid;
+            LOG(debug) << "idle agents: " << _response.m_idleAgentsCount;
+            // LOG(debug) << "active topology: "
+            // << ((_response.m_hasActiveTopology) ? _response.m_activeTopologyName
+            // : "<none>");
+        });
+    commanderInfoRequest->setMessageCallback(
+        [](const dds::tools_api::SMessageResponseData& _message) { LOG(debug) << _message; });
+    commanderInfoRequest->setDoneCallback([&]() { blocker.Signal(); });
+    fImpl->fSession.sendRequest<dds::tools_api::SCommanderInfoRequest>(commanderInfoRequest);
+    blocker.Wait();
+}
+
+auto DDSSession::ActivateTopology(const Path& topologyFile) -> void
 {
     dds::tools_api::STopologyRequestData topologyInfo;
     topologyInfo.m_updateType = dds::tools_api::STopologyRequestData::EUpdateType::ACTIVATE;
@@ -177,7 +223,16 @@ auto DDSSession::ActivateTopology(Path topologyFile) -> void
     blocker.Wait();
 }
 
-auto operator<<(std::ostream& os, DDSSession session) -> std::ostream&
+void DDSSession::StartDDSService() { fImpl->fDDSService.start(fImpl->fId); }
+
+void DDSSession::SubscribeToCommands(std::function<void(const std::string& msg, const std::string& condition, uint64_t senderId)> cb)
+{
+    fImpl->fDDSCustomCmd.subscribe(cb);
+}
+
+void DDSSession::SendCommand(const std::string& cmd) { fImpl->fDDSCustomCmd.send(cmd, ""); }
+
+auto operator<<(std::ostream& os, const DDSSession& session) -> std::ostream&
 {
     return os << "$DDS_SESSION_ID: " << session.GetId();
 }
diff --git a/fairmq/sdk/DDSSession.h b/fairmq/sdk/DDSSession.h
index 25fa6657..f3e8202e 100644
--- a/fairmq/sdk/DDSSession.h
+++ b/fairmq/sdk/DDSSession.h
@@ -9,14 +9,18 @@
 #ifndef FAIR_MQ_SDK_DDSSESSION_H
 #define FAIR_MQ_SDK_DDSSESSION_H
 
-#include <boost/filesystem.hpp>
-#include <cstdint>
+#include <fairmq/sdk/DDSEnvironment.h>
 #include <fairmq/sdk/DDSInfo.h>
+
+#include <boost/filesystem.hpp>
+
+#include <cstdint>
 #include <istream>
 #include <memory>
 #include <ostream>
 #include <stdexcept>
 #include <string>
+#include <functional>
 
 namespace fair {
 namespace mq {
@@ -47,23 +51,29 @@ class DDSSession
     using Quantity = std::uint32_t;
     using Path = boost::filesystem::path;
 
-    DDSSession() = delete;
-    explicit DDSSession(DDSEnvironment env, DDSRMSPlugin default_plugin = DDSRMSPlugin::localhost);
-    explicit DDSSession(DDSEnvironment env, Id existing_id);
-    explicit DDSSession(DDSEnvironment env, DDSRMSPlugin default_plugin, Id existing_id);
+    explicit DDSSession(DDSEnvironment env = DDSEnvironment());
+    explicit DDSSession(Id existing, DDSEnvironment env = DDSEnvironment());
 
+    auto GetEnv() const -> DDSEnvironment;
     auto GetId() const -> Id;
-    auto GetDefaultPlugin() const -> DDSRMSPlugin;
+    auto GetRMSPlugin() const -> DDSRMSPlugin;
+    auto SetRMSPlugin(DDSRMSPlugin) -> void;
+    auto GetRMSConfig() const -> Path;
+    auto SetRMSConfig(Path) const -> void;
+    auto IsStoppedOnDestruction() const -> bool;
+    auto StopOnDestruction(bool stop = true) -> void;
     auto IsRunning() const -> bool;
     auto SubmitAgents(Quantity agents) -> void;
-    auto SubmitAgents(Quantity agents, DDSRMSPlugin plugin) -> void;
-    auto SubmitAgents(Quantity agents, DDSRMSPlugin plugin, const Path& config) -> void;
-    auto SubmitAgents(Quantity agents, const Path& config) -> void;
     auto RequestAgentInfo() -> void;
-    auto ActivateTopology(Path topologyFile) -> void;
+    auto RequestCommanderInfo() -> void;
+    auto ActivateTopology(const Path& topologyFile) -> void;
     auto Stop() -> void;
 
-    friend auto operator<<(std::ostream& os, DDSSession session) -> std::ostream&;
+    void StartDDSService();
+    void SubscribeToCommands(std::function<void(const std::string& msg, const std::string& condition, uint64_t senderId)>);
+    void SendCommand(const std::string&);
+
+    friend auto operator<<(std::ostream& os, const DDSSession& session) -> std::ostream&;
   private:
     struct Impl;
     std::shared_ptr<Impl> fImpl;
diff --git a/fairmq/sdk/DDSTopology.cxx b/fairmq/sdk/DDSTopology.cxx
new file mode 100644
index 00000000..3ca2737d
--- /dev/null
+++ b/fairmq/sdk/DDSTopology.cxx
@@ -0,0 +1,96 @@
+/********************************************************************************
+ *    Copyright (C) 2019 GSI Helmholtzzentrum fuer Schwerionenforschung GmbH    *
+ *                                                                              *
+ *              This software is distributed under the terms of the             *
+ *              GNU Lesser General Public Licence (LGPL) version 3,             *
+ *                  copied verbatim in the file "LICENSE"                       *
+ ********************************************************************************/
+
+#include "DDSTopology.h"
+
+#include <fairmq/sdk/DDSEnvironment.h>
+#include <fairmq/Tools.h>
+
+#include <fairlogger/Logger.h>
+
+#include <DDS/Topology.h>
+
+#include <sstream>
+#include <stdexcept>
+#include <utility>
+#include <memory>
+
+namespace fair {
+namespace mq {
+namespace sdk {
+
+struct DDSTopology::Impl
+{
+    explicit Impl(Path topoFile, DDSEnvironment env)
+        : fEnv(std::move(env))
+        , fTopoFile(std::move(topoFile))
+        , fTopo(nullptr)
+    {
+        LOG(warn) << topoFile;
+    }
+
+    DDSEnvironment fEnv;
+    Path fTopoFile;
+    std::unique_ptr<dds::topology_api::CTopology> fTopo;
+};
+
+DDSTopology::DDSTopology(Path topoFile, DDSEnvironment env)
+    : fImpl(std::make_shared<Impl>(std::move(topoFile), std::move(env)))
+{}
+
+auto DDSTopology::GetEnv() const -> DDSEnvironment { return fImpl->fEnv; }
+
+auto DDSTopology::GetTopoFile() const -> Path
+{
+    auto file(fImpl->fTopoFile);
+    if (file.string().empty()) {
+        throw std::runtime_error("DDS topology xml spec file unknown");
+    }
+    return file;
+}
+
+void DDSTopology::CreateTopology(Path topoFile)
+{
+    fImpl->fTopo = tools::make_unique<dds::topology_api::CTopology>(fImpl->fTopoFile.c_str());
+}
+
+int DDSTopology::GetNumRequiredAgents()
+{
+    return fImpl->fTopo->getRequiredNofAgents();
+}
+
+std::vector<uint64_t> DDSTopology::GetDeviceList()
+{
+    std::vector<uint64_t> taskIDs;
+    taskIDs.reserve(fImpl->fTopo->getRequiredNofAgents());
+
+    // TODO make sure returned tasks are actually devices
+    dds::topology_api::STopoRuntimeTask::FilterIteratorPair_t taskIt = fImpl->fTopo->getRuntimeTaskIterator([](const dds::topology_api::STopoRuntimeTask::FilterIterator_t::value_type& value) -> bool {
+        return true;
+    });
+
+    for (auto& it = taskIt.first; it != taskIt.second; ++it) {
+        LOG(debug) << "Found task " << it->first << " : " << it->second.m_task->getPath();
+        taskIDs.push_back(it->first);
+    }
+
+    return taskIDs;
+}
+
+// auto DDSTopology::GetName() const -> std::string { return fImpl->fTopo.getName(); }
+
+auto operator<<(std::ostream& os, const DDSTopology& t) -> std::ostream&
+try {
+    return os << "DDS topology: " /*<< t.GetName() <<*/ " (loaded from " << t.GetTopoFile() << ")";
+} catch (std::runtime_error&) {
+    return os << "DDS topology: " /*<< t.GetName()*/;
+}
+
+}   // namespace sdk
+}   // namespace mq
+}   // namespace fair
diff --git a/fairmq/sdk/DDSTopology.h b/fairmq/sdk/DDSTopology.h
index 814fddc9..9f7cec60 100644
--- a/fairmq/sdk/DDSTopology.h
+++ b/fairmq/sdk/DDSTopology.h
@@ -9,18 +9,11 @@
 #ifndef FAIR_MQ_SDK_DDSTOPOLOGY_H
 #define FAIR_MQ_SDK_DDSTOPOLOGY_H
 
-#include <fairmq/sdk/DDSInfo.h>
+#include <boost/filesystem.hpp>
+#include <fairmq/sdk/DDSEnvironment.h>
 #include <memory>
 #include <string>
 
-namespace dds {
-namespace topology_api {
-
-class CTopology;
-
-}   // namespace topology_api
-}   // namespace dds
-
 namespace fair {
 namespace mq {
 namespace sdk {
@@ -29,23 +22,44 @@ namespace sdk {
  * @class DDSTopology DDSTopology.h <fairmq/sdk/DDSTopology.h>
  * @brief Represents a DDS topology
  */
-class DDSSession
+class DDSTopology
 {
   public:
-    using CSessionPtr = std::shared_ptr<dds::tools_api::CSession>;
+    using Path = boost::filesystem::path;
 
-    explicit DDSSession();
-    explicit DDSSession(std::string existing_session_id);
+    DDSTopology() = delete;
+
+    /// @brief Construct from file
+    /// @param topoFile DDS topology xml file
+    /// @param env DDS environment
+    explicit DDSTopology(Path topoFile, DDSEnvironment env = DDSEnvironment());
+
+    /// @brief Get associated DDS environment
+    auto GetEnv() const -> DDSEnvironment;
+
+    /// @brief Get path to DDS topology xml, if it is known
+    /// @throw std::runtime_error
+    auto GetTopoFile() const -> Path;
+
+    void CreateTopology(Path);
+
+    /// @brief Get number of required agents for this topology
+    int GetNumRequiredAgents();
+
+    /// @brief Get list of devices
+    std::vector<uint64_t> GetDeviceList();
+
+    /// @brief Get the name of the topology
+    // auto GetName() const -> std::string;
+
+    friend auto operator<<(std::ostream&, const DDSTopology&) -> std::ostream&;
 
-    auto GetId() const -> const std::string&;
-    auto IsRunning() const -> bool;
   private:
-    CSessionPtr fSession;
-    const std::string fId;
+    struct Impl;
+    std::shared_ptr<Impl> fImpl;
 };
 
-auto LoadDDSEnv(const std::string& config_home = "", const std::string& prefix = DDSInstallPrefix)
-    -> void;
+using DDSTopo = DDSTopology;
 
 }   // namespace sdk
 }   // namespace mq
diff --git a/fairmq/sdk/Topology.cxx b/fairmq/sdk/Topology.cxx
index b4a2a56b..a1129232 100644
--- a/fairmq/sdk/Topology.cxx
+++ b/fairmq/sdk/Topology.cxx
@@ -8,25 +8,166 @@
 
 #include "Topology.h"
 
-#include <DDS/Topology.h>
+#include <fairlogger/Logger.h>
+
+#include <boost/algorithm/string/split.hpp>
+#include <boost/algorithm/string/trim.hpp>
+
 #include <utility>
+#include <thread>
+#include <future>
+#include <mutex>
+#include <condition_variable>
 
 namespace fair {
 namespace mq {
+
+auto operator<<(std::ostream& os, AsyncOpResult v) -> std::ostream&
+{
+    switch (v) {
+        case AsyncOpResult::Aborted:
+            return os << "Aborted";
+        case AsyncOpResult::Timeout:
+            return os << "Timeout";
+        case AsyncOpResult::Error:
+            return os << "Error";
+        case AsyncOpResult::Ok:
+        default:
+            return os << "Ok";
+    }
+}
+
 namespace sdk {
 
-struct Topology::Impl
+const std::unordered_map<DeviceTransition, DeviceState, tools::HashEnum<DeviceTransition>> Topology::fkExpectedState =
 {
-    Impl(dds::topology_api::CTopology topo)
-        : fDDSTopology(std::move(topo))
-    {}
-
-    dds::topology_api::CTopology fDDSTopology;
+    { Transition::InitDevice,   DeviceState::InitializingDevice },
+    { Transition::CompleteInit, DeviceState::Initialized },
+    { Transition::Bind,         DeviceState::Bound },
+    { Transition::Connect,      DeviceState::DeviceReady },
+    { Transition::InitTask,     DeviceState::InitializingTask },
+    { Transition::Run,          DeviceState::Running },
+    { Transition::Stop,         DeviceState::Ready },
+    { Transition::ResetTask,    DeviceState::DeviceReady },
+    { Transition::ResetDevice,  DeviceState::Idle },
+    { Transition::End,          DeviceState::Exiting }
 };
 
-Topology::Topology(dds::topology_api::CTopology topo)
-    : fImpl(std::make_shared<Impl>(std::move(topo)))
-{}
+Topology::Topology(DDSTopology topo, DDSSession session)
+    : fDDSSession(std::move(session))
+    , fDDSTopo(std::move(topo))
+    , fTopologyState()
+    , fStateChangeOngoing(false)
+    , fExecutionThread()
+    , fShutdown(false)
+{
+    fDDSTopo.CreateTopology(fDDSTopo.GetTopoFile());
+
+    std::vector<uint64_t> deviceList = fDDSTopo.GetDeviceList();
+    for (const auto& d : deviceList) {
+        fTopologyState.emplace(d, DeviceStatus{ false, DeviceState::Ok });
+    }
+    fDDSSession.SubscribeToCommands([this](const std::string& msg, const std::string& condition, uint64_t senderId) {
+        LOG(info) << "Received from " << senderId << ": " << msg;
+        std::vector<std::string> parts;
+        boost::algorithm::split(parts, msg, boost::algorithm::is_any_of(":,"));
+        if (parts[0] == "state-change") {
+            boost::trim(parts[2]);
+            AddNewStateEntry(senderId, parts[2]);
+        } else if (parts[0] == "state-changes-subscription") {
+            if (parts[2] != "OK") {
+                LOG(error) << "state-changes-subscription failed with return code: " << parts[2];
+            }
+        } else if (parts[0] == "state-changes-unsubscription") {
+            if (parts[2] != "OK") {
+                LOG(error) << "state-changes-unsubscription failed with return code: " << parts[2];
+            }
+        }
+    });
+    fDDSSession.StartDDSService();
+    fDDSSession.SendCommand("subscribe-to-state-changes");
+
+    fExecutionThread = std::thread(&Topology::WaitForState, this);
+}
+
+auto Topology::ChangeState(fair::mq::Transition transition, ChangeStateCallback cb, const std::chrono::milliseconds& timeout) -> void
+{
+    {
+        std::lock_guard<std::mutex> guard(fMtx);
+        if (fStateChangeOngoing) {
+            LOG(error) << "State change already in progress, concurrent requested not yet supported";
+            return;
+        }
+        fStateChangeOngoing = true;
+        fChangeStateCallback = cb;
+        fStateChangeTimeout = timeout;
+
+        fDDSSession.SendCommand(GetTransitionName(transition));
+
+        fTargetState = fkExpectedState.at(transition);
+    }
+    fExecutionCV.notify_one();
+}
+
+void Topology::WaitForState()
+{
+    while (!fShutdown) {
+        if (fStateChangeOngoing) {
+            auto condition = [&] { return fShutdown || std::all_of(fTopologyState.cbegin(),
+                                                                   fTopologyState.cend(),
+                                                                   [&](TopologyState::value_type i) {
+                                                                       return i.second.state == fTargetState;
+                                                                   });
+            };
+
+            std::unique_lock<std::mutex> lock(fMtx);
+
+            if (fStateChangeTimeout > std::chrono::milliseconds(0)) {
+                if (!fCV.wait_for(lock, fStateChangeTimeout, condition)) {
+                    LOG(debug) << "timeout";
+                    // TODO: catch this from another thread...
+                    throw std::runtime_error("timeout");
+                }
+            } else {
+                fCV.wait(lock, condition);
+            }
+
+            if (fShutdown) {
+                break;
+            }
+
+            fStateChangeOngoing = false;
+            fChangeStateCallback(ChangeStateResult{AsyncOpResult::Ok, fTopologyState});
+        } else {
+            std::unique_lock<std::mutex> lock(fExecutionMtx);
+            fExecutionCV.wait(lock);
+        }
+    }
+};
+
+void Topology::AddNewStateEntry(uint64_t senderId, const std::string& state)
+{
+    {
+        std::unique_lock<std::mutex> lock(fMtx);
+        fTopologyState[senderId] = DeviceStatus{ true, fair::mq::GetState(state) };
+    }
+    fCV.notify_one();
+}
+
+Topology::~Topology()
+{
+    {
+        std::lock_guard<std::mutex> guard(fMtx);
+        fShutdown = true;
+    }
+    fExecutionCV.notify_one();
+    fExecutionThread.join();
+}
+
+auto operator<<(std::ostream& os, Topology::ChangeStateResult v) -> std::ostream&
+{
+    return os << v.rc;
+}
 
 }   // namespace sdk
 }   // namespace mq
diff --git a/fairmq/sdk/Topology.h b/fairmq/sdk/Topology.h
index 5cfdd344..675f8f3f 100644
--- a/fairmq/sdk/Topology.h
+++ b/fairmq/sdk/Topology.h
@@ -9,25 +9,45 @@
 #ifndef FAIR_MQ_SDK_TOPOLOGY_H
 #define FAIR_MQ_SDK_TOPOLOGY_H
 
+#include <fairmq/sdk/DDSInfo.h>
+#include <fairmq/sdk/DDSSession.h>
+#include <fairmq/sdk/DDSTopology.h>
 #include <fairmq/States.h>
+#include <fairmq/Tools.h>
+
 #include <functional>
+#include <unordered_map>
 #include <memory>
+#include <chrono>
 #include <ostream>
 #include <string>
 #include <vector>
 
-namespace dds {
-namespace topology_api {
-
-class CTopology;
-
-}   // namespace topology_api
-}   // namespace dds
-
 namespace fair {
 namespace mq {
+
+enum class AsyncOpResult {
+    Ok,
+    Timeout,
+    Error,
+    Aborted
+};
+auto operator<<(std::ostream& os, AsyncOpResult v) -> std::ostream&;
+
 namespace sdk {
 
+using DeviceState = fair::mq::State;
+using DeviceTransition = fair::mq::Transition;
+
+struct DeviceStatus
+{
+    bool initialized;
+    DeviceState state;
+};
+
+using TopologyState = std::unordered_map<uint64_t, DeviceStatus>;
+using TopologyTransition = fair::mq::Transition;
+
 /**
  * @class Topology Topology.h <fairmq/sdk/Topology.h>
  * @brief Represents a FairMQ topology
@@ -35,16 +55,46 @@ namespace sdk {
 class Topology
 {
   public:
+    /// @brief (Re)Construct a FairMQ topology from an existing DDS topology
+    /// @param topo Initialized DDS CTopology
+    explicit Topology(DDSTopology topo, DDSSession session = DDSSession());
+    ~Topology();
 
-    /// @brief Construct a FairMQ topology from an existing DDS session via the dds::topology_api
-    /// @param topo An initialized CTopology object
-    explicit Topology(dds::topology_api::CTopology topo);
+    struct ChangeStateResult {
+        AsyncOpResult rc;
+        TopologyState state;
+        friend auto operator<<(std::ostream& os, ChangeStateResult v) -> std::ostream&;
+    };
+    using ChangeStateCallback = std::function<void(ChangeStateResult)>;
+
+    /// @brief Initiate state transition on all FairMQ devices in this topology
+    /// @param t FairMQ device state machine transition
+    /// @param cb Completion callback
+    auto ChangeState(TopologyTransition t, ChangeStateCallback cb, const std::chrono::milliseconds& timeout = std::chrono::milliseconds(0)) -> void;
+
+    static const std::unordered_map<DeviceTransition, DeviceState, tools::HashEnum<DeviceTransition>> fkExpectedState;
 
   private:
-    struct Impl;
-    std::shared_ptr<Impl> fImpl;
+    DDSSession fDDSSession;
+    DDSTopology fDDSTopo;
+    TopologyState fTopologyState;
+    bool fStateChangeOngoing;
+    DeviceState fTargetState;
+    std::mutex fMtx;
+    std::mutex fExecutionMtx;
+    std::condition_variable fCV;
+    std::condition_variable fExecutionCV;
+    std::thread fExecutionThread;
+    ChangeStateCallback fChangeStateCallback;
+    std::chrono::milliseconds fStateChangeTimeout;
+    bool fShutdown;
+
+    void WaitForState();
+    void AddNewStateEntry(uint64_t senderId, const std::string& state);
 };
 
+using Topo = Topology;
+
 }   // namespace sdk
 }   // namespace mq
 }   // namespace fair
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index db65b394..ab18edc4 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -287,7 +287,7 @@ if(BUILD_SDK)
     add_testsuite(SDK
         SOURCES
         ${CMAKE_CURRENT_BINARY_DIR}/runner.cxx
-        # sdk/_dds.cxx
+        sdk/_dds.cxx
         sdk/_topology.cxx
         sdk/TopologyFixture.h
 
diff --git a/test/sdk/TopologyFixture.h b/test/sdk/TopologyFixture.h
index d1f7ebf5..1c0724c6 100644
--- a/test/sdk/TopologyFixture.h
+++ b/test/sdk/TopologyFixture.h
@@ -13,12 +13,10 @@
 #include <fairmq/SDK.h>
 #include <fairmq/Tools.h>
 
-#include <DDS/Topology.h>
 #include <chrono>
 #include <cstdlib>
 #include <fairlogger/Logger.h>
 #include <gtest/gtest.h>
-#include <stdlib.h>
 #include <thread>
 
 namespace fair {
@@ -45,14 +43,14 @@ struct LoggerConfig
 struct TopologyFixture : ::testing::Test
 {
     TopologyFixture()
-        : mLoggerConfig()
-        , mDDSTopologyFile(std::string(SDK_TESTSUITE_SOURCE_DIR) + "/test_topo.xml")
+        : mDDSTopoFile(tools::ToString(SDK_TESTSUITE_SOURCE_DIR, "/test_topo.xml"))
         , mDDSEnv(CMAKE_CURRENT_BINARY_DIR)
         , mDDSSession(mDDSEnv)
-        , mDDSTopology(mDDSTopologyFile)
-    {}
-    //
-//
+        , mDDSTopo(mDDSTopoFile, mDDSEnv)
+    {
+        mDDSSession.StopOnDestruction();
+    }
+
     // auto ActivateDDSTopology(const std::string& topology_file) -> void {
         // LOG(debug) << "ActivateDDSTopology(\"" << topology_file << "\")";
     // }
@@ -60,20 +58,22 @@ struct TopologyFixture : ::testing::Test
     auto SetUp() -> void override {
         LOG(info) << mDDSEnv;
         LOG(info) << mDDSSession;
+        mDDSSession.RequestCommanderInfo();
         mDDSSession.SubmitAgents(2);
+        mDDSSession.RequestCommanderInfo();
         std::this_thread::sleep_for(std::chrono::seconds(1)); // TODO implement WaitForIdleAgents
-        mDDSSession.ActivateTopology(mDDSTopologyFile);
+        mDDSSession.ActivateTopology(mDDSTopoFile);
+        mDDSSession.RequestCommanderInfo();
     }
 
     auto TearDown() -> void override {
-        mDDSSession.Stop();
     }
 
     LoggerConfig mLoggerConfig;
-    std::string mDDSTopologyFile;
+    std::string mDDSTopoFile;
     sdk::DDSEnvironment mDDSEnv;
     sdk::DDSSession mDDSSession;
-    dds::topology_api::CTopology mDDSTopology;
+    sdk::DDSTopology mDDSTopo;
 };
 
 } /* namespace test */
diff --git a/test/sdk/_dds.cxx b/test/sdk/_dds.cxx
index e15e70c8..b22ac0b2 100644
--- a/test/sdk/_dds.cxx
+++ b/test/sdk/_dds.cxx
@@ -15,7 +15,7 @@
 
 namespace {
 
-auto session_test() -> void
+auto setup() -> void
 {
     fair::Logger::SetConsoleSeverity("debug");
     fair::Logger::DefineVerbosity("user1",
@@ -23,35 +23,24 @@ auto session_test() -> void
                                                           fair::VerbositySpec::Info::severity));
     fair::Logger::SetVerbosity("user1");
     fair::Logger::SetConsoleColor();
+}
+
+TEST(DDS, Environment)
+{
+    setup();
 
     fair::mq::sdk::DDSEnvironment env(CMAKE_CURRENT_BINARY_DIR);
     LOG(debug) << env;
-    {
-        fair::mq::sdk::DDSSession session(env);
-        LOG(debug) << session;
-        session.SubmitAgents(5);
-        session.SubmitAgents(5);
-    }
-    {
-        fair::mq::sdk::DDSSession session(env);
-        LOG(debug) << session;
-        session.SubmitAgents(5);
-    }
-    {
-        fair::mq::sdk::DDSSession session(env);
-        LOG(debug) << session;
-        session.SubmitAgents(5);
-    }
 }
 
 TEST(DDS, Session)
 {
-    session_test();
-}
+    setup();
 
-TEST(DDS, Session2)
-{
-    session_test();
+    fair::mq::sdk::DDSEnvironment env(CMAKE_CURRENT_BINARY_DIR);
+    fair::mq::sdk::DDSSession session(env);
+    session.StopOnDestruction();
+    LOG(debug) << session;
 }
 
 }   // namespace
diff --git a/test/sdk/_topology.cxx b/test/sdk/_topology.cxx
index 7449688b..0ff1a3b1 100644
--- a/test/sdk/_topology.cxx
+++ b/test/sdk/_topology.cxx
@@ -8,7 +8,9 @@
 
 #include "TopologyFixture.h"
 
+#include <DDS/Topology.h>
 #include <fairmq/sdk/Topology.h>
+#include <fairmq/Tools.h>
 
 namespace {
 
@@ -16,7 +18,21 @@ using Topology = fair::mq::test::TopologyFixture;
 
 TEST_F(Topology, Construction)
 {
-  fair::mq::sdk::Topology topo(mDDSTopology);
+  fair::mq::sdk::Topology topo(mDDSTopo, mDDSSession);
+}
+
+TEST_F(Topology, ChangeState)
+{
+  using fair::mq::sdk::Topology;
+  using fair::mq::sdk::TopologyTransition;
+
+  Topology topo(mDDSTopo, mDDSSession);
+  fair::mq::tools::Semaphore blocker;
+  topo.ChangeState(TopologyTransition::Stop, [&](Topology::ChangeStateResult result) {
+      LOG(info) << result;
+      blocker.Signal();
+  });
+  blocker.Wait();
 }
 
 }   // namespace