diff --git a/airtio/Interface.cpp b/airtio/Interface.cpp
index 93892aa..cdce5fd 100644
--- a/airtio/Interface.cpp
+++ b/airtio/Interface.cpp
@@ -176,24 +176,30 @@ void airtio::Interface::abort() {
 	AIRTIO_DEBUG("abort [ END ]");
 }
 
-void airtio::Interface::setVolume(float _gainDB) {
-	std::unique_lock<std::recursive_mutex> lock(m_mutex);
-	AIRTIO_DEBUG("setVolume [BEGIN]");
-	// TODO :...
-	AIRTIO_DEBUG("setVolume [ END ]");
+bool airtio::Interface::setParameter(const std::string& _filter, const std::string& _parameter, const std::string& _value) {
+	AIRTIO_DEBUG("setParameter [BEGIN] : '" << _filter << "':'" << _parameter << "':'" << _value << "'");
+	bool out = false;
+	if (    _filter == "volume"
+	     && _parameter != "FLOW") {
+		AIRTIO_ERROR("Interface is not allowed to modify '" << _parameter << "' Volume just allowed to modify 'FLOW' volume");
+	}
+	AIRTIO_TODO("    IMPLEMENT");
+	AIRTIO_DEBUG("setParameter [ END ] : '" << out << "'");
+	return out;
 }
-
-float airtio::Interface::getVolume() const {
-	std::unique_lock<std::recursive_mutex> lock(m_mutex);
-	AIRTIO_DEBUG("getVolume [BEGIN]");
-	// TODO :...
-	AIRTIO_DEBUG("getVolume [ END ]");
-	return 0;
+std::string airtio::Interface::getParameter(const std::string& _filter, const std::string& _parameter) const {
+	AIRTIO_DEBUG("getParameter [BEGIN] : '" << _filter << "':'" << _parameter << "'");
+	std::string out;
+	AIRTIO_TODO("    IMPLEMENT");
+	AIRTIO_DEBUG("getParameter [ END ] : '" << out << "'");
+	return out;
 }
-
-std::pair<float,float> airtio::Interface::getVolumeRange() const {
-	std::unique_lock<std::recursive_mutex> lock(m_mutex);
-	return std::make_pair(-120.0f, 0.0f);
+std::string airtio::Interface::getParameterProperty(const std::string& _filter, const std::string& _parameter) const {
+	AIRTIO_DEBUG("getParameterProperty [BEGIN] : '" << _filter << "':'" << _parameter << "'");
+	std::string out;
+	AIRTIO_TODO("    IMPLEMENT");
+	AIRTIO_DEBUG("getParameterProperty [ END ] : '" << out << "'");
+	return out;
 }
 
 void airtio::Interface::write(const void* _value, size_t _nbChunk) {
@@ -274,7 +280,9 @@ void airtio::Interface::systemNewInputData(std::chrono::system_clock::time_point
 	m_process->push(_time, _data, _nbChunk);
 }
 
-void airtio::Interface::systemNeedOutputData(std::chrono::system_clock::time_point _time, void*& _data, size_t& _nbChunk, size_t _chunkSize) {
+void airtio::Interface::systemNeedOutputData(std::chrono::system_clock::time_point _time, void* _data, size_t _nbChunk, size_t _chunkSize) {
 	std::unique_lock<std::recursive_mutex> lockProcess(m_mutex);
-	m_process->pull(_time, _data, _nbChunk);//, _chunkSize);
+	m_process->pull(_time, _data, _nbChunk, _chunkSize);
 }
+
+bool airtio::Interface::systemSetVolume(const std::string& _parameter, const std::string& _value);
\ No newline at end of file
diff --git a/airtio/Interface.h b/airtio/Interface.h
index 125e0d1..28737a4 100644
--- a/airtio/Interface.h
+++ b/airtio/Interface.h
@@ -87,20 +87,34 @@ namespace airtio {
 			 */
 			virtual void abort();
 			/**
-			 * @brief Set the volume of this interface
-			 * @param[in] _gainDB Gain in decibel to apply
+			 * @brief Set a parameter in the stream flow
+			 * @param[in] _filter name of the filter (if you added some personels)
+			 * @param[in] _parameter Parameter name.
+			 * @param[in] _value Value to set.
+			 * @return true set done
+			 * @return false An error occured
+			 * @example : setParameter("volume", "FLOW", "-3dB");
+			 * @example : setParameter("LowPassFilter", "cutFrequency", "1000Hz");
 			 */
-			virtual void setVolume(float _gainDB);
+			virtual bool setParameter(const std::string& _filter, const std::string& _parameter, const std::string& _value);
 			/**
-			 * @brief Get the volume of this interface
-			 * @return The gain in decibel applyied
+			 * @brief Get a parameter value
+			 * @param[in] _filter name of the filter (if you added some personels)
+			 * @param[in] _parameter Parameter name.
+			 * @return The requested value.
+			 * @example : getParameter("volume", "FLOW"); can return something like "-3dB"
+			 * @example : getParameter("LowPassFilter", "cutFrequency"); can return something like "[-120..0]dB"
 			 */
-			virtual float getVolume() const;
+			virtual std::string getParameter(const std::string& _filter, const std::string& _parameter) const;
 			/**
-			 * @brief Get the volume range of this interface
-			 * @return The gain in decibel range of this interface
+			 * @brief Get a parameter value
+			 * @param[in] _filter name of the filter (if you added some personels)
+			 * @param[in] _parameter Parameter name.
+			 * @return The requested value.
+			 * @example : getParameter("volume", "FLOW"); can return something like "[-120..0]dB"
+			 * @example : getParameter("LowPassFilter", "cutFreqiency"); can return something like "]100..10000]Hz"
 			 */
-			virtual std::pair<float,float> getVolumeRange() const;
+			virtual std::string getParameterProperty(const std::string& _filter, const std::string& _parameter) const;
 			/**
 			 * @brief write some audio sample in the speakers
 			 * @param[in] _value Data To write on output
@@ -141,9 +155,8 @@ namespace airtio {
 			virtual std::chrono::system_clock::time_point getCurrentTime() const;
 		private:
 			virtual void systemNewInputData(std::chrono::system_clock::time_point _time, void* _data, size_t _nbChunk);
-			virtual void systemNeedOutputData(std::chrono::system_clock::time_point _time, void*& _data, size_t& _nbChunk, size_t _chunkSize);
-			
-			std::vector<int8_t> m_data;
+			virtual void systemNeedOutputData(std::chrono::system_clock::time_point _time, void* _data, size_t _nbChunk, size_t _chunkSize);
+			virtual bool systemSetVolume(const std::string& _parameter, const std::string& _value);
 			float m_volume; //!< Local channel Volume
 	};
 };
diff --git a/airtio/Manager.cpp b/airtio/Manager.cpp
index 16e8dcd..3ae195d 100644
--- a/airtio/Manager.cpp
+++ b/airtio/Manager.cpp
@@ -44,6 +44,34 @@ std::vector<std::pair<std::string,std::string> > airtio::Manager::getListStreamO
 	return output;
 }
 
+
+bool setParameter(const std::string& _flow, const std::string& _filter, const std::string& _parameter, const std::string& _value) {
+	AIRTIO_DEBUG("setParameter [BEGIN] : '" << _flow << "':'" << _filter << "':'" << _parameter << "':'" << _value << "'");
+	bool out = false;
+	if (    _filter == "volume"
+	     && _parameter != "FLOW") {
+		AIRTIO_ERROR("Interface is not allowed to modify '" << _parameter << "' Volume just allowed to modify 'FLOW' volume");
+	}
+	AIRTIO_TODO("    IMPLEMENT");
+	AIRTIO_DEBUG("setParameter [ END ] : '" << out << "'");
+	return out;
+}
+std::string getParameter(const std::string& _flow, const std::string& _filter, const std::string& _parameter) const {
+	AIRTIO_DEBUG("getParameter [BEGIN] : '" << _flow << "':'" << _filter << "':'" << _parameter << "'");
+	std::string out;
+	AIRTIO_TODO("    IMPLEMENT");
+	AIRTIO_DEBUG("getParameter [ END ] : '" << out << "'");
+	return out;
+}
+
+std::string getParameterProperty(const std::string& _flow, const std::string& _filter, const std::string& _parameter) const {
+	AIRTIO_DEBUG("getParameterProperty [BEGIN] : '" << _flow << "':'" << _filter << "':'" << _parameter << "'");
+	std::string out;
+	AIRTIO_TODO("    IMPLEMENT");
+	AIRTIO_DEBUG("getParameterProperty [ END ] : '" << out << "'");
+	return out;
+}
+
 // TODO : Deprecated ...
 void airtio::Manager::setMasterOutputVolume(float _gainDB) {
 	if (_gainDB < m_masterVolumeRange.first) {
diff --git a/airtio/Manager.h b/airtio/Manager.h
index 4fa0cda..fedb56b 100644
--- a/airtio/Manager.h
+++ b/airtio/Manager.h
@@ -44,44 +44,39 @@ namespace airtio {
 			 * @return a list of all availlables output stream (name + description)
 			 */
 			virtual std::vector<std::pair<std::string,std::string> > getListStreamOutput();
-		protected:
-			float m_masterVolume;
-			std::pair<float,float> m_masterVolumeRange;
-		public:
-			/**
-			 * @brief Set the output volume master of the Audio interface
-			 * @param[in] _gainDB Gain in decibel to apply in volume Master
-			 */
-			virtual void setMasterOutputVolume(float _gainDB);
-			/**
-			 * @brief Get the output volume master of the Audio interface
-			 * @return The gain in decibel applyied in volume Master
-			 */
-			virtual float getMasterOutputVolume();
-			/**
-			 * @brief Get the output volume master range of the Audio interface
-			 * @return The gain in decibel range of the output volume Master
-			 */
-			virtual std::pair<float,float> getMasterOutputVolumeRange();
 			
 			/**
-			 * @brief Set the section volume of the Audio interface
-			 * @param[in] _gainDB Gain in decibel to apply in volume section
-			 * @param[in] _section section name to apply volume (a section is : tts, reco, player, interjection ...)
+			 * @brief Set a parameter in the stream flow
+			 * @param[in] _flow Low level Flow name (see json config file)
+			 * @param[in] _filter name of the filter (if you added some personels)
+			 * @param[in] _parameter Parameter name.
+			 * @param[in] _value Value to set.
+			 * @return true set done
+			 * @return false An error occured
+			 * @example : setParameter("speaker", "volume", "MASTER", "-3dB");
+			 * @example : setParameter("microphone", "LowPassFilter", "cutFrequency", "1000Hz");
 			 */
-			virtual void setSectionVolume(const std::string& _section, float _gainDB);
+			virtual bool setParameter(const std::string& _flow, const std::string& _filter, const std::string& _parameter, const std::string& _value);
 			/**
-			 * @brief Get the section volume of the Audio interface
-			 * @param[in] _section section name to apply volume (a section is : tts, reco, player, interjection ...)
-			 * @return The gain in decibel applyied in volume section
+			 * @brief Get a parameter value
+			 * @param[in] _flow Low level Flow name (see json config file)
+			 * @param[in] _filter name of the filter (if you added some personels)
+			 * @param[in] _parameter Parameter name.
+			 * @return The requested value.
+			 * @example : getParameter("speaker", "volume", "MASTER"); can return something like "-3dB"
+			 * @example : getParameter("microphone", "LowPassFilter", "cutFrequency"); can return something like "[-120..0]dB"
 			 */
-			virtual float getSectionVolume(const std::string& _section);
+			virtual std::string getParameter(const std::string& _flow, const std::string& _filter, const std::string& _parameter) const;
 			/**
-			 * @brief Get the section volume range of the Audio interface
-			 * @param[in] _section section name to apply volume (a section is : tts, reco, player, interjection ...)
-			 * @return The gain in decibel range of the section volume
+			 * @brief Get a parameter value
+			 * @param[in] _flow Low level Flow name (see json config file)
+			 * @param[in] _filter name of the filter (if you added some personels)
+			 * @param[in] _parameter Parameter name.
+			 * @return The requested value.
+			 * @example : getParameter("speaker", "volume", "MASTER"); can return something like "[-120..0]dB"
+			 * @example : getParameter("microphone", "LowPassFilter", "cutFreqiency"); can return something like "]100..10000]Hz"
 			 */
-			virtual std::pair<float,float> getSectionVolumeRange(const std::string& _section);
+			virtual std::string getParameterProperty(const std::string& _flow, const std::string& _filter, const std::string& _parameter) const;
 			
 			/**
 			 * @brief Create output Interface
diff --git a/airtio/io/Node.cpp b/airtio/io/Node.cpp
index 3bbe74f..de635c8 100644
--- a/airtio/io/Node.cpp
+++ b/airtio/io/Node.cpp
@@ -37,20 +37,20 @@ int32_t airtio::io::Node::rtAudioCallback(void* _outputBuffer,
 		AIRTIO_VERBOSE("data Output");
 		std::vector<int32_t> output;
 		output.resize(_nBufferFrames*m_map.size(), 0);
-		int16_t* outputTmp = nullptr;
-		void* outputTmp2 = nullptr;
-		size_t tmpSize = 0;
+		const int16_t* outputTmp = nullptr;
+		std::vector<uint8_t> outputTmp2;
+		outputTmp2.resize(sizeof(int16_t)*m_map.size()*_nBufferFrames, 0);
 		for (auto &it : m_list) {
 			if (it != nullptr) {
+				// clear datas ...
+				memset(&outputTmp2[0], 0, sizeof(int16_t)*m_map.size()*_nBufferFrames);
 				AIRTIO_VERBOSE("    IO : " /* << std::distance(m_list.begin(), it)*/ << "/" << m_list.size() << " name="<< it->getName());
-				tmpSize = _nBufferFrames;
-				it->systemNeedOutputData(ttime, outputTmp2, tmpSize, sizeof(int16_t)*m_map.size());
-				outputTmp = static_cast<int16_t*>(outputTmp2);
+				it->systemNeedOutputData(ttime, &outputTmp2[0], _nBufferFrames, sizeof(int16_t)*m_map.size());
+				outputTmp = reinterpret_cast<const int16_t*>(&outputTmp2[0]);
 				//it->systemNeedOutputData(ttime, _outputBuffer, _nBufferFrames, sizeof(int16_t)*m_map.size());
 				// Add data to the output tmp buffer :
 				for (size_t kkk=0; kkk<output.size(); ++kkk) {
 					output[kkk] += static_cast<int32_t>(outputTmp[kkk]);
-					//*_outputBuffer++ = static_cast<int16_t>(outputTmp[kkk]);
 				}
 				break;
 			}
@@ -58,7 +58,6 @@ int32_t airtio::io::Node::rtAudioCallback(void* _outputBuffer,
 		int16_t* outputBuffer = static_cast<int16_t*>(_outputBuffer);
 		for (size_t kkk=0; kkk<output.size(); ++kkk) {
 			*outputBuffer++ = static_cast<int16_t>(std::min(std::max(INT16_MIN, output[kkk]), INT16_MAX));
-			//*_outputBuffer++ = static_cast<int16_t>(output[kkk]);
 		}
 	}
 	if (_inputBuffer != nullptr) {