diff --git a/apps/ivr/Ivr.cpp b/apps/ivr/Ivr.cpp
index 5e0d3484..5215d4d8 100644
--- a/apps/ivr/Ivr.cpp
+++ b/apps/ivr/Ivr.cpp
@@ -30,7 +30,7 @@
 #include "AmApi.h"
 #include "AmUtils.h"
 #include "AmSessionScheduler.h"
-#include "AmSessionTimer.h"
+//#include "AmSessionTimer.h"
 #include "AmPlugIn.h"
 
 #include <unistd.h>
@@ -118,7 +118,8 @@ extern "C" {
 }
 
 IvrFactory::IvrFactory(const string& _app_name)
-  : AmSessionFactory(_app_name)
+    : AmSessionFactory(_app_name),
+      user_timer_fact(NULL)
 {
 }
 
@@ -205,12 +206,18 @@ IvrDialog* IvrFactory::newDlg(const string& name)
     if(mod_it == mod_reg.end()){
 	ERROR("Unknown script name\n");
 	throw AmSession::Exception(500,"Unknown Application");
-	return NULL;
     }
 
     IvrScriptDesc& mod_desc = mod_it->second;
 
-    IvrDialog* dlg = new IvrDialog();
+    AmDynInvoke* user_timer = user_timer_fact->getInstance();
+    if(!user_timer){
+	ERROR("could not get a user timer reference\n");
+	throw AmSession::Exception(500,"could not get a user timer reference");
+    }
+	
+
+    IvrDialog* dlg = new IvrDialog(user_timer);
 
     PyObject* c_dlg = PyCObject_FromVoidPtr(dlg,NULL);
     PyObject* dlg_inst = PyObject_CallMethod(mod_desc.dlg_class,"__new__","OO",
@@ -318,6 +325,14 @@ bool IvrFactory::loadScript(const string& path)
  */
 int IvrFactory::onLoad()
 {
+    user_timer_fact = AmPlugIn::instance()->getFactory4Di("user_timer");
+    if(!user_timer_fact){
+	
+	ERROR("could not load user_timer from session_timer plug-in\n");
+	return -1;
+    }
+
+
     AmConfigReader cfg;
 
     if(cfg.loadFile(add2path(AmConfig::ModConfigPath,1,MOD_NAME ".conf")))
@@ -403,10 +418,11 @@ AmSession* IvrFactory::onInvite(const AmSipRequest& req)
 	return newDlg(req.user);
 }
 
-IvrDialog::IvrDialog()
+IvrDialog::IvrDialog(AmDynInvoke* user_timer)
     : py_mod(NULL), 
       py_dlg(NULL),
-      playlist(this)
+      playlist(this),
+      user_timer(user_timer)
 {
     sip_relay_only = false;
 }
@@ -501,12 +517,13 @@ void IvrDialog::process(AmEvent* event)
 	event->processed = true;
     }
     
-    AmTimeoutEvent* timeout_event = dynamic_cast<AmTimeoutEvent*>(event);
-    if(timeout_event && timeout_event->event_id > 0) {
+    AmPluginEvent* plugin_event = dynamic_cast<AmPluginEvent*>(event);
+    if(plugin_event && plugin_event->name == "timer_timeout") {
 	PYLOCK;
-	callPyEventHandler("onTimer", timeout_event->event_id);
+	callPyEventHandler("onTimer", plugin_event->data.get(0).asInt());
 	event->processed = true;
     }
+
     if (!event->processed)
       AmB2BCallerSession::process(event);
 
diff --git a/apps/ivr/Ivr.h b/apps/ivr/Ivr.h
index 0d8d46f4..08c221f1 100644
--- a/apps/ivr/Ivr.h
+++ b/apps/ivr/Ivr.h
@@ -44,27 +44,21 @@ struct IvrScriptDesc
 {
     PyObject* mod;
     PyObject* dlg_class;
-    // PyObject* config;
 
     IvrScriptDesc()
 	: mod(0), 
-	  dlg_class(0)// ,
-// 	  config(0)
+	  dlg_class(0)
     {}
 
     IvrScriptDesc(const IvrScriptDesc& d)
 	: mod(d.mod), 
-	  dlg_class(d.dlg_class)// ,
-// 	  config(d.config)
+	  dlg_class(d.dlg_class)
     {}
 
     IvrScriptDesc(PyObject* mod, 
-		  PyObject* dlg_class// ,
-// 		  PyObject* config
-		  )
+		  PyObject* dlg_class)
 	: mod(mod),
-	  dlg_class(dlg_class)// ,
-// 	  config(config)
+	  dlg_class(dlg_class)
     {}
 };
 
@@ -77,6 +71,8 @@ class IvrFactory: public AmSessionFactory
 
     map<string,IvrScriptDesc> mod_reg;
 
+    AmDynInvokeFactory* user_timer_fact;
+
     void init_python_interpreter();
     void import_ivr_builtins();
 
@@ -112,9 +108,10 @@ class IvrDialog : public AmB2BCallerSession
     void process(AmEvent* event);
 
 public:
+    AmDynInvoke* user_timer;
     AmPlaylist playlist;
 
-    IvrDialog();
+    IvrDialog(AmDynInvoke* user_timer);
     ~IvrDialog();
 
     // must be called before everything else.
diff --git a/apps/ivr/IvrDialogBase.cpp b/apps/ivr/IvrDialogBase.cpp
index 804260a3..41d391e7 100644
--- a/apps/ivr/IvrDialogBase.cpp
+++ b/apps/ivr/IvrDialogBase.cpp
@@ -4,7 +4,7 @@
 
 #include "IvrSipDialog.h"
 
-#include "AmSessionTimer.h"
+//#include "AmSessionTimer.h"
 
 // Data definition
 typedef struct {
@@ -290,8 +290,13 @@ static PyObject* IvrDialogBase_setTimer(IvrDialogBase* self, PyObject* args)
       return NULL;
     }
 
-    AmSessionTimer::instance()->
-      setTimer(id, interval, self->p_dlg->getLocalTag());
+    AmArgArray di_args,ret;
+    di_args.push(id);
+    di_args.push(interval);
+    di_args.push(self->p_dlg->getLocalTag().c_str());
+
+    self->p_dlg->user_timer->
+	invoke("setTimer", di_args, ret);
     
     Py_INCREF(Py_None);
     return Py_None;
@@ -310,8 +315,12 @@ static PyObject* IvrDialogBase_removeTimer(IvrDialogBase* self, PyObject* args)
       return NULL;
     }
 
-    AmSessionTimer::instance()->
-      removeTimer(id, self->p_dlg->getLocalTag());
+    AmArgArray di_args,ret;
+    di_args.push(id);
+    di_args.push(self->p_dlg->getLocalTag().c_str());
+
+    self->p_dlg->user_timer->
+      invoke("removeTimer",di_args,ret);
     
     Py_INCREF(Py_None);
     return Py_None;
@@ -322,8 +331,11 @@ static PyObject* IvrDialogBase_removeTimers(IvrDialogBase* self, PyObject* args)
 {
     assert(self->p_dlg);
     
-    AmSessionTimer::instance()->
-      removeUserTimers(self->p_dlg->getLocalTag());
+    AmArgArray di_args,ret;
+    di_args.push(self->p_dlg->getLocalTag().c_str());
+
+    self->p_dlg->user_timer->
+      invoke("removeUserTimers",di_args,ret);
     
     Py_INCREF(Py_None);
     return Py_None;
diff --git a/apps/ivr/IvrSipDialog.cpp b/apps/ivr/IvrSipDialog.cpp
index f5fb946a..eae2bfe2 100644
--- a/apps/ivr/IvrSipDialog.cpp
+++ b/apps/ivr/IvrSipDialog.cpp
@@ -1,6 +1,7 @@
 #include "IvrSipDialog.h"
-#include "AmSessionTimer.h"
+//#include "AmSessionTimer.h"
 #include "AmSipDialog.h"
+#include "log.h"
 
 // Data definition
 typedef struct {
diff --git a/apps/ivr/IvrSipRequest.cpp b/apps/ivr/IvrSipRequest.cpp
index 98d9ee04..100decc4 100644
--- a/apps/ivr/IvrSipRequest.cpp
+++ b/apps/ivr/IvrSipRequest.cpp
@@ -1,5 +1,5 @@
 #include "IvrSipRequest.h"
-#include "AmSessionTimer.h"
+//#include "AmSessionTimer.h"
 #include "AmSipRequest.h"
 
 #if 0
diff --git a/core/AmApi.cpp b/core/AmApi.cpp
index e12d52e8..909b4fef 100644
--- a/core/AmApi.cpp
+++ b/core/AmApi.cpp
@@ -29,6 +29,19 @@
 #include "log.h"
 #include "AmSession.h"
 
+AmDynInvoke::AmDynInvoke() {}
+AmDynInvoke::~AmDynInvoke() {}
+
+void AmDynInvoke::invoke(const string& method, const AmArgArray& args, AmArgArray& ret)
+{
+    throw NotImplemented(method);
+}
+
+AmDynInvokeFactory::AmDynInvokeFactory(const string& name)
+    : AmPluginFactory(name) 
+{
+}
+
 AmSessionFactory::AmSessionFactory(const string& name)
   : AmPluginFactory(name), mod_conf(AmConfig::defaultSessionTimerConfig)
 {
diff --git a/core/AmApi.h b/core/AmApi.h
index 79bbbd64..265181dd 100644
--- a/core/AmApi.h
+++ b/core/AmApi.h
@@ -27,19 +27,36 @@
 #ifndef _AmApi_h_
 #define _AmApi_h_
 
-//#include "AmRequest.h"
 #include "AmThread.h"
 #include "AmSipRequest.h"
 #include "AmConfig.h"
+#include "AmArg.h"
 
 #include <string>
 #include <map>
 using std::map;
 using std::string;
 
-class AmSession;
-class AmSessionEventHandler;
+/**
+ * Multi-purpose plugin class
+ */
+class AmDynInvoke
+{
+public:
+    struct NotImplemented {
+	string what;
+	NotImplemented(const string& w)
+	    : what(w) {}
+    };
+
+    AmDynInvoke();
+    virtual ~AmDynInvoke();
+    virtual void invoke(const string& method, const AmArgArray& args, AmArgArray& ret);
+};
 
+/**
+ * Base class for plugin factories
+ */
 class AmPluginFactory
 {
     string plugin_name;
@@ -61,6 +78,33 @@ public:
     virtual int onLoad()=0;
 };
 
+/**
+ * Factory for multi-purpose plugin classes
+ */
+class AmDynInvokeFactory: public AmPluginFactory
+{
+public:
+    AmDynInvokeFactory(const string& name);
+    virtual AmDynInvoke* getInstance()=0;
+};
+
+
+class AmSession;
+class AmSessionEventHandler;
+
+class AmSessionEventHandlerFactory: public AmPluginFactory
+{
+public:
+    AmSessionEventHandlerFactory(const string& name);
+
+    virtual AmSessionEventHandler* getHandler(AmSession*)=0;
+
+    /**
+     * @return true if session creation should be stopped
+     */
+    virtual bool onInvite(const AmSipRequest& req)=0;
+};
+
 
 class AmSessionFactory: public AmPluginFactory
 {
@@ -68,11 +112,11 @@ class AmSessionFactory: public AmPluginFactory
   AmSessionTimerConfig mod_conf;
 
 protected:
-  /**
-   * This reads the module configuration from 
-   * cfg into the modules mod_conf.
-   */
-  int configureModule(AmConfigReader& cfg);
+    /**
+     * This reads the module configuration from 
+     * cfg into the modules mod_conf.
+     */
+    int configureModule(AmConfigReader& cfg);
 
 public:
     /**
@@ -93,18 +137,6 @@ public:
     virtual AmSession* onInvite(const AmSipRequest& req)=0;
 };
 
-class AmSessionEventHandlerFactory: public AmPluginFactory
-{
-public:
-    AmSessionEventHandlerFactory(const string& name);
-
-    virtual AmSessionEventHandler* getHandler(AmSession*)=0;
-
-    /**
-     * @return true if session creation should be stopped
-     */
-    virtual bool onInvite(const AmSipRequest& req)=0;
-};
 
 #define EXPORT_FACTORY(fctname,class_name,...) \
             extern "C" void* fctname()\
@@ -129,6 +161,12 @@ typedef void* (*FactoryCreate)();
 #define EXPORT_SESSION_EVENT_HANDLER_FACTORY(class_name,app_name) \
             EXPORT_FACTORY(FACTORY_SESSION_EVENT_HANDLER_EXPORT,class_name,app_name)
 
+#define FACTORY_PLUGIN_CLASS_EXPORT     plugin_class_create
+#define FACTORY_PLUGIN_CLASS_EXPORT_STR XSTR(FACTORY_PLUGIN_CLASS_EXPORT)
+
+#define EXPORT_PLUGIN_CLASS_FACTORY(class_name,app_name) \
+            EXPORT_FACTORY(FACTORY_PLUGIN_CLASS_EXPORT,class_name,app_name)
+
 #endif
 // Local Variables:
 // mode:C++
diff --git a/core/AmArg.h b/core/AmArg.h
new file mode 100644
index 00000000..fb0157ce
--- /dev/null
+++ b/core/AmArg.h
@@ -0,0 +1,88 @@
+#ifndef _AmArg_h_
+#define _AmArg_h_
+
+#include <assert.h>
+
+#include <vector>
+using std::vector;
+
+class AmArg
+{
+public:
+    // type enum
+    enum {
+	Undef=0,
+
+	Int,
+	Double,
+	CStr
+    };
+
+private:
+    // type
+    short type;
+    
+    // value
+    union {
+	
+	int         v_int;
+	double      v_double;
+	const char* v_cstr;
+    };
+
+public:
+    AmArg(const AmArg& v)
+	: type(v.type){
+	
+	switch(type){
+	case Int: v_int = v.v_int; break;
+	case Double: v_double = v.v_double; break;
+	case CStr: v_cstr = v.v_cstr; break;
+	default: assert(0);
+	}
+    }
+
+    AmArg(const int& v)
+	: type(Int),
+	  v_int(v)
+    {}
+
+    AmArg(const double& v)
+	: type(Double),
+	  v_double(v)
+    {}
+
+    AmArg(const char* v)
+	: type(CStr),
+	  v_cstr(v)
+    {}
+
+    short getType() const { return type; }
+
+    int         asInt()    const { return v_int; }
+    double      asDouble() const { return v_double; }
+    const char* asCStr()   const { return v_cstr; }
+};
+
+class AmArgArray
+{
+    vector<AmArg> v;
+
+public:
+    AmArgArray() : v() {}
+    AmArgArray(const AmArgArray& a) : v(a.v) {}
+    
+    void push(const AmArg& a){
+	v.push_back(a);
+    }
+
+    const AmArg& get(size_t idx) const {
+	
+	assert(idx < v.size());
+	return v[idx];
+    }
+
+    size_t size() { return v.size(); }
+};
+
+#endif
diff --git a/core/AmEvent.h b/core/AmEvent.h
index 334afc34..70b6de27 100644
--- a/core/AmEvent.h
+++ b/core/AmEvent.h
@@ -1,6 +1,13 @@
 #ifndef AmEvent_h
 #define AmEvent_h
 
+#include "AmArg.h"
+
+#include <string>
+using std::string;
+
+#define E_PLUGIN 100
+
 struct AmEvent
 {
     int event_id;
@@ -10,6 +17,20 @@ struct AmEvent
     virtual ~AmEvent();
 };
 
+struct AmPluginEvent: public AmEvent
+{
+    string      name;
+    AmArgArray  data;
+
+    AmPluginEvent(const string& n)
+	: AmEvent(E_PLUGIN), name(n), data() {}
+
+    AmPluginEvent(const string& n, const AmArgArray& d)
+	: AmEvent(E_PLUGIN), name(n), data(d) {}
+};
+
+
+
 class AmEventHandler
 {
 public:
diff --git a/core/AmPlugIn.cpp b/core/AmPlugIn.cpp
index 0205e56a..9b33970e 100644
--- a/core/AmPlugIn.cpp
+++ b/core/AmPlugIn.cpp
@@ -123,6 +123,13 @@ int AmPlugIn::load(const string& directory)
 	if(err)
 	    break;
     }
+
+    for(map<string,AmDynInvokeFactory*>::iterator it = name2di.begin();
+	it != name2di.end(); it++){
+	err = it->second->onLoad();
+	if(err)
+	    break;
+    }
     
     map<string,AmSessionFactory*> apps(name2app);
     for(map<string,AmSessionFactory*>::iterator it = apps.begin();
@@ -149,6 +156,7 @@ int AmPlugIn::loadPlugIn(const string& file)
     FactoryCreate fc = NULL;
     amci_exports_t* exports = (amci_exports_t*)dlsym(h_dl,"amci_exports");
 
+    bool has_sym=false;
     if(exports){
  	if(loadAudioPlugIn(exports))
 	    goto error;
@@ -158,12 +166,20 @@ int AmPlugIn::loadPlugIn(const string& file)
     if((fc = (FactoryCreate)dlsym(h_dl,FACTORY_SESSION_EXPORT_STR)) != NULL){
 	if(loadAppPlugIn((AmPluginFactory*)fc()))
 	    goto error;
+	has_sym=true;
     }
-    else if((fc = (FactoryCreate)dlsym(h_dl,FACTORY_SESSION_EVENT_HANDLER_EXPORT_STR)) != NULL){
+    if((fc = (FactoryCreate)dlsym(h_dl,FACTORY_SESSION_EVENT_HANDLER_EXPORT_STR)) != NULL){
 	if(loadSehPlugIn((AmPluginFactory*)fc()))
 	    goto error;
+	has_sym=true;
     }
-    else {
+    if((fc = (FactoryCreate)dlsym(h_dl,FACTORY_PLUGIN_CLASS_EXPORT_STR)) != NULL){
+	if(loadDiPlugIn((AmPluginFactory*)fc()))
+	    goto error;
+	has_sym=true;
+    }
+
+    if(!has_sym){
 	ERROR("Plugin type could not be detected (%s)(%s)\n",file.c_str(),dlerror());
 	goto error;
     }
@@ -251,6 +267,14 @@ AmSessionEventHandlerFactory* AmPlugIn::getFactory4Seh(const string& name)
   return 0;
 }
 
+AmDynInvokeFactory* AmPlugIn::getFactory4Di(const string& name)
+{
+  map<string,AmDynInvokeFactory*>::iterator it = name2di.find(name);
+  if(it != name2di.end())
+    return it->second;
+  return 0;
+}
+
 int AmPlugIn::loadAudioPlugIn(amci_exports_t* exports)
 {
     if(!exports){
@@ -299,13 +323,8 @@ int AmPlugIn::loadAppPlugIn(AmPluginFactory* f)
         goto error;
     }
       
-    //if(!sf->onLoad()){
-	name2app.insert(std::make_pair(sf->getName(),sf));
-	DBG("application '%s' loaded.\n",sf->getName().c_str());
-//     }
-//     else {
-// 	goto error;
-//     }
+    name2app.insert(std::make_pair(sf->getName(),sf));
+    DBG("application '%s' loaded.\n",sf->getName().c_str());
 
     return 0;
 
@@ -326,13 +345,30 @@ int AmPlugIn::loadSehPlugIn(AmPluginFactory* f)
         goto error;
     }
       
-//     if(!sf->onLoad()){
-	name2seh.insert(std::make_pair(sf->getName(),sf));
-	DBG("session component '%s' loaded.\n",sf->getName().c_str());
-//     }
-//     else {
-// 	goto error;
-//     }
+    name2seh.insert(std::make_pair(sf->getName(),sf));
+    DBG("session component '%s' loaded.\n",sf->getName().c_str());
+
+    return 0;
+
+ error:
+    return -1;
+}
+
+int AmPlugIn::loadDiPlugIn(AmPluginFactory* f)
+{
+    AmDynInvokeFactory* sf = dynamic_cast<AmDynInvokeFactory*>(f);
+    if(!sf){
+        ERROR("invalid component plug-in!\n");
+        goto error;
+    }
+
+    if(name2di.find(sf->getName()) != name2di.end()){
+        ERROR("component '%s' already loaded !\n",sf->getName().c_str());
+        goto error;
+    }
+      
+    name2di.insert(std::make_pair(sf->getName(),sf));
+    DBG("component '%s' loaded.\n",sf->getName().c_str());
 
     return 0;
 
diff --git a/core/AmPlugIn.h b/core/AmPlugIn.h
index 49175ead..c85b5e2f 100644
--- a/core/AmPlugIn.h
+++ b/core/AmPlugIn.h
@@ -38,6 +38,7 @@ using std::vector;
 class AmPluginFactory;
 class AmSessionFactory;
 class AmSessionEventHandlerFactory;
+class AmDynInvokeFactory;
 
 struct amci_exports_t;
 struct amci_codec_t;
@@ -67,6 +68,7 @@ private:
     map<string,AmSessionFactory*>  name2app;
 
     map<string,AmSessionEventHandlerFactory*> name2seh;
+    map<string,AmDynInvokeFactory*> name2di;
 
     int dynamic_pl; // range: 96->127, see RFC 1890
     
@@ -78,6 +80,7 @@ private:
     int loadAudioPlugIn(amci_exports_t* exports);
     int loadAppPlugIn(AmPluginFactory* cb);
     int loadSehPlugIn(AmPluginFactory* cb);
+    int loadDiPlugIn(AmPluginFactory* cb);
 
     int addCodec(amci_codec_t* c);
     int addPayload(amci_payload_t* p);
@@ -136,6 +139,11 @@ private:
      */
     AmSessionEventHandlerFactory* getFactory4Seh(const string& name);
 
+    /**
+     * Dynamic invokation component
+     */
+    AmDynInvokeFactory* getFactory4Di(const string& name);
+
     /** @return true if this record has been inserted. */
     bool registerFactory4App(const string& app_name, AmSessionFactory* f);
 };
diff --git a/core/AmSession.cpp b/core/AmSession.cpp
index 922a6370..057c7c7f 100644
--- a/core/AmSession.cpp
+++ b/core/AmSession.cpp
@@ -38,7 +38,7 @@
 #include "AmSessionScheduler.h"
 #include "AmDtmfDetector.h"
 /* Session Timer: -ssa */
-#include "AmSessionTimer.h"
+//#include "AmSessionTimer.h"
 
 #include "log.h"
 
@@ -315,7 +315,7 @@ void AmSession::run()
 		}
 	    }
 	    // remove pending timers
-	    AmSessionTimer::instance()->removeTimers(getLocalTag());
+	    //AmSessionTimer::instance()->removeTimers(getLocalTag());
 	}
 	catch(const AmSession::Exception& e){ throw e; }
 	catch(const string& str){
@@ -555,10 +555,10 @@ int AmSession::acceptAudio(const AmSipRequest& req)
     return -1;
 }
 
-string AmSession::SessionTimerException::getErrorHeaders() const {
-  return "Min-SE:" + int2str(minSE) + "\n"
-    + "Supported: timer\n";
-}
+// string AmSession::SessionTimerException::getErrorHeaders() const {
+//   return "Min-SE:" + int2str(minSE) + "\n"
+//     + "Supported: timer\n";
+// }
 
 void AmSession::onSendRequest(const string& method, const string& content_type,
 			      const string& body, string& hdrs)
diff --git a/core/AmSession.h b/core/AmSession.h
index ddb90768..10b297b5 100644
--- a/core/AmSession.h
+++ b/core/AmSession.h
@@ -53,13 +53,6 @@ class AmSessionFactory;
 //class AmDialogState;
 class AmDtmfEvent;
 
-/* Session Timer: -ssa */
-class AmTimeoutEvent;
-// these are the timer IDs for session timer
-// Caution: do not use these for other purposes
-#define ID_SESSION_INTERVAL_TIMER -1
-#define ID_SESSION_REFRESH_TIMER  -2
-
 
 /**
  *  Signaling plugins must inherite from this class.
@@ -153,15 +146,15 @@ public:
 	Exception(int c, string r) : code(c), reason(r) {}
     };
 
-    struct SessionTimerException : Exception {
-      unsigned int minSE;
+//     struct SessionTimerException : Exception {
+//       unsigned int minSE;
 
-      SessionTimerException(unsigned int min_SE) 
-	: Exception(422, "Session Interval Too Small"), 
-	  minSE(min_SE) { }
+//       SessionTimerException(unsigned int min_SE) 
+// 	: Exception(422, "Session Interval Too Small"), 
+// 	  minSE(min_SE) { }
 
-      string getErrorHeaders() const;
-    };
+//       string getErrorHeaders() const;
+//     };
 
     /** 
      * Session constructor.
diff --git a/core/AmSessionContainer.cpp b/core/AmSessionContainer.cpp
index df433e35..18569f03 100644
--- a/core/AmSessionContainer.cpp
+++ b/core/AmSessionContainer.cpp
@@ -185,10 +185,10 @@ void AmSessionContainer::startSessionUAS(AmSipRequest& req)
 	    //throw AmSession::Exception(500,"internal error");
 	}
     } 
-    catch(const AmSession::SessionTimerException& e){
- 	ERROR("%i %s\n",e.code,e.reason.c_str());
-	AmSipDialog::reply_error(req,e.code,e.reason,e.getErrorHeaders());
-    }
+//     catch(const AmSession::SessionTimerException& e){
+//  	ERROR("%i %s\n",e.code,e.reason.c_str());
+// 	AmSipDialog::reply_error(req,e.code,e.reason,e.getErrorHeaders());
+//     }
     catch(const AmSession::Exception& e){
  	ERROR("%i %s\n",e.code,e.reason.c_str());
 	AmSipDialog::reply_error(req,e.code,e.reason);
diff --git a/core/plug-in/echo/Echo.cpp b/core/plug-in/echo/Echo.cpp
index b1b0ba33..72a3cf88 100644
--- a/core/plug-in/echo/Echo.cpp
+++ b/core/plug-in/echo/Echo.cpp
@@ -56,8 +56,6 @@ int EchoFactory::onLoad()
 
 AmSession* EchoFactory::onInvite(const AmSipRequest& req)
 {
-//     if()
-
     AmSession* s = new EchoDialog();
     s->addHandler(session_timer_f->getHandler(s));
 
diff --git a/core/plug-in/session_timer/SessionTimer.cpp b/core/plug-in/session_timer/SessionTimer.cpp
index df0fffd1..4630656b 100644
--- a/core/plug-in/session_timer/SessionTimer.cpp
+++ b/core/plug-in/session_timer/SessionTimer.cpp
@@ -1,6 +1,6 @@
 #include "SessionTimer.h"
 #include "AmUtils.h"
-#include "AmSessionTimer.h"
+#include "UserTimer.h"
 
 EXPORT_SESSION_EVENT_HANDLER_FACTORY(SessionTimerFactory, MOD_NAME);
 
@@ -34,7 +34,7 @@ bool SessionTimer::process(AmEvent* ev)
     /* Session Timer: -ssa */
     AmTimeoutEvent* timeout_ev = dynamic_cast<AmTimeoutEvent*>(ev);
     if (timeout_ev) {
-	DBG("received timeout Event with ID %d\n", ev->event_id);
+	DBG("received timeout Event with ID %d\n", timeout_ev->data.get(0).asInt());
 	onTimeoutEvent(timeout_ev);
 	return true;
     }
@@ -264,23 +264,23 @@ void SessionTimer::setTimers(AmSession* s)
     DBG("Setting session interval timer: %ds, tag '%s'\n", session_interval, 
 	s->getLocalTag().c_str());
 
-    AmSessionTimer::instance()->
+    UserTimer::instance()->
       setTimer(ID_SESSION_INTERVAL_TIMER, session_interval, s->getLocalTag());
     
     // set session refresh action timer, after half the expiration
     if (session_refresher == refresh_local) {
-    DBG("Setting session refresh timer: %ds, tag '%s'\n", session_interval/2, 
-	s->getLocalTag().c_str());
-      AmSessionTimer::instance()->
-	setTimer(ID_SESSION_REFRESH_TIMER, session_interval/2, s->getLocalTag());
+	DBG("Setting session refresh timer: %ds, tag '%s'\n", session_interval/2, 
+	    s->getLocalTag().c_str());
+	UserTimer::instance()->
+	    setTimer(ID_SESSION_REFRESH_TIMER, session_interval/2, s->getLocalTag());
     }
 }
 
 void SessionTimer::removeTimers(AmSession* s) 
 {
-  AmSessionTimer::instance()->
+  UserTimer::instance()->
     removeTimer(ID_SESSION_REFRESH_TIMER, s->getLocalTag());
-  AmSessionTimer::instance()->
+  UserTimer::instance()->
     removeTimer(ID_SESSION_INTERVAL_TIMER, s->getLocalTag());
 }
 
@@ -288,13 +288,14 @@ void SessionTimer::onTimeoutEvent(AmTimeoutEvent* timeout_ev)
 {
 //   if (!session_timer_conf.getEnableSessionTimer())
 //     return;
-  
-    if (timeout_ev->event_id == ID_SESSION_REFRESH_TIMER) {
+    int timer_id = timeout_ev->data.get(0).asInt();
+
+    if (timer_id == ID_SESSION_REFRESH_TIMER) {
 	if (session_refresher == refresh_local)
 	    s->sendReinvite();
 	else
 	    WARN("need session refresh but remote session is refresher\n");
-    } else if (timeout_ev->event_id == ID_SESSION_INTERVAL_TIMER) {
+    } else if (timer_id == ID_SESSION_INTERVAL_TIMER) {
 //     // let the session know it got timeout
 //     onTimeout();
 	
diff --git a/core/plug-in/session_timer/SessionTimer.h b/core/plug-in/session_timer/SessionTimer.h
index fcf9dd18..1421786c 100644
--- a/core/plug-in/session_timer/SessionTimer.h
+++ b/core/plug-in/session_timer/SessionTimer.h
@@ -6,6 +6,14 @@
 
 #define MOD_NAME "session_timer"
 
+/* Session Timer: -ssa */
+class AmTimeoutEvent;
+// these are the timer IDs for session timer
+// Caution: do not use these for other purposes
+#define ID_SESSION_INTERVAL_TIMER -1
+#define ID_SESSION_REFRESH_TIMER  -2
+
+
 class SessionTimerFactory: public AmSessionEventHandlerFactory
 {
     bool checkSessionExpires(const AmSipRequest& req);
diff --git a/core/AmSessionTimer.cpp b/core/plug-in/session_timer/UserTimer.cpp
similarity index 60%
rename from core/AmSessionTimer.cpp
rename to core/plug-in/session_timer/UserTimer.cpp
index d0bb30e3..b43954e7 100644
--- a/core/AmSessionTimer.cpp
+++ b/core/plug-in/session_timer/UserTimer.cpp
@@ -1,37 +1,64 @@
 
-#include "AmSessionTimer.h"
+#include "UserTimer.h"
 
 #include <sys/time.h>
 
 #define SESSION_TIMER_GRANULARITY 100 // check every 100 millisec
 
+class UserTimerFactory: public AmDynInvokeFactory
+{
+public:
+    UserTimerFactory(const string& name)
+	: AmDynInvokeFactory(name) {}
+
+    AmDynInvoke* getInstance(){
+	return UserTimer::instance();
+    }
+
+    int onLoad(){
+#ifdef SESSION_TIMER_THREAD
+	UserTimer::instance()->start();
+#endif
+	return 0;
+    }
+};
+
+
+EXPORT_PLUGIN_CLASS_FACTORY(UserTimerFactory,"user_timer");
+
+AmTimeoutEvent::AmTimeoutEvent(int timer_id)
+    : AmPluginEvent(TIMEOUTEVENT_NAME)
+{
+    data.push(AmArg(timer_id));
+}
+
 
-AmSessionTimer::AmSessionTimer()
+UserTimer::UserTimer()
 {
 }
 
-AmSessionTimer::~AmSessionTimer()
+UserTimer::~UserTimer()
 {
 }
 
-AmSessionTimer* AmSessionTimer::_instance=0;
+UserTimer* UserTimer::_instance=0;
 
-AmSessionTimer* AmSessionTimer::instance()
+UserTimer* UserTimer::instance()
 {
     if(!_instance)
-	_instance = new AmSessionTimer();
+	_instance = new UserTimer();
     return _instance;
 }
 
 #ifdef SESSION_TIMER_THREAD
-void AmSessionTimer::run() {
+void UserTimer::run() {
     while(1){
 	usleep(SESSION_TIMER_GRANULARITY * 1000);
         checkTimers();
     }
 }
 
-void AmSessionTimer::on_stop() {
+void UserTimer::on_stop() {
 }
 #endif // SESSION_TIMER_THREAD
 
@@ -45,7 +72,7 @@ bool operator == (const AmTimer& l, const AmTimer& r)
   return l.id == r.id;
 }
 
-void AmSessionTimer::checkTimers() {
+void UserTimer::checkTimers() {
   timers_mut.lock();
   if(timers.empty()){
     timers_mut.unlock();
@@ -68,7 +95,9 @@ void AmSessionTimer::checkTimers() {
 						   new AmTimeoutEvent(id))) {
       DBG("Timeout Event could not be posted, session does not exist any more.\n");
     }
-    
+    else {
+	DBG("Timeout Event could be posted.\n");
+    }
     
     if(timers.empty()) break;
     it = timers.begin();
@@ -76,7 +105,7 @@ void AmSessionTimer::checkTimers() {
   timers_mut.unlock();
 }
 
-void AmSessionTimer::setTimer(int id, int seconds, const string& session_id) {
+void UserTimer::setTimer(int id, int seconds, const string& session_id) {
     struct timeval tval;
     gettimeofday(&tval,NULL);
 
@@ -84,7 +113,7 @@ void AmSessionTimer::setTimer(int id, int seconds, const string& session_id) {
     setTimer(id, &tval, session_id);
 }
 
-void AmSessionTimer::setTimer(int id, struct timeval* t, 
+void UserTimer::setTimer(int id, struct timeval* t, 
 			      const string& session_id) 
 {
   timers_mut.lock();
@@ -99,13 +128,13 @@ void AmSessionTimer::setTimer(int id, struct timeval* t,
 }
 
 
-void AmSessionTimer::removeTimer(int id, const string& session_id) {
+void UserTimer::removeTimer(int id, const string& session_id) {
   timers_mut.lock();
   unsafe_removeTimer(id, session_id);
   timers_mut.unlock();
 }
 
-void AmSessionTimer::unsafe_removeTimer(int id, const string& session_id) 
+void UserTimer::unsafe_removeTimer(int id, const string& session_id) 
 {
   // erase old timer if exists
   set<AmTimer>::iterator it = timers.begin(); 
@@ -118,7 +147,7 @@ void AmSessionTimer::unsafe_removeTimer(int id, const string& session_id)
   }
 }
 
-void AmSessionTimer::removeTimers(const string& session_id) {
+void UserTimer::removeTimers(const string& session_id) {
   //  DBG("removing timers for <%s>\n", session_id.c_str());
   timers_mut.lock();
   for (set<AmTimer>::iterator it = timers.begin(); 
@@ -131,7 +160,7 @@ void AmSessionTimer::removeTimers(const string& session_id) {
   timers_mut.unlock();
 }
 
-void AmSessionTimer::removeUserTimers(const string& session_id) {
+void UserTimer::removeUserTimers(const string& session_id) {
   //  DBG("removing User timers for <%s>\n", session_id.c_str());
   timers_mut.lock();
   for (set<AmTimer>::iterator it = timers.begin(); 
@@ -143,3 +172,21 @@ void AmSessionTimer::removeUserTimers(const string& session_id) {
   }
   timers_mut.unlock();
 }
+
+void UserTimer::invoke(const string& method, const AmArgArray& args, AmArgArray& ret)
+{
+    if(method == "setTimer"){
+	setTimer(args.get(0).asInt(),
+		 args.get(1).asInt(),
+		 args.get(2).asCStr());
+    }
+    else if(method == "removeTimer"){
+	removeTimer(args.get(0).asInt(),
+		    args.get(1).asCStr());
+    }
+    else if(method == "removeUserTimers"){
+	removeUserTimers(args.get(0).asCStr());
+    }
+    else
+	throw AmDynInvoke::NotImplemented(method);
+}
diff --git a/core/AmSessionTimer.h b/core/plug-in/session_timer/UserTimer.h
similarity index 79%
rename from core/AmSessionTimer.h
rename to core/plug-in/session_timer/UserTimer.h
index fb8036e1..4998de08 100644
--- a/core/AmSessionTimer.h
+++ b/core/plug-in/session_timer/UserTimer.h
@@ -1,4 +1,3 @@
-
 /*
  * Timer class with seconds granularity 
  */
@@ -19,12 +18,24 @@
 
 #include <set>
 
-class AmTimeoutEvent : public AmEvent {
+/**
+ * Timer Event: Name
+ */
+#define TIMEOUTEVENT_NAME "timer_timeout"
+
+/**
+ * Timer Event: class
+ * data[0]: int timer_id
+ */
+class AmTimeoutEvent : public AmPluginEvent 
+{
  public:
-  AmTimeoutEvent(int timer_id)
-    : AmEvent(timer_id) { }
+    AmTimeoutEvent(int timer_id);
 };
 
+/**
+ * Timer struct containing the alarm time.
+ */
 struct AmTimer
 {
   int id;
@@ -46,22 +57,22 @@ bool operator == (const AmTimer& l, const AmTimer& r);
  * Implements a timer with session granularity.
  * On timeout an AmTimeoutEvent with the ID is posted.
  */
-class AmSessionTimer 
+class UserTimer: public AmDynInvoke
 #ifdef SESSION_TIMER_THREAD
-: public AmThread
+,public AmThread
 #endif
 {
-  static AmSessionTimer* _instance;
+  static UserTimer* _instance;
 
   std::set<AmTimer> timers;
   AmMutex         timers_mut;
 
   void unsafe_removeTimer(int id, const string& session_id);
  public:
-  AmSessionTimer();
-  ~AmSessionTimer();
+  UserTimer();
+  ~UserTimer();
 
-  static AmSessionTimer* instance();
+  static UserTimer* instance();
 
   /** set timer with ID id, fire after s seconds event in 
       session session_id  */
@@ -84,6 +95,8 @@ class AmSessionTimer
   void run();
   void on_stop();
 #endif
+
+  void invoke(const string& method, const AmArgArray& args, AmArgArray& ret);
 };
 
 #endif //AM_SESSION_TIMER_H
diff --git a/core/sems.cpp b/core/sems.cpp
index 3dd36d08..f1a2ee35 100644
--- a/core/sems.cpp
+++ b/core/sems.cpp
@@ -38,7 +38,7 @@
 #include "AmSessionScheduler.h"
 #include "AmIcmpWatcher.h"
 #include "AmRtpReceiver.h"
-#include "AmSessionTimer.h"
+//#include "AmSessionTimer.h"
 
 #include "log.h"
 
@@ -412,8 +412,8 @@ int main(int argc, char* argv[])
     DBG("Starting RTP receiver\n");
     AmRtpReceiver::instance()->start();
 
-    DBG("Starting Session Timer\n");
-    AmSessionTimer::instance()->start();
+    //DBG("Starting Session Timer\n");
+    //AmSessionTimer::instance()->start();
 
     //DBG("Starting ICMP watcher\n");
     //AmIcmpWatcher::instance()->start();