diff --git a/examples/hello_world.cpp b/examples/hello_world.cpp
index 6548a69..e78466e 100644
--- a/examples/hello_world.cpp
+++ b/examples/hello_world.cpp
@@ -67,7 +67,7 @@ void Server() {
 	// Some of the following calls might fail, but at least one will succeed
 	Manager::listen("SHM:/MTCA-server");
 	Manager::listen("TCP:0.0.0.0:42000");
-	Manager::listen("MPI:0:10");
+	Manager::listen("MPI:0"); // can be omitted 
 	Manager::listen("MPIP2P:test");
     Manager::listen("MQTT:label");
     Manager::listen("UCX:0.0.0.0:21000");
@@ -132,7 +132,7 @@ void Client() {
 	auto handle = []() {
 					  auto h = Manager::connect("MPIP2P:test");
 					  if (!h.isValid()) {
-						  auto h = Manager::connect("MPI:0:10");
+						  auto h = Manager::connect("MPI:0");
 						  if (!h.isValid()) {
 							  auto h = Manager::connect("MQTT:label");
                               if(!h.isValid()) {
diff --git a/examples/p2p-perf.cpp b/examples/p2p-perf.cpp
index 96541c0..b8fdaad 100644
--- a/examples/p2p-perf.cpp
+++ b/examples/p2p-perf.cpp
@@ -22,7 +22,7 @@
 #include <iomanip>
 #include <vector>
 #include "mtcl.hpp"
-
+using namespace MTCL;
 const int     NROUND = 100;
 const int          N = 24;
 const size_t minsize = 16;              // bytes
diff --git a/examples/pingpong.cpp b/examples/pingpong.cpp
index 1b9f8fb..f4d1632 100644
--- a/examples/pingpong.cpp
+++ b/examples/pingpong.cpp
@@ -76,8 +76,8 @@ int main(int argc, char** argv){
         to make the Manager happy in this "protocol-agnostic" example.
 */
 #ifdef ENABLE_MPI
-    listen_str = {"MPI:"};
-    connect_str = {"MPI:0:5"};
+    listen_str = {"MPI:0"};
+    connect_str = {"MPI:0"};
 #endif
 
 
diff --git a/include/collectives/collectiveContext.hpp b/include/collectives/collectiveContext.hpp
index 9920a56..4e5e69a 100644
--- a/include/collectives/collectiveContext.hpp
+++ b/include/collectives/collectiveContext.hpp
@@ -8,11 +8,11 @@
 #include "collectiveImpl.hpp"
 #include "../handle.hpp"
 
-#ifdef ENABLE_MPI
+#ifdef MTCL_ENABLE_MPI
 #include "mpiImpl.hpp"
 #endif
 
-#ifdef ENABLE_UCX
+#ifdef MTCL_ENABLE_UCX
 #include "uccImpl.hpp"
 #endif
 
@@ -57,7 +57,7 @@ class CollectiveContext : public CommunicationHandle {
                             coll = new BroadcastGeneric(participants, size, root, rank, uniqtag);
                             break;
                         case MPI:
-                            #ifdef ENABLE_MPI
+                            #ifdef MTCL_ENABLE_MPI
                             void *max_tag;
                             int flag;
                             MPI_Comm_get_attr( MPI_COMM_WORLD, MPI_TAG_UB, &max_tag, &flag);
@@ -65,7 +65,7 @@ class CollectiveContext : public CommunicationHandle {
                             #endif
                             break;
                         case UCC:
-                            #ifdef ENABLE_UCX
+                            #ifdef MTCL_ENABLE_UCX
                             coll = new BroadcastUCC(participants, size, root, rank,  uniqtag);
                             #endif
                             break;
@@ -83,7 +83,7 @@ class CollectiveContext : public CommunicationHandle {
                             coll = new ScatterGeneric(participants, size, root, rank, uniqtag);
                             break;
                         case MPI:
-                            #ifdef ENABLE_MPI
+                            #ifdef MTCL_ENABLE_MPI
                             void *max_tag;
                             int flag;
                             MPI_Comm_get_attr( MPI_COMM_WORLD, MPI_TAG_UB, &max_tag, &flag);
@@ -91,7 +91,7 @@ class CollectiveContext : public CommunicationHandle {
                             #endif
                             break;
                         case UCC:
-                            #ifdef ENABLE_UCX
+                            #ifdef MTCL_ENABLE_UCX
                             coll = new ScatterUCC(participants, size, root, rank, uniqtag);
                             #endif
                             break;
@@ -111,7 +111,7 @@ class CollectiveContext : public CommunicationHandle {
                             coll = new GatherGeneric(participants, size, root, rank, uniqtag);
                             break;
                         case MPI:
-                            #ifdef ENABLE_MPI
+                            #ifdef MTCL_ENABLE_MPI
                             void *max_tag;
                             int flag;
                             MPI_Comm_get_attr( MPI_COMM_WORLD, MPI_TAG_UB, &max_tag, &flag);
@@ -119,7 +119,7 @@ class CollectiveContext : public CommunicationHandle {
                             #endif
                             break;
                         case UCC:
-                            #ifdef ENABLE_UCX
+                            #ifdef MTCL_ENABLE_UCX
                             coll = new GatherUCC(participants, size, root, rank, uniqtag);
                             #endif
                             break;
@@ -137,7 +137,7 @@ class CollectiveContext : public CommunicationHandle {
                             coll = new AllGatherGeneric(participants, size, root, rank, uniqtag);
                             break;
                         case MPI:
-                            #ifdef ENABLE_MPI
+                            #ifdef MTCL_ENABLE_MPI
                             void *max_tag;
                             int flag;
                             MPI_Comm_get_attr( MPI_COMM_WORLD, MPI_TAG_UB, &max_tag, &flag);
@@ -145,7 +145,7 @@ class CollectiveContext : public CommunicationHandle {
                             #endif
                             break;
                         case UCC:
-                            #ifdef ENABLE_UCX
+                            #ifdef MTCL_ENABLE_UCX
                             coll = new AllGatherUCC(participants, size, root, rank, uniqtag);
                             #endif
                             break;
@@ -163,7 +163,7 @@ class CollectiveContext : public CommunicationHandle {
                             coll = new AlltoallGeneric(participants, size, root, rank, uniqtag);
                             break;
                         case MPI:
-                            #ifdef ENABLE_MPI
+                            #ifdef MTCL_ENABLE_MPI
                             void *max_tag;
                             int flag;
                             MPI_Comm_get_attr( MPI_COMM_WORLD, MPI_TAG_UB, &max_tag, &flag);
@@ -171,7 +171,7 @@ class CollectiveContext : public CommunicationHandle {
                             #endif
                             break;
                         case UCC:
-                            #ifdef ENABLE_UCX
+                            #ifdef MTCL_ENABLE_UCX
                             coll = new AlltoallUCC(participants, size, root, rank, uniqtag);
                             #endif
                             break;
diff --git a/include/manager.hpp b/include/manager.hpp
index eb65bda..bbb81fd 100644
--- a/include/manager.hpp
+++ b/include/manager.hpp
@@ -28,23 +28,23 @@
 #endif
 #endif
 
-#ifdef ENABLE_MPI
+#ifdef MTCL_ENABLE_MPI
 #include "protocols/mpi.hpp"
 #endif
 
-#ifdef ENABLE_MPIP2P
+#ifdef MTCL_ENABLE_MPIP2P
 #include "protocols/mpip2p.hpp"
 #endif
 
-#ifdef ENABLE_MQTT
+#ifdef MTCL_ENABLE_MQTT
 #include "protocols/mqtt.hpp"
 #endif
 
-#ifdef ENABLE_UCX
+#ifdef MTCL_ENABLE_UCX
 #include "protocols/ucx.hpp"
 #endif
 
-#ifdef ENABLE_SHM
+#ifdef MTCL_ENABLE_SHM
 #include "protocols/shm.hpp"
 #endif
 namespace MTCL {
@@ -75,7 +75,9 @@ class Manager {
     inline static std::map<std::string, std::tuple<std::string, std::vector<std::string>, std::vector<std::string>>> components;
 #endif
 
-    REMOVE_CODE_IF(inline static std::thread t1);
+#ifndef SINGLE_IO_THREAD
+    inline static std::thread t1;
+#endif
     inline static bool end;
     inline static bool initialized = false;
 
@@ -340,23 +342,23 @@ class Manager {
 		// default transports protocol
         registerType<ConnTcp>("TCP");
 
-#ifdef ENABLE_SHM
+#ifdef MTCL_ENABLE_SHM
 		registerType<ConnSHM>("SHM");
 #endif
 
-#ifdef ENABLE_MPI
+#ifdef MTCL_ENABLE_MPI
         registerType<ConnMPI>("MPI");
 #endif
 
-#ifdef ENABLE_MPIP2P
+#ifdef MTCL_ENABLE_MQTT
         registerType<ConnMPIP2P>("MPIP2P");
 #endif
 
-#ifdef ENABLE_MQTT
+#ifdef MTCL_ENABLE_MQTT
         registerType<ConnMQTT>("MQTT");
 #endif
 
-#ifdef ENABLE_UCX
+#ifdef MTCL_ENABLE_UCX
         registerType<ConnUCX>("UCX");
 #endif
 
@@ -389,8 +391,9 @@ class Manager {
         }
 #endif
 
-        REMOVE_CODE_IF(t1 = std::thread([&](){Manager::getReadyBackend();}));
-
+#ifndef SINGLE_IO_THREAD
+        t1 = std::thread([&](){Manager::getReadyBackend();});
+#endif
         initialized = true;
 		return 0;
     }
@@ -406,8 +409,9 @@ class Manager {
 	 */
     static void finalize(bool blockflag=false) {
 		end = true;
-        REMOVE_CODE_IF(t1.join());
-
+#ifndef SINGLE_IO_THREAD
+        t1.join();
+#endif
         //while(!handleReady.empty()) handleReady.pop();
 #ifndef MTCL_DISABLE_COLLECTIVES
         for(auto& [ctx, _] : contexts) {
@@ -438,8 +442,8 @@ class Manager {
 		// if us is not multiple of the IO_THREAD_POLL_TIMEOUT we wait a bit less....
 		// if the poll timeout is 0, we just iterate us times
 		size_t niter = us.count(); // in case IO_THREAD_POLL_TIMEOUT is set to 0
-		if constexpr (IO_THREAD_POLL_TIMEOUT)
-			niter = us/std::chrono::milliseconds(IO_THREAD_POLL_TIMEOUT);
+		if constexpr (!!IO_THREAD_POLL_TIMEOUT)
+			niter = us/std::chrono::microseconds(IO_THREAD_POLL_TIMEOUT);
 		if (niter==0) niter++;
 		size_t i=0;
 		do { 
@@ -465,7 +469,7 @@ class Manager {
 			}
 			if (i >= niter) break;
 			++i;
-			if constexpr (IO_THREAD_POLL_TIMEOUT)
+			if constexpr (!!IO_THREAD_POLL_TIMEOUT)
 				std::this_thread::sleep_for(std::chrono::microseconds(IO_THREAD_POLL_TIMEOUT));	
 		} while(true);
 		return HandleUser(nullptr, true, true);
diff --git a/include/mtcl.hpp b/include/mtcl.hpp
index 2a4409e..e563454 100644
--- a/include/mtcl.hpp
+++ b/include/mtcl.hpp
@@ -3,24 +3,36 @@
 
 namespace MTCL {
 
+
 #if defined(ENABLE_MPI)
 const bool MPI_ENABLED     = true;
+#define MTCL_ENABLE_MPI
 #else
 const bool MPI_ENABLED     = false;
 #endif
-#if defined(ENABLE_MPIP2P)
+#if defined(ENABLE_MPIP2P) && !defined(NO_MTCL_MULTITHREADED)
 const bool MPIP2P_ENABLED  = true;
+#define MTCL_ENABLE_MPIP2P
 #else
 const bool MPIP2P_ENABLED  = false;
 #endif
 #if defined(ENABLE_UCX)
 const bool UCX_ENABLED     = true;
 const bool UCC_ENABLED     = true;
+#define MTCL_ENABLE_UCX
 #else
 const bool UCX_ENABLED     = false;
 const bool UCC_ENABLED     = false;
 #endif
 
+#ifdef ENABLE_SHM
+#define MTCL_ENABLE_SHM
+#endif
+
+#ifdef ENABLE_MQTT
+#define MTCL_ENABLE_MQTT
+#endif
+
 } // namespace
 
 
diff --git a/include/protocols/mpi.hpp b/include/protocols/mpi.hpp
index 86ed2dc..61cae78 100644
--- a/include/protocols/mpi.hpp
+++ b/include/protocols/mpi.hpp
@@ -7,6 +7,7 @@
 #include <shared_mutex>
 #include <thread>
 #include <errno.h>
+#include <atomic>
 
 #include <mpi.h>
 
@@ -157,6 +158,7 @@ class ConnMPI : public ConnType {
     // <rank, tag> => <HandleMPI, busy>
     std::map<std::pair<int, int>, std::pair<HandleMPI*, bool>> connections;
     std::shared_mutex shm;
+    std::atomic<unsigned int> tag_counter_even = 100, tag_counter_odd = 101;
 
 public:
 
@@ -201,14 +203,14 @@ class ConnMPI : public ConnType {
         }
         
         int tag;
-        try {
+       /* try {
             tag = stoi(dest.substr(dest.find(":") + 1, dest.length()));
         }
         catch(std::invalid_argument&) {
             MTCL_MPI_PRINT(100, "ConnMPI::connect rank must be an integer greater than 0\n");
             errno = EINVAL;
             return nullptr;
-        }
+        }*/
 
         if(rank < 0) {
 			MTCL_MPI_PRINT(100, "ConnMPI::connect the connection rank must be greater or equal than 0\n");
@@ -216,12 +218,23 @@ class ConnMPI : public ConnType {
             return nullptr;
         }
 
-        if (tag <= (int)MPI_CONNECTION_TAG){
+        /*if (tag <= (int)MPI_CONNECTION_TAG){
 			MTCL_MPI_PRINT(100, "ConnMPI::connect the connection tag must be greater than 0\n");
 			errno = EINVAL;
             return nullptr;
         }
-        
+
+        if (connections.count({rank, tag})){
+            MTCL_MPI_PRINT(100, "ConnMPI::connect: connection already done use the previous handler!\n");
+			errno = EINVAL;
+            return nullptr;
+        }*/
+
+        if (this->rank < rank)
+            tag = tag_counter_even.fetch_add(2); 
+        else
+            tag = tag_counter_odd.fetch_add(2);
+
         int header[1];
         header[0] = tag;
         if (MPI_Send(header, 1, MPI_INT, rank, MPI_CONNECTION_TAG, MPI_COMM_WORLD) != MPI_SUCCESS) {
diff --git a/include/protocols/mpip2p.hpp b/include/protocols/mpip2p.hpp
index 19158f2..dd9d119 100644
--- a/include/protocols/mpip2p.hpp
+++ b/include/protocols/mpip2p.hpp
@@ -227,11 +227,9 @@ class ConnMPIP2P : public ConnType {
             for(int i=0; i<remote_size; i++) {
 
                 HandleMPIP2P* handle = new HandleMPIP2P(this, i, client, false);
-                {
-                    connections.insert({handle, false});
-                    ADD_CODE_IF(addinQ(true, handle));  
-                }
-                REMOVE_CODE_IF(addinQ(true, handle));
+                connections.insert({handle, false});
+                addinQ(true, handle);  
+    
             }
         }
 		MTCL_MPIP2P_PRINT(100, "Accept thread finalized.\n");        
diff --git a/include/protocols/shm.hpp b/include/protocols/shm.hpp
index 0c4db42..3e85a88 100644
--- a/include/protocols/shm.hpp
+++ b/include/protocols/shm.hpp
@@ -56,7 +56,7 @@ class ConnSHM : public ConnType {
     shmBuffer connbuff;    
     std::map<HandleSHM*, bool> connections;  // Active connections for this Connector
 
-#if !defined(SINGLE_IO_THREAD)
+#if defined(NO_MTCL_MULTITHREADED)
     std::shared_mutex shm;
 #endif
 
diff --git a/include/protocols/tcp.hpp b/include/protocols/tcp.hpp
index 530db02..76b93fb 100644
--- a/include/protocols/tcp.hpp
+++ b/include/protocols/tcp.hpp
@@ -151,7 +151,7 @@ class ConnTcp : public ConnType {
 
     fd_set set, tmpset;
     int listen_sck;
-#if defined(SINGLE_IO_THREAD)
+#if defined(NO_MTCL_MULTITHREADED)
 	int fdmax;
 #else	
     std::atomic<int> fdmax;
diff --git a/include/protocols/ucx.hpp b/include/protocols/ucx.hpp
index bb9f1cd..dc40b2c 100644
--- a/include/protocols/ucx.hpp
+++ b/include/protocols/ucx.hpp
@@ -270,7 +270,7 @@ class ConnUCX : public ConnType {
     fd_set      set, tmpset;
     int         listen_sck;
 
-#if defined(SINGLE_IO_THREAD)
+#if defined(NO_MTCL_MULTITHREADED)
         int fdmax;
 #else	
     std::atomic<int> fdmax;
diff --git a/include/utils.hpp b/include/utils.hpp
index 9961a8b..6a0a588 100644
--- a/include/utils.hpp
+++ b/include/utils.hpp
@@ -179,10 +179,11 @@ static inline int internal_connect(const std::string& address, int retry, unsign
 } // namespace
 
 
-// if SINGLE_IO_THREAD is defined, we do not use locking for accessing
+// if NO_MTCL_MULTITHREADED is defined, we do not use locking for accessing
 // internal data structures, thus some code can be removed.
 // A different case is for the MPIP2P transport protocol.
-#if defined(SINGLE_IO_THREAD)
+#if defined(NO_MTCL_MULTITHREADED)
+#define SINGLE_IO_THREAD
 #define REMOVE_CODE_IF(X)
 #define ADD_CODE_IF(X)    X
 #else
diff --git a/tests/Makefile b/tests/Makefile
new file mode 100644
index 0000000..9963527
--- /dev/null
+++ b/tests/Makefile
@@ -0,0 +1,89 @@
+ifndef CXX
+CXX 	   = g++
+endif
+
+MTCL_DIR=../
+
+CXXFLAGS  += -std=c++17
+INCS       = -I . -I $(MTCL_DIR)/include
+
+ifdef DEBUG
+	OPTIMIZE_FLAGS  += -g -fno-inline-functions
+else
+	OPTIMIZE_FLAGS  += -O3 -finline-functions -DNDEBUG
+endif
+
+ifdef SINGLE_IO_THREAD
+	CXXFLAGS +=-DSINGLE_IO_THREAD
+endif
+
+ifeq ($(findstring SHM,$(TPROTOCOL)),SHM)
+	CXXFLAGS += -DENABLE_SHM
+endif
+
+ifeq ($(findstring MPI,$(TPROTOCOL)),MPI)
+	CXX 	  = mpicxx
+	CXXFLAGS += -DENABLE_MPI
+	TARGET    = $(MTCL_DIR)protocols/stop_accept
+ifdef MPI_HOME
+	INCS   += `pkg-config --cflags-only-I $(MPI_HOME)/lib/pkgconfig/ompi-cxx.pc`
+	LIBS   += `pkg-config --libs $(MPI_HOME)/lib/pkgconfig/ompi-cxx.pc`
+endif
+endif
+
+ifeq ($(findstring MQTT, $(TPROTOCOL)),MQTT)
+	CXXFLAGS += -DENABLE_MQTT
+ifndef PAHO_HOME
+$(error PAHO_HOME env variable not defined!);
+endif
+	INCS += -I${PAHO_HOME}/include
+	LIBS += -L${PAHO_HOME}/lib -Wl,-rpath,${PAHO_HOME}/lib -lpaho-mqttpp3 -lpaho-mqtt3as -lpaho-mqtt3a
+endif
+
+ifeq ($(findstring TCP, $(TPROTOCOL)),TCP)
+	CXXFLAGS += -DENABLE_TCP
+endif
+
+ifeq ($(findstring UCX, $(TPROTOCOL)),UCX)
+ifndef UCC_HOME
+$(error UCC_HOME env variable not defined!);
+endif
+	CXXFLAGS += -DENABLE_UCX
+ifndef UCX_HOME
+$(error UCX_HOME env variable not defined!);
+endif
+	INCS += -I$(UCX_HOME)/include -I$(UCC_HOME)/include
+	LIBS += -L$(UCX_HOME)/lib -Wl,-rpath,${UCX_HOME}/lib -lucp -luct -lucs -lucm -L${UCC_HOME}/lib -Wl,-rpath,${UCC_HOME}/lib -lucc
+endif
+
+CXXFLAGS         += -Wall
+LIBS             += -I ${RAPIDJSON_HOME}/include -pthread
+INCLUDES          = $(INCS)
+
+SOURCES           = $(wildcard *.cpp)
+TARGET           += $(SOURCES:.cpp=)
+
+.PHONY: all clean cleanall 
+.SUFFIXES: .c .cpp .o
+
+%.d: %.cpp
+	@set -e; $(CXX) -MM $(INCLUDES) $(CXXFLAGS) $< \
+		| sed 's/\($*\)\.o[ :]*/\1 $@ : /g' > $@; \
+		[ -s $@ ] || rm -f $@
+%.d: %.c
+	@set -e; $(CC) -MM $(INCLUDES) $(CFLAGS)  $< \
+		| sed 's/\($*\)\.o[ :]*/\1 $@ : /g' > $@; \
+		[ -s $@ ] || rm -f $@
+%.o: %.c
+	$(CC) $(INCLUDES) $(CFLAGS) -c -o $@ $<
+%: %.cpp
+	$(CXX) $(INCLUDES) $(CXXFLAGS) $(OPTIMIZE_FLAGS) -o $@ $< $(LDFLAGS) $(LIBS)
+
+all: $(TARGET)
+
+clean: 
+	-rm -fr $(TARGET) *~
+cleanall: clean
+	-rm -fr *.d uri_file.txt $(MTCL_DIR)/protocols/stop_accept
+
+include $(SOURCES:.cpp=.d)
diff --git a/tests/test_connect.cpp b/tests/test_connect.cpp
index b2264f4..63d8485 100644
--- a/tests/test_connect.cpp
+++ b/tests/test_connect.cpp
@@ -3,7 +3,7 @@
 #include <sys/wait.h>
 #include <iostream>
 #include "mtcl.hpp"
-
+using namespace MTCL;
 const std::string str{"hello world!"}; //...........................................................................................abcdef.............................................................................ghijk..........................................................................................................................................................................................................012345..........................................................................................................................................................................................................6789.............................................................xywz................................................bye!"};
 
 std::string address{"TCP:localhost:13000"};
diff --git a/tests/test_mpi_disconnect.cpp b/tests/test_mpi_disconnect.cpp
index e197c7e..e1459cb 100644
--- a/tests/test_mpi_disconnect.cpp
+++ b/tests/test_mpi_disconnect.cpp
@@ -1,25 +1,25 @@
 #include <iostream>
-#include "../commlib.hpp"
-
+#include "mtcl.hpp"
+using namespace MTCL;
 int main(int argc, char** argv){
 #ifdef EXCLUDE_MPI
     std::cerr << "You must compile with MPI support this test\n";
     return 1;
 #endif
 
-    Manager::init();
+    Manager::init("");
 
     int rank;
     MPI_Comm_rank(MPI_COMM_WORLD, &rank);
 
     if (rank == 0){
-        Manager::connect("MPI:1:2");
+        Manager::connect("MPI:1");
         while(true){
             std::cout << "0: get an handle!\n";
             auto h = Manager::getNext();
             std::cout << "0: handle received!\n";
             char tmp;
-            if (h.read(&tmp, 1) == 0){
+            if (h.receive(&tmp, 1) == 0){
                 std::cout << "0: Peer closed connection\n";
                 h.close();
                 break;
diff --git a/tests/test_mpi_disconnect2.cpp b/tests/test_mpi_disconnect2.cpp
index fc4fb0a..53ea984 100644
--- a/tests/test_mpi_disconnect2.cpp
+++ b/tests/test_mpi_disconnect2.cpp
@@ -1,12 +1,12 @@
 #include <iostream>
-#include "../commlib.hpp"
-
+#include "mtcl.hpp"
+using namespace MTCL;
 int main(int argc, char** argv){
 #ifdef EXCLUDE_MPI
     std::cerr << "You must compile with MPI support this test\n";
     return 1;
 #endif
-    Manager::init();
+    Manager::init("");
 
     int rank;
     MPI_Comm_rank(MPI_COMM_WORLD, &rank);
@@ -16,7 +16,7 @@ int main(int argc, char** argv){
         std::cout << "0: handle received!\n";
         while(true){
             char tmp;
-            if (h.read(&tmp, 1) == 0){
+            if (h.receive(&tmp, 1) == 0){
                 std::cout << "0: Peer closed connection\n";
                 h.close();
                 break;
diff --git a/tests/test_mpi_disconnect3.cpp b/tests/test_mpi_disconnect3.cpp
index d1aa449..67c51fc 100644
--- a/tests/test_mpi_disconnect3.cpp
+++ b/tests/test_mpi_disconnect3.cpp
@@ -1,5 +1,6 @@
 #include <iostream>
-#include "../commlib.hpp"
+#include "mtcl.hpp"
+using namespace MTCL;
 
 int main(int argc, char** argv){
 #ifdef EXCLUDE_MPI
@@ -7,7 +8,7 @@ int main(int argc, char** argv){
     return 1;
 #endif
 
-    Manager::init();
+    Manager::init("");
 
     int rank;
     MPI_Comm_rank(MPI_COMM_WORLD, &rank);
@@ -17,7 +18,7 @@ int main(int argc, char** argv){
         std::cout << "0: handle received!\n";
         while(true){
             char tmp;
-            if (h.read(&tmp, 1) == 0){
+            if (h.receive(&tmp, 1) == 0){
                 std::cout << "0: Peer closed connection\n";
                 h.close();
                 break;
@@ -33,9 +34,11 @@ int main(int argc, char** argv){
             std::cout << "1: Received new connection!\n";
             h.close();
             std::cout << "1: connection closed!\n";
-            // should be an error here!
-            h.send("a", 1);
-            std::cout << "1: sended a\n";
+            // should be an error here since we send after closing connection!
+            if (h.send("a", 1) < 0)
+                std::cerr << "1: Error in sending!\n";
+            else
+                std::cout << "1: sended a\n";
         }
     }
 
diff --git a/tests/test_mpi_multiconnect.cpp b/tests/test_mpi_multiconnect.cpp
new file mode 100644
index 0000000..2f949db
--- /dev/null
+++ b/tests/test_mpi_multiconnect.cpp
@@ -0,0 +1,65 @@
+#include <iostream>
+#include "mtcl.hpp"
+
+int main(int argc, char** argv){
+#ifdef EXCLUDE_MPI
+    std::cerr << "You must compile with MPI support this test\n";
+    return 1;
+#endif
+
+    MTCL::Manager::init("e");
+
+    int rank;
+    sleep(5);
+    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+
+    if (rank == 0){
+        auto h1 = MTCL::Manager::connect("MPI:1");
+        auto h2 = MTCL::Manager::connect("MPI:1");
+
+        std::cout << "First connection id: " << h1.getID() << std::endl;
+        std::cout << "Second connection id: " << h2.getID() << std::endl;
+        sleep(1);
+        int dummy = 1000;
+        h1.send(&dummy, sizeof(dummy));
+        sleep(1);
+        h2.send(&dummy, sizeof(dummy));
+        sleep(1);
+        auto hr = MTCL::Manager::getNext();
+        std::cout << "Received message from rank 0 of id: " << hr.getID() << std::endl;
+
+    } else {
+        int dummy;
+        ///MTCL::Manager::listen("MPI:1:2");
+        auto h = MTCL::Manager::getNext();
+        if (h.isNewConnection()) {
+            std::cout << "Receiver id: " << h.getID() << std::endl;
+        }
+        h.yield();
+        h = MTCL::Manager::getNext();
+        if (h.isNewConnection()) {
+            std::cout << "Receiver id: " << h.getID() << std::endl;
+        }
+        h.yield();
+        h = MTCL::Manager::getNext();
+        std::cout << "Receiver id: " << h.getID() << std::endl;
+        size_t sz;
+        h.probe(sz);
+        assert(sz == sizeof(dummy));
+        h.receive(&dummy, sz);
+        h.yield();
+        h = MTCL::Manager::getNext();
+        std::cout << "Receiver id: " << h.getID() << std::endl;
+        h.probe(sz);
+        assert(sz == sizeof(dummy));
+        h.receive(&dummy, sz);
+
+        auto hr = MTCL::Manager::connect("MPI:0:1");
+        std::cout << "Backwards connect id: " << hr.getID() << std::endl; 
+
+    }
+
+    MTCL::Manager::finalize();
+    return 0;
+
+}
\ No newline at end of file
diff --git a/tests/test_non-matching_comm.cpp b/tests/test_non-matching_comm.cpp
index 31d5456..cfca60a 100644
--- a/tests/test_non-matching_comm.cpp
+++ b/tests/test_non-matching_comm.cpp
@@ -26,8 +26,8 @@
  * */
 
 #include <iostream>
-#include "../mtcl.hpp"
-
+#include "mtcl.hpp"
+using namespace MTCL;
 const int max_msg_size=100;          // max message size
 const std::string bye{"Bye!"};       // bye bye message
 const std::string welcome{"Hello!"}; // welcome message
@@ -53,7 +53,7 @@ int main(int argc, char** argv){
     Manager::init(argv[2]);
 
     if (rank == 0){
-        Manager::listen("MPI:0:10");
+        Manager::listen("MPI:0"); // can be omitted
         Manager::listen("UCX:0.0.0.0:21000");
         
         char *buff = new char[maxsize];
@@ -78,7 +78,7 @@ int main(int argc, char** argv){
     else {
         
         auto handle = []() {
-            auto h = Manager::connect("MPI:0:10");
+            auto h = Manager::connect("MPI:0");
             if (!h.isValid()) {
                 auto h = Manager::connect("UCX:0.0.0.0:21000");
                 assert(h.isValid());
diff --git a/tests/test_probe-nb.cpp b/tests/test_probe-nb.cpp
index 2417200..b4dd5af 100644
--- a/tests/test_probe-nb.cpp
+++ b/tests/test_probe-nb.cpp
@@ -3,7 +3,7 @@
 #include <sys/wait.h>
 #include <iostream>
 #include "mtcl.hpp"
-
+using namespace MTCL;
 int main(int argc, char** argv){
 
 	pid_t pid = fork();
diff --git a/tests/test_probe.cpp b/tests/test_probe.cpp
index 729868f..7c78498 100644
--- a/tests/test_probe.cpp
+++ b/tests/test_probe.cpp
@@ -3,7 +3,7 @@
 #include <sys/wait.h>
 #include <iostream>
 #include "mtcl.hpp"
-
+using namespace MTCL;
 int main(int argc, char** argv){
 
 	pid_t pid = fork();