diff --git a/coreapi/bellesip_sal/sal_address_impl.c b/coreapi/bellesip_sal/sal_address_impl.c
index c7a2603ca..540aa701b 100644
--- a/coreapi/bellesip_sal/sal_address_impl.c
+++ b/coreapi/bellesip_sal/sal_address_impl.c
@@ -109,6 +109,8 @@ void sal_address_set_port_int(SalAddress *addr, int port){
 }
 void sal_address_clean(SalAddress *addr){
 	belle_sip_header_address_t* header_addr = BELLE_SIP_HEADER_ADDRESS(addr);
+	belle_sip_uri_t* uri=belle_sip_header_address_get_uri(header_addr);
+	if (uri) belle_sip_parameters_clean(BELLE_SIP_PARAMETERS(uri));
 	belle_sip_parameters_clean(BELLE_SIP_PARAMETERS(header_addr));
 	return ;
 }
diff --git a/coreapi/bellesip_sal/sal_op_impl.c b/coreapi/bellesip_sal/sal_op_impl.c
index cf02d532c..b05517fad 100644
--- a/coreapi/bellesip_sal/sal_op_impl.c
+++ b/coreapi/bellesip_sal/sal_op_impl.c
@@ -146,6 +146,17 @@ static int _sal_op_send_request_with_contact(SalOp* op, belle_sip_request_t* req
 				belle_sip_message_add_header(BELLE_SIP_MESSAGE(request),BELLE_SIP_HEADER(route_header));
 			}
 		}
+		if (!sal_op_get_route_addresses(op) && belle_sip_list_size(belle_sip_provider_get_listening_points(op->base.root->prov))==1) {
+			/*compatibility mode*/
+			belle_sip_listening_point_t* lp = (belle_sip_listening_point_t*)belle_sip_provider_get_listening_points(op->base.root->prov)->data;
+			belle_sip_uri_t* to_uri=belle_sip_header_address_get_uri(BELLE_SIP_HEADER_ADDRESS(belle_sip_message_get_header_by_type(request,belle_sip_header_to_t)));
+			belle_sip_header_address_t* route=belle_sip_header_address_create(NULL,belle_sip_uri_create(NULL,belle_sip_uri_get_host(to_uri)));
+			belle_sip_uri_set_transport_param(belle_sip_header_address_get_uri(BELLE_SIP_HEADER_ADDRESS(route)),belle_sip_listening_point_get_transport(lp));
+			route_header = belle_sip_header_route_create(route);
+			belle_sip_object_unref(route);
+			belle_sip_message_add_header(BELLE_SIP_MESSAGE(request),BELLE_SIP_HEADER(route_header));
+			ms_message("Only one lp & no route, forcing transport to lp transport [%s]",belle_sip_listening_point_get_transport(lp));
+		}
 	}
 
 	client_transaction = belle_sip_provider_create_client_transaction(prov,request);
diff --git a/coreapi/linphonecore.c b/coreapi/linphonecore.c
index 0b475e15f..e443ae1b6 100644
--- a/coreapi/linphonecore.c
+++ b/coreapi/linphonecore.c
@@ -2566,14 +2566,27 @@ LinphoneCall * linphone_core_invite_address_with_params(LinphoneCore *lc, const
 		if (sal_address_get_transport((SalAddress*)addr)) {
 			sal_address_set_transport(route,sal_address_get_transport((SalAddress*)addr));
 		} else  {
+			LinphoneProxyConfig* chosen_proxy=NULL;
+
 			if (dest_proxy)
-				proxy_addr=sal_address_new(linphone_proxy_config_get_addr(dest_proxy));
+				chosen_proxy=dest_proxy;
 			else if (proxy)
-				proxy_addr=sal_address_new(linphone_proxy_config_get_addr(proxy));
+				chosen_proxy=proxy;
+			else
+				chosen_proxy=NULL;
+
+			if (chosen_proxy)
+				proxy_addr=sal_address_new(linphone_proxy_config_get_addr(chosen_proxy));
+
 			if (proxy_addr && sal_address_get_transport(proxy_addr))
 				sal_address_set_transport(route,sal_address_get_transport(proxy_addr));
+			else if (proxy_addr && linphone_proxy_config_guess_transport(chosen_proxy) && !sal_address_get_transport((SalAddress*)route)) {
+				/*compatibility mode*/
+				sal_address_set_transport((SalAddress*)route,sal_transport_parse(linphone_proxy_config_guess_transport(chosen_proxy)));
+			}
 		}
 
+
 		sal_op_add_route_address(call->op,route);
 
 	}
diff --git a/coreapi/misc.c b/coreapi/misc.c
index 85dd51d82..cd62a522f 100644
--- a/coreapi/misc.c
+++ b/coreapi/misc.c
@@ -1115,7 +1115,8 @@ static int get_local_ip_for_with_connect(int type, const char *dest, char *resul
 		ms_error("getnameinfo error: %s",strerror(errno));
 	}
 	close_socket(sock);
-	ms_message("Local interface to reach %s is %s.",dest,result);
+
+
 	return 0;
 }
 
diff --git a/coreapi/private.h b/coreapi/private.h
index 8645edbff..19e84f9dc 100644
--- a/coreapi/private.h
+++ b/coreapi/private.h
@@ -240,7 +240,10 @@ void linphone_proxy_config_write_all_to_config_file(LinphoneCore *lc);
  * Can be NULL
  * */
 const LinphoneAddress* linphone_proxy_config_get_service_route(const LinphoneProxyConfig* cfg);
-
+/*
+ *guess the transport if only one trasport is configured at core level (for backward compatibility)
+ * */
+const char* linphone_proxy_config_guess_transport(const LinphoneProxyConfig *obj);
 
 int linphone_online_status_to_eXosip(LinphoneOnlineStatus os);
 void linphone_friend_close_subscriptions(LinphoneFriend *lf);
diff --git a/coreapi/proxy.c b/coreapi/proxy.c
index 00f370c14..76f40eb99 100644
--- a/coreapi/proxy.c
+++ b/coreapi/proxy.c
@@ -347,7 +347,7 @@ LinphoneAddress *guess_contact_for_register(LinphoneProxyConfig *obj){
 	return ret;
 }
 /*use for compatibility with linphone supporting only 1 transport at a time*/
-const char* guess_transport(const LinphoneProxyConfig *obj) {
+const char* linphone_proxy_config_guess_transport(const LinphoneProxyConfig *obj) {
 	LCSipTransports transports;
 	const char* transport_name;
 	unsigned char transports_count=0;
@@ -383,8 +383,8 @@ static void linphone_proxy_config_register(LinphoneProxyConfig *obj){
 		char *contact;
 #else
 		LinphoneAddress *contact;
-		if (guess_transport(obj) && !sal_address_get_transport((SalAddress*)proxy)) {
-			sal_address_set_transport((SalAddress*)proxy,sal_transport_parse(guess_transport(obj)));
+		if (linphone_proxy_config_guess_transport(obj) && !sal_address_get_transport((SalAddress*)proxy)) {
+			sal_address_set_transport((SalAddress*)proxy,sal_transport_parse(linphone_proxy_config_guess_transport(obj)));
 		}
 #endif
 		proxy_string=linphone_address_as_string_uri_only(proxy);
diff --git a/tester/call_tester.c b/tester/call_tester.c
index 2131789ea..9c98fa00d 100644
--- a/tester/call_tester.c
+++ b/tester/call_tester.c
@@ -190,6 +190,70 @@ static void simple_call(void) {
 	linphone_core_manager_destroy(marie);
 	linphone_core_manager_destroy(pauline);
 }
+static void simple_call_compatibility_mode(void) {
+	LinphoneCoreManager* marie = linphone_core_manager_new(liblinphone_tester_file_prefix, "marie_rc");
+	LinphoneCoreManager* pauline = linphone_core_manager_new(liblinphone_tester_file_prefix, "pauline_rc");
+
+	LinphoneCore* lc_marie=marie->lc;
+	LinphoneCore* lc_pauline=pauline->lc;
+	stats* stat_marie=&marie->stat;
+	stats* stat_pauline=&pauline->stat;
+	LinphoneProxyConfig* proxy;
+	LinphoneAddress* identity;
+	LinphoneAddress* proxy_address;
+	char*tmp;
+	LCSipTransports transport;
+
+	linphone_core_get_default_proxy(lc_marie,&proxy);
+	CU_ASSERT_PTR_NOT_NULL (proxy);
+	identity = linphone_address_new(linphone_proxy_config_get_identity(proxy));
+
+
+	proxy_address=linphone_address_new(linphone_proxy_config_get_addr(proxy));
+	linphone_address_clean(proxy_address);
+	tmp=linphone_address_as_string_uri_only(proxy_address);
+	linphone_proxy_config_set_server_addr(proxy,tmp);
+	linphone_proxy_config_set_route(proxy,NULL);
+	ms_free(tmp);
+	linphone_address_destroy(proxy_address);
+	linphone_core_get_sip_transports(lc_marie,&transport);
+	transport.udp_port=0;
+	transport.tls_port=0;
+	transport.dtls_port=0;
+	/*only keep tcp*/
+	linphone_core_set_sip_transports(lc_marie,&transport);
+	stat_marie->number_of_LinphoneRegistrationOk=0;
+
+	CU_ASSERT_TRUE (wait_for(lc_marie,lc_marie,&stat_marie->number_of_LinphoneRegistrationOk,1));
+
+	linphone_core_invite(lc_marie,"pauline");
+
+	CU_ASSERT_TRUE (wait_for(lc_pauline,lc_marie,&stat_pauline->number_of_LinphoneCallIncomingReceived,1));
+	CU_ASSERT_TRUE(linphone_core_inc_invite_pending(lc_pauline));
+	CU_ASSERT_EQUAL(stat_marie->number_of_LinphoneCallOutgoingProgress,1);
+	CU_ASSERT_TRUE(wait_for(lc_pauline,lc_marie,&stat_marie->number_of_LinphoneCallOutgoingRinging,1));
+
+	CU_ASSERT_PTR_NOT_NULL(linphone_core_get_current_call_remote_address(lc_pauline));
+	if (linphone_core_get_current_call_remote_address(lc_pauline)) {
+		CU_ASSERT_TRUE(linphone_address_weak_equal(identity,linphone_core_get_current_call_remote_address(lc_pauline)));
+		linphone_address_destroy(identity);
+
+		linphone_core_accept_call(lc_pauline,linphone_core_get_current_call(lc_pauline));
+
+		CU_ASSERT_TRUE(wait_for(lc_pauline,lc_marie,&stat_pauline->number_of_LinphoneCallConnected,1));
+		CU_ASSERT_TRUE(wait_for(lc_pauline,lc_marie,&stat_marie->number_of_LinphoneCallConnected,1));
+		CU_ASSERT_TRUE(wait_for(lc_pauline,lc_marie,&stat_pauline->number_of_LinphoneCallStreamsRunning,1));
+		CU_ASSERT_TRUE(wait_for(lc_pauline,lc_marie,&stat_marie->number_of_LinphoneCallStreamsRunning,1));
+		/*just to sleep*/
+		wait_for(lc_pauline,lc_marie,&stat_marie->number_of_LinphoneCallStreamsRunning,3);
+		linphone_core_terminate_all_calls(lc_pauline);
+		CU_ASSERT_TRUE(wait_for(lc_pauline,lc_marie,&stat_pauline->number_of_LinphoneCallEnd,1));
+		CU_ASSERT_TRUE(wait_for(lc_pauline,lc_marie,&stat_marie->number_of_LinphoneCallEnd,1));
+	}
+	linphone_core_manager_destroy(marie);
+	linphone_core_manager_destroy(pauline);
+}
+
 
 static void cancelled_call(void) {
 	LinphoneCoreManager* marie = linphone_core_manager_new(liblinphone_tester_file_prefix, "marie_rc");
@@ -619,6 +683,7 @@ test_t call_tests[] = {
 	{ "Call with DNS timeout", call_with_dns_time_out },
 	{ "Cancelled ringing call", cancelled_ringing_call },
 	{ "Simple call", simple_call },
+	{ "Simple call compatibility mode", simple_call_compatibility_mode },
 	{ "Early-media call", early_media_call },
 	{ "Call terminated by caller", call_terminated_by_caller },
 	{ "Call paused resumed", call_paused_resumed },
diff --git a/tester/message_tester.c b/tester/message_tester.c
index ad172e472..730546a7d 100644
--- a/tester/message_tester.c
+++ b/tester/message_tester.c
@@ -72,6 +72,41 @@ static void text_message(void) {
 	linphone_core_manager_destroy(marie);
 	linphone_core_manager_destroy(pauline);
 }
+static void text_message_compatibility_mode(void) {
+	LinphoneCoreManager* marie = linphone_core_manager_new(liblinphone_tester_file_prefix, "marie_rc");
+	LinphoneCoreManager* pauline = linphone_core_manager_new(liblinphone_tester_file_prefix, "pauline_rc");
+	LinphoneProxyConfig* proxy;
+	LinphoneAddress* proxy_address;
+	char*tmp;
+	LCSipTransports transport;
+	char* to = linphone_address_as_string(pauline->identity);
+
+	linphone_core_get_default_proxy(marie->lc,&proxy);
+	CU_ASSERT_PTR_NOT_NULL (proxy);
+	proxy_address=linphone_address_new(linphone_proxy_config_get_addr(proxy));
+	linphone_address_clean(proxy_address);
+	tmp=linphone_address_as_string_uri_only(proxy_address);
+	linphone_proxy_config_set_server_addr(proxy,tmp);
+	linphone_proxy_config_set_route(proxy,NULL);
+	ms_free(tmp);
+	linphone_address_destroy(proxy_address);
+	linphone_core_get_sip_transports(marie->lc,&transport);
+	transport.udp_port=0;
+	transport.tls_port=0;
+	transport.dtls_port=0;
+	/*only keep tcp*/
+	linphone_core_set_sip_transports(marie->lc,&transport);
+	marie->stat.number_of_LinphoneRegistrationOk=0;
+
+	CU_ASSERT_TRUE (wait_for(marie->lc,marie->lc,&marie->stat.number_of_LinphoneRegistrationOk,1));
+
+	LinphoneChatRoom* chat_room = linphone_core_create_chat_room(marie->lc,to);
+	linphone_chat_room_send_message(chat_room,"Bla bla bla bla");
+	CU_ASSERT_TRUE(wait_for(pauline->lc,marie->lc,&pauline->stat.number_of_LinphoneMessageReceived,1));
+	CU_ASSERT_EQUAL(pauline->stat.number_of_LinphoneMessageReceivedLegacy,1);
+	linphone_core_manager_destroy(marie);
+	linphone_core_manager_destroy(pauline);
+}
 
 static void text_message_with_ack(void) {
 	LinphoneCoreManager* marie = linphone_core_manager_new(liblinphone_tester_file_prefix, "marie_rc");
@@ -126,6 +161,7 @@ static void text_message_with_send_error(void) {
 
 test_t message_tests[] = {
 	{ "Text message", text_message },
+	{ "Text message compatibility mode", text_message_compatibility_mode },
 	{ "Text message with ack", text_message_with_ack },
 	{ "Text message with send error", text_message_with_send_error },
 	{ "Text message with external body", text_message_with_external_body }
diff --git a/tester/register_tester.c b/tester/register_tester.c
index f60ebe4a5..0b5483f43 100644
--- a/tester/register_tester.c
+++ b/tester/register_tester.c
@@ -47,9 +47,8 @@ void registration_state_changed(struct _LinphoneCore *lc, LinphoneProxyConfig *c
 
 }
 
-static void register_with_refresh_base_2(LinphoneCore* lc, bool_t refresh,const char* domain,const char* route,bool_t late_auth_info) {
+static void register_with_refresh_base_2(LinphoneCore* lc, bool_t refresh,const char* domain,const char* route,bool_t late_auth_info,LCSipTransports transport) {
 	int retry=0;
-	LCSipTransports transport = {5070,5070,0,5071};
     char* addr;
 	LinphoneProxyConfig* proxy_cfg;
 	stats* counters;
@@ -102,7 +101,8 @@ static void register_with_refresh_base_2(LinphoneCore* lc, bool_t refresh,const
 }
 
 static void register_with_refresh_base(LinphoneCore* lc, bool_t refresh,const char* domain,const char* route) {
-	register_with_refresh_base_2(lc,refresh,domain,route,FALSE);
+	LCSipTransports transport = {5070,5070,0,5071};
+	register_with_refresh_base_2(lc,refresh,domain,route,FALSE,transport);
 }
 
 static void register_with_refresh(LinphoneCore* lc, bool_t refresh,const char* domain,const char* route) {
@@ -169,6 +169,14 @@ static void simple_tcp_register(){
 	register_with_refresh(lc,FALSE,test_domain,route);
 }
 
+static void simple_tcp_register_compatibility_mode(){
+	LinphoneCore* lc;
+	LCSipTransports transport = {0,5070,0,0};
+	lc = create_lc();
+	register_with_refresh_base_2(lc,FALSE,test_domain,NULL,FALSE,transport);
+}
+
+
 static void simple_tls_register(){
 	char route[256];
 	LinphoneCore* lc;
@@ -221,6 +229,7 @@ static void authenticated_register_with_late_credentials(){
 	LinphoneCore* lc;
 	stats stat;
 	stats* counters;
+	LCSipTransports transport = {5070,5070,0,5071};
 	char route[256];
 	sprintf(route,"sip:%s",test_route);
 	memset (&v_table,0,sizeof(v_table));
@@ -229,7 +238,7 @@ static void authenticated_register_with_late_credentials(){
 	lc =  linphone_core_new(&v_table,NULL,NULL,NULL);
 	linphone_core_set_user_data(lc,&stat);
 	counters = (stats*)linphone_core_get_user_data(lc);
-	register_with_refresh_base_2(lc,FALSE,auth_domain,route,TRUE);
+	register_with_refresh_base_2(lc,FALSE,auth_domain,route,TRUE,transport);
 	CU_ASSERT_EQUAL(counters->number_of_auth_info_requested,1);
 	linphone_core_destroy(lc);
 }
@@ -331,6 +340,7 @@ static void io_recv_error(){
 test_t register_tests[] = {
 	{ "Simple register", simple_register },
 	{ "TCP register", simple_tcp_register },
+	{ "TCP register compatibility mode", simple_tcp_register_compatibility_mode },
 #ifndef ANDROID
 	{ "TLS register", simple_tls_register },
 #endif