diff --git a/pjsip/src/test-pjsip/tsx_uas_test.c b/pjsip/src/test-pjsip/tsx_uas_test.c
new file mode 100644
index 0000000..fc58782
--- /dev/null
+++ b/pjsip/src/test-pjsip/tsx_uas_test.c
@@ -0,0 +1,705 @@
+/* $Id$ */
+/* 
+ * Copyright (C) 2003-2006 Benny Prijono <benny@prijono.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
+ */
+
+#include "test.h"
+#include <pjsip_core.h>
+#include <pjlib.h>
+
+#define THIS_FILE   "tsx_uas_test.c"
+
+
+/*****************************************************************************
+ **
+ ** UAS tests.
+ **
+ ** This file performs various tests for UAC transactions. Each test will have
+ ** a different Via branch param so that message receiver module and 
+ ** transaction user module can identify which test is being carried out.
+ **
+ ** TEST1_BRANCH_ID
+ **	Test that non-INVITE transaction returns 2xx response to the correct
+ **	transport and correctly terminates the transaction.
+ **
+ ** TEST2_BRANCH_ID
+ **	As above, for non-2xx final response.
+ **
+ ** TEST3_BRANCH_ID
+ **	Transaction correctly progressing to PROCEEDING state when provisional
+ **	response is sent.
+ **
+ ** TEST4_BRANCH_ID
+ **	Transaction retransmits last response (if any) without notifying 
+ **	transaction user upon receiving request  retransmissions on:
+ **	    a. TRYING state.
+ **	    a. PROCEEDING state.
+ **	    b. COMPLETED state.
+ **
+ ** TEST5_BRANCH_ID
+ **	INVITE transaction MUST retransmit final response. (Note: PJSIP also
+ **	retransmit 2xx final response until it's terminated by user).
+ **
+ ** TEST6_BRANCH_ID
+ **	INVITE transaction MUST cease retransmission of final response when
+ *	ACK is received. (Note: PJSIP also retransmit 2xx final response 
+ *	until it's terminated by user).
+ **
+ ** TEST7_BRANCH_ID
+ **	Test where INVITE UAS transaction never receives ACK
+ **
+ ** TEST8_BRANCH_ID
+ **	When UAS failed to deliver the response with the selected transport,
+ **	it should try contacting the client with other transport or begin
+ **	RFC 3263 server resolution procedure.
+ **	This should be tested on:
+ **	    a. TRYING state (when delivering first response).
+ **	    b. PROCEEDING state (when failed to retransmit last response
+ **	       upon receiving request retransmission).
+ **	    c. COMPLETED state.
+ **
+ ** TEST9_BRANCH_ID
+ **	Variant of previous test, where transaction fails to deliver the 
+ **	response using any kind of transports. Transaction should report
+ **	transport error to its transaction user.
+ **
+ **/
+
+static char *TEST1_BRANCH_ID = PJSIP_RFC3261_BRANCH_ID "-UAS-Test1";
+static char *TEST2_BRANCH_ID = PJSIP_RFC3261_BRANCH_ID "-UAS-Test2";
+static char *TEST3_BRANCH_ID = PJSIP_RFC3261_BRANCH_ID "-UAS-Test3";
+static char *TEST4_BRANCH_ID = PJSIP_RFC3261_BRANCH_ID "-UAS-Test4";
+static char *TEST5_BRANCH_ID = PJSIP_RFC3261_BRANCH_ID "-UAS-Test5";
+static char *TEST6_BRANCH_ID = PJSIP_RFC3261_BRANCH_ID "-UAS-Test6";
+static char *TEST7_BRANCH_ID = PJSIP_RFC3261_BRANCH_ID "-UAS-Test7";
+
+#define TEST1_STATUS_CODE	200
+#define TEST2_STATUS_CODE	301
+#define TEST3_PROVISIONAL_CODE	PJSIP_SC_QUEUED
+#define TEST3_STATUS_CODE	202
+
+
+static void tsx_user_on_tsx_state(pjsip_transaction *tsx, pjsip_event *e);
+static pj_bool_t on_rx_message(pjsip_rx_data *rdata);
+
+/* UAC transaction user module. */
+static pjsip_module tsx_user = 
+{
+    NULL, NULL,				/* prev and next	*/
+    { "Tsx-UAS-User", 12},		/* Name.		*/
+    -1,					/* Id			*/
+    PJSIP_MOD_PRIORITY_APPLICATION-1,	/* Priority		*/
+    NULL,				/* User data.		*/
+    0,					/* Number of methods supported (=0). */
+    { 0 },				/* Array of methods (none) */
+    NULL,				/* load()		*/
+    NULL,				/* start()		*/
+    NULL,				/* stop()		*/
+    NULL,				/* unload()		*/
+    NULL,				/* on_rx_request()	*/
+    NULL,				/* on_rx_response()	*/
+    NULL,				/* on_tx_request()	*/
+    NULL,				/* on_tx_response()	*/
+    &tsx_user_on_tsx_state,		/* on_tsx_state()	*/
+};
+
+/* Module to send request. */
+static pjsip_module msg_sender = 
+{
+    NULL, NULL,				/* prev and next	*/
+    { "Msg-Sender", 10},		/* Name.		*/
+    -1,					/* Id			*/
+    PJSIP_MOD_PRIORITY_APPLICATION-1,	/* Priority		*/
+    NULL,				/* User data.		*/
+    0,					/* Number of methods supported (=0). */
+    { 0 },				/* Array of methods (none) */
+    NULL,				/* load()		*/
+    NULL,				/* start()		*/
+    NULL,				/* stop()		*/
+    NULL,				/* unload()		*/
+    &on_rx_message,			/* on_rx_request()	*/
+    &on_rx_message,			/* on_rx_response()	*/
+    NULL,				/* on_tx_request()	*/
+    NULL,				/* on_tx_response()	*/
+    NULL,				/* on_tsx_state()	*/
+};
+
+/* Static vars, which will be reset on each test. */
+static int recv_count;
+static pj_time_val recv_last;
+static pj_bool_t test_complete;
+
+/* Loop transport instance. */
+static pjsip_transport *loop;
+
+/* UAS transaction key. */
+static char key_buf[64];
+static pj_str_t tsx_key = { key_buf, 0 };
+
+
+/* General timer entry to be used by tests. */
+static pj_timer_entry timer;
+
+/* Timer to send response via transaction. */
+struct response
+{
+    pj_str_t	     tsx_key;
+    pjsip_tx_data   *tdata;
+};
+
+static void send_response_timer( pj_timer_heap_t *timer_heap,
+				 struct pj_timer_entry *entry)
+{
+    pjsip_transaction *tsx;
+    struct response *r = entry->user_data;
+    pj_status_t status;
+
+    tsx = pjsip_tsx_layer_find_tsx(&r->tsx_key, PJ_TRUE);
+    if (!tsx) {
+	PJ_LOG(3,(THIS_FILE,"    error: timer unable to find transaction"));
+	pjsip_tx_data_dec_ref(r->tdata);
+	return;
+    }
+
+    status = pjsip_tsx_send_msg(tsx, r->tdata);
+    if (status != PJ_SUCCESS) {
+	PJ_LOG(3,(THIS_FILE,"    error: timer unable to send response"));
+	pjsip_tx_data_dec_ref(r->tdata);
+	return;
+    }
+}
+
+/* Schedule timer to send response for the specified UAS transaction */
+static void schedule_send_response( pjsip_rx_data *rdata,
+				    const pj_str_t *tsx_key,
+				    int status_code,
+				    int msec_delay )
+{
+    pj_status_t status;
+    pjsip_tx_data *tdata;
+    struct response *r;
+    pj_time_val delay;
+
+    status = pjsip_endpt_create_response( endpt, rdata, status_code, NULL, 
+					  &tdata);
+    if (status != PJ_SUCCESS) {
+	app_perror("    error: unable to create response", status);
+	test_complete = -198;
+	return;
+    }
+
+    r = pj_pool_alloc(tdata->pool, sizeof(*r));
+    pj_strdup(tdata->pool, &r->tsx_key, tsx_key);
+    r->tdata = tdata;
+
+    delay.sec = 0;
+    delay.msec = msec_delay;
+    pj_time_val_normalize(&delay);
+
+    timer.user_data = r;
+    timer.cb = &send_response_timer;
+
+    status = pjsip_endpt_schedule_timer(endpt, &timer, &delay);
+    if (status != PJ_SUCCESS) {
+	app_perror("    error: unable to schedule timer", status);
+	test_complete = -199;
+	pjsip_tx_data_dec_ref(tdata);
+	return;
+    }
+}
+
+/*
+ * This is the handler to receive state changed notification from the
+ * transaction. It is used to verify that the transaction behaves according
+ * to the test scenario.
+ */
+static void tsx_user_on_tsx_state(pjsip_transaction *tsx, pjsip_event *e)
+{
+    if (pj_strcmp2(&tsx->branch, TEST1_BRANCH_ID)==0 ||
+	pj_strcmp2(&tsx->branch, TEST2_BRANCH_ID)==0) 
+    {
+	/*
+	 * TEST1_BRANCH_ID tests that non-INVITE transaction transmits final
+	 * response using correct transport and terminates transaction after
+	 * T4 (PJSIP_T4_TIMEOUT, 5 seconds).
+	 *
+	 * TEST2_BRANCH_ID does similar test for non-2xx final response.
+	 */
+	int status_code = (pj_strcmp2(&tsx->branch, TEST1_BRANCH_ID)==0) ?
+			  TEST1_STATUS_CODE : TEST2_STATUS_CODE;
+
+	if (tsx->state == PJSIP_TSX_STATE_TERMINATED) {
+
+	    test_complete = 1;
+
+	    /* Check that status code is status_code. */
+	    if (tsx->status_code != status_code) {
+		PJ_LOG(3,(THIS_FILE, "    error: incorrect status code"));
+		test_complete = -100;
+	    }
+	    
+	    /* Previous state must be completed. */
+	    if (e->body.tsx_state.prev_state != PJSIP_TSX_STATE_COMPLETED) {
+		PJ_LOG(3,(THIS_FILE, "    error: incorrect prev_state"));
+		test_complete = -101;
+	    }
+
+	} else if (tsx->state == PJSIP_TSX_STATE_COMPLETED) {
+
+	    /* Previous state must be TRYING. */
+	    if (e->body.tsx_state.prev_state != PJSIP_TSX_STATE_TRYING) {
+		PJ_LOG(3,(THIS_FILE, "    error: incorrect prev_state"));
+		test_complete = -102;
+	    }
+	}
+
+    }
+    else
+    if (pj_strcmp2(&tsx->branch, TEST3_BRANCH_ID)==0) {
+	/*
+	 * TEST3_BRANCH_ID tests sending provisional response.
+	 */
+	if (tsx->state == PJSIP_TSX_STATE_TERMINATED) {
+
+	    test_complete = 1;
+
+	    /* Check that status code is status_code. */
+	    if (tsx->status_code != TEST3_STATUS_CODE) {
+		PJ_LOG(3,(THIS_FILE, "    error: incorrect status code"));
+		test_complete = -110;
+	    }
+	    
+	    /* Previous state must be completed. */
+	    if (e->body.tsx_state.prev_state != PJSIP_TSX_STATE_COMPLETED) {
+		PJ_LOG(3,(THIS_FILE, "    error: incorrect prev_state"));
+		test_complete = -111;
+	    }
+
+	} else if (tsx->state == PJSIP_TSX_STATE_PROCEEDING) {
+
+	    /* Previous state must be TRYING. */
+	    if (e->body.tsx_state.prev_state != PJSIP_TSX_STATE_TRYING) {
+		PJ_LOG(3,(THIS_FILE, "    error: incorrect prev_state"));
+		test_complete = -112;
+	    }
+
+	    /* Check that status code is status_code. */
+	    if (tsx->status_code != TEST3_PROVISIONAL_CODE) {
+		PJ_LOG(3,(THIS_FILE, "    error: incorrect status code"));
+		test_complete = -113;
+	    }
+
+	    /* Check that event must be TX_MSG */
+	    if (e->body.tsx_state.type != PJSIP_EVENT_TX_MSG) {
+		PJ_LOG(3,(THIS_FILE, "    error: incorrect event"));
+		test_complete = -114;
+	    }
+
+	} else if (tsx->state == PJSIP_TSX_STATE_COMPLETED) {
+
+	    /* Previous state must be PROCEEDING. */
+	    if (e->body.tsx_state.prev_state != PJSIP_TSX_STATE_PROCEEDING) {
+		PJ_LOG(3,(THIS_FILE, "    error: incorrect prev_state"));
+		test_complete = -115;
+	    }
+
+	    /* Check that status code is status_code. */
+	    if (tsx->status_code != TEST3_STATUS_CODE) {
+		PJ_LOG(3,(THIS_FILE, "    error: incorrect status code"));
+		test_complete = -116;
+	    }
+
+	    /* Check that event must be TX_MSG */
+	    if (e->body.tsx_state.type != PJSIP_EVENT_TX_MSG) {
+		PJ_LOG(3,(THIS_FILE, "    error: incorrect event"));
+		test_complete = -117;
+	    }
+
+	}
+
+    }
+
+}
+
+/* Save transaction key to global variables. */
+static void save_key(pjsip_transaction *tsx)
+{
+    pj_str_t key;
+
+    pj_strdup(tsx->pool, &key, &tsx->transaction_key);
+    pj_strcpy(&tsx_key, &key);
+}
+
+/*
+ * Message receiver handler.
+ */
+static pj_bool_t on_rx_message(pjsip_rx_data *rdata)
+{
+    pjsip_msg *msg = rdata->msg_info.msg;
+    pj_str_t branch_param = rdata->msg_info.via->branch_param;
+    pj_status_t status;
+
+    if (pj_strcmp2(&branch_param, TEST1_BRANCH_ID) == 0 ||
+	pj_strcmp2(&branch_param, TEST2_BRANCH_ID) == 0) 
+    {
+	/*
+	 * TEST1_BRANCH_ID tests that non-INVITE transaction transmits 2xx 
+	 * final response using correct transport and terminates transaction 
+	 * after 32 seconds.
+	 *
+	 * TEST2_BRANCH_ID performs similar test for non-2xx final response.
+	 */
+	int status_code = (pj_strcmp2(&branch_param, TEST1_BRANCH_ID) == 0) ?
+			  TEST1_STATUS_CODE : TEST2_STATUS_CODE;
+
+	if (msg->type == PJSIP_REQUEST_MSG) {
+	    /* On received response, create UAS and respond with final 
+	     * response. 
+	     */
+	    pjsip_transaction *tsx;
+	    pjsip_tx_data *tdata;
+
+	    status = pjsip_tsx_create_uas(&tsx_user, rdata, &tsx);
+	    if (status != PJ_SUCCESS) {
+		app_perror("    error: unable to create transaction", status);
+		test_complete = -110;
+		return PJ_TRUE;
+	    }
+
+	    save_key(tsx);
+
+	    status = pjsip_endpt_create_response(endpt, rdata, 
+						 status_code, NULL,
+						 &tdata);
+	    if (status != PJ_SUCCESS) {
+		app_perror("    error: unable to create response", status);
+		test_complete = -111;
+		return PJ_TRUE;
+	    }
+
+	    status = pjsip_tsx_send_msg(tsx, tdata);
+	    if (status != PJ_SUCCESS) {
+		app_perror("    error: unable to send response", status);
+		test_complete = -112;
+		return PJ_TRUE;
+	    }
+
+	} else {
+	    /* Verify the response received. */
+
+	    ++recv_count;
+
+	    /* Verify status code. */
+	    if (msg->line.status.code != status_code) {
+		PJ_LOG(3,(THIS_FILE, "    error: incorrect status code"));
+		test_complete = -113;
+	    }
+
+	    /* Verify that no retransmissions is received. */
+	    if (recv_count > 1) {
+		PJ_LOG(3,(THIS_FILE, "    error: retransmission received"));
+		test_complete = -114;
+	    }
+
+	}
+	return PJ_TRUE;
+
+    } else if (pj_strcmp2(&branch_param, TEST3_BRANCH_ID) == 0) {
+
+	/* TEST3_BRANCH_ID tests provisional response. */
+
+	if (msg->type == PJSIP_REQUEST_MSG) {
+	    /* On received response, create UAS and respond with provisional
+	     * response, then schedule timer to send final response.
+	     */
+	    pjsip_transaction *tsx;
+	    pjsip_tx_data *tdata;
+
+	    status = pjsip_tsx_create_uas(&tsx_user, rdata, &tsx);
+	    if (status != PJ_SUCCESS) {
+		app_perror("    error: unable to create transaction", status);
+		test_complete = -120;
+		return PJ_TRUE;
+	    }
+
+	    save_key(tsx);
+
+	    status = pjsip_endpt_create_response(endpt, rdata, 
+						 TEST3_PROVISIONAL_CODE, NULL,
+						 &tdata);
+	    if (status != PJ_SUCCESS) {
+		app_perror("    error: unable to create response", status);
+		test_complete = -121;
+		return PJ_TRUE;
+	    }
+
+	    status = pjsip_tsx_send_msg(tsx, tdata);
+	    if (status != PJ_SUCCESS) {
+		app_perror("    error: unable to send response", status);
+		test_complete = -122;
+		return PJ_TRUE;
+	    }
+
+	    schedule_send_response(rdata, &tsx->transaction_key, 
+				   TEST3_STATUS_CODE, 2000);
+
+	} else {
+	    /* Verify the response received. */
+
+	    ++recv_count;
+
+	    if (recv_count == 1) {
+		/* Verify status code. */
+		if (msg->line.status.code != TEST3_PROVISIONAL_CODE) {
+		    PJ_LOG(3,(THIS_FILE, "    error: incorrect status code"));
+		    test_complete = -123;
+		}
+	    } else if (recv_count == 2) {
+		/* Verify status code. */
+		if (msg->line.status.code != TEST3_STATUS_CODE) {
+		    PJ_LOG(3,(THIS_FILE, "    error: incorrect status code"));
+		    test_complete = -124;
+		}
+	    } else {
+		PJ_LOG(3,(THIS_FILE, "    error: retransmission received"));
+		test_complete = -125;
+	    }
+
+	}
+	return PJ_TRUE;
+
+    }
+
+    return PJ_FALSE;
+}
+
+/* 
+ * The generic test framework, used by most of the tests. 
+ */
+static int perform_test( char *target_uri, char *from_uri, 
+			 char *branch_param, int test_time, 
+			 const pjsip_method *method )
+{
+    pjsip_tx_data *tdata;
+    pj_str_t target, from;
+    pjsip_via_hdr *via;
+    pj_time_val timeout;
+    pj_status_t status;
+
+    PJ_LOG(3,(THIS_FILE, 
+	      "   please standby, this will take at most %d seconds..",
+	      test_time));
+
+    /* Reset test. */
+    recv_count = 0;
+    test_complete = 0;
+    tsx_key.slen = 0;
+
+    /* Init headers. */
+    target = pj_str(target_uri);
+    from = pj_str(from_uri);
+
+    /* Create request. */
+    status = pjsip_endpt_create_request( endpt, method, &target,
+					 &from, &target, NULL, NULL, -1, 
+					 NULL, &tdata);
+    if (status != PJ_SUCCESS) {
+	app_perror("   Error: unable to create request", status);
+	return -10;
+    }
+
+    /* Set the branch param for test 1. */
+    via = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_VIA, NULL);
+    via->branch_param = pj_str(branch_param);
+
+    /* Add additional reference to tdata to prevent transaction from
+     * deleting it.
+     */
+    pjsip_tx_data_add_ref(tdata);
+
+    /* Send the first message. */
+    status = pjsip_endpt_send_request_stateless(endpt, tdata, NULL, NULL);
+    if (status != PJ_SUCCESS) {
+	app_perror("   Error: unable to send request", status);
+	return -20;
+    }
+
+    /* Set test completion time. */
+    pj_gettimeofday(&timeout);
+    timeout.sec += test_time;
+
+    /* Wait until test complete. */
+    while (!test_complete) {
+	pj_time_val now, poll_delay = {0, 10};
+
+	pjsip_endpt_handle_events(endpt, &poll_delay);
+
+	pj_gettimeofday(&now);
+	if (now.sec > timeout.sec) {
+	    PJ_LOG(3,(THIS_FILE, "   Error: test has timed out"));
+	    pjsip_tx_data_dec_ref(tdata);
+	    return -30;
+	}
+    }
+
+    if (test_complete < 0) {
+	pjsip_transaction *tsx;
+
+	tsx = pjsip_tsx_layer_find_tsx(&tsx_key, PJ_TRUE);
+	if (tsx) {
+	    pjsip_tsx_terminate(tsx, PJSIP_SC_REQUEST_TERMINATED);
+	    pj_mutex_unlock(tsx->mutex);
+	    flush_events(1000);
+	}
+	pjsip_tx_data_dec_ref(tdata);
+	return test_complete;
+    }
+
+    /* Allow transaction to destroy itself */
+    flush_events(500);
+
+    /* Make sure transaction has been destroyed. */
+    if (pjsip_tsx_layer_find_tsx(&tsx_key, PJ_FALSE) != NULL) {
+	PJ_LOG(3,(THIS_FILE, "   Error: transaction has not been destroyed"));
+	pjsip_tx_data_dec_ref(tdata);
+	return -40;
+    }
+
+    /* Check tdata reference counter. */
+    if (pj_atomic_get(tdata->ref_cnt) != 1) {
+	PJ_LOG(3,(THIS_FILE, "   Error: tdata reference counter is %d",
+		      pj_atomic_get(tdata->ref_cnt)));
+	pjsip_tx_data_dec_ref(tdata);
+	return -50;
+    }
+
+    /* Destroy txdata */
+    pjsip_tx_data_dec_ref(tdata);
+
+    return PJ_SUCCESS;
+
+}
+
+
+/*****************************************************************************
+ **
+ ** TEST1_BRANCH_ID: Basic 2xx final response
+ ** TEST2_BRANCH_ID: Basic non-2xx final response
+ **
+ *****************************************************************************
+ */
+static int tsx_basic_final_response_test(void)
+{
+    int status;
+
+    PJ_LOG(3,(THIS_FILE,"  test1: basic sending 2xx final response"));
+
+    status = perform_test("sip:129.0.0.1;transport=loop-dgram",
+		          "sip:129.0.0.1;transport=loop-dgram",
+			  TEST1_BRANCH_ID,
+			  33, /* Test duration must be greater than 32 secs */
+			  &pjsip_options_method);
+    if (status != 0)
+	return status;
+
+    PJ_LOG(3,(THIS_FILE,"  test2: basic sending non-2xx final response"));
+
+    status = perform_test("sip:129.0.0.1;transport=loop-dgram",
+		          "sip:129.0.0.1;transport=loop-dgram",
+			  TEST2_BRANCH_ID,
+			  33, /* Test duration must be greater than 32 secs */
+			  &pjsip_options_method);
+    if (status != 0)
+	return status;
+
+    return 0;
+}
+
+
+/*****************************************************************************
+ **
+ ** TEST3_BRANCH_ID: Sending provisional response
+ **
+ *****************************************************************************
+ */
+static int tsx_basic_provisional_response_test(void)
+{
+    int status;
+
+    PJ_LOG(3,(THIS_FILE,"  test1: basic sending 2xx final response"));
+
+    status = perform_test("sip:129.0.0.1;transport=loop-dgram",
+		          "sip:129.0.0.1;transport=loop-dgram",
+			  TEST3_BRANCH_ID,
+			  35,
+			  &pjsip_options_method);
+    return status;
+}
+
+
+/*****************************************************************************
+ **
+ ** UAS Transaction Test.
+ **
+ *****************************************************************************
+ */
+int tsx_uas_test(void)
+{
+    pj_sockaddr_in addr;
+    pj_status_t status;
+
+    /* Check if loop transport is configured. */
+    status = pjsip_endpt_acquire_transport(endpt, PJSIP_TRANSPORT_LOOP_DGRAM, 
+				      &addr, sizeof(addr), &loop);
+    if (status != PJ_SUCCESS) {
+	PJ_LOG(3,(THIS_FILE, "  Error: loop transport is not configured!"));
+	return -1;
+    }
+
+    /* Register modules. */
+    status = pjsip_endpt_register_module(endpt, &tsx_user);
+    if (status != PJ_SUCCESS) {
+	app_perror("   Error: unable to register module", status);
+	return -3;
+    }
+    status = pjsip_endpt_register_module(endpt, &msg_sender);
+    if (status != PJ_SUCCESS) {
+	app_perror("   Error: unable to register module", status);
+	return -4;
+    }
+
+#if 0
+    /* TEST1_BRANCH_ID: Basic 2xx final response. 
+     * TEST2_BRANCH_ID: Basic non-2xx final response. 
+     */
+    status = tsx_basic_final_response_test();
+    if (status != 0)
+	return status;
+#endif
+
+    /* TEST3_BRANCH_ID: with provisional response
+     */
+    status = tsx_basic_provisional_response_test();
+    if (status != 0)
+	return status;
+
+
+    pjsip_transport_dec_ref(loop);
+    return 0;
+
+}
+