diff --git a/pjsip/src/pjsip/sip_endpoint.c b/pjsip/src/pjsip/sip_endpoint.c
index d299cff..ea20341 100644
--- a/pjsip/src/pjsip/sip_endpoint.c
+++ b/pjsip/src/pjsip/sip_endpoint.c
@@ -35,7 +35,7 @@
 #include <pj/lock.h>
 
 #define PJSIP_EX_NO_MEMORY  PJ_NO_MEMORY_EXCEPTION
-#define THIS_FILE	    "endpoint"
+#define THIS_FILE	    "sip_endpoint.c"
 
 #define MAX_METHODS   32
 
@@ -98,8 +98,10 @@
 /*
  * Prototypes.
  */
-static void endpt_transport_callback(pjsip_endpoint*, 
-				     pj_status_t, pjsip_rx_data*);
+static void endpt_on_rx_msg( pjsip_endpoint*, 
+			     pj_status_t, pjsip_rx_data*);
+static pj_status_t endpt_on_tx_msg( pjsip_endpoint *endpt,
+				    pjsip_tx_data *tdata );
 
 /* Defined in sip_parser.c */
 void init_sip_parser(void);
@@ -229,6 +231,9 @@
     /* Remove module from list. */
     pj_list_erase(mod);
 
+    /* Set module Id to -1. */
+    mod->id = -1;
+
     /* Done. */
     status = PJ_SUCCESS;
 
@@ -312,7 +317,7 @@
     pjsip_max_forwards_hdr *mf_hdr;
     pj_lock_t *lock = NULL;
 
-    PJ_LOG(5, (THIS_FILE, "pjsip_endpt_create()"));
+    PJ_LOG(5, (THIS_FILE, "Creating endpoint instance..."));
 
     *p_endpt = NULL;
 
@@ -382,7 +387,8 @@
 
     /* Create transport manager. */
     status = pjsip_tpmgr_create( endpt->pool, endpt,
-			         &endpt_transport_callback,
+			         &endpt_on_rx_msg,
+				 &endpt_on_tx_msg,
 				 &endpt->transport_mgr);
     if (status != PJ_SUCCESS) {
 	goto on_error;
@@ -391,7 +397,7 @@
     /* Create asynchronous DNS resolver. */
     endpt->resolver = pjsip_resolver_create(endpt->pool);
     if (!endpt->resolver) {
-	PJ_LOG(4, (THIS_FILE, "pjsip_endpt_init(): error creating resolver"));
+	PJ_LOG(4, (THIS_FILE, "Error creating resolver instance"));
 	goto on_error;
     }
 
@@ -425,7 +431,7 @@
     }
     pj_pool_release( endpt->pool );
 
-    PJ_LOG(4, (THIS_FILE, "pjsip_endpt_init() failed"));
+    PJ_LOG(4, (THIS_FILE, "Error creating endpoint"));
     return status;
 }
 
@@ -434,7 +440,14 @@
  */
 PJ_DEF(void) pjsip_endpt_destroy(pjsip_endpoint *endpt)
 {
-    PJ_LOG(5, (THIS_FILE, "pjsip_endpt_destroy()"));
+    pjsip_module *mod;
+
+    PJ_LOG(5, (THIS_FILE, "Destroying endpoing instance.."));
+
+    /* Unregister modules. */
+    while ((mod=endpt->module_list.prev) != &endpt->module_list) {
+	pjsip_endpt_unregister_module(endpt, mod);
+    }
 
     /* Shutdown and destroy all transports. */
     pjsip_tpmgr_destroy(endpt->transport_mgr);
@@ -444,6 +457,8 @@
 
     /* Finally destroy pool. */
     pj_pool_release(endpt->pool);
+
+    PJ_LOG(4, (THIS_FILE, "Endpoint %p destroyed", endpt));
 }
 
 /*
@@ -465,8 +480,6 @@
 {
     pj_pool_t *pool;
 
-    PJ_LOG(5, (THIS_FILE, "pjsip_endpt_create_pool()"));
-
     /* Lock endpoint mutex. */
     pj_mutex_lock(endpt->mutex);
 
@@ -477,9 +490,7 @@
     /* Unlock mutex. */
     pj_mutex_unlock(endpt->mutex);
 
-    if (pool) {
-	PJ_LOG(5, (THIS_FILE, "   pool %s created", pj_pool_getobjname(pool)));
-    } else {
+    if (!pool) {
 	PJ_LOG(4, (THIS_FILE, "Unable to create pool %s!", pool_name));
     }
 
@@ -492,7 +503,7 @@
  */
 PJ_DEF(void) pjsip_endpt_release_pool( pjsip_endpoint *endpt, pj_pool_t *pool )
 {
-    PJ_LOG(5, (THIS_FILE, "pjsip_endpt_release_pool(%s)", pj_pool_getobjname(pool)));
+    PJ_LOG(6, (THIS_FILE, "Releasing pool %s", pj_pool_getobjname(pool)));
 
     pj_mutex_lock(endpt->mutex);
     pj_pool_release( pool );
@@ -508,7 +519,7 @@
     /* timeout is 'out' var. This just to make compiler happy. */
     pj_time_val timeout = { 0, 0};
 
-    PJ_LOG(5, (THIS_FILE, "pjsip_endpt_handle_events()"));
+    PJ_LOG(6, (THIS_FILE, "pjsip_endpt_handle_events()"));
 
     /* Poll the timer. The timer heap has its own mutex for better 
      * granularity, so we don't need to lock end endpoint. 
@@ -534,7 +545,7 @@
 						pj_timer_entry *entry,
 						const pj_time_val *delay )
 {
-    PJ_LOG(5, (THIS_FILE, "pjsip_endpt_schedule_timer(entry=%p, delay=%u.%u)",
+    PJ_LOG(6, (THIS_FILE, "pjsip_endpt_schedule_timer(entry=%p, delay=%u.%u)",
 			 entry, delay->sec, delay->msec));
     return pj_timer_heap_schedule( endpt->timer_heap, entry, delay );
 }
@@ -545,7 +556,7 @@
 PJ_DEF(void) pjsip_endpt_cancel_timer( pjsip_endpoint *endpt, 
 				       pj_timer_entry *entry )
 {
-    PJ_LOG(5, (THIS_FILE, "pjsip_endpt_cancel_timer(entry=%p)", entry));
+    PJ_LOG(6, (THIS_FILE, "pjsip_endpt_cancel_timer(entry=%p)", entry));
     pj_timer_heap_cancel( endpt->timer_heap, entry );
 }
 
@@ -553,14 +564,12 @@
  * This is the callback that is called by the transport manager when it 
  * receives a message from the network.
  */
-static void endpt_transport_callback( pjsip_endpoint *endpt,
+static void endpt_on_rx_msg( pjsip_endpoint *endpt,
 				      pj_status_t status,
 				      pjsip_rx_data *rdata )
 {
     pjsip_msg *msg = rdata->msg_info.msg;
 
-    PJ_LOG(5, (THIS_FILE, "endpt_transport_callback(rdata=%p)", rdata));
-
     if (status != PJ_SUCCESS) {
 	PJSIP_ENDPT_LOG_ERROR((endpt, "transport", status,
 			       "Error processing packet from %s:%d, packet:--\n"
@@ -572,6 +581,9 @@
 	return;
     }
 
+    PJ_LOG(5, (THIS_FILE, "Processing incoming message: %s", 
+	       pjsip_rx_data_get_info(rdata)));
+
     /* For response, check that the value in Via sent-by match the transport.
      * If not matched, silently drop the response.
      * Ref: RFC3261 Section 18.1.2 Receiving Response
@@ -600,17 +612,19 @@
 		rdata->tp_info.transport->local_name.port)
 		mismatch = PJ_TRUE;
 	    else {
-		PJ_LOG(4,(THIS_FILE, "Response %p from %s has mismatch port in "
+		PJ_LOG(4,(THIS_FILE, "Message %s from %s has mismatch port in "
 				     "sent-by but the rport parameter is "
 				     "correct",
-				     rdata, rdata->pkt_info.src_name));
+				     pjsip_rx_data_get_info(rdata), 
+				     rdata->pkt_info.src_name));
 	    }
 	}
 
 	if (mismatch) {
 	    PJ_TODO(ENDPT_REPORT_WHEN_DROPPING_MESSAGE);
-	    PJ_LOG(4,(THIS_FILE, "Dropping response from %s:%d because sent-by"
-				 " is mismatch", 
+	    PJ_LOG(4,(THIS_FILE, "Dropping response %s from %s:%d because "
+				 "sent-by is mismatch", 
+				 pjsip_rx_data_get_info(rdata),
 				 rdata->pkt_info.src_name, 
 				 rdata->pkt_info.src_port));
 	    return;
@@ -618,7 +632,7 @@
     }
 
 
-    /* Distribute to modules. */
+    /* Distribute to modules, starting from modules with highest priority */
     pj_rwmutex_lock_read(endpt->mod_mutex);
 
     if (msg->type == PJSIP_REQUEST_MSG) {
@@ -637,8 +651,11 @@
 	/* No module is able to handle the request. */
 	if (!handled) {
 	    PJ_TODO(ENDPT_RESPOND_UNHANDLED_REQUEST);
-	    PJ_LOG(4,(THIS_FILE, "Request from %s:%d was dropped/unhandled by"
-				 " any modules"));
+	    PJ_LOG(4,(THIS_FILE, "Message %s from %s:%d was dropped/unhandled by"
+				 " any modules",
+				 pjsip_rx_data_get_info(rdata),
+				 rdata->pkt_info.src_name,
+				 rdata->pkt_info.src_port));
 	}
 
     } else {
@@ -655,8 +672,11 @@
 	}
 
 	if (!handled) {
-	    PJ_LOG(4,(THIS_FILE, "Response from %s:%d was dropped/unhandled by"
-				 " any modules"));
+	    PJ_LOG(4,(THIS_FILE, "Message %s from %s:%d was dropped/unhandled"
+				 " by any modules",
+				 pjsip_rx_data_get_info(rdata),
+				 rdata->pkt_info.src_name,
+				 rdata->pkt_info.src_port));
 	}
     }
 
@@ -664,12 +684,50 @@
 }
 
 /*
+ * This callback is called by transport manager before message is sent.
+ * Modules may inspect the message before it's actually sent.
+ */
+static pj_status_t endpt_on_tx_msg( pjsip_endpoint *endpt,
+				    pjsip_tx_data *tdata )
+{
+    pj_status_t status = PJ_SUCCESS;
+    pjsip_module *mod;
+
+    /* Distribute to modules, starting from modules with LOWEST priority */
+    pj_rwmutex_lock_read(endpt->mod_mutex);
+
+    mod = endpt->module_list.prev;
+    if (tdata->msg->type == PJSIP_REQUEST_MSG) {
+	while (mod != &endpt->module_list) {
+	    if (mod->on_tx_request)
+		status = (*mod->on_tx_request)(tdata);
+	    if (status != PJ_SUCCESS)
+		break;
+	    mod = mod->prev;
+	}
+
+    } else {
+	while (mod != &endpt->module_list) {
+	    if (mod->on_tx_response)
+		status = (*mod->on_tx_response)(tdata);
+	    if (status != PJ_SUCCESS)
+		break;
+	    mod = mod->prev;
+	}
+    }
+
+    pj_rwmutex_unlock_read(endpt->mod_mutex);
+
+    return status;
+}
+
+
+/*
  * Create transmit data buffer.
  */
 PJ_DEF(pj_status_t) pjsip_endpt_create_tdata(  pjsip_endpoint *endpt,
 					       pjsip_tx_data **p_tdata)
 {
-    PJ_LOG(5, (THIS_FILE, "pjsip_endpt_create_tdata()"));
     return pjsip_tx_data_create(endpt->transport_mgr, p_tdata);
 }
 
@@ -682,7 +740,6 @@
 				  void *token,
 				  pjsip_resolver_callback *cb)
 {
-    PJ_LOG(5, (THIS_FILE, "pjsip_endpt_resolve()"));
     pjsip_resolve( endpt->resolver, pool, target, token, cb);
 }
 
@@ -711,7 +768,6 @@
 						  int addr_len,
 						  pjsip_transport **transport)
 {
-    PJ_LOG(5, (THIS_FILE, "pjsip_endpt_acquire_transport()"));
     return pjsip_tpmgr_acquire_transport(endpt->transport_mgr, type, 
 					 remote, addr_len, transport);
 }
diff --git a/pjsip/src/pjsip/sip_errno.c b/pjsip/src/pjsip/sip_errno.c
index f7d2ddd..62de365 100644
--- a/pjsip/src/pjsip/sip_errno.c
+++ b/pjsip/src/pjsip/sip_errno.c
@@ -33,6 +33,7 @@
     /* Generic SIP errors */
     { PJSIP_EBUSY,		"Object is busy" },
     { PJSIP_ETYPEEXISTS ,	"Object with the same type exists" },
+    { PJSIP_ESHUTDOWN,		"SIP stack shutting down" },
 
     /* Messaging errors */
     { PJSIP_EINVALIDMSG,	"Invalid message/syntax error" },
diff --git a/pjsip/src/pjsip/sip_msg.c b/pjsip/src/pjsip/sip_msg.c
index cee850e..024744c 100644
--- a/pjsip/src/pjsip/sip_msg.c
+++ b/pjsip/src/pjsip/sip_msg.c
@@ -117,6 +117,7 @@
     pj_strset2( &status_phrase[183], "Session Progress");
 
     pj_strset2( &status_phrase[200], "OK");
+    pj_strset2( &status_phrase[202], "Accepted");
 
     pj_strset2( &status_phrase[300], "Multiple Choices");
     pj_strset2( &status_phrase[301], "Moved Permanently");
@@ -140,6 +141,7 @@
     pj_strset2( &status_phrase[416], "Unsupported URI Scheme");
     pj_strset2( &status_phrase[420], "Bad Extension");
     pj_strset2( &status_phrase[421], "Extension Required");
+    pj_strset2( &status_phrase[422], "Session Timer Too Small");
     pj_strset2( &status_phrase[423], "Interval Too Brief");
     pj_strset2( &status_phrase[480], "Temporarily Unavailable");
     pj_strset2( &status_phrase[481], "Call/Transaction Does Not Exist");
@@ -150,6 +152,8 @@
     pj_strset2( &status_phrase[486], "Busy Here");
     pj_strset2( &status_phrase[487], "Request Terminated");
     pj_strset2( &status_phrase[488], "Not Acceptable Here");
+    pj_strset2( &status_phrase[489], "Unknown Event");
+    pj_strset2( &status_phrase[490], "Request Updated");
     pj_strset2( &status_phrase[491], "Request Pending");
     pj_strset2( &status_phrase[493], "Undecipherable");
 
@@ -160,6 +164,7 @@
     pj_strset2( &status_phrase[504], "Server Timeout");
     pj_strset2( &status_phrase[505], "Version Not Supported");
     pj_strset2( &status_phrase[513], "Message Too Large");
+    pj_strset2( &status_phrase[580], "Precondition Failure");
 
     pj_strset2( &status_phrase[600], "Busy Everywhere");
     pj_strset2( &status_phrase[603], "Decline");
diff --git a/pjsip/src/pjsip/sip_resolve.c b/pjsip/src/pjsip/sip_resolve.c
index 4be6f56..4712b7f 100644
--- a/pjsip/src/pjsip/sip_resolve.c
+++ b/pjsip/src/pjsip/sip_resolve.c
@@ -18,9 +18,13 @@
  */
 #include <pjsip/sip_resolve.h>
 #include <pjsip/sip_transport.h>
+#include <pjsip/sip_errno.h>
 #include <pj/pool.h>
 #include <pj/ctype.h>
 #include <pj/assert.h>
+#include <pj/log.h>
+
+#define THIS_FILE   "sip_resolve.c"
 
 struct pjsip_resolver_t
 {
@@ -68,6 +72,12 @@
     PJ_UNUSED_ARG(resolver);
     PJ_UNUSED_ARG(pool);
 
+    PJ_LOG(5,(THIS_FILE, "Resolving server '%.*s:%d' type=%s",
+			 target->addr.host.slen,
+			 target->addr.host.ptr,
+			 target->addr.port,
+			 pjsip_transport_get_type_name(type)));
+
     /* We only do synchronous resolving at this moment. */
     PJ_TODO(SUPPORT_RFC3263_SERVER_RESOLUTION)
 
@@ -116,10 +126,30 @@
 	status = pj_sockaddr_in_init((pj_sockaddr_in*)&svr_addr.entry[0].addr, 
 				      &target->addr.host, 
 				     (pj_uint16_t)target->addr.port);
-	pj_assert(status == PJ_SUCCESS);
+    }
+
+    if (status != PJ_SUCCESS) {
+	char errmsg[PJSIP_ERR_MSG_SIZE];
+	PJ_LOG(4,(THIS_FILE, "Failed to resolve '%.*s'. Err=%d (%s)",
+			     target->addr.host.slen,
+			     target->addr.host.ptr,
+			     status,
+			     pjsip_strerror(status,errmsg,sizeof(errmsg)).ptr));
+	(*cb)(status, token, &svr_addr);
+	return;
     }
 
     /* Call the callback. */
+    PJ_LOG(5,(THIS_FILE, "Server resolved: '%.*s:%d' type=%s has %d entries, "
+			 "entry[0]=%s:%d type=%s",
+			 target->addr.host.slen,
+			 target->addr.host.ptr,
+			 target->addr.port,
+			 pjsip_transport_get_type_name(type),
+			 1,
+			 pj_inet_ntoa(((pj_sockaddr_in*)&svr_addr.entry[0].addr)->sin_addr),
+			 target->addr.port,
+			 pjsip_transport_get_type_name(type)));
     svr_addr.count = (status == PJ_SUCCESS) ? 1 : 0;
     svr_addr.entry[0].type = type;
     svr_addr.entry[0].addr_len = sizeof(pj_sockaddr_in);
diff --git a/pjsip/src/pjsip/sip_transaction.c b/pjsip/src/pjsip/sip_transaction.c
index cd67333..885b5bb 100644
--- a/pjsip/src/pjsip/sip_transaction.c
+++ b/pjsip/src/pjsip/sip_transaction.c
@@ -30,6 +30,8 @@
 #include <pj/guid.h>
 #include <pj/log.h>
 
+#define THIS_FILE   "sip_transaction.c"
+
 /*****************************************************************************
  **
  ** Declarations and static variable definitions section.
@@ -101,6 +103,7 @@
     TSX_HAS_PENDING_RESCHED	= 2,
     TSX_HAS_PENDING_SEND	= 4,
     TSX_HAS_PENDING_DESTROY	= 8,
+    TSX_HAS_RESOLVED_SERVER	= 16,
 };
 
 /* Transaction lock. */
@@ -412,6 +415,7 @@
 
     PJ_ASSERT_RETURN(mod_tsx_layer.endpt==NULL, PJ_EINVALIDOP);
 
+    PJ_LOG(5,(THIS_FILE, "Initializing transaction layer module"));
 
     /* Initialize TLS ID for transaction lock. */
     status = pj_thread_local_alloc(&pjsip_tsx_lock_tls_id);
@@ -461,6 +465,8 @@
 	return status;
     }
 
+    PJ_LOG(4,(THIS_FILE, "Transaction layer module initialized"));
+
     return PJ_SUCCESS;
 }
 
@@ -580,15 +586,18 @@
 {
     pj_hash_iterator_t it_buf, *it;
 
+    PJ_LOG(4,(THIS_FILE, "Stopping transaction layer module"));
+
     pj_mutex_lock(mod_tsx_layer.mutex);
 
     /* Destroy all transactions. */
     it = pj_hash_first(mod_tsx_layer.htable, &it_buf);
     while (it) {
 	pjsip_transaction *tsx = pj_hash_this(mod_tsx_layer.htable, it);
+	pj_hash_iterator_t *next = pj_hash_next(mod_tsx_layer.htable, it);
 	if (tsx)
 	    tsx_destroy(tsx);
-	it = pj_hash_next(mod_tsx_layer.htable, it);
+	it = next;
     }
 
     pj_mutex_unlock(mod_tsx_layer.mutex);
@@ -610,6 +619,8 @@
     /* Mark as unregistered. */
     mod_tsx_layer.endpt = NULL;
 
+    PJ_LOG(4,(THIS_FILE, "Transaction layer module destroyed"));
+
     return PJ_SUCCESS;
 }
 
@@ -627,7 +638,9 @@
 
     /* Find transaction. */
     pj_mutex_lock( mod_tsx_layer.mutex );
+
     tsx = pj_hash_get( mod_tsx_layer.htable, key.ptr, key.slen );
+
     if (tsx == NULL || tsx->state == PJSIP_TSX_STATE_TERMINATED) {
 	/* Transaction not found.
 	 * Reject the request so that endpoint passes the request to
@@ -666,7 +679,9 @@
 
     /* Find transaction. */
     pj_mutex_lock( mod_tsx_layer.mutex );
+
     tsx = pj_hash_get( mod_tsx_layer.htable, key.ptr, key.slen );
+
     if (tsx == NULL || tsx->state == PJSIP_TSX_STATE_TERMINATED) {
 	/* Transaction not found.
 	 * Reject the request so that endpoint passes the request to
@@ -790,7 +805,53 @@
 /* Destroy transaction. */
 static void tsx_destroy( pjsip_transaction *tsx )
 {
+    struct tsx_lock_data *lck;
+
+    /* Decrement transport reference counter. */
+    if (tsx->transport) {
+	pjsip_transport_dec_ref( tsx->transport );
+	tsx->transport = NULL;
+    }
+    /* Free last transmitted message. */
+    if (tsx->last_tx) {
+	pjsip_tx_data_dec_ref( tsx->last_tx );
+	tsx->last_tx = NULL;
+    }
+    /* Cancel timeout timer. */
+    if (tsx->timeout_timer._timer_id != -1) {
+	pjsip_endpt_cancel_timer(tsx->endpt, &tsx->timeout_timer);
+	tsx->timeout_timer._timer_id = -1;
+    }
+    /* Cancel retransmission timer. */
+    if (tsx->retransmit_timer._timer_id != -1) {
+	pjsip_endpt_cancel_timer(tsx->endpt, &tsx->retransmit_timer);
+	tsx->retransmit_timer._timer_id = -1;
+    }
+
+    /* Clear some pending flags. */
+    tsx->transport_flag &= ~(TSX_HAS_PENDING_RESCHED | TSX_HAS_PENDING_SEND);
+
+    /* Refuse to destroy transaction if it has pending resolving. */
+    if (tsx->transport_flag & TSX_HAS_PENDING_TRANSPORT) {
+	tsx->transport_flag |= TSX_HAS_PENDING_DESTROY;
+	PJ_LOG(5,(tsx->obj_name, "Will destroy later because transport is "
+				 "in progress"));
+	return;
+    }
+
+    /* Clear TLS, so that mutex will not be unlocked */
+    lck = pj_thread_local_get(pjsip_tsx_lock_tls_id);
+    while (lck) {
+	if (lck->tsx == tsx) {
+	    lck->is_alive = 0;
+	}
+	lck = lck->prev;
+    }
+
     pj_mutex_destroy(tsx->mutex);
+
+    PJ_LOG(5,(tsx->obj_name, "Transaction destroyed!"));
+
     pjsip_endpt_release_pool(tsx->endpt, tsx->pool);
 }
 
@@ -806,7 +867,7 @@
 
     PJ_UNUSED_ARG(theap);
 
-    PJ_LOG(5,(tsx->obj_name, "got timer event (%s timer)", 
+    PJ_LOG(6,(tsx->obj_name, "%s timer event", 
 	     (entry->id==TSX_TIMER_RETRANSMISSION ? "Retransmit":"Timeout")));
 
 
@@ -831,7 +892,7 @@
 			   pjsip_event_id_e event_src_type,
                            void *event_src )
 {
-    PJ_LOG(4, (tsx->obj_name, "STATE %s-->%s, cause = %s",
+    PJ_LOG(5, (tsx->obj_name, "State changed from %s to %s, event=%s",
 	       state_str[tsx->state], state_str[state], 
                pjsip_event_str(event_src_type)));
 
@@ -859,31 +920,16 @@
     if (state == PJSIP_TSX_STATE_TERMINATED) {
 	pj_time_val timeout = {0, 0};
 
-	/* Decrement transport reference counter. */
-	if (tsx->transport) {
-	    pjsip_transport_dec_ref( tsx->transport );
-	    tsx->transport = NULL;
-	}
-	/* Free last transmitted message. */
-	if (tsx->last_tx) {
-	    pjsip_tx_data_dec_ref( tsx->last_tx );
-	    tsx->last_tx = NULL;
-	}
-	/* Cancel timeout timer. */
-	if (tsx->timeout_timer._timer_id != -1) {
-	    pjsip_endpt_cancel_timer(tsx->endpt, &tsx->timeout_timer);
-	    tsx->timeout_timer._timer_id = -1;
-	}
-	/* Cancel retransmission timer. */
-	if (tsx->retransmit_timer._timer_id != -1) {
-	    pjsip_endpt_cancel_timer(tsx->endpt, &tsx->retransmit_timer);
-	    tsx->retransmit_timer._timer_id = -1;
-	}
-
 	/* Reschedule timeout timer to destroy this transaction. */
 	if (tsx->transport_flag & TSX_HAS_PENDING_TRANSPORT) {
 	    tsx->transport_flag |= TSX_HAS_PENDING_DESTROY;
 	} else {
+	    /* Cancel timeout timer. */
+	    if (tsx->timeout_timer._timer_id != -1) {
+		pjsip_endpt_cancel_timer(tsx->endpt, &tsx->timeout_timer);
+		tsx->timeout_timer._timer_id = -1;
+	    }
+
 	    pjsip_endpt_schedule_timer( tsx->endpt, &tsx->timeout_timer, 
 					&timeout);
 	}
@@ -891,15 +937,6 @@
 
     } else if (state == PJSIP_TSX_STATE_DESTROYED) {
 
-	/* Clear TLS, so that mutex will not be unlocked */
-	struct tsx_lock_data *lck = pj_thread_local_get(pjsip_tsx_lock_tls_id);
-	while (lck) {
-	    if (lck->tsx == tsx) {
-		lck->is_alive = 0;
-	    }
-	    lck = lck->prev;
-	}
-
 	/* Unregister transaction. */
 	mod_tsx_layer_unregister_tsx(tsx);
 
@@ -920,6 +957,7 @@
     pjsip_msg *msg;
     pjsip_cseq_hdr *cseq;
     pjsip_via_hdr *via;
+    pjsip_host_info dst_info;
     struct tsx_lock_data lck;
     pj_status_t status;
 
@@ -998,6 +1036,15 @@
     tsx->last_tx = tdata;
     pjsip_tx_data_add_ref(tsx->last_tx);
 
+    /* Determine whether reliable transport should be used initially.
+     * This will be updated whenever transport has changed.
+     */
+    status = pjsip_get_request_addr(tdata, &dst_info);
+    if (status != PJ_SUCCESS) {
+	tsx_destroy(tsx);
+	return status;
+    }
+    tsx->is_reliable = (dst_info.flag & PJSIP_TRANSPORT_RELIABLE);
 
     /* Register transaction to hash table. */
     mod_tsx_layer_register_tsx(tsx);
@@ -1006,6 +1053,9 @@
     /* Unlock transaction and return. */
     unlock_tsx(tsx, &lck);
 
+    PJ_LOG(5,(tsx->obj_name, "Transaction created for %s",
+	      pjsip_tx_data_get_info(tdata)));
+
     *p_tsx = tsx;
     return PJ_SUCCESS;
 }
@@ -1112,6 +1162,11 @@
     /* Unlock transaction and return. */
     unlock_tsx(tsx, &lck);
 
+
+    PJ_LOG(5,(tsx->obj_name, "Transaction created for %s",
+	      pjsip_rx_data_get_info(rdata)));
+
+
     *p_tsx = tsx;
     return PJ_SUCCESS;
 }
@@ -1127,6 +1182,9 @@
     PJ_ASSERT_RETURN(tsx != NULL, PJ_EINVAL);
     PJ_ASSERT_RETURN(code >= 200, PJ_EINVAL);
 
+    if (tsx->state == PJSIP_TSX_STATE_TERMINATED)
+	return PJ_SUCCESS;
+
     lock_tsx(tsx, &lck);
     tsx->status_code = code;
     tsx_set_state( tsx, PJSIP_TSX_STATE_TERMINATED, PJSIP_EVENT_USER, NULL);
@@ -1151,8 +1209,9 @@
 
     PJ_ASSERT_RETURN(tdata != NULL, PJ_EINVALIDOP);
 
-    PJ_LOG(5,(tsx->obj_name, "Request to transmit msg on state %s (tdata=%p)",
-                             state_str[tsx->state], tdata));
+    PJ_LOG(5,(tsx->obj_name, "Sending %s in state %s",
+                             pjsip_tx_data_get_info(tdata),
+			     state_str[tsx->state]));
 
     PJSIP_EVENT_INIT_TX_MSG(event, tsx, tdata);
 
@@ -1161,6 +1220,11 @@
     status = (*tsx->state_handler)(tsx, &event);
     unlock_tsx(tsx, &lck);
 
+    /* Will always decrement tdata reference counter
+     * (consistent with other send functions.
+     */
+    pjsip_tx_data_dec_ref(tdata);
+
     return status;
 }
 
@@ -1175,8 +1239,8 @@
     struct tsx_lock_data lck;
     pj_status_t status;
 
-    PJ_LOG(5,(tsx->obj_name, "Incoming msg on state %s (rdata=%p)", 
-	      state_str[tsx->state], rdata));
+    PJ_LOG(5,(tsx->obj_name, "Incoming %s in state %s", 
+	      pjsip_rx_data_get_info(rdata), state_str[tsx->state]));
 
     /* Put the transaction in the rdata's mod_data. */
     rdata->endpt_info.mod_data[mod_tsx_layer.mod.id] = tsx;
@@ -1205,17 +1269,30 @@
 	pj_assert(send_state->cur_transport != NULL);
 
 	if (tsx->transport != send_state->cur_transport) {
+	    /* Update transport. */
 	    if (tsx->transport) {
 		pjsip_transport_dec_ref(tsx->transport);
 		tsx->transport = NULL;
 	    }
 	    tsx->transport = send_state->cur_transport;
 	    pjsip_transport_add_ref(tsx->transport);
+
+	    /* Update remote address. */
+	    tsx->addr_len = send_state->addr.entry[send_state->cur_addr].addr_len;
+	    pj_memcpy(&tsx->addr, 
+		      &send_state->addr.entry[send_state->cur_addr].addr,
+		      tsx->addr_len);
+
+	    /* Update is_reliable flag. */
+	    tsx->is_reliable = PJSIP_TRANSPORT_IS_RELIABLE(tsx->transport);
 	}
 
 	/* Clear pending transport flag. */
 	tsx->transport_flag &= ~(TSX_HAS_PENDING_TRANSPORT);
 
+	/* Mark that we have resolved the addresses. */
+	tsx->transport_flag |= TSX_HAS_RESOLVED_SERVER;
+
 	/* Pending destroy? */
 	if (tsx->transport_flag & TSX_HAS_PENDING_DESTROY) {
 	    tsx_set_state( tsx, PJSIP_TSX_STATE_DESTROYED, 
@@ -1233,7 +1310,11 @@
 	/* Need to reschedule retransmission? */
 	if (tsx->transport_flag & TSX_HAS_PENDING_RESCHED) {
 	    tsx->transport_flag &= ~(TSX_HAS_PENDING_RESCHED);
-	    tsx_resched_retransmission(tsx);
+
+	    /* Only update when transport turns out to be unreliable. */
+	    if (!tsx->is_reliable) {
+		tsx_resched_retransmission(tsx);
+	    }
 	}
 
     } else {
@@ -1251,16 +1332,36 @@
 	}
 
 	if (!*cont) {
-	    PJ_LOG(4,(tsx->obj_name, "Failed to send message! status=%d",
-		      -sent));
+	    char errmsg[PJSIP_ERR_MSG_SIZE];
+
+	    PJ_LOG(4,(tsx->obj_name, 
+		      "Failed to send %s! err=%d (%s)",
+		      pjsip_tx_data_get_info(send_state->tdata), -sent,
+		      pjsip_strerror(-sent, errmsg, sizeof(errmsg)).ptr));
 
 	    /* Clear pending transport flag. */
 	    tsx->transport_flag &= ~(TSX_HAS_PENDING_TRANSPORT);
 
-	    /* Terminate transaction. */
+	    /* Mark that we have resolved the addresses. */
+	    tsx->transport_flag |= TSX_HAS_RESOLVED_SERVER;
+
+	    /* Terminate transaction, if it's not already terminated. */
 	    tsx->status_code = PJSIP_SC_TSX_TRANSPORT_ERROR;
-	    tsx_set_state( tsx, PJSIP_TSX_STATE_TERMINATED, 
-			   PJSIP_EVENT_TRANSPORT_ERROR, send_state->tdata );
+	    if (tsx->state != PJSIP_TSX_STATE_TERMINATED &&
+		tsx->state != PJSIP_TSX_STATE_DESTROYED)
+	    {
+		tsx_set_state( tsx, PJSIP_TSX_STATE_TERMINATED, 
+			       PJSIP_EVENT_TRANSPORT_ERROR, send_state->tdata);
+	    }
+
+	} else {
+	    char errmsg[PJSIP_ERR_MSG_SIZE];
+
+	    PJ_LOG(4,(tsx->obj_name, 
+		      "Temporary failure in sending %s, "
+		      "will try next server. Err=%d (%s)",
+		      pjsip_tx_data_get_info(send_state->tdata), -sent,
+		      pjsip_strerror(-sent, errmsg, sizeof(errmsg)).ptr));
 	}
     }
 
@@ -1275,9 +1376,11 @@
     if (sent < 0) {
 	pjsip_transaction *tsx = token;
 	struct tsx_lock_data lck;
+	char errmsg[PJSIP_ERR_MSG_SIZE];
 
-	PJ_LOG(4,(tsx->obj_name, "Failed to send message! status=%d",
-		  -sent));
+	PJ_LOG(4,(tsx->obj_name, "Transport failed to send %s! Err=%d (%s)",
+		  pjsip_tx_data_get_info(tdata), -sent,
+		  pjsip_strerror(-sent, errmsg, sizeof(errmsg)).ptr));
 
 	lock_tsx(tsx, &lck);
 
@@ -1300,7 +1403,7 @@
 static pj_status_t tsx_send_msg( pjsip_transaction *tsx, 
                                  pjsip_tx_data *tdata)
 {
-    pj_status_t status = PJ_EBUG;
+    pj_status_t status = PJ_SUCCESS;
 
     PJ_ASSERT_RETURN(tsx && tdata, PJ_EINVAL);
 
@@ -1310,70 +1413,112 @@
 	return PJ_SUCCESS;
     }
 
-    if (tdata->msg->type == PJSIP_REQUEST_MSG) {
-	/* If we have the transport, send the message using that transport.
-	 * Otherwise perform full transport resolution.
-	 */
-	if (tsx->transport) {
-	    status = pjsip_transport_send( tsx->transport, tdata, &tsx->addr,
-					   tsx->addr_len, tsx, 
-					   &transport_callback);
-	    if (status == PJ_EPENDING)
-		status = PJ_SUCCESS;
+    /* If we have the transport, send the message using that transport.
+     * Otherwise perform full transport resolution.
+     */
+    if (tsx->transport) {
+	status = pjsip_transport_send( tsx->transport, tdata, &tsx->addr,
+				       tsx->addr_len, tsx, 
+				       &transport_callback);
+	if (status == PJ_EPENDING)
+	    status = PJ_SUCCESS;
 
-	    if (status != PJ_SUCCESS) {
-		/* On error, release transport to force using full transport
-		 * resolution procedure.
-		 */
-		if (tsx->transport) {
-		    pjsip_transport_dec_ref(tsx->transport);
-		    tsx->transport = NULL;
-		}
-		tsx->addr_len = 0;
+	if (status != PJ_SUCCESS) {
+	    char errmsg[PJSIP_ERR_MSG_SIZE];
+
+	    PJ_LOG(4,(tsx->obj_name, 
+		      "Error sending %s: Err=%d (%s)",
+		      pjsip_tx_data_get_info(tdata), status, 
+		      pjsip_strerror(status, errmsg, sizeof(errmsg)).ptr));
+
+	    /* On error, release transport to force using full transport
+	     * resolution procedure.
+	     */
+	    if (tsx->transport) {
+		pjsip_transport_dec_ref(tsx->transport);
+		tsx->transport = NULL;
 	    }
-	}
-	
-	if (!tsx->transport) {
-	    tsx->transport_flag |= TSX_HAS_PENDING_TRANSPORT;
-	    status = pjsip_endpt_send_request_stateless(tsx->endpt, tdata, tsx,
-							&send_msg_callback);
-	    if (status == PJ_EPENDING)
-		status = PJ_SUCCESS;
-	}
-
-    } else {
-	/* If we have the transport, send the message using that transport.
-	 * Otherwise perform full transport resolution.
-	 */
-	if (tsx->transport) {
-	    status = pjsip_transport_send( tsx->transport, tdata, 
-					   &tsx->addr, tsx->addr_len,
-					   tsx, &transport_callback);
-	    if (status == PJ_EPENDING)
-		status = PJ_SUCCESS;
-
-	    if (status != PJ_SUCCESS) {
-		if (tsx->transport) {
-		    pjsip_transport_dec_ref(tsx->transport);
-		    tsx->transport = NULL;
-		}
-		tsx->addr_len = 0;
-		tsx->res_addr.transport = NULL;
-		tsx->res_addr.addr_len = 0;
-	    }
-
-	} 
-
-	if (!tsx->transport) {
-	    tsx->transport_flag |= TSX_HAS_PENDING_TRANSPORT;
-	    status = pjsip_endpt_send_response( tsx->endpt, &tsx->res_addr, 
-						tdata, tsx, 
-						&send_msg_callback);
-	    if (status == PJ_EPENDING)
-		status = PJ_SUCCESS;
+	    tsx->addr_len = 0;
+	    tsx->res_addr.transport = NULL;
+	    tsx->res_addr.addr_len = 0;
+	} else {
+	    return PJ_SUCCESS;
 	}
     }
 
+    /* We are here because we don't have transport, or we failed to send
+     * the message using existing transport. If we haven't resolved the
+     * server before, then begin the long process of resolving the server
+     * and send the message with possibly new server.
+     */
+    pj_assert(status != PJ_SUCCESS || tsx->transport == NULL);
+
+    /* If we have resolved the server, we treat the error as permanent error.
+     * Terminate transaction with transport error failure.
+     */
+    if (tsx->transport_flag & TSX_HAS_RESOLVED_SERVER) {
+	
+	char errmsg[PJSIP_ERR_MSG_SIZE];
+
+	if (status == PJ_SUCCESS) {
+	    pj_assert(!"Unexpected status!");
+	    status = PJ_EUNKNOWN;
+	}
+
+	/* We have resolved the server!.
+	 * Treat this as permanent transport error.
+	 */
+	PJ_LOG(4,(tsx->obj_name, 
+		  "Transport error, terminating transaction. "
+		  "Err=%d (%s)",
+		  status, 
+		  pjsip_strerror(status, errmsg, sizeof(errmsg)).ptr));
+
+	tsx->status_code = PJSIP_SC_TSX_TRANSPORT_ERROR;
+	tsx_set_state( tsx, PJSIP_TSX_STATE_TERMINATED, 
+		       PJSIP_EVENT_TRANSPORT_ERROR, NULL );
+
+	return status;
+    }
+
+    /* Must add reference counter because the send request functions
+     * decrement the reference counter.
+     */
+    pjsip_tx_data_add_ref(tdata);
+
+    /* Begin resolving destination etc to send the message. */
+    if (tdata->msg->type == PJSIP_REQUEST_MSG) {
+
+	tsx->transport_flag |= TSX_HAS_PENDING_TRANSPORT;
+	status = pjsip_endpt_send_request_stateless(tsx->endpt, tdata, tsx,
+						    &send_msg_callback);
+	if (status == PJ_EPENDING)
+	    status = PJ_SUCCESS;
+	if (status != PJ_SUCCESS)
+	    pjsip_tx_data_dec_ref(tdata);
+	
+	/* Check if transaction is terminated. */
+	if (status==PJ_SUCCESS && tsx->state == PJSIP_TSX_STATE_TERMINATED)
+	    status = PJSIP_ETSXDESTROYED;
+
+    } else {
+
+	tsx->transport_flag |= TSX_HAS_PENDING_TRANSPORT;
+	status = pjsip_endpt_send_response( tsx->endpt, &tsx->res_addr, 
+					    tdata, tsx, 
+					    &send_msg_callback);
+	if (status == PJ_EPENDING)
+	    status = PJ_SUCCESS;
+	if (status != PJ_SUCCESS)
+	    pjsip_tx_data_dec_ref(tdata);
+
+	/* Check if transaction is terminated. */
+	if (status==PJ_SUCCESS && tsx->state == PJSIP_TSX_STATE_TERMINATED)
+	    status = PJSIP_ETSXDESTROYED;
+
+    }
+
+
     return status;
 }
 
@@ -1408,8 +1553,9 @@
 
     PJ_ASSERT_RETURN(tsx->last_tx!=NULL, PJ_EBUG);
 
-    PJ_LOG(4,(tsx->obj_name, "retransmiting (tdata=%p, count=%d, restart?=%d)", 
-	      tsx->last_tx, tsx->retransmit_count, resched));
+    PJ_LOG(5,(tsx->obj_name, "Retransmiting %s, count=%d, restart?=%d", 
+	      pjsip_tx_data_get_info(tsx->last_tx), 
+	      tsx->retransmit_count, resched));
 
     ++tsx->retransmit_count;
 
@@ -1451,7 +1597,11 @@
     } else {
 	pjsip_tx_data *tdata;
 
-	/* Must be transmit event. */
+	/* Must be transmit event. 
+	 * You may got this assertion when using loop transport with delay 
+	 * set to zero. That would cause on_rx_response() callback to be 
+	 * called before tsx_send_msg() has completed.
+	 */
 	PJ_ASSERT_RETURN(event->type == PJSIP_EVENT_TX_MSG, PJ_EBUG);
 
 	/* Get the txdata */
@@ -1482,7 +1632,7 @@
 	/* Start Timer A (or timer E) for retransmission only if unreliable 
 	 * transport is being used.
 	 */
-	if (!PJSIP_TRANSPORT_IS_RELIABLE(tsx->transport))  {
+	if (!tsx->is_reliable)  {
 	    tsx->retransmit_count = 0;
 	    if (tsx->transport_flag & TSX_HAS_PENDING_TRANSPORT) {
 		tsx->transport_flag |= TSX_HAS_PENDING_RESCHED;
@@ -1527,9 +1677,11 @@
     {
 
 	/* Cancel retransmission timer. */
-	if (PJSIP_TRANSPORT_IS_RELIABLE(tsx->transport)==0) {
+	if (tsx->retransmit_timer._timer_id != -1) {
 	    pjsip_endpt_cancel_timer(tsx->endpt, &tsx->retransmit_timer);
+	    tsx->retransmit_timer._timer_id = -1;
 	}
+	tsx->transport_flag &= ~(TSX_HAS_PENDING_RESCHED);
 
 	/* Set status code */
 	tsx->status_code = PJSIP_SC_TSX_TIMEOUT;
@@ -1553,8 +1705,12 @@
 	    return PJSIP_ENOTRESPONSEMSG;
 
 	/* Cancel retransmission timer A. */
-	if (PJSIP_TRANSPORT_IS_RELIABLE(tsx->transport)==0)
+	if (tsx->retransmit_timer._timer_id != -1) {
 	    pjsip_endpt_cancel_timer(tsx->endpt, &tsx->retransmit_timer);
+	    tsx->retransmit_timer._timer_id = -1;
+	}
+	tsx->transport_flag &= ~(TSX_HAS_PENDING_RESCHED);
+
 
 	/* Cancel timer B (transaction timeout) */
 	pjsip_endpt_cancel_timer(tsx->endpt, &tsx->timeout_timer);
@@ -1738,7 +1894,7 @@
 		/* Start timer J at 64*T1 for unreliable transport or zero for
 		 * reliable transport.
 		 */
-		if (!PJSIP_TRANSPORT_IS_RELIABLE(tsx->transport)) {
+		if (!tsx->is_reliable) {
 		    timeout = timeout_timer_val;
 		} else {
 		    timeout.sec = timeout.msec = 0;
@@ -1769,7 +1925,7 @@
 	    /* For INVITE, if unreliable transport is used, retransmission 
 	     * timer G will be scheduled (retransmission).
 	     */
-	    if (!PJSIP_TRANSPORT_IS_RELIABLE(tsx->transport)) {
+	    if (!tsx->is_reliable) {
 		pjsip_cseq_hdr *cseq = pjsip_msg_find_hdr( msg, PJSIP_H_CSEQ,
                                                            NULL);
 		if (cseq->method.id == PJSIP_INVITE_METHOD) {
@@ -1893,7 +2049,7 @@
 
 	    /* For unreliable transport, start timer D (for INVITE) or 
 	     * timer K for non-INVITE. */
-	    if (PJSIP_TRANSPORT_IS_RELIABLE(tsx->transport) == 0) {
+	    if (!tsx->is_reliable) {
 		if (tsx->method.id == PJSIP_INVITE_METHOD) {
 		    timeout = td_timer_val;
 		} else {
@@ -1939,7 +2095,7 @@
 	}
 
 	/* Start Timer D with TD/T4 timer if unreliable transport is used. */
-	if (!PJSIP_TRANSPORT_IS_RELIABLE(tsx->transport)) {
+	if (!tsx->is_reliable) {
 	    if (tsx->method.id == PJSIP_INVITE_METHOD) {
 		timeout = td_timer_val;
 	    } else {
@@ -1992,7 +2148,11 @@
 	    /* Process incoming ACK request. */
 
 	    /* Cease retransmission. */
-	    pjsip_endpt_cancel_timer( tsx->endpt, &tsx->retransmit_timer );
+	    if (tsx->retransmit_timer._timer_id != -1) {
+		pjsip_endpt_cancel_timer(tsx->endpt, &tsx->retransmit_timer);
+		tsx->retransmit_timer._timer_id = -1;
+	    }
+	    tsx->transport_flag &= ~(TSX_HAS_PENDING_RESCHED);
 
 	    /* Start timer I in T4 interval (transaction termination). */
 	    pjsip_endpt_cancel_timer( tsx->endpt, &tsx->timeout_timer );
diff --git a/pjsip/src/pjsip/sip_transport.c b/pjsip/src/pjsip/sip_transport.c
index 4823feb..742cf9e 100644
--- a/pjsip/src/pjsip/sip_transport.c
+++ b/pjsip/src/pjsip/sip_transport.c
@@ -22,6 +22,7 @@
 #include <pjsip/sip_msg.h>
 #include <pjsip/sip_private.h>
 #include <pjsip/sip_errno.h>
+#include <pjsip/sip_module.h>
 #include <pj/os.h>
 #include <pj/log.h>
 #include <pj/ioqueue.h>
@@ -32,7 +33,33 @@
 #include <pj/lock.h>
 
 
-#define THIS_FILE    "transport"
+#define THIS_FILE    "sip_transport.c"
+
+/* Prototype. */
+static pj_status_t mod_on_tx_msg(pjsip_tx_data *tdata);
+
+/* This module has sole purpose to print transmit data to contigous buffer
+ * before actually transmitted to the wire. 
+ */
+static pjsip_module mod_msg_print = 
+{
+    NULL, NULL,				/* prev and next	*/
+    { "mod-msg-print", 13},		/* Name.		*/
+    -1,					/* Id			*/
+    PJSIP_MOD_PRIORITY_TRANSPORT_LAYER,	/* 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()	*/
+    &mod_on_tx_msg,			/* on_tx_request()	*/
+    &mod_on_tx_msg,			/* on_tx_response()	*/
+    NULL,				/* on_tsx_state()	*/
+};
 
 /*
  * Transport manager.
@@ -46,7 +73,8 @@
 #if defined(PJ_DEBUG) && PJ_DEBUG!=0
     pj_atomic_t	    *tdata_counter;
 #endif
-    void           (*msg_cb)(pjsip_endpoint*, pj_status_t, pjsip_rx_data*);
+    void           (*on_rx_msg)(pjsip_endpoint*, pj_status_t, pjsip_rx_data*);
+    pj_status_t	   (*on_tx_msg)(pjsip_endpoint*, pjsip_tx_data*);
 };
 
 /*****************************************************************************
@@ -66,7 +94,7 @@
     unsigned		   flag;
 } transport_names[] = 
 {
-    { PJSIP_TRANSPORT_UNSPECIFIED, 0, {NULL, 0}, 0},
+    { PJSIP_TRANSPORT_UNSPECIFIED, 0, {"Unspecified", 11}, 0},
     { PJSIP_TRANSPORT_UDP, 5060, {"UDP", 3}, PJSIP_TRANSPORT_DATAGRAM},
     { PJSIP_TRANSPORT_TCP, 5060, {"TCP", 3}, PJSIP_TRANSPORT_RELIABLE},
     { PJSIP_TRANSPORT_TLS, 5061, {"TLS", 3}, PJSIP_TRANSPORT_RELIABLE | PJSIP_TRANSPORT_SECURE},
@@ -90,6 +118,9 @@
     PJ_ASSERT_RETURN(transport_names[PJSIP_TRANSPORT_UDP].type ==
 		     PJSIP_TRANSPORT_UDP, PJSIP_TRANSPORT_UNSPECIFIED);
 
+    if (name->slen == 0)
+	return PJSIP_TRANSPORT_UNSPECIFIED;
+
     /* Get transport type from name. */
     for (i=0; i<PJ_ARRAY_SIZE(transport_names); ++i) {
 	if (pj_stricmp(name, &transport_names[i].name) == 0) {
@@ -162,6 +193,23 @@
     return transport_names[type].port;
 }
 
+/*
+ * Get transport name.
+ */
+PJ_DEF(const char*) pjsip_transport_get_type_name(pjsip_transport_type_e type)
+{
+    /* Sanity check. 
+     * Check that transport_names[] are indexed on transport type. 
+     */
+    PJ_ASSERT_RETURN(transport_names[PJSIP_TRANSPORT_UDP].type ==
+		     PJSIP_TRANSPORT_UDP, "Unknown");
+
+    /* Check that argument is valid. */
+    PJ_ASSERT_RETURN(type < PJ_ARRAY_SIZE(transport_names), "Unknown");
+
+    /* Return the port. */
+    return transport_names[type].name.ptr;
+}
 
 /*****************************************************************************
  *
@@ -181,8 +229,6 @@
 
     PJ_ASSERT_RETURN(mgr && p_tdata, PJ_EINVAL);
 
-    PJ_LOG(5, ("", "pjsip_tx_data_create"));
-
     pool = pjsip_endpt_create_pool( mgr->endpt, "tdta%p",
 				    PJSIP_POOL_LEN_TDATA,
 				    PJSIP_POOL_INC_TDATA );
@@ -234,7 +280,8 @@
 {
     pj_assert( pj_atomic_get(tdata->ref_cnt) > 0);
     if (pj_atomic_dec_and_get(tdata->ref_cnt) <= 0) {
-	PJ_LOG(5,(tdata->obj_name, "destroying txdata"));
+	PJ_LOG(5,(tdata->obj_name, "Destroying txdata %s",
+		  pjsip_tx_data_get_info(tdata)));
 #if defined(PJ_DEBUG) && PJ_DEBUG!=0
 	pj_atomic_dec( tdata->mgr->tdata_counter );
 #endif
@@ -254,6 +301,7 @@
 PJ_DEF(void) pjsip_tx_data_invalidate_msg( pjsip_tx_data *tdata )
 {
     tdata->buf.cur = tdata->buf.start;
+    tdata->info = NULL;
 }
 
 PJ_DEF(pj_bool_t) pjsip_tx_data_is_valid( pjsip_tx_data *tdata )
@@ -261,7 +309,72 @@
     return tdata->buf.cur != tdata->buf.start;
 }
 
+static char *get_msg_info(pj_pool_t *pool, const char *obj_name,
+			  const pjsip_msg *msg)
+{
+    char info_buf[128], *info;
+    const pjsip_cseq_hdr *cseq;
+    int len;
 
+    cseq = pjsip_msg_find_hdr(msg, PJSIP_H_CSEQ, NULL);
+    PJ_ASSERT_RETURN(cseq != NULL, "INVALID MSG");
+
+    if (msg->type == PJSIP_REQUEST_MSG) {
+	len = pj_snprintf(info_buf, sizeof(info_buf), 
+			  "Request msg %.*s/cseq=%d (%s)",
+			  msg->line.req.method.name.slen,
+			  msg->line.req.method.name.ptr,
+			  cseq->cseq, obj_name);
+    } else {
+	len = pj_snprintf(info_buf, sizeof(info_buf),
+			  "Response msg %d/%.*s/cseq=%d (%s)",
+			  msg->line.status.code,
+			  cseq->method.name.slen,
+			  cseq->method.name.ptr,
+			  cseq->cseq, obj_name);
+    }
+
+    if (len < 1 || len >= sizeof(info_buf)) {
+	return (char*)obj_name;
+    }
+
+    info = pj_pool_alloc(pool, len+1);
+    pj_memcpy(info, info_buf, len+1);
+
+    return info;
+}
+
+PJ_DEF(char*) pjsip_tx_data_get_info( pjsip_tx_data *tdata )
+{
+
+    PJ_ASSERT_RETURN(tdata && tdata->msg, "INVALID MSG");
+
+    if (tdata->info)
+	return tdata->info;
+
+    pj_lock_acquire(tdata->lock);
+    tdata->info = get_msg_info(tdata->pool, tdata->obj_name, tdata->msg);
+    pj_lock_release(tdata->lock);
+
+    return tdata->info;
+}
+
+PJ_DEF(char*) pjsip_rx_data_get_info(pjsip_rx_data *rdata)
+{
+    char obj_name[16];
+
+    PJ_ASSERT_RETURN(rdata->msg_info.msg, "INVALID MSG");
+
+    if (rdata->msg_info.info)
+	return rdata->msg_info.info;
+
+    pj_native_strcpy(obj_name, "rdata");
+    pj_sprintf(obj_name+5, "%p", rdata);
+
+    rdata->msg_info.info = get_msg_info(rdata->tp_info.pool, obj_name,
+					rdata->msg_info.msg);
+    return rdata->msg_info.info;
+}
 
 /*****************************************************************************
  *
@@ -298,6 +411,35 @@
     pjsip_tx_data_dec_ref(tdata);
 }
 
+/* This function is called by endpoint for on_tx_request() and on_tx_response()
+ * notification.
+ */
+static pj_status_t mod_on_tx_msg(pjsip_tx_data *tdata)
+{
+    /* Allocate buffer if necessary. */
+    if (tdata->buf.start == NULL) {
+	tdata->buf.start = pj_pool_alloc( tdata->pool, PJSIP_MAX_PKT_LEN);
+	tdata->buf.cur = tdata->buf.start;
+	tdata->buf.end = tdata->buf.start + PJSIP_MAX_PKT_LEN;
+    }
+
+    /* Do we need to reprint? */
+    if (!pjsip_tx_data_is_valid(tdata)) {
+	pj_ssize_t size;
+
+	size = pjsip_msg_print( tdata->msg, tdata->buf.start, 
+			        tdata->buf.end - tdata->buf.start);
+	if (size < 0) {
+	    return PJSIP_EMSGTOOLONG;
+	}
+	pj_assert(size != 0);
+	tdata->buf.cur += size;
+	tdata->buf.cur[size] = '\0';
+    }
+
+    return PJ_SUCCESS;
+}
+
 /*
  * Send a SIP message using the specified transport.
  */
@@ -320,25 +462,28 @@
 	return PJSIP_EPENDINGTX;
     }
 
-    /* Allocate buffer if necessary. */
-    if (tdata->buf.start == NULL) {
-	tdata->buf.start = pj_pool_alloc( tdata->pool, PJSIP_MAX_PKT_LEN);
-	tdata->buf.cur = tdata->buf.start;
-	tdata->buf.end = tdata->buf.start + PJSIP_MAX_PKT_LEN;
+    /* Fill in tp_info. */
+    tdata->tp_info.transport = tr;
+    pj_memcpy(&tdata->tp_info.dst_addr, addr, addr_len);
+    tdata->tp_info.dst_addr_len = addr_len;
+    if (addr->sa_family == PJ_AF_INET) {
+	const char *str_addr;
+	str_addr = pj_inet_ntoa(((pj_sockaddr_in*)addr)->sin_addr);
+	pj_native_strcpy(tdata->tp_info.dst_name, str_addr);
+	tdata->tp_info.dst_port = pj_ntohs(((pj_sockaddr_in*)addr)->sin_port);
+    } else {
+	pj_native_strcpy(tdata->tp_info.dst_name, "<unknown>");
+	tdata->tp_info.dst_port = 0;
     }
 
-    /* Do we need to reprint? */
-    if (!pjsip_tx_data_is_valid(tdata)) {
-	pj_ssize_t size;
-
-	size = pjsip_msg_print( tdata->msg, tdata->buf.start, 
-			        tdata->buf.end - tdata->buf.start);
-	if (size < 0) {
-	    return PJSIP_EMSGTOOLONG;
-	}
-	pj_assert(size != 0);
-	tdata->buf.cur += size;
-	tdata->buf.cur[size] = '\0';
+    /* Distribute to modules. 
+     * When the message reach mod_msg_print, the contents of the message will
+     * be "printed" to contiguous buffer.
+     */
+    if (tr->tpmgr->on_tx_msg) {
+	status = (*tr->tpmgr->on_tx_msg)(tr->endpt, tdata);
+	if (status != PJ_SUCCESS)
+	    return status;
     }
 
     /* Save callback data. */
@@ -449,18 +594,12 @@
     return PJ_SUCCESS;
 }
 
-
-/**
- * Unregister transport.
- */
-PJ_DEF(pj_status_t) pjsip_transport_unregister( pjsip_tpmgr *mgr,
-						pjsip_transport *tp)
+/* Force destroy transport (e.g. during transport manager shutdown. */
+static pj_status_t destroy_transport( pjsip_tpmgr *mgr,
+				      pjsip_transport *tp )
 {
     int key_len;
 
-    /* Must have no user. */
-    PJ_ASSERT_RETURN(pj_atomic_get(tp->ref_cnt) == 0, PJSIP_EBUSY);
-
     pj_lock_acquire(tp->lock);
     pj_lock_acquire(mgr->lock);
 
@@ -485,6 +624,19 @@
     return tp->destroy(tp);
 }
 
+/**
+ * Unregister transport.
+ */
+PJ_DEF(pj_status_t) pjsip_transport_unregister( pjsip_tpmgr *mgr,
+						pjsip_transport *tp)
+{
+    /* Must have no user. */
+    PJ_ASSERT_RETURN(pj_atomic_get(tp->ref_cnt) == 0, PJSIP_EBUSY);
+
+    /* Destroy. */
+    return destroy_transport(mgr, tp);
+}
+
 
 
 /*****************************************************************************
@@ -556,21 +708,28 @@
  */
 PJ_DEF(pj_status_t) pjsip_tpmgr_create( pj_pool_t *pool,
 					pjsip_endpoint *endpt,
-					void (*cb)(pjsip_endpoint*,
-						   pj_status_t,
-						   pjsip_rx_data *),
+					void (*rx_cb)(pjsip_endpoint*,
+						      pj_status_t,
+						      pjsip_rx_data *),
+					pj_status_t (*tx_cb)(pjsip_endpoint*,
+							     pjsip_tx_data*),
 					pjsip_tpmgr **p_mgr)
 {
     pjsip_tpmgr *mgr;
     pj_status_t status;
 
-    PJ_ASSERT_RETURN(pool && endpt && cb && p_mgr, PJ_EINVAL);
+    PJ_ASSERT_RETURN(pool && endpt && rx_cb && p_mgr, PJ_EINVAL);
 
-    PJ_LOG(5, (THIS_FILE, "pjsip_tpmgr_create()"));
+    /* Register mod_msg_print module. */
+    status = pjsip_endpt_register_module(endpt, &mod_msg_print);
+    if (status != PJ_SUCCESS)
+	return status;
 
+    /* Create and initialize transport manager. */
     mgr = pj_pool_zalloc(pool, sizeof(*mgr));
     mgr->endpt = endpt;
-    mgr->msg_cb = cb;
+    mgr->on_rx_msg = rx_cb;
+    mgr->on_tx_msg = tx_cb;
     pj_list_init(&mgr->factory_list);
 
     mgr->table = pj_hash_create(pool, PJSIP_TPMGR_HTABLE_SIZE);
@@ -587,6 +746,8 @@
 	return status;
 #endif
 
+    PJ_LOG(5, (THIS_FILE, "Transport manager created."));
+
     *p_mgr = mgr;
     return PJ_SUCCESS;
 }
@@ -600,12 +761,9 @@
 {
     pj_hash_iterator_t itr_val;
     pj_hash_iterator_t *itr;
+    pjsip_endpoint *endpt = mgr->endpt;
     
-    PJ_LOG(5, (THIS_FILE, "pjsip_tpmgr_destroy()"));
-
-#if defined(PJ_DEBUG) && PJ_DEBUG!=0
-    pj_assert(pj_atomic_get(mgr->tdata_counter) == 0);
-#endif
+    PJ_LOG(5, (THIS_FILE, "Destroying transport manager"));
 
     pj_lock_acquire(mgr->lock);
 
@@ -618,8 +776,7 @@
 
 	next = pj_hash_next(mgr->table, itr);
 
-	pj_atomic_set(transport->ref_cnt, 0);
-	pjsip_transport_unregister(mgr, transport);
+	destroy_transport(mgr, transport);
 
 	itr = next;
     }
@@ -627,6 +784,19 @@
     pj_lock_release(mgr->lock);
     pj_lock_destroy(mgr->lock);
 
+    /* Unregister mod_msg_print. */
+    if (mod_msg_print.id != -1) {
+	pjsip_endpt_unregister_module(endpt, &mod_msg_print);
+    }
+
+#if defined(PJ_DEBUG) && PJ_DEBUG!=0
+    /* If you encounter assert error on this line, it means there are
+     * leakings in transmit data (i.e. some transmit data have not been
+     * destroyed).
+     */
+    pj_assert(pj_atomic_get(mgr->tdata_counter) == 0);
+#endif
+
     return PJ_SUCCESS;
 }
 
@@ -685,7 +855,7 @@
                                         &msg_fragment_size);
 	    if (msg_status != PJ_SUCCESS) {
 		if (remaining_len == PJSIP_MAX_PKT_LEN) {
-		    mgr->msg_cb(mgr->endpt, PJSIP_ERXOVERFLOW, rdata);
+		    mgr->on_rx_msg(mgr->endpt, PJSIP_ERXOVERFLOW, rdata);
 		    /* Exhaust all data. */
 		    return rdata->pkt_info.len;
 		} else {
@@ -702,7 +872,7 @@
 	rdata->msg_info.msg = msg = 
 	    pjsip_parse_rdata( current_pkt, msg_fragment_size, rdata);
 	if (msg == NULL) {
-	    mgr->msg_cb(mgr->endpt, PJSIP_EINVALIDMSG, rdata);
+	    mgr->on_rx_msg(mgr->endpt, PJSIP_EINVALIDMSG, rdata);
 	    goto finish_process_fragment;
 	}
 
@@ -713,7 +883,7 @@
 	    rdata->msg_info.via == NULL || 
 	    rdata->msg_info.cseq == NULL) 
 	{
-	    mgr->msg_cb(mgr->endpt, PJSIP_EMISSINGHDR, rdata);
+	    mgr->on_rx_msg(mgr->endpt, PJSIP_EMISSINGHDR, rdata);
 	    goto finish_process_fragment;
 	}
 
@@ -737,7 +907,7 @@
 	    if (hdr != &msg->hdr) {
 		hdr = pjsip_msg_find_hdr(msg, PJSIP_H_VIA, hdr);
 		if (hdr) {
-		    mgr->msg_cb(mgr->endpt, PJSIP_EMULTIPLEVIA, rdata);
+		    mgr->on_rx_msg(mgr->endpt, PJSIP_EMULTIPLEVIA, rdata);
 		    goto finish_process_fragment;
 		}
 	    }
@@ -745,7 +915,7 @@
 
 	/* Call the transport manager's upstream message callback.
 	 */
-	mgr->msg_cb(mgr->endpt, PJ_SUCCESS, rdata);
+	mgr->on_rx_msg(mgr->endpt, PJ_SUCCESS, rdata);
 
 
 finish_process_fragment:
@@ -795,17 +965,25 @@
 	unsigned flag = pjsip_transport_get_flag_from_type(type);
 	const pj_sockaddr *remote_addr = (const pj_sockaddr*)remote;
 
-	/* For datagram transports, try lookup with zero address. 
+	/* Ignore address for loop transports. */
+	if (type == PJSIP_TRANSPORT_LOOP ||
+	         type == PJSIP_TRANSPORT_LOOP_DGRAM)
+	{
+	    pj_sockaddr_in *addr = (pj_sockaddr_in*)&key.addr;
+
+	    pj_memset(addr, 0, sizeof(pj_sockaddr_in));
+	    key_len = sizeof(key.type) + sizeof(pj_sockaddr_in);
+	    transport = pj_hash_get(mgr->table, &key, key_len);
+	}
+	/* For datagram INET transports, try lookup with zero address.
 	 */
-	if ( (flag & PJSIP_TRANSPORT_DATAGRAM) && 
-	     (remote_addr->sa_family == PJ_AF_INET)) 
+	else if ((flag & PJSIP_TRANSPORT_DATAGRAM) && 
+	         (remote_addr->sa_family == PJ_AF_INET)) 
 	{
 	    pj_sockaddr_in *addr = (pj_sockaddr_in*)&key.addr;
 
 	    pj_memset(addr, 0, sizeof(pj_sockaddr_in));
 	    addr->sin_family = PJ_AF_INET;
-	    addr->sin_addr.s_addr = 0;
-	    addr->sin_port = 0;
 
 	    key_len = sizeof(key.type) + sizeof(pj_sockaddr_in);
 	    transport = pj_hash_get(mgr->table, &key, key_len);
diff --git a/pjsip/src/pjsip/sip_transport_loop.c b/pjsip/src/pjsip/sip_transport_loop.c
index 38f44ce..de2f85a 100644
--- a/pjsip/src/pjsip/sip_transport_loop.c
+++ b/pjsip/src/pjsip/sip_transport_loop.c
@@ -27,9 +27,6 @@
 #include <pj/compat/socket.h>
 
 
-#define FAIL_IMMEDIATE	1
-#define FAIL_CALLBACK	2
-
 #define ADDR_LOOP	"128.0.0.1"
 #define ADDR_LOOP_DGRAM	"129.0.0.1"
 
@@ -61,7 +58,8 @@
     pj_bool_t		     thread_quit_flag;
     pj_bool_t		     discard;
     int			     fail_mode;
-    unsigned		     delay;
+    unsigned		     recv_delay;
+    unsigned		     send_delay;
     struct recv_list	     recv_list;
     struct send_list	     send_list;
 };
@@ -100,7 +98,7 @@
 
     /* When do we need to "deliver" this packet. */
     pj_gettimeofday(&pkt->rdata.pkt_info.timestamp);
-    pkt->rdata.pkt_info.timestamp.msec += loop->delay;
+    pkt->rdata.pkt_info.timestamp.msec += loop->recv_delay;
     pj_time_val_normalize(&pkt->rdata.pkt_info.timestamp);
 
     /* Done. */
@@ -130,7 +128,7 @@
     sent_status->callback = callback;
 
     pj_gettimeofday(&sent_status->sent_time);
-    sent_status->sent_time.msec += loop->delay;
+    sent_status->sent_time.msec += loop->send_delay;
     pj_time_val_normalize(&sent_status->sent_time);
 
     pj_lock_acquire(loop->base.lock);
@@ -160,17 +158,16 @@
     PJ_UNUSED_ARG(addr_len);
 
 
-    /* Need to send failure immediately? */
-    if (loop->fail_mode == FAIL_IMMEDIATE) {
-	return PJ_STATUS_FROM_OS(OSERR_ECONNRESET);
+    /* Need to send failure? */
+    if (loop->fail_mode) {
+	if (loop->send_delay == 0) {
+	    return PJ_STATUS_FROM_OS(OSERR_ECONNRESET);
+	} else {
+	    add_notification(loop, tdata, -PJ_STATUS_FROM_OS(OSERR_ECONNRESET),
+			     token, cb);
 
-    /* Need to send failure later? */
-    } else if (loop->fail_mode == FAIL_CALLBACK) {
-
-	add_notification(loop, tdata, -PJ_STATUS_FROM_OS(OSERR_ECONNRESET), 
-			 token, cb);
-
-	return PJ_EPENDING;
+	    return PJ_EPENDING;
+	}
     }
 
     /* Discard any packets? */
@@ -183,7 +180,7 @@
 	return PJ_ENOMEM;
 
     /* If delay is not configured, deliver this packet now! */
-    if (loop->delay == 0) {
+    if (loop->recv_delay == 0) {
 	pj_ssize_t size_eaten;
 
 	size_eaten = pjsip_tpmgr_receive_packet( loop->base.tpmgr, 
@@ -192,20 +189,22 @@
 
 	pjsip_endpt_release_pool(loop->base.endpt, 
 				 recv_pkt->rdata.tp_info.pool);
-	return PJ_SUCCESS;
 
     } else {
 	/* Otherwise if delay is configured, add the "packet" to the 
-	 * receive list to be processed by worker thread, and add
-	 * pending notification for calling the callback.
+	 * receive list to be processed by worker thread.
 	 */
-	add_notification(loop, tdata, tdata->buf.cur - tdata->buf.start, 
-			 token, cb);
-
 	pj_lock_acquire(loop->base.lock);
 	pj_list_push_back(&loop->recv_list, recv_pkt);
 	pj_lock_release(loop->base.lock);
+    }
+
+    if (loop->send_delay != 0) {
+	add_notification(loop, tdata, tdata->buf.cur - tdata->buf.start,
+			 token, cb);
 	return PJ_EPENDING;
+    } else {
+	return PJ_SUCCESS;
     }
 }
 
@@ -223,6 +222,26 @@
     pj_thread_join(loop->thread);
     pj_thread_destroy(loop->thread);
 
+    /* Clear pending send notifications. */
+    while (!pj_list_empty(&loop->send_list)) {
+	struct send_list *node = loop->send_list.next;
+	/* Notify callback. */
+	if (node->callback) {
+	    (*node->callback)(&loop->base, node->token, -PJSIP_ESHUTDOWN);
+	}
+	pj_list_erase(node);
+	pjsip_tx_data_dec_ref(node->tdata);
+    }
+
+    /* Clear "incoming" packets in the queue. */
+    while (!pj_list_empty(&loop->recv_list)) {
+	struct recv_list *node = loop->recv_list.next;
+	pj_list_erase(node);
+	pjsip_endpt_release_pool(loop->base.endpt,
+				 node->rdata.tp_info.pool);
+    }
+
+    /* Self destruct.. heheh.. */
     pj_lock_destroy(loop->base.lock);
     pj_atomic_destroy(loop->base.ref_cnt);
     pjsip_endpt_release_pool(loop->base.endpt, loop->base.pool);
@@ -238,7 +257,7 @@
     while (!loop->thread_quit_flag) {
 	pj_time_val now;
 
-	pj_thread_sleep(10);
+	pj_thread_sleep(1);
 	pj_gettimeofday(&now);
 
 	pj_lock_acquire(loop->base.lock);
@@ -320,7 +339,7 @@
     if (status != PJ_SUCCESS)
 	goto on_error;
     loop->base.key.type = PJSIP_TRANSPORT_LOOP_DGRAM;
-    loop->base.key.rem_addr.sa_family = PJ_AF_INET;
+    //loop->base.key.rem_addr.sa_family = PJ_AF_INET;
     loop->base.type_name = "LOOP-DGRAM";
     loop->base.info = "LOOP-DGRAM";
     loop->base.flag = PJSIP_TRANSPORT_DATAGRAM;
@@ -356,7 +375,9 @@
      * Done.
      */
 
-    *transport = &loop->base;
+    if (transport)
+	*transport = &loop->base;
+
     return PJ_SUCCESS;
 
 on_error:
@@ -405,9 +426,9 @@
 }
 
 
-PJ_DEF(pj_status_t) pjsip_loop_set_delay( pjsip_transport *tp,
-					  unsigned delay,
-					  unsigned *prev_value)
+PJ_DEF(pj_status_t) pjsip_loop_set_recv_delay( pjsip_transport *tp,
+					       unsigned delay,
+					       unsigned *prev_value)
 {
     struct loop_transport *loop = (struct loop_transport*)tp;
 
@@ -415,8 +436,37 @@
 	             tp->key.type == PJSIP_TRANSPORT_LOOP_DGRAM), PJ_EINVAL);
 
     if (prev_value)
-	*prev_value = loop->delay;
-    loop->delay = delay;
+	*prev_value = loop->recv_delay;
+    loop->recv_delay = delay;
+
+    return PJ_SUCCESS;
+}
+
+PJ_DEF(pj_status_t) pjsip_loop_set_send_callback_delay( pjsip_transport *tp,
+							unsigned delay,
+							unsigned *prev_value)
+{
+    struct loop_transport *loop = (struct loop_transport*)tp;
+
+    PJ_ASSERT_RETURN(tp && (tp->key.type == PJSIP_TRANSPORT_LOOP ||
+	             tp->key.type == PJSIP_TRANSPORT_LOOP_DGRAM), PJ_EINVAL);
+
+    if (prev_value)
+	*prev_value = loop->send_delay;
+    loop->send_delay = delay;
+
+    return PJ_SUCCESS;
+}
+
+PJ_DEF(pj_status_t) pjsip_loop_set_delay( pjsip_transport *tp, unsigned delay )
+{
+    struct loop_transport *loop = (struct loop_transport*)tp;
+
+    PJ_ASSERT_RETURN(tp && (tp->key.type == PJSIP_TRANSPORT_LOOP ||
+	             tp->key.type == PJSIP_TRANSPORT_LOOP_DGRAM), PJ_EINVAL);
+
+    loop->recv_delay = delay;
+    loop->send_delay = delay;
 
     return PJ_SUCCESS;
 }
diff --git a/pjsip/src/pjsip/sip_transport_udp.c b/pjsip/src/pjsip/sip_transport_udp.c
index f925d8c..010c53d 100644
--- a/pjsip/src/pjsip/sip_transport_udp.c
+++ b/pjsip/src/pjsip/sip_transport_udp.c
@@ -58,8 +58,10 @@
     pj_status_t status;
 
     /* Don't do anything if transport is closing. */
-    if (tp->is_closing)
+    if (tp->is_closing) {
+	tp->is_closing++;
 	return;
+    }
 
     /*
      * The idea of the loop is to process immediate data received by
@@ -228,10 +230,17 @@
     tp->is_closing = 1;
 
     /* Cancel all pending operations. */
+    /* blp: NO NO NO...
+     *      No need to post queued completion as we poll the ioqueue until
+     *      we've got events anyway. Posting completion will only cause
+     *      callback to be called twice with IOCP: one for the post completion
+     *      and another one for closing the socket.
+     *
     for (i=0; i<tp->rdata_cnt; ++i) {
 	pj_ioqueue_post_completion(tp->key, 
 				   &tp->rdata[i]->tp_info.op_key.op_key, -1);
     }
+    */
 
     /* Unregister from ioqueue. */
     if (tp->key)
@@ -241,6 +250,20 @@
     if (tp->sock && tp->sock != PJ_INVALID_SOCKET)
 	pj_sock_close(tp->sock);
 
+    /* Must poll ioqueue because IOCP calls the callback when socket
+     * is closed. We poll the ioqueue until all pending callbacks 
+     * have been called.
+     */
+    for (i=0; i<50 && tp->is_closing < 1+tp->rdata_cnt; ++i) {
+	int cnt;
+	pj_time_val timeout = {0, 1};
+
+	cnt = pj_ioqueue_poll(pjsip_endpt_get_ioqueue(transport->endpt), 
+			      &timeout);
+	if (cnt == 0)
+	    break;
+    }
+
     /* Destroy reference counter. */
     if (tp->base.ref_cnt)
 	pj_atomic_destroy(tp->base.ref_cnt);
diff --git a/pjsip/src/pjsip/sip_util.c b/pjsip/src/pjsip/sip_util.c
index 0760e32..d6ba5e9 100644
--- a/pjsip/src/pjsip/sip_util.c
+++ b/pjsip/src/pjsip/sip_util.c
@@ -129,11 +129,8 @@
 	msg->body = body;
     }
 
-    PJ_LOG(4,(THIS_FILE, "Request %s (CSeq=%d/%.*s) created.", 
-			 tdata->obj_name, 
-			 param_cseq->cseq, 
-			 param_cseq->method.name.slen,
-			 param_cseq->method.name.ptr));
+    PJ_LOG(5,(THIS_FILE, "%s created.", 
+			 pjsip_tx_data_get_info(tdata)));
 
 }
 
@@ -162,8 +159,6 @@
     pj_status_t status;
     PJ_USE_EXCEPTION;
 
-    PJ_LOG(5,(THIS_FILE, "Entering pjsip_endpt_create_request()"));
-
     status = pjsip_endpt_create_tdata(endpt, &tdata);
     if (status != PJ_SUCCESS)
 	return status;
@@ -272,8 +267,6 @@
     pj_status_t status;
     PJ_USE_EXCEPTION;
 
-    PJ_LOG(5,(THIS_FILE, "Entering pjsip_endpt_create_request_from_hdr()"));
-
     /* Check arguments. */
     PJ_ASSERT_RETURN(endpt && method && param_target && param_from &&
 		     param_to && p_tdata, PJ_EINVAL);
@@ -343,10 +336,6 @@
     req_msg = rdata->msg_info.msg;
     pj_assert(req_msg->type == PJSIP_REQUEST_MSG);
 
-    /* Log this action. */
-    PJ_LOG(5,(THIS_FILE, "pjsip_endpt_create_response(rdata=%p, code=%d)", 
-		         rdata, st_code));
-
     /* Create a new transmit buffer. */
     status = pjsip_endpt_create_tdata( endpt, &tdata);
     if (status != PJ_SUCCESS)
@@ -408,6 +397,8 @@
 
     /* All done. */
     *p_tdata = tdata;
+
+    PJ_LOG(5,(THIS_FILE, "%s created", pjsip_tx_data_get_info(tdata)));
     return PJ_SUCCESS;
 }
 
@@ -432,9 +423,6 @@
     pjsip_to_hdr *to;
     pj_status_t status;
 
-    /* Log this action. */
-    PJ_LOG(5,(THIS_FILE, "pjsip_endpt_create_ack(rdata=%p)", rdata));
-
     /* rdata must be a final response. */
     pj_assert(rdata->msg_info.msg->type==PJSIP_RESPONSE_MSG &&
 	      rdata->msg_info.msg->line.status.code >= 300);
@@ -525,9 +513,6 @@
     const pjsip_hdr *hdr;
     pj_status_t status;
 
-    /* Log this action. */
-    PJ_LOG(5,(THIS_FILE, "pjsip_endpt_create_cancel(tdata=%p)", req_tdata));
-
     /* The transmit buffer must INVITE request. */
     PJ_ASSERT_RETURN(req_tdata->msg->type == PJSIP_REQUEST_MSG &&
 		     req_tdata->msg->line.req.method.id == PJSIP_INVITE_METHOD,
@@ -702,13 +687,8 @@
 	dest_info->addr.port = url->port;
 	dest_info->type = 
             pjsip_transport_get_type_from_name(&url->transport_param);
-#if PJ_HAS_TCP
-	if (dest_info->type == PJSIP_TRANSPORT_TCP || 
-	    dest_info->type == PJSIP_TRANSPORT_SCTP) 
-	{
-	    dest_info->flag |= PJSIP_TRANSPORT_RELIABLE;
-	}
-#endif
+	dest_info->flag = 
+	    pjsip_transport_get_flag_from_type(dest_info->type);
     } else {
         pj_assert(!"Unsupported URI scheme!");
 	PJ_TODO(SUPPORT_REQUEST_ADDR_RESOLUTION_FOR_TEL_URI);
diff --git a/pjsip/src/test-pjsip/msg_logger.c b/pjsip/src/test-pjsip/msg_logger.c
new file mode 100644
index 0000000..faa36b5
--- /dev/null
+++ b/pjsip/src/test-pjsip/msg_logger.c
@@ -0,0 +1,102 @@
+/* $Id$ */
+/* 
+ * 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   "msg_logger.c"
+
+static pj_bool_t msg_log_enabled;
+
+static pj_bool_t on_rx_msg(pjsip_rx_data *rdata)
+{
+    if (msg_log_enabled) {
+	PJ_LOG(4,(THIS_FILE, "RX %d bytes %s from %s:%d:\n"
+			     "%s\n"
+			     "--end msg--",
+			     rdata->msg_info.len,
+			     pjsip_rx_data_get_info(rdata),
+			     rdata->pkt_info.src_name,
+			     rdata->pkt_info.src_port,
+			     rdata->msg_info.msg_buf));
+    }
+
+    return PJ_FALSE;
+}
+
+static pj_status_t on_tx_msg(pjsip_tx_data *tdata)
+{
+    if (msg_log_enabled) {
+	PJ_LOG(4,(THIS_FILE, "TX %d bytes %s to %s:%d:\n"
+			     "%s\n"
+			     "--end msg--",
+			     (tdata->buf.cur - tdata->buf.start),
+			     pjsip_tx_data_get_info(tdata),
+			     tdata->tp_info.dst_name,
+			     tdata->tp_info.dst_port,
+			     tdata->buf.start));
+    }
+    return PJ_SUCCESS;
+}
+
+
+/* Message logger module. */
+static pjsip_module mod_msg_logger = 
+{
+    NULL, NULL,				/* prev and next	*/
+    { "mod-msg-logger", 14},		/* Name.		*/
+    -1,					/* Id			*/
+    PJSIP_MOD_PRIORITY_TRANSPORT_LAYER-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_msg,				/* on_rx_request()	*/
+    &on_rx_msg,				/* on_rx_response()	*/
+    &on_tx_msg,				/* on_tx_request()	*/
+    &on_tx_msg,				/* on_tx_response()	*/
+    NULL,				/* on_tsx_state()	*/
+};
+
+int init_msg_logger(void)
+{
+    pj_status_t status;
+
+    if (mod_msg_logger.id != -1)
+	return 0;
+
+    status = pjsip_endpt_register_module(endpt, &mod_msg_logger);
+    if (status != PJ_SUCCESS) {
+	app_perror("  error registering module", status);
+	return -10;
+    }
+
+    return 0;
+}
+
+int msg_logger_set_enabled(pj_bool_t enabled)
+{
+    int val = msg_log_enabled;
+    msg_log_enabled = enabled;
+    return val;
+}
+
diff --git a/pjsip/src/test-pjsip/msg_test.c b/pjsip/src/test-pjsip/msg_test.c
index 11a69b4..f49f125 100644
--- a/pjsip/src/test-pjsip/msg_test.c
+++ b/pjsip/src/test-pjsip/msg_test.c
@@ -23,6 +23,7 @@
 #define POOL_SIZE	8000
 #define LOOP		10000
 #define AVERAGE_MSG_LEN	800
+#define THIS_FILE	"msg_test.c"
 
 static pjsip_msg *create_msg0(pj_pool_t *pool);
 static pjsip_msg *create_msg1(pj_pool_t *pool);
@@ -142,7 +143,7 @@
 	}
     }
     if (msg_size != entry->len) {
-	PJ_LOG(3,("", "   error: size mismatch"));
+	PJ_LOG(3,(THIS_FILE, "   error: size mismatch"));
 	return -6;
     }
     pj_get_timestamp(&t2);
@@ -162,7 +163,7 @@
 	if (entry->expected_status != STATUS_SYNTAX_ERROR) {
 	    status = -10;
 	    if (err_list.next != &err_list) {
-		PJ_LOG(3,("", "   Syntax error in line %d col %d",
+		PJ_LOG(3,(THIS_FILE, "   Syntax error in line %d col %d",
 			      err_list.next->line, err_list.next->col));
 	    }
 	    goto on_return;
@@ -207,14 +208,14 @@
 	}
     } else {
 	if (parsed_msg->line.status.code != ref_msg->line.status.code) {
-	    PJ_LOG(3,("", "   error: status code mismatch"));
+	    PJ_LOG(3,(THIS_FILE, "   error: status code mismatch"));
 	    status = -32;
 	    goto on_return;
 	}
 	if (pj_strcmp(&parsed_msg->line.status.reason, 
 		      &ref_msg->line.status.reason) != 0) 
 	{
-	    PJ_LOG(3,("", "   error: status text mismatch"));
+	    PJ_LOG(3,(THIS_FILE, "   error: status text mismatch"));
 	    status = -33;
 	    goto on_return;
 	}
@@ -243,7 +244,7 @@
 
 	if (pj_strcmp(&str1, &str2) != 0) {
 	    status = -60;
-	    PJ_LOG(3,("", "   error: header string mismatch:\n"
+	    PJ_LOG(3,(THIS_FILE, "   error: header string mismatch:\n"
 		          "   h1='%s'\n"
 			  "   h2='%s'\n",
 			  str1.ptr, str2.ptr));
@@ -683,7 +684,7 @@
     pj_time_val elapsed;
     pj_highprec_t avg_detect, avg_parse, avg_print, kbytes;
 
-    PJ_LOG(3,("", "  simple test.."));
+    PJ_LOG(3,(THIS_FILE, "  simple test.."));
     for (i=0; i<PJ_ARRAY_SIZE(test_array); ++i) {
 	pool = pjsip_endpt_create_pool(endpt, NULL, POOL_SIZE, POOL_SIZE);
 	status = test_entry( pool, &test_array[i] );
@@ -693,7 +694,7 @@
 	    return status;
     }
 
-    PJ_LOG(3,("", "  benchmarking.."));
+    PJ_LOG(3,(THIS_FILE, "  benchmarking.."));
     detect_len = parse_len = print_len = 0;
     zero.u64 = detect_time.u64 = parse_time.u64 = print_time.u64 = 0;
     
@@ -717,10 +718,11 @@
     pj_highprec_div(avg_detect, detect_len);
     avg_detect = 1000000 / avg_detect;
 
-    PJ_LOG(3,("", "    %u.%u MB detected in %d.%03ds (avg=%d msg detection/sec)", 
-		  (unsigned)(detect_len/1000000), (unsigned)kbytes,
-		  elapsed.sec, elapsed.msec,
-		  (unsigned)avg_detect));
+    PJ_LOG(3,(THIS_FILE, 
+	      "    %u.%u MB detected in %d.%03ds (avg=%d msg detection/sec)", 
+	      (unsigned)(detect_len/1000000), (unsigned)kbytes,
+	      elapsed.sec, elapsed.msec,
+	      (unsigned)avg_detect));
 
     kbytes = parse_len;
     pj_highprec_mod(kbytes, 1000000);
@@ -731,10 +733,11 @@
     pj_highprec_div(avg_parse, parse_len);
     avg_parse = 1000000 / avg_parse;
 
-    PJ_LOG(3,("", "    %u.%u MB parsed in %d.%03ds (avg=%d msg parsing/sec)", 
-		  (unsigned)(parse_len/1000000), (unsigned)kbytes,
-		  elapsed.sec, elapsed.msec,
-		  (unsigned)avg_parse));
+    PJ_LOG(3,(THIS_FILE, 
+	      "    %u.%u MB parsed in %d.%03ds (avg=%d msg parsing/sec)", 
+	      (unsigned)(parse_len/1000000), (unsigned)kbytes,
+	      elapsed.sec, elapsed.msec,
+	      (unsigned)avg_parse));
 
     kbytes = print_len;
     pj_highprec_mod(kbytes, 1000000);
@@ -745,10 +748,11 @@
     pj_highprec_div(avg_print, print_len);
     avg_print = 1000000 / avg_print;
 
-    PJ_LOG(3,("", "    %u.%u MB printed in %d.%03ds (avg=%d msg print/sec)", 
-		  (unsigned)(print_len/1000000), (unsigned)kbytes,
-		  elapsed.sec, elapsed.msec,
-		  (unsigned)avg_print));
+    PJ_LOG(3,(THIS_FILE, 
+	      "    %u.%u MB printed in %d.%03ds (avg=%d msg print/sec)", 
+	      (unsigned)(print_len/1000000), (unsigned)kbytes,
+	      elapsed.sec, elapsed.msec,
+	      (unsigned)avg_print));
 
     return status;
 }
diff --git a/pjsip/src/test-pjsip/test.c b/pjsip/src/test-pjsip/test.c
index fbb7291..fdc6a7d 100644
--- a/pjsip/src/test-pjsip/test.c
+++ b/pjsip/src/test-pjsip/test.c
@@ -22,10 +22,12 @@
 #include <pjlib.h>
 #include <pjsip_core.h>
 
+#define THIS_FILE   "test.c"
+
 #define DO_TEST(test)	do { \
-			    PJ_LOG(3, ("test", "Running %s...", #test));  \
+			    PJ_LOG(3, (THIS_FILE, "Running %s...", #test));  \
 			    rc = test; \
-			    PJ_LOG(3, ("test",  \
+			    PJ_LOG(3, (THIS_FILE,  \
 				       "%s(%d)",  \
 				       (rc ? "..ERROR" : "..success"), rc)); \
 			    if (rc!=0) goto on_return; \
@@ -42,10 +44,30 @@
     PJ_CHECK_STACK();
 
     pjsip_strerror(rc, errbuf, sizeof(errbuf));
-    PJ_LOG(3,("test", "%s: [pj_status_t=%d] %s", msg, rc, errbuf));
+    PJ_LOG(3,(THIS_FILE, "%s: [pj_status_t=%d] %s", msg, rc, errbuf));
 
 }
 
+void flush_events(unsigned duration)
+{
+    pj_time_val stop_time;
+
+    pj_gettimeofday(&stop_time);
+    stop_time.msec += duration;
+    pj_time_val_normalize(&stop_time);
+
+    /* Process all events for the specified duration. */
+    for (;;) {
+	pj_time_val timeout = {0, 1}, now;
+
+	pjsip_endpt_handle_events(endpt, &timeout);
+
+	pj_gettimeofday(&now);
+	if (PJ_TIME_VAL_GTE(now, stop_time))
+	    break;
+    }
+}
+
 pj_status_t register_static_modules(pj_size_t *count, pjsip_module **modules)
 {
     *count = 0;
@@ -59,9 +81,11 @@
     const char *filename;
     int line;
 
-    pj_log_set_level(3);
+    pj_log_set_level(5);
+    /*
     pj_log_set_decor(PJ_LOG_HAS_NEWLINE | PJ_LOG_HAS_TIME | 
                      PJ_LOG_HAS_MICRO_SEC);
+     */
 
     if ((rc=pj_init()) != PJ_SUCCESS) {
 	app_perror("pj_init", rc);
@@ -79,30 +103,50 @@
 	return rc;
     }
 
-    PJ_LOG(3,("",""));
+    PJ_LOG(3,(THIS_FILE,""));
+
+    /* Init logger module. */
+    init_msg_logger();
+    msg_logger_set_enabled(1);
+
+    /* Start transaction layer module. */
+    rc = pjsip_tsx_layer_init(endpt);
+    if (rc != PJ_SUCCESS) {
+	app_perror("   Error initializing transaction module", rc);
+	goto on_return;
+    }
+
+    /* Create loop transport. */
+    rc = pjsip_loop_start(endpt, NULL);
+    if (rc != PJ_SUCCESS) {
+	app_perror("   error: unable to create datagram loop transport", 
+		   rc);
+	goto on_return;
+    }
 
     //DO_TEST(uri_test());
     //DO_TEST(msg_test());
     //DO_TEST(txdata_test());
     //DO_TEST(transport_udp_test());
-    DO_TEST(transport_loop_test());
-    //DO_TEST(tsx_uac_test());
+    //DO_TEST(transport_loop_test());
+    //DO_TEST(tsx_basic_test());
+    DO_TEST(tsx_uac_test());
 
 on_return:
 
     pjsip_endpt_destroy(endpt);
     pj_caching_pool_destroy(&caching_pool);
 
-    PJ_LOG(3,("test", ""));
+    PJ_LOG(3,(THIS_FILE, ""));
  
     pj_thread_get_stack_info(pj_thread_this(), &filename, &line);
-    PJ_LOG(3,("test", "Stack max usage: %u, deepest: %s:%u", 
+    PJ_LOG(3,(THIS_FILE, "Stack max usage: %u, deepest: %s:%u", 
 	              pj_thread_get_stack_max_usage(pj_thread_this()),
 		      filename, line));
     if (rc == 0)
-	PJ_LOG(3,("test", "Looks like everything is okay!.."));
+	PJ_LOG(3,(THIS_FILE, "Looks like everything is okay!.."));
     else
-	PJ_LOG(3,("test", "Test completed with error(s)"));
+	PJ_LOG(3,(THIS_FILE, "Test completed with error(s)"));
 
     return 0;
 }
diff --git a/pjsip/src/test-pjsip/test.h b/pjsip/src/test-pjsip/test.h
index db12e39..2012781 100644
--- a/pjsip/src/test-pjsip/test.h
+++ b/pjsip/src/test-pjsip/test.h
@@ -32,6 +32,7 @@
 int txdata_test(void);
 int transport_udp_test(void);
 int transport_loop_test(void);
+int tsx_basic_test(void);
 int tsx_uac_test(void);
 
 /* Transport test helpers (transport_test.c). */
@@ -41,13 +42,16 @@
 			      char *target_url );
 int transport_rt_test( pjsip_transport_type_e tp_type,
 		       pjsip_transport *ref_tp,
-		       char *target_url );
+		       char *target_url,
+		       int *pkt_lost);
 
 /* Test main entry */
 int  test_main(void);
 
 /* Test utilities. */
 void app_perror(const char *msg, pj_status_t status);
-
+int init_msg_logger(void);
+int msg_logger_set_enabled(pj_bool_t enabled);
+void flush_events(unsigned duration);
 
 #endif	/* __TEST_H__ */
diff --git a/pjsip/src/test-pjsip/transport_loop_test.c b/pjsip/src/test-pjsip/transport_loop_test.c
index 467f327..f4e6bb3 100644
--- a/pjsip/src/test-pjsip/transport_loop_test.c
+++ b/pjsip/src/test-pjsip/transport_loop_test.c
@@ -21,40 +21,25 @@
 #include <pjsip_core.h>
 #include <pjlib.h>
 
+#define THIS_FILE   "transport_loop_test.c"
+
 static int datagram_loop_test()
 {
-    pjsip_transport *loop, *tp;
-    pj_str_t s;
-    int i, log_level;
+    pjsip_transport *loop;
+    int i, pkt_lost;
     pj_sockaddr_in addr;
     pj_status_t status;
 
-    PJ_LOG(3,("", "testing datagram loop transport"));
-
-    /* Create loop transport. */
-    status = pjsip_loop_start(endpt, &loop);
-    if (status != PJ_SUCCESS) {
-	app_perror("   error: unable to create datagram loop transport", 
-		   status);
-	return -10;
-    }
-
-    /* Create dummy address. */
-    pj_sockaddr_in_init(&addr, pj_cstr(&s, "130.0.0.1"), TEST_UDP_PORT);
+    PJ_LOG(3,(THIS_FILE, "testing datagram loop transport"));
 
     /* Test acquire transport. */
     status = pjsip_endpt_acquire_transport( endpt, PJSIP_TRANSPORT_LOOP_DGRAM,
-					    &addr, sizeof(addr), &tp);
+					    &addr, sizeof(addr), &loop);
     if (status != PJ_SUCCESS) {
-	app_perror("   error: unable to acquire transport", status);
+	app_perror("   error: loop transport is not configured", status);
 	return -20;
     }
 
-    /* Check that this is the right transport. */
-    if (tp != loop) {
-	return -30;
-    }
-
     /* Test basic transport attributes */
     status = generic_transport_test(loop);
     if (status != PJ_SUCCESS)
@@ -68,45 +53,40 @@
 	    return status;
     }
 
-    /* For multithreaded round-trip test to work, delay must be set
-     * (otherwise functions will be called recursively until no memory is
-     * left in the system)
-     */
+    /* Multi-threaded round-trip test. */
+    status = transport_rt_test(PJSIP_TRANSPORT_LOOP_DGRAM, loop, 
+			       "sip:bob@130.0.0.1;transport=loop-dgram",
+			       &pkt_lost);
+    if (status != 0)
+	return status;
+
+    if (pkt_lost != 0) {
+	PJ_LOG(3,(THIS_FILE, "   error: %d packet(s) was lost", pkt_lost));
+	return -40;
+    }
 
     /* Put delay. */
-    pjsip_loop_set_delay(loop, 1, NULL);
+    PJ_LOG(3,(THIS_FILE,"  setting network delay to 10 ms"));
+    pjsip_loop_set_delay(loop, 10);
 
     /* Multi-threaded round-trip test. */
-    status = transport_rt_test(PJSIP_TRANSPORT_LOOP_DGRAM, tp, 
-			       "sip:bob@130.0.0.1;transport=loop-dgram");
+    status = transport_rt_test(PJSIP_TRANSPORT_LOOP_DGRAM, loop, 
+			       "sip:bob@130.0.0.1;transport=loop-dgram",
+			       &pkt_lost);
     if (status != 0)
 	return status;
 
+    if (pkt_lost != 0) {
+	PJ_LOG(3,(THIS_FILE, "   error: %d packet(s) was lost", pkt_lost));
+	return -50;
+    }
 
-    /* Next test will test without delay.
-     * This will stress-test the system.
-     */
-    PJ_LOG(3,("","  performing another multithreaded round-trip test..."));
-
-    /* Remove delay. */
-    pjsip_loop_set_delay(loop, 0, NULL);
-
-    /* Ignore errors. */
-    log_level = pj_log_get_level();
-    pj_log_set_level(2);
-
-    /* Multi-threaded round-trip test. */
-    status = transport_rt_test(PJSIP_TRANSPORT_LOOP_DGRAM, tp, 
-			       "sip:bob@130.0.0.1;transport=loop-dgram");
-    if (status != 0)
-	return status;
-
-    /* Restore log level. */
-    pj_log_set_level(log_level);
+    /* Restore delay. */
+    pjsip_loop_set_delay(loop, 0);
 
     /* Check that reference counter is one. */
     if (pj_atomic_get(loop->ref_cnt) != 1) {
-	return -30;
+	return -50;
     }
 
     /* Decrement reference. */
diff --git a/pjsip/src/test-pjsip/transport_test.c b/pjsip/src/test-pjsip/transport_test.c
index 76b6bb9..b57fedb 100644
--- a/pjsip/src/test-pjsip/transport_test.c
+++ b/pjsip/src/test-pjsip/transport_test.c
@@ -21,6 +21,8 @@
 #include <pjsip_core.h>
 #include <pjlib.h>
 
+#define THIS_FILE   "transport_test.c"
+
 ///////////////////////////////////////////////////////////////////////////////
 /*
  * Generic testing for transport, to make sure that basic
@@ -28,7 +30,7 @@
  */
 int generic_transport_test(pjsip_transport *tp)
 {
-    PJ_LOG(3,("", "  structure test..."));
+    PJ_LOG(3,(THIS_FILE, "  structure test..."));
 
     /* Check that local address name is valid. */
     {
@@ -37,7 +39,7 @@
 	/* Note: inet_aton() returns non-zero if addr is valid! */
 	if (pj_inet_aton(&tp->local_name.host, &addr) != 0) {
 	    if (addr.s_addr==PJ_INADDR_ANY || addr.s_addr==PJ_INADDR_NONE) {
-		PJ_LOG(3,("", "   Error: invalid address name"));
+		PJ_LOG(3,(THIS_FILE, "   Error: invalid address name"));
 		return -420;
 	    }
 	} else {
@@ -121,13 +123,6 @@
 	pjsip_response_addr res_addr;
 	pj_status_t status;
 
-	PJ_LOG(4,("test", "Received %d bytes request: --begin-\n"
-			  "%s\n"
-			  "--end--",
-			  rdata->msg_info.len,
-			  rdata->msg_info.msg_buf));
-
-
 	status = pjsip_endpt_create_response( endpt, rdata, 200, NULL, &tdata);
 	if (status != PJ_SUCCESS) {
 	    recv_status = status;
@@ -155,12 +150,6 @@
 static pj_bool_t my_on_rx_response(pjsip_rx_data *rdata)
 {
     if (pj_strcmp2(&rdata->msg_info.call_id, CALL_ID_HDR) == 0) {
-	PJ_LOG(4,("test", "Received %d bytes response: --begin-\n"
-			  "%s\n"
-			  "--end--",
-			  rdata->msg_info.len,
-			  rdata->msg_info.msg_buf));
-
 	pj_get_timestamp(&my_recv_time);
 	recv_status = PJ_SUCCESS;
 	return PJ_TRUE;
@@ -189,13 +178,14 @@
 			      pjsip_transport *ref_tp,
 			      char *target_url )
 {
+    pj_bool_t msg_log_enabled;
     pj_status_t status;
     pj_str_t target, from, to, contact, call_id, body;
     pjsip_method method;
     pjsip_tx_data *tdata;
     pj_time_val timeout;
 
-    PJ_LOG(3,("", "  single message round-trip test..."));
+    PJ_LOG(3,(THIS_FILE, "  single message round-trip test..."));
 
     /* Register out test module to receive the message (if necessary). */
     if (my_module.id == -1) {
@@ -206,6 +196,9 @@
 	}
     }
 
+    /* Disable message logging. */
+    msg_log_enabled = msg_logger_set_enabled(0);
+
     /* Create a request message. */
     target = pj_str(target_url);
     from = pj_str(FROM_HDR);
@@ -249,7 +242,7 @@
 
 	pj_gettimeofday(&now);
 	if (PJ_TIME_VAL_GTE(now, timeout)) {
-	    PJ_LOG(3,("", "   error: timeout in send/recv test"));
+	    PJ_LOG(3,(THIS_FILE, "   error: timeout in send/recv test"));
 	    status = -540;
 	    goto on_return;
 	}
@@ -278,9 +271,12 @@
     if (status == PJ_SUCCESS) {
 	unsigned usec_rt;
 	usec_rt = pj_elapsed_usec(&my_send_time, &my_recv_time);
-	PJ_LOG(3,("", "    round-trip = %d usec", usec_rt));
+	PJ_LOG(3,(THIS_FILE, "    round-trip = %d usec", usec_rt));
     }
 
+    /* Restore message logging. */
+    msg_logger_set_enabled(msg_log_enabled);
+
     status = PJ_SUCCESS;
 
 on_return:
@@ -327,6 +323,9 @@
     pj_timestamp total_rt_time;
     int sent_request_count, recv_response_count;
     pj_str_t call_id;
+    pj_timer_entry timeout_timer;
+    pj_timer_entry tx_timer;
+    pj_mutex_t *mutex;
 } rt_test_data[16];
 
 static char	 rt_target_uri[64];
@@ -371,6 +370,9 @@
     pj_status_t status;
     pj_str_t target, from, to, contact, call_id;
     pjsip_tx_data *tdata;
+    pj_time_val timeout_delay;
+
+    pj_mutex_lock(rt_test_data[thread_id].mutex);
 
     /* Create a request message. */
     target = pj_str(rt_target_uri);
@@ -384,7 +386,8 @@
 					 &contact, &call_id, -1, 
 					 NULL, &tdata );
     if (status != PJ_SUCCESS) {
-	app_perror("   error: unable to create request", status);
+	app_perror("    error: unable to create request", status);
+	pj_mutex_unlock(rt_test_data[thread_id].mutex);
 	return -610;
     }
 
@@ -395,14 +398,25 @@
     status = pjsip_endpt_send_request_stateless( endpt, tdata, NULL, NULL);
     if (status != PJ_SUCCESS) {
 	/* Immediate error! */
-	app_perror("   error: send request", status);
+	app_perror("    error: send request", status);
 	pjsip_tx_data_dec_ref(tdata);
+	pj_mutex_unlock(rt_test_data[thread_id].mutex);
 	return -620;
     }
 
     /* Update counter. */
     rt_test_data[thread_id].sent_request_count++;
 
+    /* Set timeout timer. */
+    if (rt_test_data[thread_id].timeout_timer.user_data != NULL) {
+	pjsip_endpt_cancel_timer(endpt, &rt_test_data[thread_id].timeout_timer);
+    }
+    timeout_delay.sec = 100; timeout_delay.msec = 0;
+    rt_test_data[thread_id].timeout_timer.user_data = (void*)1;
+    pjsip_endpt_schedule_timer(endpt, &rt_test_data[thread_id].timeout_timer,
+			       &timeout_delay);
+
+    pj_mutex_unlock(rt_test_data[thread_id].mutex);
     return PJ_SUCCESS;
 }
 
@@ -413,6 +427,11 @@
 	int thread_id = (*pos - '0');
 	pj_timestamp recv_time;
 
+	pj_mutex_lock(rt_test_data[thread_id].mutex);
+
+	/* Stop timer. */
+	pjsip_endpt_cancel_timer(endpt, &rt_test_data[thread_id].timeout_timer);
+
 	/* Update counter and end-time. */
 	rt_test_data[thread_id].recv_response_count++;
 	pj_get_timestamp(&recv_time);
@@ -420,14 +439,55 @@
 	pj_sub_timestamp(&recv_time, &rt_test_data[thread_id].send_time);
 	pj_add_timestamp(&rt_test_data[thread_id].total_rt_time, &recv_time);
 
-	if (!rt_stop)
-	    rt_send_request(thread_id);
+	if (!rt_stop) {
+	    pj_time_val tx_delay = { 0, 0 };
+	    pj_assert(rt_test_data[thread_id].tx_timer.user_data == NULL);
+	    rt_test_data[thread_id].tx_timer.user_data = (void*)1;
+	    pjsip_endpt_schedule_timer(endpt, &rt_test_data[thread_id].tx_timer,
+				       &tx_delay);
+	}
+
+	pj_mutex_unlock(rt_test_data[thread_id].mutex);
+
 	return PJ_TRUE;
     }
     return PJ_FALSE;
 }
 
-static int rt_thread(void *arg)
+static void rt_timeout_timer( pj_timer_heap_t *timer_heap,
+			      struct pj_timer_entry *entry )
+{
+    pj_mutex_lock(rt_test_data[entry->id].mutex);
+
+    PJ_UNUSED_ARG(timer_heap);
+    PJ_LOG(3,(THIS_FILE, "    timeout waiting for response"));
+    rt_test_data[entry->id].timeout_timer.user_data = NULL;
+    
+    if (rt_test_data[entry->id].tx_timer.user_data == NULL) {
+	pj_time_val delay = { 0, 0 };
+	rt_test_data[entry->id].tx_timer.user_data = (void*)1;
+	pjsip_endpt_schedule_timer(endpt, &rt_test_data[entry->id].tx_timer,
+				   &delay);
+    }
+
+    pj_mutex_unlock(rt_test_data[entry->id].mutex);
+}
+
+static void rt_tx_timer( pj_timer_heap_t *timer_heap,
+			 struct pj_timer_entry *entry )
+{
+    pj_mutex_lock(rt_test_data[entry->id].mutex);
+
+    PJ_UNUSED_ARG(timer_heap);
+    pj_assert(rt_test_data[entry->id].tx_timer.user_data != NULL);
+    rt_test_data[entry->id].tx_timer.user_data = NULL;
+    rt_send_request(entry->id);
+
+    pj_mutex_unlock(rt_test_data[entry->id].mutex);
+}
+
+
+static int rt_worker_thread(void *arg)
 {
     int i, thread_id = (int)arg;
     pj_time_val poll_delay = { 0, 10 };
@@ -435,10 +495,6 @@
     /* Sleep to allow main threads to run. */
     pj_thread_sleep(10);
 
-    /* Send the first request. */
-    if (rt_send_request(thread_id) != PJ_SUCCESS)
-	return -1;
-
     while (!rt_stop) {
 	pjsip_endpt_handle_events(endpt, &poll_delay);
     }
@@ -452,13 +508,14 @@
 
 int transport_rt_test( pjsip_transport_type_e tp_type,
 		       pjsip_transport *ref_tp,
-		       char *target_url )
+		       char *target_url,
+		       int *lost)
 {
     enum { THREADS = 4, INTERVAL = 10 };
     int i;
     pj_status_t status;
     pj_pool_t *pool;
-    pj_bool_t is_reliable;
+    pj_bool_t logger_enabled;
 
     pj_timestamp zero_time, total_time;
     unsigned usec_rt;
@@ -466,11 +523,13 @@
     unsigned total_recv;
 
 
-    PJ_LOG(3,("", "  multithreaded round-trip test (%d threads)...",
+    PJ_LOG(3,(THIS_FILE, "  multithreaded round-trip test (%d threads)...",
 		  THREADS));
-    PJ_LOG(3,("", "    this will take approx %d seconds, please wait..", INTERVAL));
+    PJ_LOG(3,(THIS_FILE, "    this will take approx %d seconds, please wait..",
+		INTERVAL));
 
-    is_reliable = (pjsip_transport_get_flag_from_type(tp_type) & PJSIP_TRANSPORT_RELIABLE);
+    /* Make sure msg logger is disabled. */
+    logger_enabled = msg_logger_set_enabled(0);
 
     /* Register module (if not yet registered) */
     if (rt_module.id == -1) {
@@ -498,14 +557,27 @@
 
 	pj_memset(&rt_test_data[i], 0, sizeof(rt_test_data[i]));
 
+	/* Init timer entry */
+	rt_test_data[i].tx_timer.id = i;
+	rt_test_data[i].tx_timer.cb = &rt_tx_timer;
+	rt_test_data[i].timeout_timer.id = i;
+	rt_test_data[i].timeout_timer.cb = &rt_timeout_timer;
+
 	/* Generate Call-ID for each thread. */
 	rt_test_data[i].call_id.ptr = pj_pool_alloc(pool, rt_call_id.slen+1);
 	pj_strcpy(&rt_test_data[i].call_id, &rt_call_id);
 	buf[0] = '0' + i;
 	pj_strcat(&rt_test_data[i].call_id, &str_id);
 
+	/* Init mutex. */
+	status = pj_mutex_create_recursive(pool, "rt", &rt_test_data[i].mutex);
+	if (status != PJ_SUCCESS) {
+	    app_perror("   error: unable to create mutex", status);
+	    return -615;
+	}
+
 	/* Create thread, suspended. */
-	status = pj_thread_create(pool, "rttest%p", &rt_thread, (void*)i, 0,
+	status = pj_thread_create(pool, "rttest%p", &rt_worker_thread, (void*)i, 0,
 				  PJ_THREAD_SUSPENDED, &rt_test_data[i].thread);
 	if (status != PJ_SUCCESS) {
 	    app_perror("   error: unable to create thread", status);
@@ -515,7 +587,12 @@
 
     /* Start threads! */
     for (i=0; i<THREADS; ++i) {
+	pj_time_val delay = {0,0};
 	pj_thread_resume(rt_test_data[i].thread);
+
+	/* Schedule first message transmissions. */
+	rt_test_data[i].tx_timer.user_data = (void*)1;
+	pjsip_endpt_schedule_timer(endpt, &rt_test_data[i].tx_timer, &delay);
     }
 
     /* Sleep for some time. */
@@ -530,6 +607,12 @@
 	pj_thread_destroy(rt_test_data[i].thread);
     }
 
+    /* Destroy rt_test_data */
+    for (i=0; i<THREADS; ++i) {
+	pj_mutex_destroy(rt_test_data[i].mutex);
+	pjsip_endpt_cancel_timer(endpt, &rt_test_data[i].timeout_timer);
+    }
+
     /* Gather statistics. */
     pj_memset(&total_time, 0, sizeof(total_time));
     pj_memset(&zero_time, 0, sizeof(zero_time));
@@ -546,19 +629,19 @@
     else
 	total_time.u64 = 0;
     usec_rt = pj_elapsed_usec(&zero_time, &total_time);
-    PJ_LOG(3,("", "    done."));
-    PJ_LOG(3,("", "    total %d messages sent", total_sent));
-    if (total_sent-total_recv)
-	PJ_LOG(2,("", "    total %d messages LOST", total_sent-total_recv));
-    else
-	PJ_LOG(3,("", "    no message was lost"));
-    PJ_LOG(3,("", "    average round-trip=%d usec", usec_rt));
+    PJ_LOG(3,(THIS_FILE, "    done."));
+    PJ_LOG(3,(THIS_FILE, "    total %d messages sent", total_sent));
+    PJ_LOG(3,(THIS_FILE, "    average round-trip=%d usec", usec_rt));
 
     pjsip_endpt_release_pool(endpt, pool);
 
-    if (is_reliable && (total_sent != total_recv)) {
-	PJ_LOG(3,("", "   error: %d messages lost", total_sent-total_recv));
-	return -650;
-    }
+    *lost = total_sent-total_recv;
+
+    /* Flush events. */
+    flush_events(500);
+
+    /* Restore msg logger. */
+    msg_logger_set_enabled(logger_enabled);
+
     return 0;
 }
diff --git a/pjsip/src/test-pjsip/transport_udp_test.c b/pjsip/src/test-pjsip/transport_udp_test.c
index 0fdbdda..ebc0557 100644
--- a/pjsip/src/test-pjsip/transport_udp_test.c
+++ b/pjsip/src/test-pjsip/transport_udp_test.c
@@ -21,6 +21,8 @@
 #include <pjsip_core.h>
 #include <pjlib.h>
 
+#define THIS_FILE   "transport_udp_test.c"
+
 
 /*
  * UDP transport test.
@@ -32,7 +34,7 @@
     pj_sockaddr_in addr, rem_addr;
     pj_str_t s;
     pj_status_t status;
-    int i;
+    int i, pkt_lost;
 
     pj_sockaddr_in_init(&addr, NULL, TEST_UDP_PORT);
 
@@ -84,10 +86,14 @@
 
     /* Multi-threaded round-trip test. */
     status = transport_rt_test(PJSIP_TRANSPORT_UDP, tp, 
-			       "sip:alice@127.0.0.1:"TEST_UDP_PORT_STR);
+			       "sip:alice@127.0.0.1:"TEST_UDP_PORT_STR, 
+			       &pkt_lost);
     if (status != 0)
 	return status;
 
+    if (pkt_lost != 0)
+	PJ_LOG(3,(THIS_FILE, "   note: %d packet(s) was lost", pkt_lost));
+
     /* Check again that reference counter is 1. */
     if (pj_atomic_get(udp_tp->ref_cnt) != 1)
 	return -80;
@@ -100,6 +106,9 @@
     if (status != PJ_SUCCESS)
 	return -90;
 
+    /* Flush events. */
+    PJ_LOG(3,(THIS_FILE, "   Flushing events, 1 second..."));
+    flush_events(1000);
 
     /* Done */
     return 0;
diff --git a/pjsip/src/test-pjsip/tsx_basic_test.c b/pjsip/src/test-pjsip/tsx_basic_test.c
new file mode 100644
index 0000000..1db86f8
--- /dev/null
+++ b/pjsip/src/test-pjsip/tsx_basic_test.c
@@ -0,0 +1,147 @@
+/* $Id$ */
+/* 
+ * 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_basic_test.c"
+
+/* Test transaction layer. */
+static int tsx_layer_test(void)
+{
+    pj_str_t target, from, tsx_key;
+    pjsip_tx_data *tdata;
+    pjsip_transaction *tsx, *found;
+    pj_status_t status;
+
+    PJ_LOG(3,(THIS_FILE, "  transaction layer test"));
+
+    target = pj_str("sip:alice@localhost");
+    from = pj_str("sip:bob@localhost");
+
+    status = pjsip_endpt_create_request(endpt, &pjsip_invite_method, &target,
+					&from, &target, NULL, NULL, -1, NULL,
+					&tdata);
+    if (status != PJ_SUCCESS) {
+	app_perror("  error: unable to create request", status);
+	return -110;
+    }
+
+    status = pjsip_tsx_create_uac(NULL, tdata, &tsx);
+    if (status != PJ_SUCCESS) {
+	app_perror("   error: unable to create transaction", status);
+	return -120;
+    }
+
+    pj_strdup(tdata->pool, &tsx_key, &tsx->transaction_key);
+
+    found = pjsip_tsx_layer_find_tsx(&tsx_key, PJ_FALSE);
+    if (found != tsx) {
+	return -130;
+    }
+
+    pjsip_tsx_terminate(tsx, PJSIP_SC_REQUEST_TERMINATED);
+    flush_events(500);
+
+    if (pjsip_tx_data_dec_ref(tdata) != PJSIP_EBUFDESTROYED) {
+	return -140;
+    }
+
+    return 0;
+}
+
+/* Double terminate test. */
+static int double_terminate(void)
+{
+    pj_str_t target, from, tsx_key;
+    pjsip_tx_data *tdata;
+    pjsip_transaction *tsx;
+    pj_status_t status;
+
+    PJ_LOG(3,(THIS_FILE, "  double terminate test"));
+
+    target = pj_str("sip:alice@localhost;transport=loop-dgram");
+    from = pj_str("sip:bob@localhost");
+
+    /* Create request. */
+    status = pjsip_endpt_create_request(endpt, &pjsip_invite_method, &target,
+					&from, &target, NULL, NULL, -1, NULL,
+					&tdata);
+    if (status != PJ_SUCCESS) {
+	app_perror("  error: unable to create request", status);
+	return -10;
+    }
+
+    /* Create transaction. */
+    status = pjsip_tsx_create_uac(NULL, tdata, &tsx);
+    if (status != PJ_SUCCESS) {
+	app_perror("   error: unable to create transaction", status);
+	return -20;
+    }
+
+    /* Save transaction key for later. */
+    pj_strdup_with_null(tdata->pool, &tsx_key, &tsx->transaction_key);
+
+    /* Add reference to transmit buffer (tsx_send_msg() will dec txdata). */
+    pjsip_tx_data_add_ref(tdata);
+
+    /* Send message to start timeout timer. */
+    status = pjsip_tsx_send_msg(tsx, NULL);
+
+    /* Terminate transaction. */
+    status = pjsip_tsx_terminate(tsx, PJSIP_SC_REQUEST_TERMINATED);
+    if (status != PJ_SUCCESS) {
+	app_perror("   error: unable to terminate transaction", status);
+	return -30;
+    }
+
+    tsx = pjsip_tsx_layer_find_tsx(&tsx_key, PJ_TRUE);
+    if (tsx) {
+	/* Terminate transaction again. */
+	pjsip_tsx_terminate(tsx, PJSIP_SC_REQUEST_TERMINATED);
+	if (status != PJ_SUCCESS) {
+	    app_perror("   error: unable to terminate transaction", status);
+	    return -40;
+	}
+	pj_mutex_unlock(tsx->mutex);
+    }
+
+    flush_events(500);
+    if (pjsip_tx_data_dec_ref(tdata) != PJSIP_EBUFDESTROYED) {
+	return -50;
+    }
+
+    return PJ_SUCCESS;
+}
+
+int tsx_basic_test(void)
+{
+    int status;
+
+    status = tsx_layer_test();
+    if (status != 0)
+	return status;
+
+    status = double_terminate();
+    if (status != 0)
+	return status;
+
+    return 0;
+}
diff --git a/pjsip/src/test-pjsip/tsx_uac_test.c b/pjsip/src/test-pjsip/tsx_uac_test.c
index 24af41e..cf40e5d 100644
--- a/pjsip/src/test-pjsip/tsx_uac_test.c
+++ b/pjsip/src/test-pjsip/tsx_uac_test.c
@@ -21,17 +21,77 @@
 #include <pjsip_core.h>
 #include <pjlib.h>
 
+#define THIS_FILE   "tsx_uac_test.c"
+
+
 /*****************************************************************************
  **
- ** UAC basic retransmission and timeout test.
+ ** UAC tests.
  **
- ** This will test the retransmission of the UAC transaction. Remote will not
- ** answer the transaction, so the transaction should fail.
+ ** 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
+ **	Perform basic retransmission and timeout test. Message receiver will
+ **	verify that retransmission is received at correct time.
+ **     This test verifies the following requirements:
+ **	    - retransmit timer doubles for INVITE
+ **	    - retransmit timer doubles and caps off for non-INVITE
+ **	    - retransmit timer timer is precise
+ **	    - correct timeout and retransmission count
+ **     Requirements not tested:
+ **	    - retransmit timer only starts after resolving has completed.
+ **
+ ** TEST2_BRANCH_ID
+ **	Test scenario where resolver is unable to resolve destination host.
+ **
+ ** TEST3_BRANCH_ID
+ **	Test scenario where transaction is terminated while resolver is still
+ **	running.
+ **
+ ** TEST4_BRANCH_ID
+ **	Test scenario where transport failed after several retransmissions.
+ **
+ ** TEST5_BRANCH_ID
+ **	Test scenario where transaction is terminated by user after several
+ **	retransmissions.
+ **
+ ** TEST6_BRANCH_ID
+ **	Test successfull non-INVITE transaction.
+ **     It tests the following requirements:
+ **	    - transaction correctly moves to COMPLETED state.
+ **	    - retransmission must cease.
+ **	    - tx_data must be maintained until state is terminated.
+ **
+ ** TEST7_BRANCH_ID
+ **	Test successfull non-INVITE transaction, with provisional response.
+ **
+ ** TEST8_BRANCH_ID
+ **	Test failed INVITE transaction (e.g. ACK must be received)
+ **
+ ** TEST9_BRANCH_ID
+ **	Test failed INVITE transaction with provisional response.
+ **
+ **	
  *****************************************************************************
  */
 
-static char *CALL_ID1 = "UAC-Tsx-Basic-Test1";
+static char *TEST1_BRANCH_ID = PJSIP_RFC3261_BRANCH_ID "-Test1";
+static char *TEST2_BRANCH_ID = PJSIP_RFC3261_BRANCH_ID "-Test2";
+static char *TEST3_BRANCH_ID = PJSIP_RFC3261_BRANCH_ID "-Test3";
+static char *TEST4_BRANCH_ID = PJSIP_RFC3261_BRANCH_ID "-Test4";
+static char *TEST5_BRANCH_ID = PJSIP_RFC3261_BRANCH_ID "-Test5";
+static char *TEST6_BRANCH_ID = PJSIP_RFC3261_BRANCH_ID "-Test6";
+static char *TEST7_BRANCH_ID = PJSIP_RFC3261_BRANCH_ID "-Test7";
+static char *TEST8_BRANCH_ID = PJSIP_RFC3261_BRANCH_ID "-Test8";
+static char *TEST9_BRANCH_ID = PJSIP_RFC3261_BRANCH_ID "-Test9";
+
+#define      TEST1_ALLOWED_DIFF	    (150)
+#define      TEST4_RETRANSMIT_CNT   3
+#define	     TEST5_RETRANSMIT_CNT   3
+
+
 static void tsx_user_on_tsx_state(pjsip_transaction *tsx, pjsip_event *e);
 static pj_bool_t msg_receiver_on_rx_request(pjsip_rx_data *rdata);
 
@@ -51,6 +111,8 @@
     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()	*/
 };
 
@@ -70,39 +132,205 @@
     NULL,				/* unload()		*/
     &msg_receiver_on_rx_request,	/* on_rx_request()	*/
     NULL,				/* on_rx_response()	*/
+    NULL,				/* on_tx_request()	*/
+    NULL,				/* on_tx_response()	*/
     NULL,				/* on_tsx_state()	*/
 };
 
-/* Static vars. */
+/* 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;
+
+/*
+ * 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 (tsx->state == PJSIP_TSX_STATE_TERMINATED && test_complete==0)
-	test_complete = 1;
+    if (pj_strcmp2(&tsx->branch, TEST1_BRANCH_ID)==0) {
+	/*
+	 * Transaction with TEST1_BRANCH_ID should terminate with transaction
+	 * timeout status.
+	 */
+	if (tsx->state == PJSIP_TSX_STATE_TERMINATED) {
+
+	    if (test_complete == 0)
+		test_complete = 1;
+
+	    /* Test the status code. */
+	    if (tsx->status_code != PJSIP_SC_TSX_TIMEOUT) {
+		PJ_LOG(3,(THIS_FILE, 
+			  "    error: status code is %d instead of %d",
+			  tsx->status_code, PJSIP_SC_TSX_TIMEOUT));
+		test_complete = -710;
+	    }
+	}
+
+    } else if (pj_strcmp2(&tsx->branch, TEST2_BRANCH_ID)==0) {
+	/*
+	 * Transaction with TEST2_BRANCH_ID should terminate with transport error.
+	 */
+	if (tsx->state == PJSIP_TSX_STATE_TERMINATED) {
+
+	    /* Test the status code. */
+	    if (tsx->status_code != PJSIP_SC_TSX_TRANSPORT_ERROR) {
+		PJ_LOG(3,(THIS_FILE, 
+			  "    error: status code is %d instead of %d",
+			  tsx->status_code, PJSIP_SC_TSX_TRANSPORT_ERROR));
+		test_complete = -720;
+	    }
+
+	    if (test_complete == 0)
+		test_complete = 1;
+	}
+
+    } else if (pj_strcmp2(&tsx->branch, TEST3_BRANCH_ID)==0) {
+	/*
+	 * This test terminates the transaction while resolver is still
+	 * running. 
+	 */
+	if (tsx->state == PJSIP_TSX_STATE_CALLING) {
+
+	    /* Terminate the transaction. */
+	    pjsip_tsx_terminate(tsx, PJSIP_SC_REQUEST_TERMINATED);
+
+	} else if (tsx->state == PJSIP_TSX_STATE_TERMINATED) {
+
+	    /* Check if status code is correct. */
+	    if (tsx->status_code != PJSIP_SC_REQUEST_TERMINATED) {
+		PJ_LOG(3,(THIS_FILE, 
+			  "    error: status code is %d instead of %d",
+			  tsx->status_code, PJSIP_SC_REQUEST_TERMINATED));
+		test_complete = -730;
+	    }
+
+	    if (test_complete == 0)
+		test_complete = 1;
+
+	}
+
+    } else if (pj_strcmp2(&tsx->branch, TEST4_BRANCH_ID)==0) {
+	/* 
+	 * This test simulates transport failure after several 
+	 * retransmissions.
+	 */
+	if (tsx->state == PJSIP_TSX_STATE_TERMINATED) {
+
+	    /* Status code must be transport error. */
+	    if (tsx->status_code != PJSIP_SC_TSX_TRANSPORT_ERROR) {
+		PJ_LOG(3,(THIS_FILE, 
+			  "    error: status code is %d instead of %d",
+			  tsx->status_code, PJSIP_SC_TSX_TRANSPORT_ERROR));
+		test_complete = -730;
+	    }
+
+	    /* Must have correct retransmission count. */
+	    if (tsx->retransmit_count != TEST4_RETRANSMIT_CNT) {
+		PJ_LOG(3,(THIS_FILE, 
+			  "    error: retransmit cnt is %d instead of %d",
+			  tsx->retransmit_count, TEST4_RETRANSMIT_CNT));
+		test_complete = -731;
+	    }
+
+	    if (test_complete == 0)
+		test_complete = 1;
+	}
+
+
+    } else if (pj_strcmp2(&tsx->branch, TEST5_BRANCH_ID)==0) {
+	/* 
+	 * This test simulates transport failure after several 
+	 * retransmissions.
+	 */
+	if (tsx->state == PJSIP_TSX_STATE_TERMINATED) {
+
+	    /* Status code must be PJSIP_SC_REQUEST_TERMINATED. */
+	    if (tsx->status_code != PJSIP_SC_REQUEST_TERMINATED) {
+		PJ_LOG(3,(THIS_FILE, 
+			  "    error: status code is %d instead of %d",
+			  tsx->status_code, PJSIP_SC_REQUEST_TERMINATED));
+		test_complete = -733;
+	    }
+
+	    /* Must have correct retransmission count. */
+	    if (tsx->retransmit_count != TEST5_RETRANSMIT_CNT) {
+		PJ_LOG(3,(THIS_FILE, 
+			  "    error: retransmit cnt is %d instead of %d",
+			  tsx->retransmit_count, TEST5_RETRANSMIT_CNT));
+		test_complete = -734;
+	    }
+
+	    if (test_complete == 0)
+		test_complete = 1;
+	}
+
+
+    } else if (pj_strcmp2(&tsx->branch, TEST6_BRANCH_ID)==0) {
+	/* 
+	 * Successfull non-INVITE transaction.
+	 */
+	if (tsx->state == PJSIP_TSX_STATE_COMPLETED) {
+
+	    /* Status code must be 202. */
+	    if (tsx->status_code != 202) {
+		PJ_LOG(3,(THIS_FILE, 
+			  "    error: status code is %d instead of %d",
+			  tsx->status_code, 202));
+		test_complete = -736;
+	    }
+
+	    /* Must have correct retransmission count. */
+	    if (tsx->retransmit_count != 0) {
+		PJ_LOG(3,(THIS_FILE, 
+			  "    error: retransmit cnt is %d instead of %d",
+			  tsx->retransmit_count, 0));
+		test_complete = -737;
+	    }
+
+	    /* Must still keep last_tx */
+	    if (tsx->last_tx == NULL) {
+		PJ_LOG(3,(THIS_FILE, 
+			  "    error: transaction lost last_tx"));
+		test_complete = -738;
+	    }
+
+	    if (test_complete == 0) {
+		test_complete = 1;
+		pjsip_tsx_terminate(tsx, 202);
+	    }
+	}
+    }
 }
 
 #define DIFF(a,b)   ((a<b) ? (b-a) : (a-b))
 
+/*
+ * This is the handler to receive message for this test. It is used to
+ * control and verify the behavior of the message transmitted by the
+ * transaction.
+ */
 static pj_bool_t msg_receiver_on_rx_request(pjsip_rx_data *rdata)
 {
-    if (pj_strcmp2(&rdata->msg_info.call_id, CALL_ID1) == 0) {
+    if (pj_strcmp2(&rdata->msg_info.via->branch_param, TEST1_BRANCH_ID) == 0) {
 	/*
-	 * The CALL_ID1 test performs the verifications for transaction
+	 * The TEST1_BRANCH_ID test performs the verifications for transaction
 	 * retransmission mechanism. It will not answer the incoming request
 	 * with any response.
 	 */
 	pjsip_msg *msg = rdata->msg_info.msg;
 
-	PJ_LOG(4,("", "   received request"));
+	PJ_LOG(4,(THIS_FILE, "    received request"));
 
 	/* Only wants to take INVITE or OPTIONS method. */
 	if (msg->line.req.method.id != PJSIP_INVITE_METHOD &&
 	    msg->line.req.method.id != PJSIP_OPTIONS_METHOD)
 	{
-	    PJ_LOG(3,("", "   error: received unexpected method %.*s",
+	    PJ_LOG(3,(THIS_FILE, "    error: received unexpected method %.*s",
 			  msg->line.req.method.name.slen,
 			  msg->line.req.method.name.ptr));
 	    test_complete = -600;
@@ -111,12 +339,15 @@
 
 	if (recv_count == 0) {
 	    recv_count++;
-	    pj_gettimeofday(&recv_last);
+	    //pj_gettimeofday(&recv_last);
+	    recv_last = rdata->pkt_info.timestamp;
 	} else {
 	    pj_time_val now;
 	    unsigned msec_expected, msec_elapsed;
+	    int max_received;
 
-	    pj_gettimeofday(&now);
+	    //pj_gettimeofday(&now);
+	    now = rdata->pkt_info.timestamp;
 	    PJ_TIME_VAL_SUB(now, recv_last);
 	    msec_elapsed = now.sec*1000 + now.msec;
 
@@ -126,63 +357,165 @@
 	    if (msg->line.req.method.id != PJSIP_INVITE_METHOD) {
 		if (msec_expected > PJSIP_T2_TIMEOUT)
 		    msec_expected = PJSIP_T2_TIMEOUT;
+		max_received = 11;
+	    } else {
+		max_received = 7;
 	    }
 
-	    if (DIFF(msec_expected, msec_elapsed) > 100) {
-		PJ_LOG(3,("","   error: expecting %d-th retransmission in %d "
-			     "ms, received in %d ms",
-			     recv_count-1, msec_expected, msec_elapsed));
+	    if (DIFF(msec_expected, msec_elapsed) > TEST1_ALLOWED_DIFF) {
+		PJ_LOG(3,(THIS_FILE,
+			  "    error: expecting retransmission no. %d in %d "
+			  "ms, received in %d ms",
+			  recv_count-1, msec_expected, msec_elapsed));
 		test_complete = -610;
 	    }
 
-	    if (recv_count > 7) {
-		PJ_LOG(3,("", "   error: too many messages (%d) received",
-			      recv_count));
+	    
+	    if (recv_count > max_received) {
+		PJ_LOG(3,(THIS_FILE, 
+			  "    error: too many messages (%d) received",
+			  recv_count));
 		test_complete = -620;
 	    }
 
-	    pj_gettimeofday(&recv_last);
+	    //pj_gettimeofday(&recv_last);
+	    recv_last = rdata->pkt_info.timestamp;
 	}
 	return PJ_TRUE;
+
+    } else
+    if (pj_strcmp2(&rdata->msg_info.via->branch_param, TEST4_BRANCH_ID) == 0) {
+	/*
+	 * The TEST4_BRANCH_ID test simulates transport failure after several
+	 * retransmissions.
+	 */
+	recv_count++;
+
+	if (recv_count == TEST4_RETRANSMIT_CNT) {
+	    /* Simulate transport failure. */
+	    pjsip_loop_set_failure(loop, 2, NULL);
+
+	} else if (recv_count > TEST4_RETRANSMIT_CNT) {
+	    PJ_LOG(3,(THIS_FILE,"   error: not expecting %d-th packet!",
+		      recv_count));
+	    test_complete = -631;
+	}
+
+	return PJ_TRUE;
+
+
+    } else
+    if (pj_strcmp2(&rdata->msg_info.via->branch_param, TEST5_BRANCH_ID) == 0) {
+	/*
+	 * The TEST5_BRANCH_ID test simulates user terminating the transaction
+	 * after several retransmissions.
+	 */
+	recv_count++;
+
+	if (recv_count == TEST5_RETRANSMIT_CNT+1) {
+	    pj_str_t key;
+	    pjsip_transaction *tsx;
+
+	    pjsip_tsx_create_key( rdata->tp_info.pool, &key, PJSIP_ROLE_UAC,
+				  &rdata->msg_info.msg->line.req.method, rdata);
+	    tsx = pjsip_tsx_layer_find_tsx(&key, PJ_TRUE);
+	    if (tsx) {
+		pjsip_tsx_terminate(tsx, PJSIP_SC_REQUEST_TERMINATED);
+		pj_mutex_unlock(tsx->mutex);
+	    } else {
+		PJ_LOG(3,(THIS_FILE, "    error: uac transaction not found!"));
+		test_complete = -633;
+	    }
+
+	} else if (recv_count > TEST5_RETRANSMIT_CNT+1) {
+	    PJ_LOG(3,(THIS_FILE,"   error: not expecting %d-th packet!",
+		      recv_count));
+	    test_complete = -634;
+	}
+
+	return PJ_TRUE;
+
+    } else
+    if (pj_strcmp2(&rdata->msg_info.via->branch_param, TEST6_BRANCH_ID) == 0) {
+	/*
+	 * The TEST5_BRANCH_ID test successfull non-INVITE transaction.
+	 */
+	pjsip_tx_data *tdata;
+	pjsip_response_addr res_addr;
+	pj_status_t status;
+
+	recv_count++;
+
+	if (recv_count > 1) {
+	    PJ_LOG(3,(THIS_FILE,"   error: not expecting %d-th packet!",
+		      recv_count));
+	    test_complete = -635;
+	}
+
+	status = pjsip_endpt_create_response(endpt, rdata, 202, NULL, &tdata);
+	if (status != PJ_SUCCESS) {
+	    app_perror("    error: unable to create response", status);
+	    test_complete = -636;
+	}
+
+	status = pjsip_get_response_addr(tdata->pool, rdata, &res_addr);
+	if (status != PJ_SUCCESS) {
+	    app_perror("    error: unable to get response addr", status);
+	    test_complete = -637;
+	}
+
+	status = pjsip_endpt_send_response(endpt, &res_addr, tdata, NULL,NULL);
+	if (status != PJ_SUCCESS) {
+	    app_perror("    error: unable to send response", status);
+	    test_complete = -638;
+	    pjsip_tx_data_dec_ref(tdata);
+	}
+
+	return PJ_TRUE;
     }
+
     return PJ_FALSE;
 }
 
-/*****************************************************************************
- **
- ** UAC basic retransmission and timeout test.
- **
- ** This will test the retransmission of the UAC transaction. Remote will not
- ** answer the transaction, so the transaction should fail. The Call-ID
- ** CALL_ID1 will be used for this test.
- **
- *****************************************************************************
+/* 
+ * The generic test framework, used by most of the tests. 
  */
-static int tsx_uac_retransmit_test(const pjsip_method *method)
+static int perform_tsx_test(int dummy, char *target_uri, char *from_uri, 
+			    char *branch_param, int test_time, 
+			    const pjsip_method *method)
 {
     pjsip_tx_data *tdata;
     pjsip_transaction *tsx;
-    char buf[80];
-    pj_str_t target, from, call_id, tsx_key;
+    pj_str_t target, from, tsx_key;
+    pjsip_via_hdr *via;
     pj_time_val timeout;
     pj_status_t status;
 
-    PJ_LOG(3,("", "  basic uac retransmission and timeout test"));
+    PJ_LOG(3,(THIS_FILE, 
+	      "   please standby, this will take at most %d seconds..",
+	      test_time));
 
-    pj_sprintf(buf, "sip:alice@127.0.0.1:%d", TEST_UDP_PORT);
-    target = pj_str(buf);
-    from = pj_str("sip:bob@127.0.0.1");
-    call_id = pj_str(CALL_ID1);
+    /* Reset test. */
+    recv_count = 0;
+    test_complete = 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, &call_id, -1, 
+					 &from, &target, NULL, NULL, -1, 
 					 NULL, &tdata);
     if (status != PJ_SUCCESS) {
 	app_perror("   Error: unable to create request", status);
-	return -500;
+	return -100;
     }
 
+    /* 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.
      */
@@ -192,7 +525,8 @@
     status = pjsip_tsx_create_uac( &tsx_user, tdata, &tsx);
     if (status != PJ_SUCCESS) {
 	app_perror("   Error: unable to create UAC transaction", status);
-	return -510;
+	pjsip_tx_data_dec_ref(tdata);
+	return -110;
     }
 
     /* Get transaction key. */
@@ -200,42 +534,65 @@
 
     /* Send the message. */
     status = pjsip_tsx_send_msg(tsx, NULL);
-    if (status != PJ_SUCCESS) {
-	app_perror("   Error: unable to send request", status);
-	return -520;
-    }
+    // Ignore send result. Some tests do deliberately triggers error
+    // when sending message.
+    //if (status != PJ_SUCCESS) {
+    //	app_perror("   Error: unable to send request", status);
+    //  pjsip_tx_data_dec_ref(tdata);
+    //	return -120;
+    //}
+
 
     /* Set test completion time. */
     pj_gettimeofday(&timeout);
-    timeout.sec += 33;
+    timeout.sec += test_time;
 
     /* Wait until test complete. */
     while (!test_complete) {
-	pj_time_val now;
+	pj_time_val now, poll_delay = {0, 10};
 
-	pjsip_endpt_handle_events(endpt, NULL);
+	pjsip_endpt_handle_events(endpt, &poll_delay);
 
 	pj_gettimeofday(&now);
 	if (now.sec > timeout.sec) {
-	    PJ_LOG(3,("", "   Error: test has timed out"));
-	    return -530;
+	    PJ_LOG(3,(THIS_FILE, "   Error: test has timed out"));
+	    pjsip_tx_data_dec_ref(tdata);
+	    return -130;
 	}
     }
 
-    if (status < 0)
+    if (status < 0) {
+	pjsip_tx_data_dec_ref(tdata);
 	return status;
+    }
+
+    if (test_complete < 0) {
+	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,("", "   Error: transaction has not been destroyed"));
-	return -540;
+	PJ_LOG(3,(THIS_FILE, "   Error: transaction has not been destroyed"));
+	pjsip_tx_data_dec_ref(tdata);
+	return -140;
     }
 
     /* Check tdata reference counter. */
     if (pj_atomic_get(tdata->ref_cnt) != 1) {
-	PJ_LOG(3,("", "   Error: tdata reference counter is %d",
+	PJ_LOG(3,(THIS_FILE, "   Error: tdata reference counter is %d",
 		      pj_atomic_get(tdata->ref_cnt)));
-	return -550;
+	pjsip_tx_data_dec_ref(tdata);
+	return -150;
     }
 
     /* Destroy txdata */
@@ -246,6 +603,265 @@
 
 /*****************************************************************************
  **
+ ** TEST1_BRANCH_ID: UAC basic retransmission and timeout test.
+ **
+ ** This will test the retransmission of the UAC transaction. Remote will not
+ ** answer the transaction, so the transaction should fail. The Via branch prm
+ ** TEST1_BRANCH_ID will be used for this test.
+ **
+ *****************************************************************************
+ */
+static int tsx_uac_retransmit_test(void)
+{
+    int status, enabled;
+    int i;
+    struct {
+	const pjsip_method *method;
+	unsigned      delay;
+    } sub_test[] = 
+    {
+	{ &pjsip_invite_method, 0},
+	{ &pjsip_invite_method, TEST1_ALLOWED_DIFF*2},
+	{ &pjsip_options_method, 0},
+	{ &pjsip_options_method, TEST1_ALLOWED_DIFF*2}
+    };
+
+    PJ_LOG(3,(THIS_FILE, "  test1: basic uac retransmit and timeout test"));
+
+
+    /* For this test. message printing shound be disabled because it makes
+     * incorrect timing.
+     */
+    enabled = msg_logger_set_enabled(0);
+
+    for (i=0; i<PJ_ARRAY_SIZE(sub_test); ++i) {
+
+	PJ_LOG(3,(THIS_FILE, 
+		  "   variant %c: %s with %d ms network delay",
+		  ('a' + i),
+		  sub_test[i].method->name.ptr,
+		  sub_test[i].delay));
+
+	/* Configure transport */
+	pjsip_loop_set_failure(loop, 0, NULL);
+	pjsip_loop_set_recv_delay(loop, sub_test[i].delay, NULL);
+
+	/* Do the test. */
+	status = perform_tsx_test(-500, "sip:bob@127.0.0.1;transport=loop-dgram",
+				  "sip:alice@127.0.0.1;transport=loop-dgram", 
+				  TEST1_BRANCH_ID,
+				  35, sub_test[i].method);
+	if (status != 0)
+	    break;
+    }
+
+    /* Restore transport. */
+    pjsip_loop_set_recv_delay(loop, 0, NULL);
+
+    /* Restore msg logger. */
+    msg_logger_set_enabled(enabled);
+
+    /* Done. */
+    return status;
+}
+
+/*****************************************************************************
+ **
+ ** TEST2_BRANCH_ID: UAC resolve error test.
+ **
+ ** Test the scenario where destination host is unresolvable. There are
+ ** two variants:
+ **  (a) resolver returns immediate error
+ **  (b) resolver returns error via the callback.
+ **
+ *****************************************************************************
+ */
+static int tsx_resolve_error_test(void)
+{
+    int status;
+
+    PJ_LOG(3,(THIS_FILE, "  test2: resolve error test"));
+
+    /*
+     * Variant (a): immediate resolve error.
+     */
+    PJ_LOG(3,(THIS_FILE, "   variant a: immediate resolving error"));
+
+    status = perform_tsx_test(-800, 
+			      "sip:bob@unresolved-host;transport=loop-dgram",
+			      "sip:alice@127.0.0.1;transport=loop-dgram", 
+			      TEST2_BRANCH_ID, 10, 
+			      &pjsip_options_method);
+    if (status != 0)
+	return status;
+
+    /*
+     * Variant (b): error via callback.
+     */
+    PJ_LOG(3,(THIS_FILE, "   variant b: error via callback"));
+
+    /* Set loop transport to return delayed error. */
+    pjsip_loop_set_failure(loop, 2, NULL);
+    pjsip_loop_set_send_callback_delay(loop, 10, NULL);
+
+    status = perform_tsx_test(-800, "sip:bob@127.0.0.1;transport=loop-dgram",
+			      "sip:alice@127.0.0.1;transport=loop-dgram", 
+			      TEST2_BRANCH_ID, 2, 
+			      &pjsip_options_method);
+    if (status != 0)
+	return status;
+
+    /* Restore loop transport settings. */
+    pjsip_loop_set_failure(loop, 0, NULL);
+    pjsip_loop_set_send_callback_delay(loop, 0, NULL);
+
+    return status;
+}
+
+
+/*****************************************************************************
+ **
+ ** TEST3_BRANCH_ID: UAC terminate while resolving test.
+ **
+ ** Terminate the transaction while resolver is still running.
+ **
+ *****************************************************************************
+ */
+static int tsx_terminate_resolving_test(void)
+{
+    unsigned prev_delay;
+    pj_status_t status;
+
+    PJ_LOG(3,(THIS_FILE, "  test3: terminate while resolving test"));
+
+    /* Configure transport delay. */
+    pjsip_loop_set_send_callback_delay(loop, 100, &prev_delay);
+
+    /* Start the test. */
+    status = perform_tsx_test(-900, "sip:127.0.0.1;transport=loop-dgram",
+			      "sip:127.0.0.1;transport=loop-dgram",
+			      TEST3_BRANCH_ID, 2, &pjsip_options_method);
+
+    /* Restore delay. */
+    pjsip_loop_set_send_callback_delay(loop, prev_delay, NULL);
+
+    return status;
+}
+
+
+/*****************************************************************************
+ **
+ ** TEST4_BRANCH_ID: Transport failed after several retransmissions
+ **
+ ** There are two variants of this test: (a) failure occurs immediately when
+ ** transaction calls pjsip_transport_send() or (b) failure is reported via
+ ** transport callback.
+ **
+ *****************************************************************************
+ */
+static int tsx_retransmit_fail_test(void)
+{
+    int i;
+    unsigned delay[] = {0, 10};
+    pj_status_t status;
+
+    PJ_LOG(3,(THIS_FILE, 
+	      "  test4: transport fails after several retransmissions test"));
+
+
+    for (i=0; i<PJ_ARRAY_SIZE(delay); ++i) {
+
+	PJ_LOG(3,(THIS_FILE, 
+		  "   variant %c: transport delay %d ms", ('a'+i), delay[i]));
+
+	/* Configure transport delay. */
+	pjsip_loop_set_send_callback_delay(loop, delay[i], NULL);
+
+	/* Restore transport failure mode. */
+	pjsip_loop_set_failure(loop, 0, 0);
+
+	/* Start the test. */
+	status = perform_tsx_test(-1000, "sip:127.0.0.1;transport=loop-dgram",
+				  "sip:127.0.0.1;transport=loop-dgram",
+				  TEST4_BRANCH_ID, 6, &pjsip_options_method);
+
+	if (status != 0)
+	    break;
+
+    }
+
+    /* Restore delay. */
+    pjsip_loop_set_send_callback_delay(loop, 0, NULL);
+
+    /* Restore transport failure mode. */
+    pjsip_loop_set_failure(loop, 0, 0);
+
+    return status;
+}
+
+
+/*****************************************************************************
+ **
+ ** TEST5_BRANCH_ID: Terminate transaction after several retransmissions
+ **
+ *****************************************************************************
+ */
+static int tsx_terminate_after_retransmit_test(void)
+{
+    int status;
+
+    PJ_LOG(3,(THIS_FILE, "  test5: terminate after retransmissions"));
+
+    /* Do the test. */
+    status = perform_tsx_test(-1100, "sip:bob@127.0.0.1;transport=loop-dgram",
+			      "sip:alice@127.0.0.1;transport=loop-dgram", 
+			      TEST5_BRANCH_ID,
+			      6, &pjsip_options_method);
+
+    /* Done. */
+    return status;
+}
+
+
+/*****************************************************************************
+ **
+ ** TEST6_BRANCH_ID: Successfull non-invite transaction
+ **
+ *****************************************************************************
+ */
+static int tsx_successfull_non_invite_test(void)
+{
+    int i, status;
+    unsigned delay[] = { 1, 200 };
+
+    PJ_LOG(3,(THIS_FILE, "  test6: successfull non-invite transaction"));
+
+    /* Do the test. */
+    for (i=0; i<PJ_ARRAY_SIZE(delay); ++i) {
+	
+	PJ_LOG(3,(THIS_FILE, "   variant %c: with %d ms transport delay",
+			     ('a'+i), delay[i]));
+
+	pjsip_loop_set_delay(loop, delay[i]);
+
+	status = perform_tsx_test(-1200, 
+				  "sip:bob@127.0.0.1;transport=loop-dgram",
+				  "sip:alice@127.0.0.1;transport=loop-dgram",
+				  TEST6_BRANCH_ID,
+				  2, &pjsip_options_method);
+	if (status != 0)
+	    return status;
+    }
+
+    pjsip_loop_set_delay(loop, 0);
+
+    /* Done. */
+    return status;
+}
+
+
+/*****************************************************************************
+ **
  ** UAC Transaction Test.
  **
  *****************************************************************************
@@ -253,31 +869,14 @@
 int tsx_uac_test(void)
 {
     pj_sockaddr_in addr;
-    pj_str_t tmp;
-    pjsip_transport *tp;
     pj_status_t status;
 
-    pj_sockaddr_in_init(&addr, pj_cstr(&tmp, "127.0.0.1"), TEST_UDP_PORT);
-
-    /* Start UDP transport if necessary. */
-    if (pjsip_endpt_acquire_transport(endpt, PJSIP_TRANSPORT_UDP, &addr,
-				      sizeof(addr), &tp) != PJ_SUCCESS)
-    {
-	addr.sin_addr.s_addr = 0;
-	status = pjsip_udp_transport_start( endpt, &addr, NULL, 1, NULL);
-	if (status != PJ_SUCCESS) {
-	    app_perror("   Error: unable to start UDP transport", status);
-	    return -10;
-	}
-    } else {
-	pjsip_transport_dec_ref(tp);
-    }
-
-    /* Start transaction layer module. */
-    status = pjsip_tsx_layer_init(endpt);
+    /* Check if loop transport is configured. */
+    status = pjsip_endpt_acquire_transport(endpt, PJSIP_TRANSPORT_LOOP_DGRAM, 
+				      &addr, sizeof(addr), &loop);
     if (status != PJ_SUCCESS) {
-	app_perror("   Error initializing transaction module", status);
-	return -20;
+	PJ_LOG(3,(THIS_FILE, "  Error: loop transport is not configured!"));
+	return -10;
     }
 
     /* Register modules. */
@@ -289,18 +888,43 @@
     status = pjsip_endpt_register_module(endpt, &msg_receiver);
     if (status != PJ_SUCCESS) {
 	app_perror("   Error: unable to register module", status);
-	return -30;
+	return -40;
     }
 
-    /* Basic retransmit and timeout test for INVITE. */
-    status = tsx_uac_retransmit_test(&pjsip_invite_method);
+#if 0
+    /* TEST1_BRANCH_ID: Basic retransmit and timeout test. */
+    status = tsx_uac_retransmit_test();
     if (status != 0)
 	return status;
 
-    /* Basic retransmit and timeout test for non-INVITE. */
-    status = tsx_uac_retransmit_test(&pjsip_options_method);
+    /* TEST2_BRANCH_ID: Resolve error test. */
+    status = tsx_resolve_error_test();
     if (status != 0)
 	return status;
 
+    /* TEST3_BRANCH_ID: UAC terminate while resolving test. */
+    status = tsx_terminate_resolving_test();
+    if (status != 0)
+	return status;
+
+    /* TEST4_BRANCH_ID: Transport failed after several retransmissions */
+    status = tsx_retransmit_fail_test();
+    if (status != 0)
+	return status;
+
+    /* TEST5_BRANCH_ID: Terminate transaction after several retransmissions */
+    status = tsx_terminate_after_retransmit_test();
+    if (status != 0)
+	return status;
+#endif
+
+    /* TEST6_BRANCH_ID: Successfull non-invite transaction */
+    status = tsx_successfull_non_invite_test();
+    if (status != 0)
+	return status;
+
+
+    pjsip_transport_dec_ref(loop);
     return 0;
 }
+
diff --git a/pjsip/src/test-pjsip/txdata_test.c b/pjsip/src/test-pjsip/txdata_test.c
index 08cad02..b740c6f 100644
--- a/pjsip/src/test-pjsip/txdata_test.c
+++ b/pjsip/src/test-pjsip/txdata_test.c
@@ -23,6 +23,9 @@
 
 #define HFIND(msg,h,H) ((pjsip_##h##_hdr*) pjsip_msg_find_hdr(msg, PJSIP_H_##H, NULL))
 
+#define THIS_FILE   "txdata_test.c"
+
+
 /*
  * This tests various core message creation functions. 
  */
@@ -50,12 +53,12 @@
 
     /* Buffer must be invalid. */
     if (pjsip_tx_data_is_valid(invite) != 0) {
-	PJ_LOG(3,("", "   error: buffer must be invalid"));
+	PJ_LOG(3,(THIS_FILE, "   error: buffer must be invalid"));
 	return -14;
     }
     /* Reference counter must be set to 1. */
     if (pj_atomic_get(invite->ref_cnt) != 1) {
-	PJ_LOG(3,("", "   error: invalid reference counter"));
+	PJ_LOG(3,(THIS_FILE, "   error: invalid reference counter"));
 	return -15;
     }
     /* Check message type. */
@@ -102,12 +105,12 @@
     
     /* Buffer must be invalid. */
     if (pjsip_tx_data_is_valid(invite2) != 0) {
-	PJ_LOG(3,("", "   error: buffer must be invalid"));
+	PJ_LOG(3,(THIS_FILE, "   error: buffer must be invalid"));
 	return -34;
     }
     /* Reference counter must be set to 1. */
     if (pj_atomic_get(invite2->ref_cnt) != 1) {
-	PJ_LOG(3,("", "   error: invalid reference counter"));
+	PJ_LOG(3,(THIS_FILE, "   error: invalid reference counter"));
 	return -35;
     }
     /* Check message type. */
@@ -141,7 +144,7 @@
 
     /* Done checking invite2. We can delete this. */
     if (pjsip_tx_data_dec_ref(invite2) != PJSIP_EBUFDESTROYED) {
-	PJ_LOG(3,("", "   error: request buffer not destroyed!"));
+	PJ_LOG(3,(THIS_FILE, "   error: request buffer not destroyed!"));
 	return -49;
     }
 
@@ -172,12 +175,12 @@
     
     /* Buffer must be invalid. */
     if (pjsip_tx_data_is_valid(response) != 0) {
-	PJ_LOG(3,("", "   error: buffer must be invalid"));
+	PJ_LOG(3,(THIS_FILE, "   error: buffer must be invalid"));
 	return -54;
     }
     /* Check reference counter. */
     if (pj_atomic_get(response->ref_cnt) != 1) {
-	PJ_LOG(3,("", "   error: invalid ref count in response"));
+	PJ_LOG(3,(THIS_FILE, "   error: invalid ref count in response"));
 	return -55;
     }
     /* Check message type. */
@@ -214,12 +217,12 @@
 
     /* Buffer must be invalid. */
     if (pjsip_tx_data_is_valid(cancel) != 0) {
-	PJ_LOG(3,("", "   error: buffer must be invalid"));
+	PJ_LOG(3,(THIS_FILE, "   error: buffer must be invalid"));
 	return -84;
     }
     /* Check reference counter. */
     if (pj_atomic_get(cancel->ref_cnt) != 1) {
-	PJ_LOG(3,("", "   error: invalid ref count in CANCEL request"));
+	PJ_LOG(3,(THIS_FILE, "   error: invalid ref count in CANCEL request"));
 	return -85;
     }
     /* Check message type. */
@@ -247,7 +250,7 @@
 
     /* Done checking CANCEL request. */
     if (pjsip_tx_data_dec_ref(cancel) != PJSIP_EBUFDESTROYED) {
-	PJ_LOG(3,("", "   error: response buffer not destroyed!"));
+	PJ_LOG(3,(THIS_FILE, "   error: response buffer not destroyed!"));
 	return -99;
     }
 
@@ -259,17 +262,17 @@
     /* Create ACK request */
     status = pjsip_endpt_create_ack( endpt, invite, &dummy_rdata, &ack );
     if (status != PJ_SUCCESS) {
-	PJ_LOG(3,("", "   error: unable to create ACK"));
+	PJ_LOG(3,(THIS_FILE, "   error: unable to create ACK"));
 	return -100;
     }
     /* Buffer must be invalid. */
     if (pjsip_tx_data_is_valid(ack) != 0) {
-	PJ_LOG(3,("", "   error: buffer must be invalid"));
+	PJ_LOG(3,(THIS_FILE, "   error: buffer must be invalid"));
 	return -104;
     }
     /* Check reference counter. */
     if (pj_atomic_get(ack->ref_cnt) != 1) {
-	PJ_LOG(3,("", "   error: invalid ref count in ACK request"));
+	PJ_LOG(3,(THIS_FILE, "   error: invalid ref count in ACK request"));
 	return -105;
     }
     /* Check message type. */
@@ -298,19 +301,19 @@
 
     /* Done checking invite message. */
     if (pjsip_tx_data_dec_ref(invite) != PJSIP_EBUFDESTROYED) {
-	PJ_LOG(3,("", "   error: response buffer not destroyed!"));
+	PJ_LOG(3,(THIS_FILE, "   error: response buffer not destroyed!"));
 	return -120;
     }
 
     /* Done checking response message. */
     if (pjsip_tx_data_dec_ref(response) != PJSIP_EBUFDESTROYED) {
-	PJ_LOG(3,("", "   error: response buffer not destroyed!"));
+	PJ_LOG(3,(THIS_FILE, "   error: response buffer not destroyed!"));
 	return -130;
     }
 
     /* Done checking ack message. */
     if (pjsip_tx_data_dec_ref(ack) != PJSIP_EBUFDESTROYED) {
-	PJ_LOG(3,("", "   error: response buffer not destroyed!"));
+	PJ_LOG(3,(THIS_FILE, "   error: response buffer not destroyed!"));
 	return -140;
     }
 
diff --git a/pjsip/src/test-pjsip/uri_test.c b/pjsip/src/test-pjsip/uri_test.c
index de9604b..46edd66 100644
--- a/pjsip/src/test-pjsip/uri_test.c
+++ b/pjsip/src/test-pjsip/uri_test.c
@@ -20,6 +20,8 @@
 #include <pjsip_core.h>
 #include <pjlib.h>
 
+#define THIS_FILE   "uri_test.c"
+
 
 #define ALPHANUM    "abcdefghijklmnopqrstuvwxyz" \
 		    "ABCDEFGHIJKLMNOPQRSTUVWXYZ" \
@@ -692,9 +694,9 @@
 	 */
 	status = entry->status==ERR_SYNTAX_ERR ? PJ_SUCCESS : -10;
 	if (status != 0) {
-	    PJ_LOG(3,("", "   uri parse error!\n"
-			  "   uri='%s'\n",
-			  entry->str));
+	    PJ_LOG(3,(THIS_FILE, "   uri parse error!\n"
+				 "   uri='%s'\n",
+				 entry->str));
 	}
 	goto on_return;
     }
@@ -738,10 +740,10 @@
 	/* Not equal. See if this is the expected status. */
 	status = entry->status==ERR_NOT_EQUAL ? PJ_SUCCESS : -40;
 	if (status != 0) {
-	    PJ_LOG(3,("", "   uri comparison mismatch, status=%d:\n"
-			  "    uri1='%s'\n"
-			  "    uri2='%s'",
-			  status, s1.ptr, s2.ptr));
+	    PJ_LOG(3,(THIS_FILE, "   uri comparison mismatch, status=%d:\n"
+				 "    uri1='%s'\n"
+				 "    uri2='%s'",
+				 status, s1.ptr, s2.ptr));
 	}
 	goto on_return;
 
@@ -762,19 +764,19 @@
     if (entry->printed) {
 	if (pj_strcmp2(&s1, entry->printed) != 0) {
 	    /* Not equal. */
-	    PJ_LOG(3,("", "   uri print mismatch:\n"
-			  "    printed='%s'\n"
-			  "    expectd='%s'",
-			  s1.ptr, entry->printed));
+	    PJ_LOG(3,(THIS_FILE, "   uri print mismatch:\n"
+				 "    printed='%s'\n"
+				 "    expectd='%s'",
+				 s1.ptr, entry->printed));
 	    status = -60;
 	}
     } else {
 	if (pj_strcmp(&s1, &s2) != 0) {
 	    /* Not equal. */
-	    PJ_LOG(3,("", "   uri print mismatch:\n"
-			  "    uri1='%s'\n"
-			  "    uri2='%s'",
-			  s1.ptr, s2.ptr));
+	    PJ_LOG(3,(THIS_FILE, "   uri print mismatch:\n"
+				 "    uri1='%s'\n"
+				 "    uri2='%s'",
+				 s1.ptr, s2.ptr));
 	    status = -70;
 	}
     }
@@ -794,19 +796,19 @@
 
     zero.u32.hi = zero.u32.lo = 0;
 
-    PJ_LOG(3,("", "  simple test"));
+    PJ_LOG(3,(THIS_FILE, "  simple test"));
     pool = pjsip_endpt_create_pool(endpt, "", POOL_SIZE, POOL_SIZE);
     for (i=0; i<PJ_ARRAY_SIZE(uri_test_array); ++i) {
 	status = do_uri_test(pool, &uri_test_array[i]);
 	if (status != PJ_SUCCESS) {
-	    PJ_LOG(3,("uri_test", "  error %d when testing entry %d",
+	    PJ_LOG(3,(THIS_FILE, "  error %d when testing entry %d",
 		      status, i));
 	    goto on_return;
 	}
     }
     pjsip_endpt_release_pool(endpt, pool);
 
-    PJ_LOG(3,("", "  benchmarking..."));
+    PJ_LOG(3,(THIS_FILE, "  benchmarking..."));
     parse_len = print_len = cmp_len = 0;
     parse_time.u32.hi = parse_time.u32.lo = 0;
     print_time.u32.hi = print_time.u32.lo = 0;
@@ -816,7 +818,7 @@
 	for (i=0; i<PJ_ARRAY_SIZE(uri_test_array); ++i) {
 	    status = do_uri_test(pool, &uri_test_array[i]);
 	    if (status != PJ_SUCCESS) {
-		PJ_LOG(3,("uri_test", "  error %d when testing entry %d",
+		PJ_LOG(3,(THIS_FILE, "  error %d when testing entry %d",
 			  status, i));
 		pjsip_endpt_release_pool(endpt, pool);
 		goto on_return;
@@ -834,10 +836,11 @@
     pj_highprec_div(avg_parse, parse_len);
     avg_parse = 1000000 / avg_parse;
 
-    PJ_LOG(3,("", "    %u.%u MB of urls parsed in %d.%03ds (avg=%d urls/sec)", 
-		  (unsigned)(parse_len/1000000), (unsigned)kbytes,
-		  elapsed.sec, elapsed.msec,
-		  (unsigned)avg_parse));
+    PJ_LOG(3,(THIS_FILE, 
+	      "    %u.%u MB of urls parsed in %d.%03ds (avg=%d urls/sec)", 
+	      (unsigned)(parse_len/1000000), (unsigned)kbytes,
+	      elapsed.sec, elapsed.msec,
+	      (unsigned)avg_parse));
 
     kbytes = print_len;
     pj_highprec_mod(kbytes, 1000000);
@@ -848,10 +851,11 @@
     pj_highprec_div(avg_print, parse_len);
     avg_print = 1000000 / avg_print;
 
-    PJ_LOG(3,("", "    %u.%u MB of urls printed in %d.%03ds (avg=%d urls/sec)", 
-		  (unsigned)(print_len/1000000), (unsigned)kbytes,
-		  elapsed.sec, elapsed.msec,
-		  (unsigned)avg_print));
+    PJ_LOG(3,(THIS_FILE, 
+	      "    %u.%u MB of urls printed in %d.%03ds (avg=%d urls/sec)", 
+	      (unsigned)(print_len/1000000), (unsigned)kbytes,
+	      elapsed.sec, elapsed.msec,
+	      (unsigned)avg_print));
 
     kbytes = cmp_len;
     pj_highprec_mod(kbytes, 1000000);
@@ -862,12 +866,13 @@
     pj_highprec_div(avg_cmp, cmp_len);
     avg_cmp = 1000000 / avg_cmp;
 
-    PJ_LOG(3,("", "    %u.%u MB of urls compared in %d.%03ds (avg=%d urls/sec)", 
-		  (unsigned)(cmp_len/1000000), (unsigned)kbytes,
-		  elapsed.sec, elapsed.msec,
-		  (unsigned)avg_cmp));
+    PJ_LOG(3,(THIS_FILE, 
+	      "    %u.%u MB of urls compared in %d.%03ds (avg=%d urls/sec)", 
+	      (unsigned)(cmp_len/1000000), (unsigned)kbytes,
+	      elapsed.sec, elapsed.msec,
+	      (unsigned)avg_cmp));
 
-    PJ_LOG(3,("", "  multithreaded test"));
+    PJ_LOG(3,(THIS_FILE, "  multithreaded test"));
 
 
 on_return: