diff --git a/lib/sbi/client.c b/lib/sbi/client.c
index e7a435093..bf67276a2 100644
--- a/lib/sbi/client.c
+++ b/lib/sbi/client.c
@@ -305,6 +305,9 @@ static connection_t *connection_add(
 #else
             curl_easy_setopt(conn->easy, CURLOPT_EXPECT_100_TIMEOUT_MS, 0L);
 #endif
+            ogs_debug("SENDING...[%d]", (int)request->http.content_length);
+            if (request->http.content_length)
+                ogs_debug("%s", request->http.content);
         }
     }
 
@@ -439,9 +442,16 @@ static void check_multi_info(ogs_sbi_client_t *client)
                 /* remove https://localhost:8000 */
                 response->h.uri = ogs_strdup(url);
 
+                ogs_debug("[%d:%s] %s",
+                        response->status, response->h.method, response->h.uri);
+
                 response->http.content = ogs_memdup(conn->memory, conn->size);
                 response->http.content_length = conn->size;
 
+                ogs_debug("RECEIVED[%d]", (int)response->http.content_length);
+                if (response->http.content_length && response->http.content)
+                    ogs_debug("%s", response->http.content);
+
                 if (content_type)
                     ogs_sbi_header_set(response->http.headers,
                             OGS_SBI_CONTENT_TYPE, content_type);
diff --git a/lib/sbi/message.c b/lib/sbi/message.c
index 865426b1a..001357720 100644
--- a/lib/sbi/message.c
+++ b/lib/sbi/message.c
@@ -524,8 +524,6 @@ int ogs_sbi_parse_header(ogs_sbi_message_t *message, ogs_sbi_header_t *header)
     message->h.method = header->method;
     message->h.uri = header->uri;
     ogs_assert(message->h.uri);
-    ogs_debug("[%s] %s", message->h.method ? message->h.method : "Notify",
-            message->h.uri);
 
     uri = ogs_strdup(header->uri);
     ogs_assert(uri);
diff --git a/lib/sbi/nghttp2-server.c b/lib/sbi/nghttp2-server.c
index fed2ac39e..4edf2ae7e 100644
--- a/lib/sbi/nghttp2-server.c
+++ b/lib/sbi/nghttp2-server.c
@@ -332,12 +332,17 @@ static void server_send_response(
         add_header(&nva[i++], ogs_hash_this_key(hi), ogs_hash_this_val(hi));
     }
 
+    ogs_debug("STATUS [%d]", response->status);
+
     if (response->http.content && response->http.content_length) {
         nghttp2_data_provider data_prd;
 
         data_prd.source.ptr = response;
         data_prd.read_callback = response_read_callback;
 
+        ogs_debug("SENDING...: %d", (int)response->http.content_length);
+        ogs_debug("%s", response->http.content);
+
         rv = nghttp2_submit_response(sbi_sess->session,
                 stream->stream_id, nva, nvlen, &data_prd);
     } else {
@@ -749,6 +754,13 @@ static int on_frame_recv(nghttp2_session *session,
         /* HEADERS or DATA frame with +END_STREAM flag */
         if (frame->hd.flags & NGHTTP2_FLAG_END_STREAM) {
 
+            ogs_debug("[%s] %s", request->h.method, request->h.uri);
+
+            if (request->http.content_length && request->http.content) {
+                ogs_debug("RECEIVED: %d", (int)request->http.content_length);
+                ogs_debug("%s", request->http.content);
+            }
+
             if (server->cb(request, stream) != OGS_OK) {
                 ogs_warn("server callback error");
                 ogs_sbi_server_send_error(stream,
@@ -850,7 +862,6 @@ static int on_header(nghttp2_session *session, const nghttp2_frame *frame,
         ogs_assert(request->h.uri == NULL);
         request->h.uri = ogs_sbi_parse_uri(valuestr, "?", &saveptr);
         ogs_assert(request->h.uri);
-        ogs_debug("path: %s", request->h.uri);
 
         memset(params, 0, sizeof(params));
 
@@ -878,7 +889,6 @@ static int on_header(nghttp2_session *session, const nghttp2_frame *frame,
 
         ogs_assert(request->h.method == NULL);
         request->h.method = ogs_strdup(valuestr);
-        ogs_debug("method: %s", request->h.method);
 
     } else {
 
@@ -936,10 +946,6 @@ static int on_data_chunk_recv(nghttp2_session *session, uint8_t flags,
     memcpy(request->http.content + offset, data, len);
     request->http.content[request->http.content_length] = '\0';
 
-    ogs_debug("RECEIVED");
-    ogs_debug("content-length: %d", (int)request->http.content_length);
-    ogs_debug("%s", request->http.content);
-
     return 0;
 }
 
@@ -1114,10 +1120,6 @@ static int on_send_data(nghttp2_session *session, nghttp2_frame *frame,
     ogs_assert(framehd);
     ogs_assert(length);
 
-    ogs_debug("SENDING...");
-    ogs_debug("content-length: %d", (int)response->http.content_length);
-    ogs_debug("%s", response->http.content);
-
     pkbuf = ogs_pkbuf_alloc(NULL, OGS_MAX_SDU_LEN);
     ogs_assert(pkbuf);
     ogs_pkbuf_put_data(pkbuf, framehd, 9);
diff --git a/src/amf/context.c b/src/amf/context.c
index b5fa79018..48c1daf47 100644
--- a/src/amf/context.c
+++ b/src/amf/context.c
@@ -1205,8 +1205,13 @@ void amf_ue_remove_all()
 {
     amf_ue_t *amf_ue = NULL, *next = NULL;;
 
-    ogs_list_for_each_safe(&self.amf_ue_list, next, amf_ue)
+    ogs_list_for_each_safe(&self.amf_ue_list, next, amf_ue) {
+        ran_ue_t *ran_ue = ran_ue_cycle(amf_ue->ran_ue);
+
+        if (ran_ue) ran_ue_remove(ran_ue);
+
         amf_ue_remove(amf_ue);
+    }
 }
 
 void amf_ue_fsm_init(amf_ue_t *amf_ue)
@@ -1319,7 +1324,7 @@ amf_ue_t *amf_ue_find_by_message(ogs_nas_5gs_message_t *message)
                     amf_ue->suci ? amf_ue->suci : "Unknown",
                     ogs_amf_id_hexdump(&nas_guti.amf_id), nas_guti.m_tmsi);
             } else {
-                ogs_warn("Unknown UE by 5G-S_TMSI[AMF_ID:0x%x,M_TMSI:0x%x]",
+                ogs_info("Unknown UE by 5G-S_TMSI[AMF_ID:0x%x,M_TMSI:0x%x]",
                     ogs_amf_id_hexdump(&nas_guti.amf_id), nas_guti.m_tmsi);
             }
             break;
diff --git a/src/amf/gmm-build.c b/src/amf/gmm-build.c
index d4358fa26..2266b01a0 100644
--- a/src/amf/gmm-build.c
+++ b/src/amf/gmm-build.c
@@ -486,14 +486,14 @@ ogs_pkbuf_t *gmm_build_configuration_update_command(
         ogs_gmtime(tv.tv_sec, &gmt);
         ogs_localtime(tv.tv_sec, &local);
 
-        ogs_debug("    GMT Time[Y:M:D H:M:S GMT:DST] - "
-                    "%d:%d:%d, %d:%d:%d, %d:%d",
-            gmt.tm_year, gmt.tm_mon, gmt.tm_mday,
+        ogs_info("    UTC [%04d-%02d-%02dT%02d:%02d:%02d] "
+                "Timezone[%d]/DST[%d]",
+            gmt.tm_year+1900, gmt.tm_mon+1, gmt.tm_mday,
             gmt.tm_hour, gmt.tm_min, gmt.tm_sec,
             (int)gmt.tm_gmtoff, gmt.tm_isdst);
-        ogs_debug("    LOCAL Time[Y:M:D H:M:S GMT:DST] - "
-                    "%d:%d:%d, %d:%d:%d, %d:%d",
-            local.tm_year, local.tm_mon, local.tm_mday,
+        ogs_info("    LOCAL [%04d-%02d-%02dT%02d:%02d:%02d] "
+                "Timezone[%d]/DST[%d]",
+            local.tm_year+1900, local.tm_mon+1, local.tm_mday,
             local.tm_hour, local.tm_min, local.tm_sec,
             (int)local.tm_gmtoff, local.tm_isdst);
 
diff --git a/src/amf/gmm-handler.c b/src/amf/gmm-handler.c
index 3efcb555d..34ec359e4 100644
--- a/src/amf/gmm-handler.c
+++ b/src/amf/gmm-handler.c
@@ -56,8 +56,6 @@ int gmm_handle_registration_request(amf_ue_t *amf_ue,
     ue_security_capability = &registration_request->ue_security_capability;
     ogs_assert(ue_security_capability);
 
-    ogs_debug("Registration request");
-
     if (!mobile_identity->length || !mobile_identity->buffer) {
         ogs_error("No Mobile Identity");
         nas_5gs_send_registration_reject(amf_ue,
@@ -71,7 +69,7 @@ int gmm_handle_registration_request(amf_ue_t *amf_ue,
     switch (mobile_identity_header->type) {
     case OGS_NAS_5GS_MOBILE_IDENTITY_SUCI:
         amf_ue_set_suci(amf_ue, mobile_identity);
-        ogs_debug("[%s]    SUCI", amf_ue->suci);
+        ogs_info("[%s]    SUCI", amf_ue->suci);
         break;
     case OGS_NAS_5GS_MOBILE_IDENTITY_GUTI:
         mobile_identity_guti =
@@ -84,7 +82,7 @@ int gmm_handle_registration_request(amf_ue_t *amf_ue,
         ogs_nas_5gs_mobile_identity_guti_to_nas_guti(
             mobile_identity_guti, &nas_guti);
 
-        ogs_debug("[%s]    5G-S_GUTI[AMF_ID:0x%x,M_TMSI:0x%x]",
+        ogs_info("[%s]    5G-S_GUTI[AMF_ID:0x%x,M_TMSI:0x%x]",
             AMF_UE_HAVE_SUCI(amf_ue) ? amf_ue->suci : "Unknown ID",
             ogs_amf_id_hexdump(&nas_guti.amf_id), nas_guti.m_tmsi);
         break;
@@ -338,8 +336,6 @@ int gmm_handle_service_request(amf_ue_t *amf_ue,
     ngksi = &service_request->ngksi;
     ogs_assert(ngksi);
 
-    ogs_debug("Service request");
-
     amf_ue->nas.message_type = OGS_NAS_5GS_SERVICE_REQUEST;
     amf_ue->nas.tsc = ngksi->tsc;
     amf_ue->nas.ksi = ngksi->value;
@@ -391,7 +387,7 @@ int gmm_handle_service_request(amf_ue_t *amf_ue,
     }
     ogs_debug("    SERVED_TAI_INDEX[%d]", served_tai_index);
 
-    ogs_debug("[%s]    5G-S_GUTI[AMF_ID:0x%x,M_TMSI:0x%x]",
+    ogs_info("[%s]    5G-S_GUTI[AMF_ID:0x%x,M_TMSI:0x%x]",
         AMF_UE_HAVE_SUCI(amf_ue) ? amf_ue->suci : "Unknown ID",
         ogs_amf_id_hexdump(&amf_ue->guti.amf_id), amf_ue->guti.m_tmsi);
 
@@ -515,8 +511,6 @@ int gmm_handle_deregistration_request(amf_ue_t *amf_ue,
 
     de_registration_type = &deregistration_request->de_registration_type;
 
-    ogs_debug("[%s] Deregistration request", amf_ue->supi);
-
     /* Set 5GS Attach Type */
     memcpy(&amf_ue->nas.de_registration,
             de_registration_type, sizeof(ogs_nas_de_registration_type_t));
@@ -531,6 +525,8 @@ int gmm_handle_deregistration_request(amf_ue_t *amf_ue,
     if (deregistration_request->de_registration_type.switch_off)
         ogs_debug("    Switch-Off");
 
+    ogs_info("[%s]    SUCI", amf_ue->suci);
+
     amf_sbi_send_release_all_sessions(
             amf_ue, AMF_RELEASE_SM_CONTEXT_NO_STATE);
 
@@ -612,7 +608,7 @@ int gmm_handle_identity_response(amf_ue_t *amf_ue,
 
     if (mobile_identity_header->type == OGS_NAS_5GS_MOBILE_IDENTITY_SUCI) {
         amf_ue_set_suci(amf_ue, mobile_identity);
-        ogs_debug("[%s]    SUCI", amf_ue->suci);
+        ogs_info("[%s]    SUCI", amf_ue->suci);
     } else {
         ogs_error("Not supported Identity type[%d]",
                 mobile_identity_header->type);
diff --git a/src/amf/gmm-sm.c b/src/amf/gmm-sm.c
index cc4a4b266..ca34da5bb 100644
--- a/src/amf/gmm-sm.c
+++ b/src/amf/gmm-sm.c
@@ -126,6 +126,7 @@ static void common_register_state(ogs_fsm_t *s, amf_event_t *e)
 
         switch (nas_message->gmm.h.message_type) {
         case OGS_NAS_5GS_REGISTRATION_REQUEST:
+            ogs_info("Registration request");
             rv = gmm_handle_registration_request(
                     amf_ue, &nas_message->gmm.registration_request);
             if (rv != OGS_OK) {
@@ -170,6 +171,8 @@ static void common_register_state(ogs_fsm_t *s, amf_event_t *e)
             break;
 
         case OGS_NAS_5GS_SERVICE_REQUEST:
+            ogs_info("Service request");
+
             rv = gmm_handle_service_request(
                     amf_ue, &nas_message->gmm.service_request);
             if (rv != OGS_OK) {
@@ -179,7 +182,7 @@ static void common_register_state(ogs_fsm_t *s, amf_event_t *e)
             }
 
             if (!AMF_UE_HAVE_SUCI(amf_ue)) {
-                ogs_error("Service request : Unknown UE");
+                ogs_info("Service request : Unknown UE");
                 nas_5gs_send_service_reject(amf_ue,
                 OGS_5GMM_CAUSE_UE_IDENTITY_CANNOT_BE_DERIVED_BY_THE_NETWORK);
                 OGS_FSM_TRAN(s, gmm_state_exception);
@@ -207,6 +210,7 @@ static void common_register_state(ogs_fsm_t *s, amf_event_t *e)
         case OGS_NAS_5GS_IDENTITY_RESPONSE:
             CLEAR_AMF_UE_TIMER(amf_ue->t3570);
 
+            ogs_info("Identity response");
             rv = gmm_handle_identity_response(amf_ue,
                     &nas_message->gmm.identity_response);
             if (rv != OGS_OK) {
@@ -297,6 +301,8 @@ static void common_register_state(ogs_fsm_t *s, amf_event_t *e)
             break;
 
         case OGS_NAS_5GS_DEREGISTRATION_REQUEST:
+            ogs_info("[%s] Deregistration request", amf_ue->supi);
+
             gmm_handle_deregistration_request(
                     amf_ue, &nas_message->gmm.deregistration_request_from_ue);
             OGS_FSM_TRAN(s, &gmm_state_de_registered);
@@ -510,6 +516,8 @@ void gmm_state_authentication(ogs_fsm_t *s, amf_event_t *e)
             break;
 
         case OGS_NAS_5GS_DEREGISTRATION_REQUEST:
+            ogs_warn("[%s] Deregistration request", amf_ue->supi);
+
             gmm_handle_deregistration_request(
                     amf_ue, &nas_message->gmm.deregistration_request_from_ue);
             OGS_FSM_TRAN(s, &gmm_state_de_registered);
@@ -727,7 +735,7 @@ void gmm_state_security_mode(ogs_fsm_t *s, amf_event_t *e)
             OGS_FSM_TRAN(s, &gmm_state_authentication);
             break;
         case OGS_NAS_5GS_SERVICE_REQUEST:
-            ogs_debug("[%s] Service request", amf_ue->supi);
+            ogs_info("[%s] Service request", amf_ue->supi);
             nas_5gs_send_service_reject(amf_ue,
                     OGS_5GMM_CAUSE_SECURITY_MODE_REJECTED_UNSPECIFIED);
             OGS_FSM_TRAN(s, &gmm_state_exception);
@@ -749,6 +757,8 @@ void gmm_state_security_mode(ogs_fsm_t *s, amf_event_t *e)
             break;
 
         case OGS_NAS_5GS_DEREGISTRATION_REQUEST:
+            ogs_warn("[%s] Deregistration request", amf_ue->supi);
+
             gmm_handle_deregistration_request(
                     amf_ue, &nas_message->gmm.deregistration_request_from_ue);
             OGS_FSM_TRAN(s, &gmm_state_de_registered);
@@ -947,7 +957,7 @@ void gmm_state_initial_context_setup(ogs_fsm_t *s, amf_event_t *e)
 
         switch (nas_message->gmm.h.message_type) {
         case OGS_NAS_5GS_REGISTRATION_COMPLETE:
-            ogs_debug("[%s] Registration complete", amf_ue->supi);
+            ogs_info("[%s] Registration complete", amf_ue->supi);
 
             /*
              * TS24.501
@@ -1006,6 +1016,8 @@ void gmm_state_initial_context_setup(ogs_fsm_t *s, amf_event_t *e)
             break;
 
         case OGS_NAS_5GS_DEREGISTRATION_REQUEST:
+            ogs_warn("[%s] Deregistration request", amf_ue->supi);
+
             gmm_handle_deregistration_request(
                     amf_ue, &nas_message->gmm.deregistration_request_from_ue);
             OGS_FSM_TRAN(s, &gmm_state_de_registered);
@@ -1081,6 +1093,7 @@ void gmm_state_exception(ogs_fsm_t *s, amf_event_t *e)
 
         switch (nas_message->gmm.h.message_type) {
         case OGS_NAS_5GS_REGISTRATION_REQUEST:
+            ogs_info("Registration request");
             rv = gmm_handle_registration_request(
                     amf_ue, &nas_message->gmm.registration_request);
             if (rv != OGS_OK) {
diff --git a/src/amf/nas-path.c b/src/amf/nas-path.c
index c71d4ed04..5706a8f6e 100644
--- a/src/amf/nas-path.c
+++ b/src/amf/nas-path.c
@@ -284,7 +284,7 @@ void nas_5gs_send_configuration_update_command(
 
     ogs_assert(amf_ue);
 
-    ogs_debug("[%s] Configuration update command", amf_ue->supi);
+    ogs_info("[%s] Configuration update command", amf_ue->supi);
 
     if (amf_ue->t3555.pkbuf) {
         gmmbuf = amf_ue->t3555.pkbuf;
diff --git a/src/amf/ngap-handler.c b/src/amf/ngap-handler.c
index 795d22236..a1ab9c7b6 100644
--- a/src/amf/ngap-handler.c
+++ b/src/amf/ngap-handler.c
@@ -344,7 +344,7 @@ void ngap_handle_initial_ue_message(amf_gnb_t *gnb, ogs_ngap_message_t *message)
     InitialUEMessage = &initiatingMessage->value.choice.InitialUEMessage;
     ogs_assert(InitialUEMessage);
 
-    ogs_debug("Initial UE Message");
+    ogs_info("Initial UE Message");
 
     for (i = 0; i < InitialUEMessage->protocolIEs.list.count; i++) {
         ie = InitialUEMessage->protocolIEs.list.array[i];
@@ -410,10 +410,10 @@ void ngap_handle_initial_ue_message(amf_gnb_t *gnb, ogs_ngap_message_t *message)
 
             amf_ue = amf_ue_find_by_guti(&nas_guti);
             if (!amf_ue) {
-                ogs_debug("Unknown UE by 5G-S_TMSI[AMF_ID:0x%x,M_TMSI:0x%x]",
+                ogs_info("Unknown UE by 5G-S_TMSI[AMF_ID:0x%x,M_TMSI:0x%x]",
                     ogs_amf_id_hexdump(&nas_guti.amf_id), nas_guti.m_tmsi);
             } else {
-                ogs_debug("[%s]    5G-S_TMSI[AMF_ID:0x%x,M_TMSI:0x%x]",
+                ogs_info("[%s]    5G-S_TMSI[AMF_ID:0x%x,M_TMSI:0x%x]",
                         AMF_UE_HAVE_SUCI(amf_ue) ? amf_ue->suci : "Unknown ID",
                         ogs_amf_id_hexdump(&amf_ue->guti.amf_id),
                         amf_ue->guti.m_tmsi);
@@ -473,7 +473,7 @@ void ngap_handle_initial_ue_message(amf_gnb_t *gnb, ogs_ngap_message_t *message)
         return;
     }
 
-    ogs_debug("    RAN_UE_NGAP_ID[%d] AMF_UE_NGAP_ID[%lld] "
+    ogs_info("    RAN_UE_NGAP_ID[%d] AMF_UE_NGAP_ID[%lld] "
             "TAC[%d] CellID[0x%llx]",
         ran_ue->ran_ue_ngap_id, (long long)ran_ue->amf_ue_ngap_id,
         ran_ue->saved.tai.tac.v, (long long)ran_ue->saved.nr_cgi.cell_id);
@@ -1171,6 +1171,11 @@ void ngap_handle_ue_context_release_action(ran_ue_t *ran_ue)
 
     ogs_assert(ran_ue);
 
+    if (ran_ue_cycle(ran_ue) == NULL) {
+        ogs_error("NG context has already been removed");
+        return;
+    }
+
     amf_ue = ran_ue->amf_ue;
 
     ogs_info("UE Context Release [Action:%d]", ran_ue->ue_ctx_rel_action);
@@ -1758,7 +1763,7 @@ void ngap_handle_path_switch_request(
     PathSwitchRequest = &initiatingMessage->value.choice.PathSwitchRequest;
     ogs_assert(PathSwitchRequest);
 
-    ogs_debug("Path switch request");
+    ogs_info("Path switch request");
     
     for (i = 0; i < PathSwitchRequest->protocolIEs.list.count; i++) {
         ie = PathSwitchRequest->protocolIEs.list.array[i];
@@ -1824,9 +1829,9 @@ void ngap_handle_path_switch_request(
         return;
     }
 
-    ogs_debug("    [OLD] RAN_UE_NGAP_ID[%d] AMF_UE_NGAP_ID[%lld] ",
+    ogs_info("    [OLD] RAN_UE_NGAP_ID[%d] AMF_UE_NGAP_ID[%lld] ",
         ran_ue->ran_ue_ngap_id, (long long)ran_ue->amf_ue_ngap_id);
-    ogs_debug("    [OLD] TAC[%d] CellID[0x%llx]",
+    ogs_info("    [OLD] TAC[%d] CellID[0x%llx]",
         amf_ue->tai.tac.v, (long long)amf_ue->nr_cgi.cell_id);
 
     /* Update RAN-UE-NGAP-ID */
@@ -1851,7 +1856,7 @@ void ngap_handle_path_switch_request(
         return;
     }
 
-    ogs_debug("    [NEW] RAN_UE_NGAP_ID[%d] AMF_UE_NGAP_ID[%lld] ",
+    ogs_info("    [NEW] RAN_UE_NGAP_ID[%d] AMF_UE_NGAP_ID[%lld] ",
         ran_ue->ran_ue_ngap_id, (long long)ran_ue->amf_ue_ngap_id);
 
     UserLocationInformationNR =
@@ -1866,7 +1871,7 @@ void ngap_handle_path_switch_request(
     memcpy(&amf_ue->tai, &ran_ue->saved.tai, sizeof(ogs_5gs_tai_t));
     memcpy(&amf_ue->nr_cgi, &ran_ue->saved.nr_cgi, sizeof(ogs_nr_cgi_t));
 
-    ogs_debug("    [NEW] TAC[%d] CellID[0x%llx]",
+    ogs_info("    [NEW] TAC[%d] CellID[0x%llx]",
         amf_ue->tai.tac.v, (long long)amf_ue->nr_cgi.cell_id);
 
     if (!UESecurityCapabilities) {
diff --git a/src/amf/ngap-sctp.c b/src/amf/ngap-sctp.c
index 84be6ac66..94c8a4324 100644
--- a/src/amf/ngap-sctp.c
+++ b/src/amf/ngap-sctp.c
@@ -179,25 +179,10 @@ void ngap_recv_handler(ogs_sock_t *sock)
             }
             break;
         case SCTP_SHUTDOWN_EVENT :
-        case SCTP_SEND_FAILED :
-            if (not->sn_header.sn_type == SCTP_SHUTDOWN_EVENT)
-                ogs_debug("SCTP_SHUTDOWN_EVENT:[T:%d, F:0x%x, L:%d]", 
-                        not->sn_shutdown_event.sse_type,
-                        not->sn_shutdown_event.sse_flags,
-                        not->sn_shutdown_event.sse_length);
-            if (not->sn_header.sn_type == SCTP_SEND_FAILED)
-#if HAVE_USRSCTP
-                ogs_error("SCTP_SEND_FAILED:[T:%d, F:0x%x, S:%d]", 
-                        not->sn_send_failed_event.ssfe_type,
-                        not->sn_send_failed_event.ssfe_flags,
-                        not->sn_send_failed_event.ssfe_error);
-#else
-                ogs_error("SCTP_SEND_FAILED:[T:%d, F:0x%x, S:%d]", 
-                        not->sn_send_failed.ssf_type,
-                        not->sn_send_failed.ssf_flags,
-                        not->sn_send_failed.ssf_error);
-#endif
-
+            ogs_debug("SCTP_SHUTDOWN_EVENT:[T:%d, F:0x%x, L:%d]",
+                    not->sn_shutdown_event.sse_type,
+                    not->sn_shutdown_event.sse_flags,
+                    not->sn_shutdown_event.sse_length);
             addr = ogs_calloc(1, sizeof(ogs_sockaddr_t));
             ogs_assert(addr);
             memcpy(addr, &from, sizeof(ogs_sockaddr_t));
@@ -205,6 +190,21 @@ void ngap_recv_handler(ogs_sock_t *sock)
             ngap_event_push(AMF_EVT_NGAP_LO_CONNREFUSED,
                     sock, addr, NULL, 0, 0);
             break;
+
+        case SCTP_SEND_FAILED :
+#if HAVE_USRSCTP
+            ogs_error("SCTP_SEND_FAILED:[T:%d, F:0x%x, S:%d]",
+                    not->sn_send_failed_event.ssfe_type,
+                    not->sn_send_failed_event.ssfe_flags,
+                    not->sn_send_failed_event.ssfe_error);
+#else
+            ogs_error("SCTP_SEND_FAILED:[T:%d, F:0x%x, S:%d]",
+                    not->sn_send_failed.ssf_type,
+                    not->sn_send_failed.ssf_flags,
+                    not->sn_send_failed.ssf_error);
+#endif
+            break;
+
         case SCTP_PEER_ADDR_CHANGE:
             ogs_warn("SCTP_PEER_ADDR_CHANGE:[T:%d, F:0x%x, S:%d]", 
                     not->sn_paddr_change.spc_type,
diff --git a/src/amf/sbi-path.c b/src/amf/sbi-path.c
index 1c9dbaaf1..2b62103e7 100644
--- a/src/amf/sbi-path.c
+++ b/src/amf/sbi-path.c
@@ -221,18 +221,31 @@ void amf_sbi_send_deactivate_all_ue_in_gnb(amf_gnb_t *gnb, int state)
         int old_xact_count = 0, new_xact_count = 0;
 
         amf_ue = ran_ue->amf_ue;
-        ogs_assert(amf_ue);
 
-        old_xact_count = amf_sess_xact_count(amf_ue);
+        if (amf_ue) {
+            old_xact_count = amf_sess_xact_count(amf_ue);
 
-        amf_sbi_send_deactivate_all_sessions(
+            amf_sbi_send_deactivate_all_sessions(
                 amf_ue, state, NGAP_Cause_PR_radioNetwork,
                 NGAP_CauseRadioNetwork_failure_in_radio_interface_procedure);
 
-        new_xact_count = amf_sess_xact_count(amf_ue);
+            new_xact_count = amf_sess_xact_count(amf_ue);
 
-        if (old_xact_count == new_xact_count) {
-            ran_ue_remove(ran_ue);
+            if (old_xact_count == new_xact_count) {
+                ran_ue_remove(ran_ue);
+            }
+        } else {
+            ogs_warn("amf_sbi_send_deactivate_all_ue_in_gnb()");
+            ogs_warn("    RAN_UE_NGAP_ID[%d] AMF_UE_NGAP_ID[%lld] State[%d]",
+                ran_ue->ran_ue_ngap_id, (long long)ran_ue->amf_ue_ngap_id,
+                state);
+
+            if (state == AMF_UPDATE_SM_CONTEXT_NG_RESET) {
+                ran_ue_remove(ran_ue);
+            } else {
+                /* At this point, it does not support other action */
+                ogs_assert_if_reached();
+            }
         }
     }
 }
diff --git a/src/mme/emm-handler.c b/src/mme/emm-handler.c
index 64e09129e..15cc2253f 100644
--- a/src/mme/emm-handler.c
+++ b/src/mme/emm-handler.c
@@ -168,7 +168,7 @@ int emm_handle_attach_request(mme_ue_t *mme_ue,
             imsi_bcd);
         mme_ue_set_imsi(mme_ue, imsi_bcd);
 
-        ogs_debug("    IMSI[%s]", imsi_bcd);
+        ogs_info("    IMSI[%s]", imsi_bcd);
 
         break;
     case OGS_NAS_EPS_MOBILE_IDENTITY_GUTI:
@@ -179,7 +179,7 @@ int emm_handle_attach_request(mme_ue_t *mme_ue,
         nas_guti.mme_code = eps_mobile_identity_guti->mme_code;
         nas_guti.m_tmsi = eps_mobile_identity_guti->m_tmsi;
 
-        ogs_debug("    GUTI[G:%d,C:%d,M_TMSI:0x%x] IMSI[%s]",
+        ogs_info("    GUTI[G:%d,C:%d,M_TMSI:0x%x] IMSI[%s]",
                 nas_guti.mme_gid,
                 nas_guti.mme_code,
                 nas_guti.m_tmsi,
@@ -220,12 +220,13 @@ int emm_handle_attach_complete(
 
     ogs_assert(mme_ue);
 
-    ogs_debug("    GMT Time[Y:M:D H:M:S GMT:DST] - %d:%d:%d, %d:%d:%d, %d:%d",
-        gmt.tm_year, gmt.tm_mon, gmt.tm_mday,
+    ogs_info("    IMSI[%s]", mme_ue->imsi_bcd);
+    ogs_info("    UTC [%04d-%02d-%02dT%02d:%02d:%02d] Timezone[%d]/DST[%d]",
+        gmt.tm_year+1900, gmt.tm_mon+1, gmt.tm_mday,
         gmt.tm_hour, gmt.tm_min, gmt.tm_sec,
         (int)gmt.tm_gmtoff, gmt.tm_isdst);
-    ogs_debug("    LOCAL Time[Y:M:D H:M:S GMT:DST] - %d:%d:%d, %d:%d:%d, %d:%d",
-        local.tm_year, local.tm_mon, local.tm_mday,
+    ogs_info("    LOCAL [%04d-%02d-%02dT%02d:%02d:%02d] Timezone[%d]/DST[%d]",
+        local.tm_year+1900, local.tm_mon+1, local.tm_mday,
         local.tm_hour, local.tm_min, local.tm_sec,
         (int)local.tm_gmtoff, local.tm_isdst);
 
@@ -332,6 +333,8 @@ int emm_handle_identity_response(
             ogs_error("Invalid IMSI LEN[%d]", mme_ue->imsi_len);
             return OGS_ERROR;
         }
+
+        ogs_info("    IMSI[%s]", mme_ue->imsi_bcd);
     } else {
         ogs_warn("Not supported Identity type[%d]", mobile_identity->imsi.type);
     }
@@ -379,6 +382,8 @@ int emm_handle_detach_request(
     if (detach_request->detach_type.switch_off)
         ogs_debug("    Switch-Off");
 
+    ogs_info("    IMSI[%s]", mme_ue->imsi_bcd);
+
     return OGS_OK;
 }
 
@@ -411,7 +416,7 @@ int emm_handle_service_request(
         mme_ue->nhcc = 1;
     }
 
-    ogs_debug("    GUTI[G:%d,C:%d,M_TMSI:0x%x] IMSI[%s]",
+    ogs_info("    GUTI[G:%d,C:%d,M_TMSI:0x%x] IMSI[%s]",
             mme_ue->guti.mme_gid,
             mme_ue->guti.mme_code,
             mme_ue->guti.m_tmsi,
@@ -534,7 +539,7 @@ int emm_handle_tau_request(mme_ue_t *mme_ue,
         nas_guti.mme_code = eps_mobile_identity_guti->mme_code;
         nas_guti.m_tmsi = eps_mobile_identity_guti->m_tmsi;
 
-        ogs_debug("    GUTI[G:%d,C:%d,M_TMSI:0x%x] IMSI:[%s]",
+        ogs_info("    GUTI[G:%d,C:%d,M_TMSI:0x%x] IMSI:[%s]",
                 nas_guti.mme_gid,
                 nas_guti.mme_code,
                 nas_guti.m_tmsi,
@@ -615,7 +620,7 @@ int emm_handle_extended_service_request(mme_ue_t *mme_ue,
     case OGS_NAS_MOBILE_IDENTITY_TMSI:
         mobile_identity_tmsi = &mobile_identity->tmsi;
 
-        ogs_debug("    M-TMSI:[0x%x] IMSI:[%s]",
+        ogs_info("    M-TMSI:[0x%x] IMSI:[%s]",
                 mobile_identity_tmsi->tmsi,
                 MME_UE_HAVE_IMSI(mme_ue) ? mme_ue->imsi_bcd : "Unknown");
         break;
diff --git a/src/mme/emm-sm.c b/src/mme/emm-sm.c
index dfbd6786a..3c25c9480 100644
--- a/src/mme/emm-sm.c
+++ b/src/mme/emm-sm.c
@@ -120,7 +120,7 @@ static void common_register_state(ogs_fsm_t *s, mme_event_t *e)
 
         if (message->emm.h.security_header_type
                 == OGS_NAS_SECURITY_HEADER_FOR_SERVICE_REQUEST_MESSAGE) {
-            ogs_debug("Service request");
+            ogs_info("Service request");
             rv = emm_handle_service_request(
                     mme_ue, &message->emm.service_request);
             if (rv != OGS_OK) {
@@ -168,7 +168,7 @@ static void common_register_state(ogs_fsm_t *s, mme_event_t *e)
 
         switch (message->emm.h.message_type) {
         case OGS_NAS_EPS_IDENTITY_RESPONSE:
-            ogs_debug("Identity response");
+            ogs_info("Identity response");
             CLEAR_MME_UE_TIMER(mme_ue->t3470);
 
             rv = emm_handle_identity_response(mme_ue,
@@ -185,8 +185,6 @@ static void common_register_state(ogs_fsm_t *s, mme_event_t *e)
                 break;
             }
 
-            ogs_debug("    IMSI[%s]", mme_ue->imsi_bcd);
-
             if (SESSION_CONTEXT_IS_AVAILABLE(mme_ue)) {
                 mme_gtp_send_delete_all_sessions(mme_ue,
                         OGS_GTP_DELETE_SEND_AUTHENTICATION_REQUEST);
@@ -197,7 +195,7 @@ static void common_register_state(ogs_fsm_t *s, mme_event_t *e)
             break;
 
         case OGS_NAS_EPS_ATTACH_REQUEST:
-            ogs_debug("Attach request[%s]", mme_ue->imsi_bcd);
+            ogs_info("Attach request");
             rv = emm_handle_attach_request(
                     mme_ue, &message->emm.attach_request, e->pkbuf);
             if (rv != OGS_OK) {
@@ -241,7 +239,7 @@ static void common_register_state(ogs_fsm_t *s, mme_event_t *e)
             break;
 
         case OGS_NAS_EPS_TRACKING_AREA_UPDATE_REQUEST:
-            ogs_debug("Tracking area update request");
+            ogs_info("Tracking area update request");
             rv = emm_handle_tau_request(mme_ue,
                     &message->emm.tracking_area_update_request, e->pkbuf);
             if (rv != OGS_OK) {
@@ -304,12 +302,12 @@ static void common_register_state(ogs_fsm_t *s, mme_event_t *e)
             break;
 
         case OGS_NAS_EPS_TRACKING_AREA_UPDATE_COMPLETE:
-            ogs_debug("Tracking area update complete");
-            ogs_debug("    IMSI[%s]", mme_ue->imsi_bcd);
+            ogs_info("Tracking area update complete");
+            ogs_info("    IMSI[%s]", mme_ue->imsi_bcd);
             break;
 
         case OGS_NAS_EPS_EXTENDED_SERVICE_REQUEST:
-            ogs_debug("Extended service request");
+            ogs_info("Extended service request");
             rv = emm_handle_extended_service_request(
                     mme_ue, &message->emm.extended_service_request);
             if (rv != OGS_OK) {
@@ -424,8 +422,7 @@ static void common_register_state(ogs_fsm_t *s, mme_event_t *e)
             break;
 
         case OGS_NAS_EPS_DETACH_REQUEST:
-            ogs_debug("Detach request");
-            ogs_debug("    IMSI[%s]", mme_ue->imsi_bcd);
+            ogs_info("Detach request");
             rv = emm_handle_detach_request(
                     mme_ue, &message->emm.detach_request_from_ue);
             if (rv != OGS_OK) {
@@ -646,8 +643,7 @@ void emm_state_authentication(ogs_fsm_t *s, mme_event_t *e)
             OGS_FSM_TRAN(s, &emm_state_exception);
             break;
         case OGS_NAS_EPS_DETACH_REQUEST:
-            ogs_debug("Detach request");
-            ogs_debug("    IMSI[%s]", mme_ue->imsi_bcd);
+            ogs_warn("Detach request");
             rv = emm_handle_detach_request(
                     mme_ue, &message->emm.detach_request_from_ue);
             if (rv != OGS_OK) {
@@ -810,8 +806,7 @@ void emm_state_security_mode(ogs_fsm_t *s, mme_event_t *e)
             OGS_FSM_TRAN(s, &emm_state_exception);
             break;
         case OGS_NAS_EPS_DETACH_REQUEST:
-            ogs_debug("Detach request");
-            ogs_debug("    IMSI[%s]", mme_ue->imsi_bcd);
+            ogs_warn("Detach request");
             rv = emm_handle_detach_request(
                     mme_ue, &message->emm.detach_request_from_ue);
             if (rv != OGS_OK) {
@@ -884,8 +879,7 @@ void emm_state_initial_context_setup(ogs_fsm_t *s, mme_event_t *e)
 
         switch (message->emm.h.message_type) {
         case OGS_NAS_EPS_ATTACH_COMPLETE:
-            ogs_debug("Attach complete");
-            ogs_debug("    IMSI[%s]", mme_ue->imsi_bcd);
+            ogs_info("Attach complete");
 
             h.type = e->nas_type;
             if (h.integrity_protected == 0) {
@@ -941,8 +935,7 @@ void emm_state_initial_context_setup(ogs_fsm_t *s, mme_event_t *e)
             OGS_FSM_TRAN(s, &emm_state_exception);
             break;
         case OGS_NAS_EPS_DETACH_REQUEST:
-            ogs_debug("Detach request");
-            ogs_debug("    IMSI[%s]", mme_ue->imsi_bcd);
+            ogs_warn("Detach request");
             rv = emm_handle_detach_request(
                     mme_ue, &message->emm.detach_request_from_ue);
             if (rv != OGS_OK) {
@@ -1012,7 +1005,7 @@ void emm_state_exception(ogs_fsm_t *s, mme_event_t *e)
 
         switch (message->emm.h.message_type) {
         case OGS_NAS_EPS_ATTACH_REQUEST:
-            ogs_debug("Attach request[%s]", mme_ue->imsi_bcd);
+            ogs_info("Attach request[%s]", mme_ue->imsi_bcd);
             rv = emm_handle_attach_request(
                     mme_ue, &message->emm.attach_request, e->pkbuf);
             if (rv != OGS_OK) {
diff --git a/src/mme/esm-handler.c b/src/mme/esm-handler.c
index fd2ce84a4..93092b482 100644
--- a/src/mme/esm-handler.c
+++ b/src/mme/esm-handler.c
@@ -66,6 +66,7 @@ int esm_handle_pdn_connectivity_request(mme_bearer_t *bearer,
             /* Invalid APN */
             nas_eps_send_pdn_connectivity_reject(
                     sess, ESM_CAUSE_MISSING_OR_UNKNOWN_APN);
+            ogs_warn("Invalid APN");
             return OGS_ERROR;
         }
     }
@@ -113,6 +114,7 @@ int esm_handle_pdn_connectivity_request(mme_bearer_t *bearer,
 
         mme_gtp_send_create_session_request(sess);
     } else {
+        ogs_error("No APN");
         nas_eps_send_pdn_connectivity_reject(
                 sess, ESM_CAUSE_MISSING_OR_UNKNOWN_APN);
         return OGS_ERROR;
@@ -162,6 +164,7 @@ int esm_handle_information_response(mme_sess_t *sess,
             mme_gtp_send_create_session_request(sess);
         }
     } else {
+        ogs_error("No APN");
         nas_eps_send_pdn_connectivity_reject(
                 sess, ESM_CAUSE_MISSING_OR_UNKNOWN_APN);
         return OGS_ERROR;
diff --git a/src/mme/mme-context.c b/src/mme/mme-context.c
index 797542fc6..1a44a6c80 100644
--- a/src/mme/mme-context.c
+++ b/src/mme/mme-context.c
@@ -2289,8 +2289,13 @@ void mme_ue_remove_all(void)
 {
     mme_ue_t *mme_ue = NULL, *next = NULL;;
 
-    ogs_list_for_each_safe(&self.mme_ue_list, next, mme_ue)
+    ogs_list_for_each_safe(&self.mme_ue_list, next, mme_ue) {
+        enb_ue_t *enb_ue = enb_ue_cycle(mme_ue->enb_ue);
+
+        if (enb_ue) enb_ue_remove(enb_ue);
+
         mme_ue_remove(mme_ue);
+    }
 }
 
 void mme_ue_fsm_init(mme_ue_t *mme_ue)
diff --git a/src/mme/mme-gtp-path.c b/src/mme/mme-gtp-path.c
index e2c9abd29..1f9366060 100644
--- a/src/mme/mme-gtp-path.c
+++ b/src/mme/mme-gtp-path.c
@@ -436,9 +436,23 @@ void mme_gtp_send_release_all_ue_in_enb(mme_enb_t *enb, int action)
 
     ogs_list_for_each(&enb->enb_ue_list, enb_ue) {
         mme_ue = enb_ue->mme_ue;
-        ogs_assert(mme_ue);
 
-        mme_gtp_send_release_access_bearers_request(mme_ue, action);
+        if (mme_ue) {
+
+            mme_gtp_send_release_access_bearers_request(mme_ue, action);
+
+        } else {
+            ogs_warn("mme_gtp_send_release_all_ue_in_enb()");
+            ogs_warn("    ENB_UE_S1AP_ID[%d] MME_UE_S1AP_ID[%d] Action[%d]",
+                enb_ue->enb_ue_s1ap_id, enb_ue->mme_ue_s1ap_id, action);
+
+            if (action == OGS_GTP_RELEASE_S1_CONTEXT_REMOVE) {
+                enb_ue_remove(enb_ue);
+            } else {
+                /* At this point, it does not support other action */
+                ogs_assert_if_reached();
+            }
+        }
     }
 }
 
diff --git a/src/mme/mme-s11-handler.c b/src/mme/mme-s11-handler.c
index 69ffbe9a0..ad0cddd0c 100644
--- a/src/mme/mme-s11-handler.c
+++ b/src/mme/mme-s11-handler.c
@@ -783,7 +783,7 @@ void mme_s11_handle_downlink_data_notification(
     }
 
     if (!mme_ue) {
-        ogs_error("No Context");
+        ogs_error("No UE Context");
         cause_value = OGS_GTP_CAUSE_CONTEXT_NOT_FOUND;
     }
 
@@ -795,7 +795,7 @@ void mme_s11_handle_downlink_data_notification(
     }
 
     if (!bearer) {
-        ogs_error("No context");
+        ogs_error("No Bearer Context");
         cause_value = OGS_GTP_CAUSE_CONTEXT_NOT_FOUND;
     }
 
diff --git a/src/mme/mme-sm.c b/src/mme/mme-sm.c
index f990bfe3a..dbb043a0e 100644
--- a/src/mme/mme-sm.c
+++ b/src/mme/mme-sm.c
@@ -613,6 +613,8 @@ void mme_state_operational(ogs_fsm_t *s, mme_event_t *e)
                     ogs_warn("No Context : TEID[%d]", gtp_message.h.teid);
                 else
                     ogs_warn("No Context : No TEID");
+
+                break;
             }
             mme_s11_handle_downlink_data_notification(
                 xact, mme_ue, &gtp_message.downlink_data_notification);
diff --git a/src/mme/s1ap-handler.c b/src/mme/s1ap-handler.c
index e330abef7..aee98389d 100644
--- a/src/mme/s1ap-handler.c
+++ b/src/mme/s1ap-handler.c
@@ -90,7 +90,7 @@ void s1ap_handle_s1_setup_request(mme_enb_t *enb, ogs_s1ap_message_t *message)
     S1SetupRequest = &initiatingMessage->value.choice.S1SetupRequest;
     ogs_assert(S1SetupRequest);
 
-    ogs_debug("[MME] S1-Setup request");
+    ogs_debug("S1-Setup request");
 
     for (i = 0; i < S1SetupRequest->protocolIEs.list.count; i++) {
         ie = S1SetupRequest->protocolIEs.list.array[i];
@@ -220,7 +220,7 @@ void s1ap_handle_initial_ue_message(mme_enb_t *enb, ogs_s1ap_message_t *message)
     InitialUEMessage = &initiatingMessage->value.choice.InitialUEMessage;
     ogs_assert(InitialUEMessage);
 
-    ogs_debug("[MME] Initial UE Message");
+    ogs_info("Initial UE Message");
 
     for (i = 0; i < InitialUEMessage->protocolIEs.list.count; i++) {
         ie = InitialUEMessage->protocolIEs.list.array[i];
@@ -284,7 +284,7 @@ void s1ap_handle_initial_ue_message(mme_enb_t *enb, ogs_s1ap_message_t *message)
                 ogs_info("Unknown UE by S_TMSI[G:%d,C:%d,M_TMSI:0x%x]",
                         nas_guti.mme_gid, nas_guti.mme_code, nas_guti.m_tmsi);
             } else {
-                ogs_debug("    S_TMSI[G:%d,C:%d,M_TMSI:0x%x] IMSI:[%s]",
+                ogs_info("    S_TMSI[G:%d,C:%d,M_TMSI:0x%x] IMSI:[%s]",
                         mme_ue->guti.mme_gid,
                         mme_ue->guti.mme_code,
                         mme_ue->guti.m_tmsi,
@@ -337,7 +337,7 @@ void s1ap_handle_initial_ue_message(mme_enb_t *enb, ogs_s1ap_message_t *message)
             sizeof(enb_ue->saved.e_cgi.cell_id));
     enb_ue->saved.e_cgi.cell_id = (be32toh(enb_ue->saved.e_cgi.cell_id) >> 4);
 
-    ogs_debug("    ENB_UE_S1AP_ID[%d] MME_UE_S1AP_ID[%d] TAC[%d]",
+    ogs_info("    ENB_UE_S1AP_ID[%d] MME_UE_S1AP_ID[%d] TAC[%d]",
         enb_ue->enb_ue_s1ap_id, enb_ue->mme_ue_s1ap_id, enb_ue->saved.tai.tac);
 
     s1ap_send_to_nas(enb_ue,
@@ -368,7 +368,7 @@ void s1ap_handle_uplink_nas_transport(
     UplinkNASTransport = &initiatingMessage->value.choice.UplinkNASTransport;
     ogs_assert(UplinkNASTransport);
 
-    ogs_debug("[MME] Uplink NAS transport");
+    ogs_debug("Uplink NAS transport");
 
     for (i = 0; i < UplinkNASTransport->protocolIEs.list.count; i++) {
         ie = UplinkNASTransport->protocolIEs.list.array[i];
@@ -437,7 +437,7 @@ void s1ap_handle_ue_capability_info_indication(
         &initiatingMessage->value.choice.UECapabilityInfoIndication;
     ogs_assert(UECapabilityInfoIndication);
 
-    ogs_debug("[MME] UE capability info indication");
+    ogs_debug("UE capability info indication");
 
     for (i = 0; i < UECapabilityInfoIndication->protocolIEs.list.count; i++) {
         ie = UECapabilityInfoIndication->protocolIEs.list.array[i];
@@ -497,7 +497,7 @@ void s1ap_handle_initial_context_setup_response(
         &successfulOutcome->value.choice.InitialContextSetupResponse;
     ogs_assert(InitialContextSetupResponse);
 
-    ogs_debug("[MME] Initial context setup response");
+    ogs_debug("Initial context setup response");
 
     for (i = 0; i < InitialContextSetupResponse->protocolIEs.list.count; i++) {
         ie = InitialContextSetupResponse->protocolIEs.list.array[i];
@@ -635,7 +635,7 @@ void s1ap_handle_initial_context_setup_failure(
         &unsuccessfulOutcome->value.choice.InitialContextSetupFailure;
     ogs_assert(InitialContextSetupFailure);
 
-    ogs_debug("[MME] Initial context setup failure");
+    ogs_debug("Initial context setup failure");
 
     for (i = 0; i < InitialContextSetupFailure->protocolIEs.list.count; i++) {
         ie = InitialContextSetupFailure->protocolIEs.list.array[i];
@@ -723,7 +723,7 @@ void s1ap_handle_ue_context_modification_response(
         &successfulOutcome->value.choice.UEContextModificationResponse;
     ogs_assert(UEContextModificationResponse);
 
-    ogs_debug("[MME] UE context modification response");
+    ogs_debug("UE context modification response");
 
     for (i = 0; i < UEContextModificationResponse->protocolIEs.list.count; i++) {
         ie = UEContextModificationResponse->protocolIEs.list.array[i];
@@ -792,7 +792,7 @@ void s1ap_handle_ue_context_modification_failure(
         &unsuccessfulOutcome->value.choice.UEContextModificationFailure;
     ogs_assert(UEContextModificationFailure);
 
-    ogs_warn("[MME] UE context modification failure");
+    ogs_warn("UE context modification failure");
 
     for (i = 0; i < UEContextModificationFailure->protocolIEs.list.count; i++) {
         ie = UEContextModificationFailure->protocolIEs.list.array[i];
@@ -869,7 +869,7 @@ void s1ap_handle_e_rab_setup_response(
     E_RABSetupResponse = &successfulOutcome->value.choice.E_RABSetupResponse;
     ogs_assert(E_RABSetupResponse);
 
-    ogs_debug("[MME] E-RAB setup response");
+    ogs_debug("E-RAB setup response");
 
     for (i = 0; i < E_RABSetupResponse->protocolIEs.list.count; i++) {
         ie = E_RABSetupResponse->protocolIEs.list.array[i];
@@ -997,7 +997,7 @@ void s1ap_handle_ue_context_release_request(
         &initiatingMessage->value.choice.UEContextReleaseRequest;
     ogs_assert(UEContextReleaseRequest);
 
-    ogs_debug("[MME] UE Context release request");
+    ogs_debug("UE Context release request");
 
     for (i = 0; i < UEContextReleaseRequest->protocolIEs.list.count; i++) {
         ie = UEContextReleaseRequest->protocolIEs.list.array[i];
@@ -1085,7 +1085,7 @@ void s1ap_handle_ue_context_release_complete(
         &successfulOutcome->value.choice.UEContextReleaseComplete;
     ogs_assert(UEContextReleaseComplete);
 
-    ogs_debug("[MME] UE Context release complete");
+    ogs_debug("UE Context release complete");
 
     for (i = 0; i < UEContextReleaseComplete->protocolIEs.list.count; i++) {
         ie = UEContextReleaseComplete->protocolIEs.list.array[i];
@@ -1128,6 +1128,11 @@ void s1ap_handle_ue_context_release_action(enb_ue_t *enb_ue)
 
     ogs_assert(enb_ue);
 
+    if (enb_ue_cycle(enb_ue) == NULL) {
+        ogs_error("S1 context has already been removed");
+        return;
+    }
+
     mme_ue = enb_ue->mme_ue;
 
     ogs_info("UE Context Release [Action:%d]", enb_ue->ue_ctx_rel_action);
@@ -1223,7 +1228,7 @@ void s1ap_handle_path_switch_request(
     PathSwitchRequest = &initiatingMessage->value.choice.PathSwitchRequest;
     ogs_assert(PathSwitchRequest);
 
-    ogs_debug("[MME] Path switch request");
+    ogs_info("Path switch request");
 
     for (i = 0; i < PathSwitchRequest->protocolIEs.list.count; i++) {
         ie = PathSwitchRequest->protocolIEs.list.array[i];
@@ -1274,16 +1279,16 @@ void s1ap_handle_path_switch_request(
         return;
     }
 
-    ogs_debug("    ENB_UE_S1AP_ID[%d] MME_UE_S1AP_ID[%d]",
+    ogs_info("    OLD ENB_UE_S1AP_ID[%d] MME_UE_S1AP_ID[%d]",
             enb_ue->enb_ue_s1ap_id, enb_ue->mme_ue_s1ap_id);
 
     mme_ue = enb_ue->mme_ue;
     ogs_expect_or_return(mme_ue);
 
-    ogs_debug("    OLD TAI[PLMN_ID:%06x,TAC:%d]",
+    ogs_info("    OLD TAI[PLMN_ID:%06x,TAC:%d]",
             ogs_plmn_id_hexdump(&mme_ue->tai.plmn_id),
             mme_ue->tai.tac);
-    ogs_debug("    OLD E_CGI[PLMN_ID:%06x,CELL_ID:%d]",
+    ogs_info("    OLD E_CGI[PLMN_ID:%06x,CELL_ID:%d]",
             ogs_plmn_id_hexdump(&mme_ue->e_cgi.plmn_id),
             mme_ue->e_cgi.cell_id);
 
@@ -1293,6 +1298,9 @@ void s1ap_handle_path_switch_request(
     /* Change enb_ue to the NEW eNB */
     enb_ue_switch_to_enb(enb_ue, enb);
 
+    ogs_info("    NEW ENB_UE_S1AP_ID[%d] MME_UE_S1AP_ID[%d]",
+            enb_ue->enb_ue_s1ap_id, enb_ue->mme_ue_s1ap_id);
+
     ogs_assert(EUTRAN_CGI);
     pLMNidentity = &EUTRAN_CGI->pLMNidentity;
     ogs_assert(pLMNidentity && pLMNidentity->size == sizeof(ogs_plmn_id_t));
@@ -1316,10 +1324,10 @@ void s1ap_handle_path_switch_request(
             sizeof(enb_ue->saved.e_cgi.cell_id));
     enb_ue->saved.e_cgi.cell_id = (be32toh(enb_ue->saved.e_cgi.cell_id) >> 4);
 
-    ogs_debug("    TAI[PLMN_ID:%06x,TAC:%d]",
+    ogs_info("    TAI[PLMN_ID:%06x,TAC:%d]",
             ogs_plmn_id_hexdump(&enb_ue->saved.tai.plmn_id),
             enb_ue->saved.tai.tac);
-    ogs_debug("    E_CGI[PLMN_ID:%06x,CELL_ID:%d]",
+    ogs_info("    E_CGI[PLMN_ID:%06x,CELL_ID:%d]",
             ogs_plmn_id_hexdump(&enb_ue->saved.e_cgi.plmn_id),
             enb_ue->saved.e_cgi.cell_id);
 
@@ -1413,7 +1421,7 @@ void s1ap_handle_enb_configuration_transfer(
         &initiatingMessage->value.choice.ENBConfigurationTransfer;
     ogs_assert(ENBConfigurationTransfer);
 
-    ogs_debug("[MME] ENB configuration transfer");
+    ogs_debug("ENB configuration transfer");
     for (i = 0; i < ENBConfigurationTransfer->protocolIEs.list.count; i++) {
         ie = ENBConfigurationTransfer->protocolIEs.list.array[i];
         switch (ie->id) {
@@ -1507,7 +1515,7 @@ void s1ap_handle_handover_required(mme_enb_t *enb, ogs_s1ap_message_t *message)
     mme_enb_t *target_enb = NULL;
     uint32_t target_enb_id = 0;
 
-    ogs_debug("[MME] Handover required");
+    ogs_debug("Handover required");
     for (i = 0; i < HandoverRequired->protocolIEs.list.count; i++) {
         ie = HandoverRequired->protocolIEs.list.array[i];
         switch (ie->id) {
@@ -1620,7 +1628,7 @@ void s1ap_handle_handover_request_ack(
         &successfulOutcome->value.choice.HandoverRequestAcknowledge;
     ogs_assert(HandoverRequestAcknowledge);
 
-    ogs_debug("[MME] Handover request acknowledge");
+    ogs_debug("Handover request acknowledge");
     for (i = 0; i < HandoverRequestAcknowledge->protocolIEs.list.count; i++) {
         ie = HandoverRequestAcknowledge->protocolIEs.list.array[i];
         switch (ie->id) {
@@ -1744,7 +1752,7 @@ void s1ap_handle_handover_failure(mme_enb_t *enb, ogs_s1ap_message_t *message)
     HandoverFailure = &unsuccessfulOutcome->value.choice.HandoverFailure;
     ogs_assert(HandoverFailure);
 
-    ogs_debug("[MME] Handover failure");
+    ogs_debug("Handover failure");
     for (i = 0; i < HandoverFailure->protocolIEs.list.count; i++) {
         ie = HandoverFailure->protocolIEs.list.array[i];
         switch (ie->id) {
@@ -1809,7 +1817,7 @@ void s1ap_handle_handover_cancel(mme_enb_t *enb, ogs_s1ap_message_t *message)
     HandoverCancel = &initiatingMessage->value.choice.HandoverCancel;
     ogs_assert(HandoverCancel);
 
-    ogs_debug("[MME] Handover cancel");
+    ogs_debug("Handover cancel");
     for (i = 0; i < HandoverCancel->protocolIEs.list.count; i++) {
         ie = HandoverCancel->protocolIEs.list.array[i];
         switch (ie->id) {
@@ -1853,7 +1861,7 @@ void s1ap_handle_handover_cancel(mme_enb_t *enb, ogs_s1ap_message_t *message)
             S1AP_UE_CTX_REL_DELETE_INDIRECT_TUNNEL,
             ogs_time_from_msec(300));
 
-    ogs_debug("[MME] Handover Cancel : "
+    ogs_debug("Handover Cancel : "
             "UE[eNB-UE-S1AP-ID(%d)] --> eNB[%s:%d]",
             source_ue->enb_ue_s1ap_id,
             OGS_ADDR(enb->sctp.addr, buf), enb->enb_id);
@@ -1884,7 +1892,7 @@ void s1ap_handle_enb_status_transfer(mme_enb_t *enb, ogs_s1ap_message_t *message
     ENBStatusTransfer = &initiatingMessage->value.choice.ENBStatusTransfer;
     ogs_assert(ENBStatusTransfer);
 
-    ogs_debug("[MME] ENB status transfer");
+    ogs_debug("ENB status transfer");
     for (i = 0; i < ENBStatusTransfer->protocolIEs.list.count; i++) {
         ie = ENBStatusTransfer->protocolIEs.list.array[i];
         switch (ie->id) {
@@ -1959,7 +1967,7 @@ void s1ap_handle_handover_notification(
     HandoverNotify = &initiatingMessage->value.choice.HandoverNotify;
     ogs_assert(HandoverNotify);
 
-    ogs_debug("[MME] Handover notification");
+    ogs_debug("Handover notification");
     for (i = 0; i < HandoverNotify->protocolIEs.list.count; i++) {
         ie = HandoverNotify->protocolIEs.list.array[i];
         switch (ie->id) {
@@ -2084,7 +2092,7 @@ void s1ap_handle_s1_reset(
     Reset = &initiatingMessage->value.choice.Reset;
     ogs_assert(Reset);
 
-    ogs_warn("[MME] Reset");
+    ogs_warn("Reset");
 
     for (i = 0; i < Reset->protocolIEs.list.count; i++) {
         ie = Reset->protocolIEs.list.array[i];
@@ -2219,7 +2227,7 @@ void s1ap_handle_write_replace_warning_response(
         &successfulOutcome->value.choice.WriteReplaceWarningResponse;
     ogs_assert(WriteReplaceWarningResponse);
 
-    ogs_debug("[MME] Write replace warning response");
+    ogs_debug("Write replace warning response");
 
     ogs_debug("    IP[%s] ENB_ID[%d]",
             OGS_ADDR(enb->sctp.addr, buf), enb->enb_id);
@@ -2244,7 +2252,7 @@ void s1ap_handle_kill_response(
         &successfulOutcome->value.choice.KillResponse;
     ogs_assert(KillResponse);
 
-    ogs_debug("[MME] Kill response");
+    ogs_debug("Kill response");
 
     ogs_debug("    IP[%s] ENB_ID[%d]",
             OGS_ADDR(enb->sctp.addr, buf), enb->enb_id);
diff --git a/src/mme/s1ap-path.c b/src/mme/s1ap-path.c
index cdba53480..557a6b0c8 100644
--- a/src/mme/s1ap-path.c
+++ b/src/mme/s1ap-path.c
@@ -443,7 +443,7 @@ void s1ap_send_handover_request(
 
     enb_ue_t *source_ue = NULL, *target_ue = NULL;
 
-    ogs_debug("[MME] Handover request");
+    ogs_info("Handover request");
     
     ogs_assert(target_enb);
 
@@ -455,9 +455,9 @@ void s1ap_send_handover_request(
     target_ue = enb_ue_add(target_enb, INVALID_UE_S1AP_ID);
     ogs_assert(target_ue);
 
-    ogs_debug("    Source : ENB_UE_S1AP_ID[%d] MME_UE_S1AP_ID[%d]",
+    ogs_info("    Source : ENB_UE_S1AP_ID[%d] MME_UE_S1AP_ID[%d]",
             source_ue->enb_ue_s1ap_id, source_ue->mme_ue_s1ap_id);
-    ogs_debug("    Target : ENB_UE_S1AP_ID[Unknown] MME_UE_S1AP_ID[%d]",
+    ogs_info("    Target : ENB_UE_S1AP_ID[Unknown] MME_UE_S1AP_ID[%d]",
             target_ue->mme_ue_s1ap_id);
 
     source_ue_associate_target_ue(source_ue, target_ue);
diff --git a/src/mme/s1ap-sctp.c b/src/mme/s1ap-sctp.c
index 241d2dd49..185e7abde 100644
--- a/src/mme/s1ap-sctp.c
+++ b/src/mme/s1ap-sctp.c
@@ -178,25 +178,12 @@ void s1ap_recv_handler(ogs_sock_t *sock)
                         sock, addr, NULL, 0, 0);
             }
             break;
+
         case SCTP_SHUTDOWN_EVENT :
-        case SCTP_SEND_FAILED :
-            if (not->sn_header.sn_type == SCTP_SHUTDOWN_EVENT)
-                ogs_debug("SCTP_SHUTDOWN_EVENT:[T:%d, F:0x%x, L:%d]", 
-                        not->sn_shutdown_event.sse_type,
-                        not->sn_shutdown_event.sse_flags,
-                        not->sn_shutdown_event.sse_length);
-            if (not->sn_header.sn_type == SCTP_SEND_FAILED)
-#if HAVE_USRSCTP
-                ogs_error("SCTP_SEND_FAILED:[T:%d, F:0x%x, S:%d]", 
-                        not->sn_send_failed_event.ssfe_type,
-                        not->sn_send_failed_event.ssfe_flags,
-                        not->sn_send_failed_event.ssfe_error);
-#else
-                ogs_error("SCTP_SEND_FAILED:[T:%d, F:0x%x, S:%d]", 
-                        not->sn_send_failed.ssf_type,
-                        not->sn_send_failed.ssf_flags,
-                        not->sn_send_failed.ssf_error);
-#endif
+            ogs_debug("SCTP_SHUTDOWN_EVENT:[T:%d, F:0x%x, L:%d]",
+                    not->sn_shutdown_event.sse_type,
+                    not->sn_shutdown_event.sse_flags,
+                    not->sn_shutdown_event.sse_length);
 
             addr = ogs_calloc(1, sizeof(ogs_sockaddr_t));
             ogs_assert(addr);
@@ -205,6 +192,21 @@ void s1ap_recv_handler(ogs_sock_t *sock)
             s1ap_event_push(MME_EVT_S1AP_LO_CONNREFUSED,
                     sock, addr, NULL, 0, 0);
             break;
+
+        case SCTP_SEND_FAILED :
+#if HAVE_USRSCTP
+            ogs_error("SCTP_SEND_FAILED:[T:%d, F:0x%x, S:%d]",
+                    not->sn_send_failed_event.ssfe_type,
+                    not->sn_send_failed_event.ssfe_flags,
+                    not->sn_send_failed_event.ssfe_error);
+#else
+            ogs_error("SCTP_SEND_FAILED:[T:%d, F:0x%x, S:%d]",
+                    not->sn_send_failed.ssf_type,
+                    not->sn_send_failed.ssf_flags,
+                    not->sn_send_failed.ssf_error);
+#endif
+            break;
+
         case SCTP_PEER_ADDR_CHANGE:
             ogs_warn("SCTP_PEER_ADDR_CHANGE:[T:%d, F:0x%x, S:%d]", 
                     not->sn_paddr_change.spc_type,
diff --git a/src/mme/s1ap-sm.c b/src/mme/s1ap-sm.c
index c6edc7616..0f29b4593 100644
--- a/src/mme/s1ap-sm.c
+++ b/src/mme/s1ap-sm.c
@@ -94,10 +94,10 @@ void s1ap_state_operational(ogs_fsm_t *s, mme_event_t *e)
                 s1ap_handle_uplink_nas_transport(enb, pdu);
                 break;
             case S1AP_ProcedureCode_id_UECapabilityInfoIndication :
-                s1ap_handle_ue_capability_info_indication( enb, pdu);
+                s1ap_handle_ue_capability_info_indication(enb, pdu);
                 break;
             case S1AP_ProcedureCode_id_UEContextReleaseRequest:
-                s1ap_handle_ue_context_release_request( enb, pdu);
+                s1ap_handle_ue_context_release_request(enb, pdu);
                 break;
             case S1AP_ProcedureCode_id_PathSwitchRequest:
                 s1ap_handle_path_switch_request(enb, pdu);
diff --git a/src/sgwc/gtp-path.c b/src/sgwc/gtp-path.c
index 5c74aa159..a1dc3435b 100644
--- a/src/sgwc/gtp-path.c
+++ b/src/sgwc/gtp-path.c
@@ -157,7 +157,7 @@ static void bearer_timeout(ogs_gtp_xact_t *xact, void *data)
 
     switch (type) {
     case OGS_GTP_DOWNLINK_DATA_NOTIFICATION_TYPE:
-        ogs_error("[%s] No Downlink Data Notification ACK", sgwc_ue->imsi_bcd);
+        ogs_warn("[%s] No Downlink Data Notification ACK", sgwc_ue->imsi_bcd);
         break;
     default:
         ogs_error("GTP Timeout : IMSI[%s] Message-Type[%d]",
diff --git a/src/sgwu/gtp-path.c b/src/sgwu/gtp-path.c
index 634651c7d..f6833aca7 100644
--- a/src/sgwu/gtp-path.c
+++ b/src/sgwu/gtp-path.c
@@ -144,7 +144,7 @@ static void _gtpv1_u_recv_cb(short when, ogs_socket_t fd, void *data)
             }
 
         } else {
-            ogs_error("[DROP] Cannot decode Error-Indication");
+            ogs_error("[DROP] Cannot find FAR by Error-Indication");
             ogs_log_hexdump(OGS_LOG_ERROR, pkbuf->data, pkbuf->len);
         }
     } else if (gtp_h->type == OGS_GTPU_MSGTYPE_GPDU) {