diff -Nur channels.old/chan_mobile.c channels/chan_mobile.c
--- channels.old/chan_mobile.c	2009-07-11 20:49:42.000000000 +0200
+++ channels/chan_mobile.c	2009-07-13 22:03:10.000000000 +0200
@@ -137,6 +137,7 @@
 	int ring_sched_id;
 	struct ast_dsp *dsp;
 	struct sched_context *sched;
+	int hangupcause;
 
 	/* flags */
 	unsigned int outgoing:1;	/*!< outgoing call */
@@ -162,6 +163,9 @@
 static int handle_response_cmti(struct mbl_pvt *pvt, char *buf);
 static int handle_response_cmgr(struct mbl_pvt *pvt, char *buf);
 static int handle_response_cusd(struct mbl_pvt *pvt, char *buf);
+static int handle_response_busy(struct mbl_pvt *pvt);
+static int handle_response_no_dialtone(struct mbl_pvt *pvt, char *buf);
+static int handle_response_no_carrier(struct mbl_pvt *pvt, char *buf);
 static int handle_sms_prompt(struct mbl_pvt *pvt, char *buf);
 
 /* CLI stuff */
@@ -420,6 +424,9 @@
 	AT_CMER,
 	AT_CIND_TEST,
 	AT_CUSD,
+	AT_BUSY,
+	AT_NO_DIALTONE,
+	AT_NO_CARRIER,
 } at_message_t;
 
 static int at_match_prefix(char *buf, char *prefix);
@@ -963,6 +970,7 @@
 			ast_log(LOG_ERROR, "error sending ATD command on %s\n", pvt->id);
 			return -1;
 		}
+		pvt->hangupcause = 0;
 		pvt->needchup = 1;
 		msg_queue_push(pvt, AT_OK, AT_D);
 	} else {
@@ -1294,6 +1302,9 @@
 			if (ast_channel_trylock(pvt->owner)) {
 				DEADLOCK_AVOIDANCE(&pvt->lock);
 			} else {
+				if (pvt->hangupcause != 0) {
+					pvt->owner->hangupcause = pvt->hangupcause;
+				}
 				ast_queue_hangup(pvt->owner);
 				ast_channel_unlock(pvt->owner);
 				break;
@@ -1883,6 +1894,12 @@
 		return AT_VGS;
 	} else if (at_match_prefix(buf, "+CUSD:")) {
 		return AT_CUSD;
+	} else if (at_match_prefix(buf, "BUSY")) {
+		return AT_BUSY;
+	} else if (at_match_prefix(buf, "NO DIALTONE")) {
+		return AT_NO_DIALTONE;
+	} else if (at_match_prefix(buf, "NO CARRIER")) {
+		return AT_NO_CARRIER;
 	} else {
 		return AT_UNKNOWN;
 	}
@@ -1927,6 +1944,12 @@
 		return "SMS PROMPT";
 	case AT_CMS_ERROR:
 		return "+CMS ERROR";
+	case AT_BUSY:
+		return "BUSY";
+	case AT_NO_DIALTONE:
+		return "NO DIALTONE";
+	case AT_NO_CARRIER:
+		return "NO CARRIER";
 	/* at commands */
 	case AT_A:
 		return "ATA";
@@ -3515,6 +3538,49 @@
 	return 0;
 }
 
+/*!
+ * \brief Handle BUSY messages.
+ * \param pvt a mbl_pvt structure
+ * \retval 0 success
+ * \retval -1 error
+ */
+static int handle_response_busy(struct mbl_pvt *pvt)
+{
+	pvt->hangupcause = AST_CAUSE_USER_BUSY;
+	pvt->needchup = 1;
+	return 0;
+}
+
+/*!
+ * \brief Handle NO DIALTONE messages.
+ * \param pvt a mbl_pvt structure
+ * \param buf a null terminated buffer containing an AT message
+ * \retval 0 success
+ * \retval -1 error
+ */
+static int handle_response_no_dialtone(struct mbl_pvt *pvt, char *buf)
+{
+	ast_verb(1, "[%s] mobile reports NO DIALTONE\n", pvt->id);
+	pvt->needchup = 1;
+	mbl_queue_control(pvt, AST_CONTROL_CONGESTION);
+	return 0;
+}
+
+/*!
+ * \brief Handle NO CARRIER messages.
+ * \param pvt a mbl_pvt structure
+ * \param buf a null terminated buffer containing an AT message
+ * \retval 0 success
+ * \retval -1 error
+ */
+static int handle_response_no_carrier(struct mbl_pvt *pvt, char *buf)
+{
+	ast_verb(1, "[%s] mobile reports NO CARRIER\n", pvt->id);
+	pvt->needchup = 1;
+	mbl_queue_control(pvt, AST_CONTROL_CONGESTION);
+	return 0;
+}
+
 
 static void *do_monitor_phone(void *data)
 {
@@ -3673,6 +3739,30 @@
 			}
 			ast_mutex_unlock(&pvt->lock);
 			break;
+		case AT_BUSY:
+			ast_mutex_lock(&pvt->lock);
+			if (handle_response_busy(pvt)) {
+				ast_mutex_unlock(&pvt->lock);
+				goto e_cleanup;
+			}
+			ast_mutex_unlock(&pvt->lock);
+			break;
+		case AT_NO_DIALTONE:
+			ast_mutex_lock(&pvt->lock);
+			if (handle_response_no_dialtone(pvt, buf)) {
+				ast_mutex_unlock(&pvt->lock);
+				goto e_cleanup;
+			}
+			ast_mutex_unlock(&pvt->lock);
+			break;
+		case AT_NO_CARRIER:
+			ast_mutex_lock(&pvt->lock);
+			if (handle_response_no_carrier(pvt, buf)) {
+				ast_mutex_unlock(&pvt->lock);
+				goto e_cleanup;
+			}
+			ast_mutex_unlock(&pvt->lock);
+			break;
 		case AT_UNKNOWN:
 			ast_debug(1, "[%s] ignoring unknown message: %s\n", pvt->id, buf);
 			break;