diff --git a/libpri.h b/libpri.h
index bfab67c..f9986c5 100644
--- a/libpri.h
+++ b/libpri.h
@@ -1296,6 +1296,8 @@ enum PRI_TIMERS_AND_COUNTERS {
 	PRI_TIMER_T_HOLD,	/*!< Maximum time to wait for HOLD request response. */
 	PRI_TIMER_T_RETRIEVE,	/*!< Maximum time to wait for RETRIEVE request response. */
 
+	PRI_TIMER_T_RESPONSE,	/*!< Maximum time to wait for a typical APDU response. */
+
 	/* Must be last in the enum list */
 	PRI_MAX_TIMERS
 };
diff --git a/pri.c b/pri.c
index 964da7a..b3c6877 100644
--- a/pri.c
+++ b/pri.c
@@ -88,6 +88,7 @@ static const struct pri_timer_table pri_timer[] = {
 	{ "T322",           PRI_TIMER_T322,             PRI_ALL_SWITCHES },
 	{ "T-HOLD",         PRI_TIMER_T_HOLD,           PRI_ALL_SWITCHES },
 	{ "T-RETRIEVE",     PRI_TIMER_T_RETRIEVE,       PRI_ALL_SWITCHES },
+	{ "T-RESPONSE",     PRI_TIMER_T_RESPONSE,       PRI_ALL_SWITCHES },
 /* *INDENT-ON* */
 };
 
@@ -157,6 +158,8 @@ static void pri_default_timers(struct pri *ctrl, int switchtype)
 	ctrl->timers[PRI_TIMER_T_HOLD] = 4 * 1000;	/* Wait for HOLD request response. */
 	ctrl->timers[PRI_TIMER_T_RETRIEVE] = 4 * 1000;/* Wait for RETRIEVE request response. */
 
+	ctrl->timers[PRI_TIMER_T_RESPONSE] = 4 * 1000;	/* Maximum time to wait for a typical APDU response. */
+
 	/* Set any switch specific override default values */
 	switch (switchtype) {
 	default:
diff --git a/pri_facility.c b/pri_facility.c
index 284136b..fa34e3c 100644
--- a/pri_facility.c
+++ b/pri_facility.c
@@ -1023,7 +1023,7 @@ int rose_diverting_leg_information1_encode(struct pri *ctrl, q931_call *call)
 		return -1;
 	}
 
-	return pri_call_apdu_queue(call, Q931_FACILITY, buffer, end - buffer);
+	return pri_call_apdu_queue(call, Q931_FACILITY, buffer, end - buffer, NULL);
 }
 
 /*!
@@ -1192,7 +1192,7 @@ static int rose_diverting_leg_information2_encode(struct pri *ctrl, q931_call *c
 		return -1;
 	}
 
-	return pri_call_apdu_queue(call, Q931_SETUP, buffer, end - buffer);
+	return pri_call_apdu_queue(call, Q931_SETUP, buffer, end - buffer, NULL);
 }
 
 /*!
@@ -1314,7 +1314,7 @@ int rose_diverting_leg_information3_encode(struct pri *ctrl, q931_call *call,
 		return -1;
 	}
 
-	return pri_call_apdu_queue(call, messagetype, buffer, end - buffer);
+	return pri_call_apdu_queue(call, messagetype, buffer, end - buffer, NULL);
 }
 
 /*!
@@ -1385,7 +1385,7 @@ int rlt_initiate_transfer(struct pri *ctrl, q931_call *c1, q931_call *c2)
 		return -1;
 	}
 
-	if (pri_call_apdu_queue(apdubearer, Q931_FACILITY, buffer, end - buffer)) {
+	if (pri_call_apdu_queue(apdubearer, Q931_FACILITY, buffer, end - buffer, NULL)) {
 		return -1;
 	}
 
@@ -1448,7 +1448,7 @@ static int add_dms100_transfer_ability_apdu(struct pri *ctrl, q931_call *call)
 		return -1;
 	}
 
-	return pri_call_apdu_queue(call, Q931_SETUP, buffer, end - buffer);
+	return pri_call_apdu_queue(call, Q931_SETUP, buffer, end - buffer, NULL);
 }
 
 /*!
@@ -1557,7 +1557,7 @@ static int add_callername_facility_ies(struct pri *ctrl, q931_call *call, int cp
 			return -1;
 		}
 
-		if (pri_call_apdu_queue(call, Q931_SETUP, buffer, end - buffer)) {
+		if (pri_call_apdu_queue(call, Q931_SETUP, buffer, end - buffer, NULL)) {
 			return -1;
 		}
 
@@ -1580,7 +1580,7 @@ static int add_callername_facility_ies(struct pri *ctrl, q931_call *call, int cp
 		mymessage = Q931_FACILITY;
 	}
 
-	return pri_call_apdu_queue(call, mymessage, buffer, end - buffer);
+	return pri_call_apdu_queue(call, mymessage, buffer, end - buffer, NULL);
 }
 /* End Callername */
 
@@ -1714,7 +1714,7 @@ int mwi_message_send(struct pri *ctrl, q931_call *call, struct pri_sr *req, int
 		return -1;
 	}
 
-	return pri_call_apdu_queue(call, Q931_SETUP, buffer, end - buffer);
+	return pri_call_apdu_queue(call, Q931_SETUP, buffer, end - buffer, NULL);
 }
 /* End MWI */
 
@@ -1773,7 +1773,7 @@ int eect_initiate_transfer(struct pri *ctrl, q931_call *c1, q931_call *c2)
 		return -1;
 	}
 
-	if (pri_call_apdu_queue(c1, Q931_FACILITY, buffer, end - buffer)) {
+	if (pri_call_apdu_queue(c1, Q931_FACILITY, buffer, end - buffer, NULL)) {
 		pri_message(ctrl, "Could not queue APDU in facility message\n");
 		return -1;
 	}
@@ -2094,7 +2094,7 @@ static int rose_reroute_request_encode(struct pri *ctrl, q931_call *call,
 		return -1;
 	}
 
-	return pri_call_apdu_queue(call, Q931_FACILITY, buffer, end - buffer);
+	return pri_call_apdu_queue(call, Q931_FACILITY, buffer, end - buffer, NULL);
 }
 
 /*!
@@ -2221,14 +2221,10 @@ static int anfpr_pathreplacement_respond(struct pri *ctrl, q931_call *call, q931
 {
 	int res;
 
-	res = pri_call_apdu_queue_cleanup(call->bridged_call);
-	if (res) {
-		pri_message(ctrl, "Could not Clear queue ADPU\n");
-		return -1;
-	}
+	pri_call_apdu_queue_cleanup(call->bridged_call);
 
 	/* Send message */
-	res = pri_call_apdu_queue(call->bridged_call, Q931_FACILITY, ie->data, ie->len);
+	res = pri_call_apdu_queue(call->bridged_call, Q931_FACILITY, ie->data, ie->len, NULL);
 	if (res) {
 		pri_message(ctrl, "Could not queue ADPU in facility message\n");
 		return -1;
@@ -2296,7 +2292,7 @@ int anfpr_initiate_transfer(struct pri *ctrl, q931_call *c1, q931_call *c2)
 		return -1;
 	}
 
-	res = pri_call_apdu_queue(c1, Q931_FACILITY, buffer, pos - buffer);
+	res = pri_call_apdu_queue(c1, Q931_FACILITY, buffer, pos - buffer, NULL);
 	if (res) {
 		pri_message(ctrl, "Could not queue ADPU in facility message\n");
 		return -1;
@@ -2325,7 +2321,7 @@ int anfpr_initiate_transfer(struct pri *ctrl, q931_call *c1, q931_call *c2)
 		return -1;
 	}
 
-	res = pri_call_apdu_queue(c2, Q931_FACILITY, buffer, pos - buffer);
+	res = pri_call_apdu_queue(c2, Q931_FACILITY, buffer, pos - buffer, NULL);
 	if (res) {
 		pri_message(ctrl, "Could not queue ADPU in facility message\n");
 		return -1;
@@ -2410,7 +2406,7 @@ static int aoc_aoce_charging_unit_encode(struct pri *ctrl, q931_call *call,
 
 	/* Remember that if we queue a facility IE for a facility message we
 	 * have to explicitly send the facility message ourselves */
-	if (pri_call_apdu_queue(call, Q931_FACILITY, buffer, end - buffer)
+	if (pri_call_apdu_queue(call, Q931_FACILITY, buffer, end - buffer, NULL)
 		|| q931_facility(call->pri, call)) {
 		pri_message(ctrl, "Could not schedule facility message for call %d\n", call->cr);
 		return -1;
@@ -2556,7 +2552,7 @@ static int rose_call_transfer_complete_encode(struct pri *ctrl, q931_call *call,
 		return -1;
 	}
 
-	return pri_call_apdu_queue(call, Q931_FACILITY, buffer, end - buffer);
+	return pri_call_apdu_queue(call, Q931_FACILITY, buffer, end - buffer, NULL);
 }
 
 /* ===== End Call Transfer Supplementary Service (ECMA-178) ===== */
@@ -2624,7 +2620,7 @@ int rose_called_name_encode(struct pri *ctrl, q931_call *call, int messagetype)
 		return -1;
 	}
 
-	return pri_call_apdu_queue(call, messagetype, buffer, end - buffer);
+	return pri_call_apdu_queue(call, messagetype, buffer, end - buffer, NULL);
 }
 
 /*!
@@ -2690,7 +2686,7 @@ int rose_connected_name_encode(struct pri *ctrl, q931_call *call, int messagetyp
 		return -1;
 	}
 
-	return pri_call_apdu_queue(call, messagetype, buffer, end - buffer);
+	return pri_call_apdu_queue(call, messagetype, buffer, end - buffer, NULL);
 }
 
 /*!
@@ -2700,11 +2696,18 @@ int rose_connected_name_encode(struct pri *ctrl, q931_call *call, int messagetyp
  * \param messagetype Q.931 message type.
  * \param apdu Facility ie contents buffer.
  * \param apdu_len Length of the contents buffer.
+ * \param response Sender supplied information to handle APDU response messages.
+ *        NULL if don't care about responses.
+ *
+ * \note
+ * Only APDU messages with an invoke component can supply a response pointer.
+ * If any other APDU messages supply a response pointer then aliasing of the
+ * invoke_id can occur.
  *
  * \retval 0 on success.
  * \retval -1 on error.
  */
-int pri_call_apdu_queue(q931_call *call, int messagetype, const unsigned char *apdu, int apdu_len)
+int pri_call_apdu_queue(q931_call *call, int messagetype, const unsigned char *apdu, int apdu_len, struct apdu_callback_data *response)
 {
 	struct apdu_event *cur = NULL;
 	struct apdu_event *new_event = NULL;
@@ -2731,11 +2734,16 @@ int pri_call_apdu_queue(q931_call *call, int messagetype, const unsigned char *a
 		return -1;
 	}
 
+	/* Fill in the APDU event */
 	new_event->message = messagetype;
+	if (response) {
+		new_event->response = *response;
+	}
+	new_event->call = call;
 	new_event->apdu_len = apdu_len;
 	memcpy(new_event->apdu, apdu, apdu_len);
 
-	/* Append APDU to the end of the list. */
+	/* Append APDU event to the end of the list. */
 	if (call->apdus) {
 		for (cur = call->apdus; cur->next; cur = cur->next) {
 		}
@@ -2747,22 +2755,85 @@ int pri_call_apdu_queue(q931_call *call, int messagetype, const unsigned char *a
 	return 0;
 }
 
-int pri_call_apdu_queue_cleanup(q931_call *call)
+/* Used by q931.c to cleanup the apdu queue upon destruction of a call */
+void pri_call_apdu_queue_cleanup(q931_call *call)
 {
-	struct apdu_event *cur_event = NULL, *free_event = NULL;
+	struct apdu_event *cur_event;
+	struct apdu_event *free_event;
 
-	if (call && call->apdus) {
+	if (call) {
 		cur_event = call->apdus;
 		call->apdus = NULL;
 		while (cur_event) {
-			/* TODO: callbacks, some way of giving return res on status of apdu */
+			if (cur_event->response.callback) {
+				/* Indicate to callback that the APDU is being cleaned up. */
+				cur_event->response.callback(APDU_CALLBACK_REASON_CLEANUP, call->pri,
+					call, cur_event, NULL);
+
+				/* Stop any response timeout. */
+				pri_schedule_del(call->pri, cur_event->timer);
+			}
 			free_event = cur_event;
 			cur_event = cur_event->next;
 			free(free_event);
 		}
 	}
+}
 
-	return 0;
+/*!
+ * \internal
+ * \brief Find an outstanding APDU with the given invoke id.
+ *
+ * \param call Call to find APDU.
+ * \param invoke_id Invoke id to match outstanding APDUs in queue.
+ *
+ * \retval apdu_event if found.
+ * \retval NULL if not found.
+ */
+static struct apdu_event *pri_call_apdu_find(struct q931_call *call, int invoke_id)
+{
+	struct apdu_event *apdu;
+
+	for (apdu = call->apdus; apdu; apdu = apdu->next) {
+		/*
+		 * Note: The APDU cannot be sent and still in the queue without a
+		 * callback and timeout timer active.  Therefore, an invoke_id of
+		 * zero is valid and not just the result of a memset().
+		 */
+		if (apdu->response.invoke_id == invoke_id && apdu->sent) {
+			break;
+		}
+	}
+	return apdu;
+}
+
+/*!
+ * \brief Delete the given APDU event from the given call.
+ *
+ * \param call Call to remove the APDU.
+ * \param doomed APDU event to delete.
+ *
+ * \return Nothing
+ */
+void pri_call_apdu_delete(struct q931_call *call, struct apdu_event *doomed)
+{
+	struct apdu_event **prev;
+	struct apdu_event *cur;
+
+	/* Find APDU in list. */
+	for (prev = &call->apdus, cur = call->apdus;
+		cur;
+		prev = &cur->next, cur = cur->next) {
+		if (cur == doomed) {
+			/* Stop any response timeout. */
+			pri_schedule_del(call->pri, cur->timer);
+
+			/* Remove APDU from list. */
+			*prev = cur->next;
+			free(cur);
+			break;
+		}
+	}
 }
 
 /*! \note Only called when sending the SETUP message. */
@@ -2948,7 +3019,7 @@ static int rose_facility_error_encode(struct pri *ctrl, q931_call *call, int inv
 		return -1;
 	}
 
-	return pri_call_apdu_queue(call, Q931_FACILITY, buffer, end - buffer);
+	return pri_call_apdu_queue(call, Q931_FACILITY, buffer, end - buffer, NULL);
 }
 
 /*!
@@ -3080,7 +3151,7 @@ static int rose_result_ok_encode(struct pri *ctrl, q931_call *call, int msgtype,
 		return -1;
 	}
 
-	return pri_call_apdu_queue(call, msgtype, buffer, end - buffer);
+	return pri_call_apdu_queue(call, msgtype, buffer, end - buffer, NULL);
 }
 
 /*!
@@ -3163,11 +3234,39 @@ int pri_rerouting_rsp(struct pri *ctrl, q931_call *call, int invoke_id, enum PRI
 void rose_handle_reject(struct pri *ctrl, q931_call *call, int msgtype, q931_ie *ie,
 	const struct fac_extension_header *header, const struct rose_msg_reject *reject)
 {
+	struct apdu_event *apdu;
+	union apdu_msg_data msg;
+
+	/* Gripe to the user about getting rejected. */
 	pri_error(ctrl, "ROSE REJECT:\n");
 	if (reject->invoke_id_present) {
 		pri_error(ctrl, "\tINVOKE ID: %d\n", reject->invoke_id);
 	}
 	pri_error(ctrl, "\tPROBLEM: %s\n", rose_reject2str(reject->code));
+
+	switch (ctrl->switchtype) {
+	case PRI_SWITCH_DMS100:
+		/* The DMS-100 switch apparently handles invoke_id as an invoke operation. */
+		return;
+	default:
+		break;
+	}
+
+	if (!reject->invoke_id_present) {
+		/*
+		 * No invoke id to look up so we cannot match it to any outstanding APDUs.
+		 * This REJECT is apparently meant for someone monitoring the link.
+		 */
+		return;
+	}
+	apdu = pri_call_apdu_find(call, reject->invoke_id);
+	if (!apdu) {
+		return;
+	}
+	msg.reject = reject;
+	if (apdu->response.callback(APDU_CALLBACK_REASON_MSG_REJECT, ctrl, call, apdu, &msg)) {
+		pri_call_apdu_delete(call, apdu);
+	}
 }
 
 /*!
@@ -3186,7 +3285,10 @@ void rose_handle_error(struct pri *ctrl, q931_call *call, int msgtype, q931_ie *
 	const struct fac_extension_header *header, const struct rose_msg_error *error)
 {
 	const char *dms100_operation;
+	struct apdu_event *apdu;
+	union apdu_msg_data msg;
 
+	/* Gripe to the user about getting an error. */
 	pri_error(ctrl, "ROSE RETURN ERROR:\n");
 	switch (ctrl->switchtype) {
 	case PRI_SWITCH_DMS100:
@@ -3211,6 +3313,23 @@ void rose_handle_error(struct pri *ctrl, q931_call *call, int msgtype, q931_ie *
 		break;
 	}
 	pri_error(ctrl, "\tERROR: %s\n", rose_error2str(error->code));
+
+	switch (ctrl->switchtype) {
+	case PRI_SWITCH_DMS100:
+		/* The DMS-100 switch apparently handles invoke_id as an invoke operation. */
+		return;
+	default:
+		break;
+	}
+
+	apdu = pri_call_apdu_find(call, error->invoke_id);
+	if (!apdu) {
+		return;
+	}
+	msg.error = error;
+	if (apdu->response.callback(APDU_CALLBACK_REASON_MSG_ERROR, ctrl, call, apdu, &msg)) {
+		pri_call_apdu_delete(call, apdu);
+	}
 }
 
 /*!
@@ -3228,8 +3347,12 @@ void rose_handle_error(struct pri *ctrl, q931_call *call, int msgtype, q931_ie *
 void rose_handle_result(struct pri *ctrl, q931_call *call, int msgtype, q931_ie *ie,
 	const struct fac_extension_header *header, const struct rose_msg_result *result)
 {
+	struct apdu_event *apdu;
+	union apdu_msg_data msg;
+
 	switch (ctrl->switchtype) {
 	case PRI_SWITCH_DMS100:
+		/* The DMS-100 switch apparently handles invoke_id as an invoke operation. */
 		switch (result->invoke_id) {
 		case ROSE_DMS100_RLT_OPERATION_IND:
 			if (result->operation != ROSE_DMS100_RLT_OperationInd) {
@@ -3256,87 +3379,13 @@ void rose_handle_result(struct pri *ctrl, q931_call *call, int msgtype, q931_ie
 		break;
 	}
 
-	switch (result->operation) {
-	case ROSE_None:
-		/*
-		 * This is simply a positive ACK to the invoke request.
-		 * The invoke ID must be used to distinguish between outstanding
-		 * invoke requests.
-		 */
-		break;
-#if 0	/* Not handled yet */
-	case ROSE_ETSI_ActivationDiversion:
-		break;
-	case ROSE_ETSI_DeactivationDiversion:
-		break;
-	case ROSE_ETSI_InterrogationDiversion:
-		break;
-#endif	/* Not handled yet */
-	case ROSE_ETSI_CallDeflection:
-		/* Successfully completed call deflection.  Nothing to do. */
-		break;
-	case ROSE_ETSI_CallRerouting:
-		/* Successfully completed call rerouting.  Nothing to do. */
-		break;
-#if 0	/* Not handled yet */
-	case ROSE_ETSI_InterrogateServedUserNumbers:
-		break;
-#endif	/* Not handled yet */
-#if 0	/* Not handled yet */
-	case ROSE_ETSI_ChargingRequest:
-		break;
-#endif	/* Not handled yet */
-#if 0	/* Not handled yet */
-	case ROSE_ETSI_EctExecute:
-		break;
-	case ROSE_ETSI_ExplicitEctExecute:
-		break;
-	case ROSE_ETSI_EctLinkIdRequest:
-		break;
-	case ROSE_ETSI_EctLoopTest:
-		break;
-#endif	/* Not handled yet */
-#if 0	/* Not handled yet */
-	case ROSE_QSIG_ChargeRequest:
-		break;
-	case ROSE_QSIG_AocComplete:
-		break;
-#endif	/* Not handled yet */
-#if 0	/* Not handled yet */
-	case ROSE_QSIG_CallTransferIdentify:
-		break;
-	case ROSE_QSIG_CallTransferInitiate:
-		break;
-	case ROSE_QSIG_CallTransferSetup:
-		break;
-#endif	/* Not handled yet */
-#if 0	/* Not handled yet */
-	case ROSE_QSIG_ActivateDiversionQ:
-		break;
-	case ROSE_QSIG_DeactivateDiversionQ:
-		break;
-	case ROSE_QSIG_InterrogateDiversionQ:
-		break;
-	case ROSE_QSIG_CheckRestriction:
-		break;
-#endif	/* Not handled yet */
-	case ROSE_QSIG_CallRerouting:
-		/* Successfully completed call rerouting.  Nothing to do. */
-		break;
-#if 0	/* Not handled yet */
-	case ROSE_QSIG_MWIActivate:
-		break;
-	case ROSE_QSIG_MWIDeactivate:
-		break;
-	case ROSE_QSIG_MWIInterrogate:
-		break;
-#endif	/* Not handled yet */
-	default:
-		if (ctrl->debug & PRI_DEBUG_APDU) {
-			pri_message(ctrl, "!! ROSE result operation not handled! %s\n",
-				rose_operation2str(result->operation));
-		}
-		break;
+	apdu = pri_call_apdu_find(call, result->invoke_id);
+	if (!apdu) {
+		return;
+	}
+	msg.result = result;
+	if (apdu->response.callback(APDU_CALLBACK_REASON_MSG_RESULT, ctrl, call, apdu, &msg)) {
+		pri_call_apdu_delete(call, apdu);
 	}
 }
 
diff --git a/pri_facility.h b/pri_facility.h
index 6c9bbdd..018e7d2 100644
--- a/pri_facility.h
+++ b/pri_facility.h
@@ -31,6 +31,13 @@
 #define _PRI_FACILITY_H
 #include "pri_q931.h"
 
+/* Forward declare some structs */
+struct fac_extension_header;
+struct rose_msg_invoke;
+struct rose_msg_result;
+struct rose_msg_error;
+struct rose_msg_reject;
+
 /* Protocol Profile field */
 #define Q932_PROTOCOL_MASK			0x1F
 #define Q932_PROTOCOL_ROSE			0x11	/* X.219 & X.229 */
@@ -65,6 +72,107 @@
 #define QSIG_NOTIFICATION_WITHOUT_DIVERTED_TO_NR	0x01
 #define QSIG_NOTIFICATION_WITH_DIVERTED_TO_NR		0x02
 
+/*! Reasons an APDU callback is called. */
+enum APDU_CALLBACK_REASON {
+	/*!
+	 * \brief Send setup error.  Abort and cleanup.
+	 * \note The message may or may not actually get sent.
+	 * \note The callback cannot generate an event subcmd.
+	 * \note The callback should not send messages.  Out of order messages will result.
+	 */
+	APDU_CALLBACK_REASON_ERROR,
+	/*!
+	 * \brief Abort and cleanup.
+	 * \note The APDU queue is being destroyed.
+	 * \note The callback cannot generate an event subcmd.
+	 * \note The callback cannot send messages as the call is likely being destroyed.
+	 */
+	APDU_CALLBACK_REASON_CLEANUP,
+	/*!
+	 * \brief Timeout waiting for responses to the message.
+	 * \note The callback can generate an event subcmd.
+	 * \note The callback can send messages.
+	 */
+	APDU_CALLBACK_REASON_TIMEOUT,
+	/*!
+	 * \brief Received a facility response message.
+	 * \note The callback can generate an event subcmd.
+	 * \note The callback can send messages.
+	 */
+	APDU_CALLBACK_REASON_MSG_RESULT,
+	/*!
+	 * \brief Received a facility error message.
+	 * \note The callback can generate an event subcmd.
+	 * \note The callback can send messages.
+	 */
+	APDU_CALLBACK_REASON_MSG_ERROR,
+	/*!
+	 * \brief Received a facility reject message.
+	 * \note The callback can generate an event subcmd.
+	 * \note The callback can send messages.
+	 */
+	APDU_CALLBACK_REASON_MSG_REJECT,
+};
+
+union apdu_msg_data {
+	const struct rose_msg_result *result;
+	const struct rose_msg_error *error;
+	const struct rose_msg_reject *reject;
+};
+
+union apdu_callback_param {
+	void *ptr;
+	long value;
+	char pad[8];
+};
+
+struct apdu_callback_data {
+	/*! APDU invoke id to match with any response messages. (Result/Error/Reject) */
+	int invoke_id;
+	/*!
+	 * \brief Time to wait for responses to APDU in ms.
+	 * \note Set to 0 if send the message only.
+	 * \note Set to less than 0 for PRI_TIMER_T_RESPONSE time.
+	 */
+	int timeout_time;
+	/*!
+	 * \brief APDU callback function.
+	 *
+	 * \param reason Reason callback is called.
+	 * \param ctrl D channel controller.
+	 * \param call Q.931 call leg.
+	 * \param apdu APDU queued entry.  Do not change!
+	 * \param msg APDU response message data.  (NULL if was not the reason called.)
+	 *
+	 * \note
+	 * A callback must be supplied if the sender cares about any APDU_CALLBACK_REASON.
+	 *
+	 * \return TRUE if no more responses are expected.
+	 */
+	int (*callback)(enum APDU_CALLBACK_REASON reason, struct pri *ctrl, struct q931_call *call, struct apdu_event *apdu, const union apdu_msg_data *msg);
+	/*! \brief Sender data for the callback function to identify the particular APDU. */
+	union apdu_callback_param user;
+};
+
+struct apdu_event {
+	/*! Linked list pointer */
+	struct apdu_event *next;
+	/*! TRUE if this APDU has been sent. */
+	int sent;
+	/*! What message to send the ADPU in */
+	int message;
+	/*! Sender supplied information to handle APDU response messages. */
+	struct apdu_callback_data response;
+	/*! Q.931 call leg.  (Needed for the APDU timeout.) */
+	struct q931_call *call;
+	/*! Response timeout timer. */
+	int timer;
+	/*! Length of ADPU */
+	int apdu_len;
+	/*! ADPU to send */
+	unsigned char apdu[255];
+};
+
 /* Queues an MWI apdu on a the given call */
 int mwi_message_send(struct pri *pri, q931_call *call, struct pri_sr *req, int activate);
 
@@ -87,23 +195,15 @@ int rose_diverting_leg_information3_encode(struct pri *pri, q931_call *call, int
 int rose_connected_name_encode(struct pri *pri, q931_call *call, int messagetype);
 int rose_called_name_encode(struct pri *pri, q931_call *call, int messagetype);
 
-int pri_call_apdu_queue(q931_call *call, int messagetype, const unsigned char *apdu, int apdu_len);
-
-/* Used by q931.c to cleanup the apdu queue upon destruction of a call */
-int pri_call_apdu_queue_cleanup(q931_call *call);
+int pri_call_apdu_queue(q931_call *call, int messagetype, const unsigned char *apdu, int apdu_len, struct apdu_callback_data *response);
+void pri_call_apdu_queue_cleanup(q931_call *call);
+void pri_call_apdu_delete(struct q931_call *call, struct apdu_event *doomed);
 
 /* Adds the "standard" APDUs to a call */
 int pri_call_add_standard_apdus(struct pri *pri, q931_call *call);
 
 void asn1_dump(struct pri *ctrl, const unsigned char *start_asn1, const unsigned char *end);
 
-/* Forward declare some ROSE structures for the following prototypes */
-struct fac_extension_header;
-struct rose_msg_invoke;
-struct rose_msg_result;
-struct rose_msg_error;
-struct rose_msg_reject;
-
 void rose_handle_invoke(struct pri *ctrl, q931_call *call, int msgtype, q931_ie *ie, const struct fac_extension_header *header, const struct rose_msg_invoke *invoke);
 void rose_handle_result(struct pri *ctrl, q931_call *call, int msgtype, q931_ie *ie, const struct fac_extension_header *header, const struct rose_msg_result *result);
 void rose_handle_error(struct pri *ctrl, q931_call *call, int msgtype, q931_ie *ie, const struct fac_extension_header *header, const struct rose_msg_error *error);
diff --git a/pri_internal.h b/pri_internal.h
index fbde7e1..7181c75 100644
--- a/pri_internal.h
+++ b/pri_internal.h
@@ -40,6 +40,9 @@
 #define DBGHEAD __FILE__ ":%d %s: "
 #define DBGINFO __LINE__,__PRETTY_FUNCTION__
 
+/* Forward declare some structs */
+struct apdu_event;
+
 struct pri_sched {
 	struct timeval when;
 	void (*callback)(void *data);
@@ -307,13 +310,6 @@ struct pri_sr {
 
 #define Q931_MAX_TEI	8
 
-struct apdu_event {
-	struct apdu_event *next;	/* Linked list pointer */
-	int message;			/* What message to send the ADPU in */
-	int apdu_len; 			/* Length of ADPU */
-	unsigned char apdu[255];			/* ADPU to send */
-};
-
 /*! \brief Incoming call transfer states. */
 enum INCOMING_CT_STATE {
 	/*!
diff --git a/q931.c b/q931.c
index 0c117b0..3640722 100644
--- a/q931.c
+++ b/q931.c
@@ -2266,6 +2266,8 @@ static int receive_progress_indicator(int full_ie, struct pri *ctrl, q931_call *
 	return 0;
 }
 
+static void q931_apdu_timeout(void *data);
+
 static int transmit_facility(int full_ie, struct pri *ctrl, q931_call *call, int msgtype, q931_ie *ie, int len, int order)
 {
 	struct apdu_event **prev;
@@ -2275,9 +2277,7 @@ static int transmit_facility(int full_ie, struct pri *ctrl, q931_call *call, int
 	for (prev = &call->apdus, cur = call->apdus;
 		cur;
 		prev = &cur->next, cur = cur->next) {
-		if (cur->message == msgtype) {
-			/* Remove APDU from list. */
-			*prev = cur->next;
+		if (!cur->sent && cur->message == msgtype) {
 			break;
 		}
 	}
@@ -2292,15 +2292,52 @@ static int transmit_facility(int full_ie, struct pri *ctrl, q931_call *call, int
 		facility_decode_dump(ctrl, cur->apdu, cur->apdu_len);
 	}
 
-	if (cur->apdu_len > 235) { /* TODO: find out how much space we can use */
-		pri_message(ctrl, "Requested APDU (%d bytes) is too long\n", cur->apdu_len);
+	if (len < cur->apdu_len) { 
+		pri_error(ctrl,
+			"Could not fit facility ie in message.  Size needed:%d  Available space:%d\n",
+			cur->apdu_len + 2, len);
+
+		/* Remove APDU from list. */
+		*prev = cur->next;
+
+		if (cur->response.callback) {
+			/* Indicate to callback that the APDU had a problem getting sent. */
+			cur->response.callback(APDU_CALLBACK_REASON_ERROR, ctrl, call, cur, NULL);
+		}
+
 		free(cur);
 		return 0;
 	}
 
 	memcpy(ie->data, cur->apdu, cur->apdu_len);
 	apdu_len = cur->apdu_len;
-	free(cur);
+	cur->sent = 1;
+
+	if (cur->response.callback && cur->response.timeout_time) {
+		int duration;
+
+		if (0 < cur->response.timeout_time) {
+			/* Sender specified timeout duration. */
+			duration = cur->response.timeout_time;
+		} else {
+			/* Sender wants to use the typical timeout duration. */
+			duration = ctrl->timers[PRI_TIMER_T_RESPONSE];
+		}
+		cur->timer = pri_schedule_event(ctrl, duration, q931_apdu_timeout, cur);
+		if (!cur->timer) {
+			/* Remove APDU from list. */
+			*prev = cur->next;
+
+			/* Indicate to callback that the APDU had a problem getting sent. */
+			cur->response.callback(APDU_CALLBACK_REASON_ERROR, ctrl, call, cur, NULL);
+
+			free(cur);
+		}
+	} else if (!cur->timer) {
+		/* Remove APDU from list. */
+		*prev = cur->next;
+		free(cur);
+	}
 
 	return apdu_len + 2;
 }
@@ -6223,6 +6260,34 @@ static void q931_fill_facility_event(struct pri *ctrl, struct q931_call *call)
 	ctrl->ev.facility.callingplan = call->remote_id.number.plan;
 }
 
+/*!
+ * \internal
+ * \brief APDU wait for response message timeout.
+ *
+ * \param data Callback data pointer.
+ *
+ * \return Nothing
+ */
+static void q931_apdu_timeout(void *data)
+{
+	struct apdu_event *apdu;
+	struct pri *ctrl;
+	struct q931_call *call;
+
+	apdu = data;
+	call = apdu->call;
+	ctrl = call->pri;
+
+	q931_clr_subcommands(ctrl);
+	apdu->response.callback(APDU_CALLBACK_REASON_TIMEOUT, ctrl, call, apdu, NULL);
+	if (ctrl->subcmds.counter_subcmd) {
+		q931_fill_facility_event(ctrl, call);
+		ctrl->schedev = 1;
+	}
+
+	pri_call_apdu_delete(call, apdu);
+}
+
 /*!
  * \internal
  * \brief Find the active call given the held call.
@@ -6510,7 +6575,7 @@ static int post_handle_q931_message(struct pri *ctrl, struct q931_mh *mh, struct
 		c->useruserinfo[0] = '\0';
 
 		for (cur = c->apdus; cur; cur = cur->next) {
-			if (cur->message == Q931_FACILITY) {
+			if (!cur->sent && cur->message == Q931_FACILITY) {
 				q931_facility(ctrl, c);
 				break;
 			}
@@ -6615,7 +6680,7 @@ static int post_handle_q931_message(struct pri *ctrl, struct q931_mh *mh, struct
 		ctrl->ev.proceeding.call = c->master_call;
 
 		for (cur = c->apdus; cur; cur = cur->next) {
-			if (cur->message == Q931_FACILITY) {
+			if (!cur->sent && cur->message == Q931_FACILITY) {
 				q931_facility(ctrl, c);
 				break;
 			}
@@ -6892,7 +6957,7 @@ static int post_handle_q931_message(struct pri *ctrl, struct q931_mh *mh, struct
 		ctrl->ev.setup_ack.call = c->master_call;
 
 		for (cur = c->apdus; cur; cur = cur->next) {
-			if (cur->message == Q931_FACILITY) {
+			if (!cur->sent && cur->message == Q931_FACILITY) {
 				q931_facility(ctrl, c);
 				break;
 			}