diff --git a/openbsc/src/libbsc/bsc_vty.c b/openbsc/src/libbsc/bsc_vty.c
index 04f2cc6..b0e8764 100644
--- a/openbsc/src/libbsc/bsc_vty.c
+++ b/openbsc/src/libbsc/bsc_vty.c
@@ -195,6 +195,10 @@
 	if (net->authorized_reg_str)
 		vty_out(vty, ", authorized regexp: %s", net->authorized_reg_str);
 	vty_out(vty, "%s", VTY_NEWLINE);
+	vty_out(vty, "  Auto create subscriber: %s%s",
+		net->auto_create_subscr ? "yes" : "no", VTY_NEWLINE);
+	vty_out(vty, "  Auto assign extension: %s%s",
+		net->auto_assign_exten ? "yes" : "no", VTY_NEWLINE);
 	vty_out(vty, "  Location updating reject cause: %u%s",
 		net->reject_cause, VTY_NEWLINE);
 	vty_out(vty, "  Encryption: A5/%u%s", net->a5_encryption,
diff --git a/openbsc/src/libbsc/net_init.c b/openbsc/src/libbsc/net_init.c
index 4636d57..0e99097 100644
--- a/openbsc/src/libbsc/net_init.c
+++ b/openbsc/src/libbsc/net_init.c
@@ -21,10 +21,13 @@
 #include <openbsc/osmo_msc_data.h>
 #include <openbsc/gsm_subscriber.h>
 
+#include <stdbool.h>
+
 struct gsm_network *gsm_network_init(uint16_t country_code, uint16_t network_code,
 				     int (*mncc_recv)(struct gsm_network *, struct msgb *))
 {
 	struct gsm_network *net;
+	const char *default_regexp = "*";
 
 	net = talloc_zero(tall_bsc_ctx, struct gsm_network);
 	if (!net)
@@ -42,13 +45,18 @@
 		return NULL;
 	}
 
+	if (gsm_parse_reg(net, &net->authorized_regexp, &net->authorized_reg_str, 1,
+			  &default_regexp) != 0)
+		return NULL;
+
 	/* Init back pointer */
 	net->bsc_data->auto_off_timeout = -1;
 	net->bsc_data->network = net;
 	INIT_LLIST_HEAD(&net->bsc_data->mscs);
 
 	net->subscr_group->net = net;
-	net->subscr_creation_mode = GSM_SUBSCR_CREAT_W_RAND_EXT;
+	net->auto_create_subscr = true;
+	net->auto_assign_exten = true;
 
 	net->country_code = country_code;
 	net->network_code = network_code;
diff --git a/openbsc/src/libmsc/ctrl_commands.c b/openbsc/src/libmsc/ctrl_commands.c
index a02db36..79e136d 100644
--- a/openbsc/src/libmsc/ctrl_commands.c
+++ b/openbsc/src/libmsc/ctrl_commands.c
@@ -25,6 +25,8 @@
 #include <openbsc/db.h>
 #include <openbsc/debug.h>
 
+#include <stdbool.h>
+
 static bool alg_supported(const char *alg)
 {
 	/*
@@ -96,9 +98,7 @@
 
 	subscr = subscr_get_by_imsi(net->subscr_group, imsi);
 	if (!subscr)
-		subscr = subscr_create_subscriber(net->subscr_group, imsi,
-						  net->ext_min,
-						  net->ext_max);
+		subscr = subscr_create_subscriber(net->subscr_group, imsi);
 	if (!subscr)
 		goto fail;
 
diff --git a/openbsc/src/libmsc/db.c b/openbsc/src/libmsc/db.c
index b367139..68eba3e 100644
--- a/openbsc/src/libmsc/db.c
+++ b/openbsc/src/libmsc/db.c
@@ -23,6 +23,7 @@
 #include <inttypes.h>
 #include <libgen.h>
 #include <stdio.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
@@ -519,7 +520,7 @@
 }
 
 struct gsm_subscriber *db_create_subscriber(const char *imsi, uint64_t smin,
-					    uint64_t smax)
+					    uint64_t smax, bool alloc_exten)
 {
 	dbi_result result;
 	struct gsm_subscriber *subscr;
@@ -551,7 +552,8 @@
 	strncpy(subscr->imsi, imsi, sizeof(subscr->imsi)-1);
 	dbi_result_free(result);
 	LOGP(DDB, LOGL_INFO, "New Subscriber: ID %llu, IMSI %s\n", subscr->id, subscr->imsi);
-	db_subscriber_alloc_exten(subscr, smin, smax);
+	if (alloc_exten)
+		db_subscriber_alloc_exten(subscr, smin, smax);
 	return subscr;
 }
 
@@ -956,8 +958,11 @@
 
 	dbi_conn_quote_string_copy(conn, 
 				   subscriber->name, &q_name);
-	dbi_conn_quote_string_copy(conn, 
-				   subscriber->extension, &q_extension);
+	if (subscriber->extension[0] != '\0')
+		dbi_conn_quote_string_copy(conn,
+					   subscriber->extension, &q_extension);
+	else
+		q_extension = strdup("NULL");
 	
 	if (subscriber->tmsi != GSM_RESERVED_TMSI) {
 		sprintf(tmsi, "%u", subscriber->tmsi);
@@ -1062,15 +1067,17 @@
 	}
 	dbi_result_free(result);
 
-	result = dbi_conn_queryf(conn,
-			"DELETE FROM SMS WHERE src_addr=%s OR dest_addr=%s",
-			subscr->extension, subscr->extension);
-	if (!result) {
-		LOGP(DDB, LOGL_ERROR,
-			"Failed to delete SMS for %llu\n", subscr->id);
-		return -1;
+	if (subscr->extension[0] != '\0') {
+		result = dbi_conn_queryf(conn,
+			    "DELETE FROM SMS WHERE src_addr=%s OR dest_addr=%s",
+					 subscr->extension, subscr->extension);
+		if (!result) {
+			LOGP(DDB, LOGL_ERROR,
+			     "Failed to delete SMS for %llu\n", subscr->id);
+			return -1;
+		}
+		dbi_result_free(result);
 	}
-	dbi_result_free(result);
 
 	result = dbi_conn_queryf(conn,
 			"DELETE FROM VLR WHERE subscriber_id=%llu",
diff --git a/openbsc/src/libmsc/gsm_04_08.c b/openbsc/src/libmsc/gsm_04_08.c
index 6704497..1b02efe 100644
--- a/openbsc/src/libmsc/gsm_04_08.c
+++ b/openbsc/src/libmsc/gsm_04_08.c
@@ -530,15 +530,13 @@
 static struct gsm_subscriber *subscr_create(const struct gsm_network *net,
 					    const char *imsi)
 {
-	if (net->subscr_creation_mode == GSM_SUBSCR_DONT_CREATE)
+	if (!net->auto_create_subscr)
 		return NULL;
 
-	if (net->subscr_creation_mode & GSM_SUBSCR_CREAT_W_REGEXP)
-		if (!subscr_regexp_check(net, imsi))
-			return NULL;
+	if (!subscr_regexp_check(net, imsi))
+		return NULL;
 
-	return subscr_create_subscriber(net->subscr_group, imsi, net->ext_min,
-					net->ext_max);
+	return subscr_create_subscriber(net->subscr_group, imsi);
 }
 
 /* Parse Chapter 9.2.11 Identity Response */
diff --git a/openbsc/src/libmsc/gsm_subscriber.c b/openbsc/src/libmsc/gsm_subscriber.c
index 1dc2cc2..08198c7 100644
--- a/openbsc/src/libmsc/gsm_subscriber.c
+++ b/openbsc/src/libmsc/gsm_subscriber.c
@@ -26,6 +26,7 @@
 #include <string.h>
 #include <assert.h>
 #include <time.h>
+#include <stdbool.h>
 
 #include <osmocom/core/talloc.h>
 
@@ -203,10 +204,12 @@
 }
 
 struct gsm_subscriber *subscr_create_subscriber(struct gsm_subscriber_group *sgrp,
-						const char *imsi, uint64_t smin,
-						uint64_t smax)
+						const char *imsi)
 {
-	struct gsm_subscriber *subscr = db_create_subscriber(imsi, smin, smax);
+	struct gsm_subscriber *subscr = db_create_subscriber(imsi,
+							     sgrp->net->ext_min,
+							     sgrp->net->ext_max,
+							     sgrp->net->auto_assign_exten);
 	if (subscr)
 		subscr->group = sgrp;
 	return subscr;
diff --git a/openbsc/src/libmsc/vty_interface_layer3.c b/openbsc/src/libmsc/vty_interface_layer3.c
index a035bf9..74da1d7 100644
--- a/openbsc/src/libmsc/vty_interface_layer3.c
+++ b/openbsc/src/libmsc/vty_interface_layer3.c
@@ -242,9 +242,7 @@
 	if (subscr)
 		db_sync_subscriber(subscr);
 	else {
-		subscr = subscr_create_subscriber(gsmnet->subscr_group, argv[0],
-						  gsmnet->ext_min,
-						  gsmnet->ext_max);
+		subscr = subscr_create_subscriber(gsmnet->subscr_group, argv[0]);
 
 		if (!subscr) {
 			vty_out(vty, "%% No subscriber created for IMSI %s%s",
@@ -1044,6 +1042,8 @@
 {
 	struct gsm_network *gsmnet = gsmnet_from_vty(vty);
 	uint64_t mi = atoi(argv[0]), ma = atoi(argv[1]);
+	gsmnet->auto_create_subscr = true;
+	gsmnet->auto_assign_exten = true;
 	if (mi >= ma) {
 		vty_out(vty, "Incorrect range: %s >= %s, expected MIN < MAX%s",
 			argv[0], argv[1], VTY_NEWLINE);
@@ -1055,15 +1055,13 @@
 }
 
 DEFUN(cfg_nitb_subscr_create, cfg_nitb_subscr_create_cmd,
-      "subscriber-create-on-demand [regexp]",
+      "subscriber-create-on-demand [no-extension]",
       "Make a new record when a subscriber is first seen.\n"
-      "Create subscribers only if IMSI matches the regexp specified in "
-      "authorized-regexp command\n")
+      "Do not automatically assign extension to created subscribers\n")
 {
 	struct gsm_network *gsmnet = gsmnet_from_vty(vty);
-	gsmnet->subscr_creation_mode = GSM_SUBSCR_CREAT_W_RAND_EXT;
-	if (argc)
-		gsmnet->subscr_creation_mode |= GSM_SUBSCR_CREAT_W_REGEXP;
+	gsmnet->auto_create_subscr = true;
+	gsmnet->auto_assign_exten = argc ? false : true;
 	return CMD_SUCCESS;
 }
 
@@ -1072,7 +1070,7 @@
       NO_STR "Make a new record when a subscriber is first seen.\n")
 {
 	struct gsm_network *gsmnet = gsmnet_from_vty(vty);
-	gsmnet->subscr_creation_mode = GSM_SUBSCR_DONT_CREATE;
+	gsmnet->auto_create_subscr = false;
 	return CMD_SUCCESS;
 }
 
@@ -1097,12 +1095,15 @@
 static int config_write_nitb(struct vty *vty)
 {
 	struct gsm_network *gsmnet = gsmnet_from_vty(vty);
-	enum gsm_subscr_creation_mode scm = gsmnet->subscr_creation_mode;
-	const char *reg = (scm & GSM_SUBSCR_CREAT_W_REGEXP) ? " regexp" : "",
-		*pref = scm ? "" : "no ";
+
 	vty_out(vty, "nitb%s", VTY_NEWLINE);
-	vty_out(vty, " %ssubscriber-create-on-demand%s%s",
-		pref, reg, VTY_NEWLINE);
+	if (!gsmnet->auto_create_subscr)
+		vty_out(vty, " no subscriber-create-on-demand%s", VTY_NEWLINE);
+	else
+		vty_out(vty, " subscriber-create-on-demand%s%s",
+			gsmnet->auto_assign_exten ? "" : " no-extension",
+			VTY_NEWLINE);
+
 	if (gsmnet->ext_min != GSM_MIN_EXTEN || gsmnet->ext_max != GSM_MAX_EXTEN)
 		vty_out(vty, " subscriber-create-on-demand random %"PRIu64" %"
 			PRIu64"%s", gsmnet->ext_min, gsmnet->ext_max,