diff --git a/src/main.c b/src/main.c
index 478599b..f8acb37 100644
--- a/src/main.c
+++ b/src/main.c
@@ -108,6 +108,10 @@ static const struct e1inp_line_ops v5le_e1_line_ops = {
 static void hdlc_rx_cb(struct e1inp_ts *ts, struct msgb *msg)
 {
 #warning HACKING
+		if (llist_empty(&v5i->interfaces)) {
+			msgb_free(msg);
+			return;
+		}
 		struct v5x_interface *v5if = (struct v5x_interface *)v5i->interfaces.next;
 
 	LOGP(DLINP, LOGL_DEBUG, "L1->L2: %s\n", msgb_hexdump(msg));
@@ -122,6 +126,10 @@ static void hdlc_rx_cb(struct e1inp_ts *ts, struct msgb *msg)
 static void raw_rx_cb(struct e1inp_ts *ts, struct msgb *msg)
 {
 #warning HACKING
+		if (llist_empty(&v5i->interfaces)) {
+			msgb_free(msg);
+			return;
+		}
 		struct v5x_interface *v5if = (struct v5x_interface *)v5i->interfaces.next;
 		struct v5x_user_port *v5up = v5if->links[0].ts[ts->num].v5up;
 
@@ -405,13 +413,6 @@ int main(int argc, char **argv)
 	if (!v5i)
 		return -ENOMEM;
 
-	// FIXME: move this to VTY code
-	/* create v5x interface */
-	struct v5x_interface *v5if;
-	v5if = v5x_interface_alloc(v5i, V5X_DIALECT_V51, ph_data_req);
-	if (!v5if)
-		return -ENOMEM;
-
 	rc = vty_read_config_file(config_file, NULL);
 	if (rc < 0) {
 		fprintf(stderr, "Failed to read config file '%s'.\n", config_file);
diff --git a/src/v5x_vty.c b/src/v5x_vty.c
index e3a393b..119f807 100644
--- a/src/v5x_vty.c
+++ b/src/v5x_vty.c
@@ -8,12 +8,19 @@
 extern struct v5x_instance *v5i;
 
 enum v5_vty_node {
-	INTERFACE_NODE = _LAST_OSMOVTY_NODE + 1,
+	INTERFACE_NODE_V51 = _LAST_OSMOVTY_NODE + 1,
+	INTERFACE_NODE_V52,
 };
 
-static struct cmd_node interface_node = {
-	INTERFACE_NODE,
-	"%s(config-if)# ",
+static struct cmd_node interface_node_v51 = {
+	INTERFACE_NODE_V51,
+	"%s(config-v5.1-if)# ",
+	1,
+};
+
+static struct cmd_node interface_node_v52 = {
+	INTERFACE_NODE_V52,
+	"%s(config-v5.2-if)# ",
 	1,
 };
 
@@ -49,16 +56,54 @@ struct vty_app_info vty_info = {
 	.is_config_node	= v5le_vty_is_config_node,
 };
 
-DEFUN(cfg_interface, cfg_interface_cmd,
-	"interface", "Configure the V5 interface")
-{
-	struct v5x_interface *v5if = (struct v5x_interface *)v5i->interfaces.next;
+#warning hacking
+int ph_data_req(struct msgb *msg, void *cbdata);
 
-        vty->node = INTERFACE_NODE;
+DEFUN(cfg_interface, cfg_interface_cmd,
+	"interface (v5.1|v5.2)",
+	"Configure V5 interface\n" "Configure as V5.1 interface\n" "Configure as V5.2 interface")
+{
+	struct v5x_interface *v5if = NULL;
+	enum v5x_dialect dialect = V5X_DIALECT_V51;
+
+	if (!llist_empty(&v5i->interfaces))
+		v5if = (struct v5x_interface *)v5i->interfaces.next;
+
+	if (!strcasecmp(argv[0], "v5.2"))
+		dialect = V5X_DIALECT_V52;
+
+	if (!v5if) {
+		v5if = v5x_interface_alloc(v5i, dialect, ph_data_req);
+		if (!v5if) {
+			vty_out(vty, "%%Failed to create interface%s", VTY_NEWLINE);
+			return CMD_WARNING;
+		}
+	} else {
+		vty_out(vty, "%%Interface already created. If interface type has been changed, restart this "
+				"application.%s", VTY_NEWLINE);
+	}
+
+        vty->node = (v5if->dialect == V5X_DIALECT_V51) ? INTERFACE_NODE_V51 : INTERFACE_NODE_V52;
 	vty->index = v5if;
         return CMD_SUCCESS;
 }
 
+DEFUN(cfg_no_interface, cfg_no_interface_cmd,
+	"no interface",
+	NO_STR "Remove V5 interface")
+{
+	struct v5x_interface *v5if = NULL;
+
+	if (!llist_empty(&v5i->interfaces))
+		v5if = (struct v5x_interface *)v5i->interfaces.next;
+
+	if (v5if) {
+		v5x_interface_free(v5if);
+	}
+
+        return CMD_SUCCESS;
+}
+
 DEFUN(cfg_interface_id, cfg_interface_id_cmd,
 	"id <0-16777215>",
 	"Set interface ID\n" "Interface ID")
@@ -79,7 +124,7 @@ DEFUN(cfg_interface_variant, cfg_interface_variant_cmd,
 	return CMD_SUCCESS;
 }
 
-DEFUN(cfg_port_pstn, cfg_port_pstn_cmd,
+DEFUN(cfg_port_pstn_v51, cfg_port_pstn_cmd_v51,
 	"port pstn <0-32767> <1-31>",
 	"Create V5 user port\n" "PSTN user port\n" "L3 address\n" "Time slot")
 {
@@ -99,6 +144,26 @@ DEFUN(cfg_port_pstn, cfg_port_pstn_cmd,
 	return CMD_SUCCESS;
 }
 
+DEFUN(cfg_port_pstn_v52, cfg_port_pstn_cmd_v52,
+	"port pstn <0-32767>",
+	"Create V5 user port\n" "PSTN user port\n" "L3 address")
+{
+	struct v5x_interface *v5if = vty->index;
+	struct v5x_user_port *v5up;
+
+	v5up = v5x_user_port_find(v5if, atoi(argv[0]), false);
+	if (v5up) {
+		vty_out(vty, "%%Given PSTN user port already exists, remove first.%s", VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+	v5up = v5x_user_port_create(v5if, atoi(argv[0]), V5X_USER_TYPE_PSTN, 0, 0);
+	if (!v5up) {
+		vty_out(vty, "%%Failed to create PSTN user port.%s", VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+	return CMD_SUCCESS;
+}
+
 DEFUN(cfg_no_port_pstn, cfg_no_port_pstn_cmd,
 	"no port pstn <0-32767>",
 	NO_STR "Delete V5 user port\n" "PSTN user port\n" "L3 address\n")
@@ -115,7 +180,7 @@ DEFUN(cfg_no_port_pstn, cfg_no_port_pstn_cmd,
 	return CMD_SUCCESS;
 }
 
-DEFUN(cfg_port_isdn, cfg_port_isdn_cmd,
+DEFUN(cfg_port_isdn_v51, cfg_port_isdn_cmd_v51,
 	"port isdn <0-8175> <1-31> <1-31>",
 	"Create V5 user port\n" "ISDN user port\n" "L3 address\n" "Time slot 1\n" "Time slot 2\n")
 {
@@ -135,6 +200,26 @@ DEFUN(cfg_port_isdn, cfg_port_isdn_cmd,
 	return CMD_SUCCESS;
 }
 
+DEFUN(cfg_port_isdn_v52, cfg_port_isdn_cmd_v52,
+	"port isdn <0-8175>",
+	"Create V5 user port\n" "ISDN user port\n" "L3 address\n")
+{
+	struct v5x_interface *v5if = vty->index;
+	struct v5x_user_port *v5up;
+
+	v5up = v5x_user_port_find(v5if, atoi(argv[0]), true);
+	if (v5up) {
+		vty_out(vty, "%%Given ISDN user port already exists, remove first.%s", VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+	v5up = v5x_user_port_create(v5if, atoi(argv[0]), V5X_USER_TYPE_ISDN, 0, 0);
+	if (!v5up) {
+		vty_out(vty, "%%Failed to create ISDN user port.%s", VTY_NEWLINE);
+		return CMD_WARNING;
+	}
+	return CMD_SUCCESS;
+}
+
 DEFUN(cfg_no_port_isdn, cfg_no_port_isdn_cmd,
 	"no port isdn <0-8175>",
 	NO_STR "Delete V5 user port\n" "ISDN user port\n" "L3 address\n")
@@ -151,23 +236,58 @@ DEFUN(cfg_no_port_isdn, cfg_no_port_isdn_cmd,
 	return CMD_SUCCESS;
 }
 
-static int config_write_interface(struct vty *vty)
+static int config_write_interface_v51(struct vty *vty)
 {
-	struct v5x_interface *v5if = (struct v5x_interface *)v5i->interfaces.next;
+	struct v5x_interface *v5if = NULL;
 	struct v5x_user_port *v5up;
 
+	if (!llist_empty(&v5i->interfaces))
+		v5if = (struct v5x_interface *)v5i->interfaces.next;
+
 	vty_out(vty, "!%s", VTY_NEWLINE);
-	vty_out(vty, "interface%s", VTY_NEWLINE);
-	vty_out(vty, " id %d%s", v5if->id, VTY_NEWLINE);
-	vty_out(vty, " variant %d%s", v5if->variant, VTY_NEWLINE);
-	llist_for_each_entry(v5up, &v5if->user_ports, list) {
-		switch (v5up->type) {
-		case V5X_USER_TYPE_PSTN:
-			vty_out(vty, " port pstn %d %d%s", v5up->nr, v5up->ts_nr[0], VTY_NEWLINE);
-			break;
-		case V5X_USER_TYPE_ISDN:
-			vty_out(vty, " port isdn %d %d %d%s", v5up->nr, v5up->ts_nr[0], v5up->ts_nr[1], VTY_NEWLINE);
-			break;
+	if (!v5if)
+		vty_out(vty, "no interface%s", VTY_NEWLINE);
+	if (v5if && v5if->dialect == V5X_DIALECT_V51) {
+		vty_out(vty, "interface v5.1%s", VTY_NEWLINE);
+		vty_out(vty, " id %d%s", v5if->id, VTY_NEWLINE);
+		vty_out(vty, " variant %d%s", v5if->variant, VTY_NEWLINE);
+		llist_for_each_entry(v5up, &v5if->user_ports, list) {
+			switch (v5up->type) {
+			case V5X_USER_TYPE_PSTN:
+				vty_out(vty, " port pstn %d %d%s", v5up->nr, v5up->ts_nr[0], VTY_NEWLINE);
+				break;
+			case V5X_USER_TYPE_ISDN:
+				vty_out(vty, " port isdn %d %d %d%s", v5up->nr, v5up->ts_nr[0], v5up->ts_nr[1],
+						VTY_NEWLINE);
+				break;
+			}
+		}
+	}
+	return CMD_SUCCESS;
+}
+
+static int config_write_interface_v52(struct vty *vty)
+{
+	struct v5x_interface *v5if = NULL;
+	struct v5x_user_port *v5up;
+
+	if (!llist_empty(&v5i->interfaces))
+		v5if = (struct v5x_interface *)v5i->interfaces.next;
+
+	vty_out(vty, "!%s", VTY_NEWLINE);
+	if (v5if && v5if->dialect == V5X_DIALECT_V52) {
+		vty_out(vty, "interface v5.2%s", VTY_NEWLINE);
+		vty_out(vty, " id %d%s", v5if->id, VTY_NEWLINE);
+		vty_out(vty, " variant %d%s", v5if->variant, VTY_NEWLINE);
+		llist_for_each_entry(v5up, &v5if->user_ports, list) {
+			switch (v5up->type) {
+			case V5X_USER_TYPE_PSTN:
+				vty_out(vty, " port pstn %d%s", v5up->nr, VTY_NEWLINE);
+				break;
+			case V5X_USER_TYPE_ISDN:
+				vty_out(vty, " port isdn %d%s", v5up->nr, VTY_NEWLINE);
+				break;
+			}
 		}
 	}
 	return CMD_SUCCESS;
@@ -176,13 +296,21 @@ static int config_write_interface(struct vty *vty)
 int v5x_vty_init(void)
 {
 	install_element(CONFIG_NODE, &cfg_interface_cmd);
-	install_node(&interface_node, config_write_interface);
-	install_element(INTERFACE_NODE, &cfg_interface_id_cmd);
-	install_element(INTERFACE_NODE, &cfg_interface_variant_cmd);
-	install_element(INTERFACE_NODE, &cfg_port_pstn_cmd);
-	install_element(INTERFACE_NODE, &cfg_no_port_pstn_cmd);
-	install_element(INTERFACE_NODE, &cfg_port_isdn_cmd);
-	install_element(INTERFACE_NODE, &cfg_no_port_isdn_cmd);
+	install_element(CONFIG_NODE, &cfg_no_interface_cmd);
+	install_node(&interface_node_v51, config_write_interface_v51);
+	install_node(&interface_node_v52, config_write_interface_v52);
+	install_element(INTERFACE_NODE_V51, &cfg_interface_id_cmd);
+	install_element(INTERFACE_NODE_V51, &cfg_interface_variant_cmd);
+	install_element(INTERFACE_NODE_V51, &cfg_port_pstn_cmd_v51);
+	install_element(INTERFACE_NODE_V51, &cfg_no_port_pstn_cmd);
+	install_element(INTERFACE_NODE_V51, &cfg_port_isdn_cmd_v51);
+	install_element(INTERFACE_NODE_V51, &cfg_no_port_isdn_cmd);
+	install_element(INTERFACE_NODE_V52, &cfg_interface_id_cmd);
+	install_element(INTERFACE_NODE_V52, &cfg_interface_variant_cmd);
+	install_element(INTERFACE_NODE_V52, &cfg_port_pstn_cmd_v52);
+	install_element(INTERFACE_NODE_V52, &cfg_no_port_pstn_cmd);
+	install_element(INTERFACE_NODE_V52, &cfg_port_isdn_cmd_v52);
+	install_element(INTERFACE_NODE_V52, &cfg_no_port_isdn_cmd);
 
 	return 0;
 }