diff --git a/chan_capi_chat.c b/chan_capi_chat.c
index 4c50ab6..e21db15 100644
--- a/chan_capi_chat.c
+++ b/chan_capi_chat.c
@@ -286,7 +286,8 @@ int pbx_capi_chat(struct ast_channel *c, char *param)
 	struct capi_pvt *i = NULL; 
 	char *roomname, *controller, *options;
 	struct capichat_s *room;
-	unsigned int contr = 1;
+	ast_group_t tmpcntr;
+	unsigned long contr = 0;
 
 	roomname = strsep(&param, "|");
 	controller = strsep(&param, "|");
@@ -302,7 +303,8 @@ int pbx_capi_chat(struct ast_channel *c, char *param)
 		c->name, roomname, controller, options);
 
 	if (controller) {
-		contr = (unsigned int)strtoul(controller, NULL, 0);
+		tmpcntr = ast_get_group(controller);
+		contr = (unsigned long)(tmpcntr >> 1);
 	}
 
 	if (c->tech == &capi_tech) {
diff --git a/chan_capi_utils.c b/chan_capi_utils.c
index 1f896d4..60fa4d9 100644
--- a/chan_capi_utils.c
+++ b/chan_capi_utils.c
@@ -38,6 +38,7 @@ AST_MUTEX_DEFINE_STATIC(nullif_lock);
 static _cword capi_MessageNumber;
 
 static struct capi_pvt *nulliflist = NULL;
+static int controller_nullplcis[CAPI_MAX_CONTROLLERS];
 
 #define CAPI_MAX_PEERLINKCHANNELS  32
 static struct peerlink_s {
@@ -117,6 +118,7 @@ void capi_remove_nullif(struct capi_pvt *i)
 				ast_smoother_free(i->smoother);
 			cc_mutex_destroy(&i->lock);
 			ast_cond_destroy(&i->event_trigger);
+			controller_nullplcis[i->controller - 1]--;
 			free(i);
 			break;
 		}
@@ -129,9 +131,22 @@ void capi_remove_nullif(struct capi_pvt *i)
 /*
  * create new null-interface
  */
-struct capi_pvt *capi_mknullif(struct ast_channel *c, unsigned int controller)
+struct capi_pvt *capi_mknullif(struct ast_channel *c, unsigned long controllermask)
 {
 	struct capi_pvt *tmp;
+	unsigned int controller = 1;
+	int contrcount;
+	int channelcount = 0xffff;
+
+	/* find the next controller of mask with least plcis used */	
+	for (contrcount = 0; contrcount < CAPI_MAX_CONTROLLERS; contrcount++) {
+		if ((controllermask & (1 << contrcount))) {
+			if (controller_nullplcis[contrcount] < channelcount) {
+				channelcount = controller_nullplcis[contrcount];
+				controller = contrcount + 1;
+			}
+		}
+	}
 
 	tmp = malloc(sizeof(struct capi_pvt));
 	if (!tmp) {
@@ -178,6 +193,7 @@ struct capi_pvt *capi_mknullif(struct ast_channel *c, unsigned int controller)
 	cc_mutex_lock(&nullif_lock);
 	tmp->next = nulliflist; /* prepend */
 	nulliflist = tmp;
+	controller_nullplcis[tmp->controller - 1]++;
 	cc_mutex_unlock(&nullif_lock);
 
 	/* connect to driver */
@@ -189,8 +205,8 @@ struct capi_pvt *capi_mknullif(struct ast_channel *c, unsigned int controller)
 		"w()()()()(www()()()())()()()((wwbbb)()()())",
 		 0,       1,1,0,              3,0,0,0,0);
 
-	cc_verbose(3, 1, VERBOSE_PREFIX_4 "%s: created null-interface.\n",
-		tmp->vname);
+	cc_verbose(3, 1, VERBOSE_PREFIX_4 "%s: created null-interface on controller %d.\n",
+		tmp->vname, tmp->controller);
 
 	return tmp;
 }
diff --git a/chan_capi_utils.h b/chan_capi_utils.h
index 606bfb5..702496e 100644
--- a/chan_capi_utils.h
+++ b/chan_capi_utils.h
@@ -34,7 +34,7 @@ extern char *capi_number_func(unsigned char *data, unsigned int strip, char *buf
 extern int cc_add_peer_link_id(struct ast_channel *c);
 extern struct ast_channel *cc_get_peer_link_id(const char *p);
 extern void capi_remove_nullif(struct capi_pvt *i);
-extern struct capi_pvt *capi_mknullif(struct ast_channel *c, unsigned int controller);
+extern struct capi_pvt *capi_mknullif(struct ast_channel *c, unsigned long controllermask);
 extern int capi_create_reader_writer_pipe(struct capi_pvt *i);
 extern struct ast_frame *capi_read_pipeframe(struct capi_pvt *i);
 extern int capi_write_frame(struct capi_pvt *i, struct ast_frame *f);