Stop dailtone if disconnection happened

channels/chan_brcm.c

@@ -646,6 +646,7 @@ static int brcm_indicate(struct ast_channel *ast, int condition, const void *dat
 				}
 				res = -1;
 		  default:
+			  brcm_stop_dialtone(sub->parent); // stop any dialtone exist if disconnection happened.
 			  ast_debug(1, "Don't know how to handle cause code %d\n", ast_cause);
 			  break;
 		  }
@@ -1411,6 +1412,7 @@ static int brcm_signal_dialtone(struct brcm_pvt *p) {
 			endpt_signal(p->line_id, "dial", "off", NULL);
 			endpt_signal(p->line_id, "stutter", "off", NULL);
 			endpt_signal(p->line_id, "unobtainable", "off", NULL);
+			endpt_signal(p->line_id, "ringback", "off", NULL);
 			break;
 		case DIALTONE_ON:
 			endpt_signal(p->line_id, "dial", "on", NULL);