--- libss7-2.0.original/isup.h	2014-06-09 23:48:47.000000000 +0400
+++ libss7-2.0/isup.h	2016-03-21 16:01:29.469313914 +0300
@@ -343,6 +343,8 @@
 	unsigned char called_party_status_ind;
 	unsigned char local_echocontrol_ind;
 	unsigned char echocontrol_ind;
+	/* Optional backward call indicators */
+	unsigned char inband_available;
 	/* Suspend/Resume Indicator */
 	int network_isdn_indicator;
 	unsigned char inr_ind[2];