sccp: Introduce test TC_it_avoids_tiar

Related: OS#4343
Change-Id: I3a970a9b7ed7fb178095760025dd83c570dcff5e
diff --git a/library/SCCP_Templates.ttcn b/library/SCCP_Templates.ttcn
index b3e3392..b0e6df7 100644
--- a/library/SCCP_Templates.ttcn
+++ b/library/SCCP_Templates.ttcn
@@ -166,6 +166,24 @@
 	}
 }
 
+template PDU_SCCP ts_SCCP_IT(template (present) OCT3 source_lref,
+			     template (present) OCT3 dest_lref) := {
+	inacttest := {
+		messageType := it,
+		destLocRef := dest_lref,
+		sourceLocRef := source_lref,
+		protClass := c_class2,
+		/* rfc3868 3.3.11: sequencing and credit are ignored with class2 */
+		sequencingSegmenting := {
+			reserved := '0'B,
+			p_s := '0000000'B,
+			more := '0'B,
+			pr := '0000000'B
+		},
+		credit := '00'O
+	}
+}
+
 template PDU_SCCP tr_SCCP_RLSD(template (present) OCT3 source_lref := ?,
 			       template (present) OCT3 dest_lref := ?,
 			       template (present) SCCP_param_ReleaseCause relcause := ?) := {