diff --git a/sccp/SCCP_Tests_RAW.ttcn b/sccp/SCCP_Tests_RAW.ttcn
index 3d16706..03ef4af 100644
--- a/sccp/SCCP_Tests_RAW.ttcn
+++ b/sccp/SCCP_Tests_RAW.ttcn
@@ -38,6 +38,33 @@
 	port SCCP_CODEC_PT MTP3;
 
 	var MSC_SCCP_MTP3_parameters g_param;
+
+	/*Configure T(tias) over VTY, seconds */
+	var integer g_demo_sccp_timer_ias :=  7 * 60;
+	/*Configure T(tiar) over VTY, seconds */
+	var integer g_demo_sccp_timer_iar := 15 * 60;
+}
+
+type record of charstring Commands;
+private function f_cs7_inst_0_cfg(TELNETasp_PT pt, Commands cmds := {})
+{
+	f_vty_enter_cfg_cs7_inst(pt, 0);
+	for (var integer i := 0; i < sizeof(cmds); i := i+1) {
+		f_vty_transceive(pt, cmds[i]);
+	}
+	f_vty_transceive(pt, "end");
+}
+
+function f_init_vty() runs on SCCP_Test_RAW_CT {
+	if (SCCP_DEMO_USER_VTY.checkstate("Mapped")) {
+		/* skip initialization if already executed once */
+		return;
+	}
+	map(self:SCCP_DEMO_USER_VTY, system:SCCP_DEMO_USER_VTY);
+	f_vty_set_prompts(SCCP_DEMO_USER_VTY);
+	f_vty_transceive(SCCP_DEMO_USER_VTY, "enable");
+	f_cs7_inst_0_cfg(SCCP_DEMO_USER_VTY, {"sccp-timer ias " & int2str(g_demo_sccp_timer_ias),
+			  "sccp-timer iar " & int2str(g_demo_sccp_timer_iar)});
 }
 
 private function f_init_raw(SCCP_Configuration cfg) runs on SCCP_Test_RAW_CT {
@@ -54,9 +81,7 @@
 		ssn := cfg.own_ssn
 	};
 
-	map(self:SCCP_DEMO_USER_VTY, system:SCCP_DEMO_USER_VTY);
-	f_vty_set_prompts(SCCP_DEMO_USER_VTY);
-	f_vty_transceive(SCCP_DEMO_USER_VTY, "enable");
+	f_init_vty();
 
 	/* Create and connect test components */
 	vc_M3UA := M3UA_CT.create;
@@ -73,51 +98,6 @@
 	self.stop
 }
 
-/* connection oriented SCCP */
-const SCCP_param_ProtocolClass c_class2 := { class:='0010'B, messageHandling:='0000'B };//class 2
-
-function ts_SCCP_CR(OCT3 source_lref, SCCP_PAR_Address calling, SCCP_PAR_Address called)
-return template (value) PDU_SCCP {
-	var SCCP_param_CPartyAddressEnc calling_enc := ConvertASPAddressToEncodedAddress_itu(calling);
-
-	var template (value) PDU_SCCP ret := {
-		connrequest := {
-			messageType := cr,
-			sourceLocRef := source_lref,
-			protClass := c_class2,
-			pointer1 := 2,
-			pointer2 := 0, /* overwritten */
-			calledPAddress := ConvertASPAddressToEncodedAddress_itu(called),
-			optionalPart := {
-				credit := omit,
-				callingPAddress := {
-					paramName := con_SCCP_cgPA,
-					paramLength := calling_enc.paramLength, /* overwritten */
-					addr := calling_enc.addr
-				},
-				data := omit,
-				hopCounter := omit,
-				importance := omit
-			},
-			eop := { paramName:= con_SCCP_eop }
-		}
-	}
-	return ret;
-}
-
-template (present) PDU_SCCP tr_SCCP_CC(template (present) OCT3 dest_lref,
-				       template (present) OCT3 source_lref) := {
-	connconfirm := {
-		messageType := cc,
-		destLocRef := dest_lref,
-		sourceLocRef := source_lref,
-		protClass := c_class2,
-		pointer1 := ?,
-		optionalPart := *,
-		eop := *
-	}
-}
-
 private function f_send_sccp(template PDU_SCCP sccp) runs on SCCP_Test_RAW_CT {
 	var SCCP_MTP3_TRANSFERreq tx := {
 		sio := g_param.sio,
@@ -155,21 +135,65 @@
 	}
 }
 
+private function f_establish_conn(SCCP_PAR_Address calling, SCCP_PAR_Address called) runs on SCCP_Test_RAW_CT {
+
+	f_send_sccp(ts_SCCP_CR('000001'O, calling, called));
+	f_exp_sccp(tr_SCCP_CC('000000'O, '000001'O));
+}
+
+private function f_tx_udt_exp(SCCP_PAR_Address calling, SCCP_PAR_Address called, octetstring data) runs on SCCP_Test_RAW_CT {
+
+	f_send_sccp(ts_SCCP_UDT(calling, called, data));
+	f_exp_sccp(tr_SCCP_UDT(called, calling, data));
+}
+
 /* Verify sccp_demo_user answers a CR with a CC for PC and SSN set up to echo back */
 testcase TC_cr_cc() runs on SCCP_Test_RAW_CT {
 	var SCCP_PAR_Address calling, called;
+
+	f_init_raw(mp_sccp_cfg[0]);
+	f_sleep(1.0);
+
 	called := valueof(ts_SccpAddr_PC_SSN(mp_sccp_cfg[0].peer_pc, mp_sccp_cfg[0].peer_ssn,
 					     mp_sccp_cfg[0].sio, mp_sccp_cfg[0].sccp_service_type));
 	calling := valueof(ts_SccpAddr_PC_SSN(mp_sccp_cfg[0].own_pc, mp_sccp_cfg[0].own_ssn,
 					     mp_sccp_cfg[0].sio, mp_sccp_cfg[0].sccp_service_type));
+	f_establish_conn(calling, called);
+}
+
+/* Verify T(iar) triggers and releases the channel */
+testcase TC_tiar_timeout() runs on SCCP_Test_RAW_CT {
+	var SCCP_PAR_Address calling, called;
+	var octetstring data := f_rnd_octstring(f_rnd_int(100));
+
+	/* Set T(iar) in sccp_demo_user low enough that it will trigger before other side
+	   has time to keep alive with a T(ias). Keep recommended ratio of
+	   T(iar) >= T(ias)*2 */
+	g_demo_sccp_timer_ias := 2;
+	g_demo_sccp_timer_iar := 5;
 	f_init_raw(mp_sccp_cfg[0]);
 	f_sleep(1.0);
-	f_send_sccp(ts_SCCP_CR('000001'O, calling, called));
-	f_exp_sccp(tr_SCCP_CC('000001'O, ?));
+
+	called := valueof(ts_SccpAddr_PC_SSN(mp_sccp_cfg[0].peer_pc, mp_sccp_cfg[0].peer_ssn,
+					     mp_sccp_cfg[0].sio, mp_sccp_cfg[0].sccp_service_type));
+	calling := valueof(ts_SccpAddr_PC_SSN(mp_sccp_cfg[0].own_pc, mp_sccp_cfg[0].own_ssn,
+					     mp_sccp_cfg[0].sio, mp_sccp_cfg[0].sccp_service_type));
+	f_establish_conn(calling, called);
+	f_tx_udt_exp(calling, called, data);
+
+	log("Waiting for first IT");
+	f_exp_sccp(tr_SCCP_IT(?, ?));
+	log("Waiting for second IT");
+	f_exp_sccp(tr_SCCP_IT(?, ?));
+
+	log("Waiting for RLSD");
+	f_exp_sccp(tr_SCCP_RLSD(?, ?, hex2int('0D'H))); /* Cause: Expiration of Rx Inactivity Timer */
+	f_send_sccp(ts_SCCP_RLC('000001'O, '000000'O));
 }
 
 control {
 	execute( TC_cr_cc() );
+	execute( TC_tiar_timeout() );
 }