diff --git a/library/GTPv2_Templates.ttcn b/library/GTPv2_Templates.ttcn
new file mode 100644
index 0000000..23b0053
--- /dev/null
+++ b/library/GTPv2_Templates.ttcn
@@ -0,0 +1,323 @@
+module GTPv2_Templates {
+
+/* (C) 2019 by Harald Welte <laforge@gnumonks.org>
+ * All rights reserved.
+ *
+ * Released under the terms of GNU General Public License, Version 2 or
+ * (at your option) any later version.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+import from General_Types all;
+import from Osmocom_Types all;
+import from GTPv2_Types all;
+
+private function fs_GTP2C_t_bit(template (omit) OCT4 teid) return BIT1 {
+	if (istemplatekind(teid, "omit")) {
+		return '0'B;
+	} else {
+		return '1'B;
+	}
+}
+
+private function fs_GTP2C_p_bit(template (omit) PDU_GTPCv2 piggyback) return BIT1 {
+	if (istemplatekind(piggyback, "omit")) {
+		return '0'B;
+	} else {
+		return '1'B;
+	}
+}
+
+template (present) PDU_GTPCv2 tr_PDU_GTP2C(template OCT4 teid := ?,
+					   template (present) GTPCv2_PDUs pdus := ?,
+					   template PDU_GTPCv2 piggyback := omit) := {
+	spare := '000'B,
+	t_Bit := ?,
+	p_Bit := ?,
+	version := '010'B,
+	messageType := ?,
+	lengthf := ?,
+	tEID := teid,
+	sequenceNumber := ?,
+	spare3 := '00'O,
+	gtpcv2_pdu := pdus,
+	piggybackPDU_GTPCv2 := piggyback
+}
+
+
+/* 8.3 */
+template (value) IMSI ts_GTP2C_Imsi(template (value) hexstring imsi) := {
+	elementIdentifier := '01'O,
+	lengthIndicator := 0, /* overwritten */
+	instance := '0000'B,
+	spare := '0000'B,
+	iMSI_Value := imsi
+}
+template (present) IMSI tr_GTP2C_Imsi(template (present) hexstring imsi) := {
+	elementIdentifier := '01'O,
+	lengthIndicator := ?,
+	instance := ?,
+	spare := '0000'B,
+	iMSI_Value := imsi
+}
+
+/* 8.4-1 */
+/*
+type enumerated GTP2C_Cause {
+	Local_Detach 				(2),
+	Complete_Detach				(3),
+	RAT_changed_from_3GPP_to_Non_3GPP	(4),
+	ISR_deactivation			(5),
+	Error_Ind_from_RNC_eNB_SGSN_MME		(5),
+	IMSI_Detach_Only			(7),
+	Reactivation_Required			(8),
+}
+*/
+
+const integer c_GTP2C_Cause_LocalDetach := 1;
+
+/* 8.4 */
+template (value) Cause ts_GTP2C_Cause(template (value) OCT1 cause,
+				      template (value) BIT1 cs) := {
+	elementIdentifier := '02'O,
+	lengthIndicator := 0, /* overwritten */
+	instance := '0000'B,
+	spare := '0000'B,
+	causeValue := cause,
+	cS := cs,
+	bCE := '0'B,
+	pCE := '0'B,
+	spare2 := '00000'B,
+	typeOfOffendingIE := omit,
+	lengthIndicator2 := omit,
+	instanceOfOffendingIE := omit,
+	spare3 := omit
+}
+template (present) Cause tr_GTP2C_Cause(template (present) OCT1 cause) := {
+	elementIdentifier := '02'O,
+	lengthIndicator := ?,
+	instance := ?,
+	spare := '0000'B,
+	causeValue := cause,
+	cS := ?,
+	bCE := ?,
+	pCE := ?,
+	spare2 := '00000'B,
+	typeOfOffendingIE := *,
+	lengthIndicator2 := *,
+	instanceOfOffendingIE := *,
+	spare3 := *
+}
+
+/* 8.5 */
+template (value) AccessPointName ts_GTP2C_APN(template (value) octetstring apn) := {
+	elementIdentifier := '48'O,
+	lengthIndicator := 0, /* overwritten */
+	instance := '0000'B,
+	spare := '0000'B,
+	aPN_Value := apn
+}
+template (present) AccessPointName tr_GTP2C_APN(template (present) octetstring apn) := {
+	elementIdentifier := '48'O,
+	lengthIndicator := ?,
+	instance := ?,
+	spare := '0000'B,
+	aPN_Value := apn
+}
+
+/* 8.14 */
+template (value) PDN_AddressAllocation
+ts_GTP2C_PdnAddrAlloc(template (value) BIT3 pdn_type,
+		      template (value) PDN_Address_and_Prefix addr_pfx) := {
+	elementIdentifier := '4F'O,
+	lengthIndicator := 0, /* overwritten */
+	instance := '0000'B,
+	spare := '0000'B,
+	pDN_Type := pdn_type,
+	spare2 := '00000'B,
+	pDN_Address_and_Prefix := addr_pfx
+}
+template (present) PDN_AddressAllocation
+tr_GTP2C_PdnAddrAlloc(template (present) BIT3 pdn_type,
+		      template (present) PDN_Address_and_Prefix addr_pfx) := {
+	elementIdentifier := '4F'O,
+	lengthIndicator := ?,
+	instance := ?,
+	spare := '0000'B,
+	pDN_Type := pdn_type,
+	spare2 := '00000'B,
+	pDN_Address_and_Prefix := addr_pfx
+}
+template (value) PDN_AddressAllocation
+ts_GTP2C_PdnAddrAlloc_v4(template (value) OCT4 addr) :=
+	ts_GTP2C_PdnAddrAlloc('001'B, {iPv4_Address:=addr});
+template (present) PDN_AddressAllocation
+tr_GTP2C_PdnAddrAlloc_v4(template (present) OCT4 addr) :=
+	ts_GTP2C_PdnAddrAlloc('001'B, {iPv4_Address:=addr});
+
+/* 8.17 */
+template (value) RAT_Type ts_GTP2C_RatType(template (value) integer rat) := {
+	elementIdentifier := '53'O,
+	lengthIndicator := 0, /* overwritten */
+	instance := '0000'B,
+	spare := '0000'B,
+	rAT_TypeValue := rat,
+	additionalOctets := omit
+}
+template (present) RAT_Type tr_GTP2C_RatType(template (present) integer rat) := {
+	elementIdentifier := '53'O,
+	lengthIndicator := ?,
+	instance := ?,
+	spare := '0000'B,
+	rAT_TypeValue := rat,
+	additionalOctets := *
+}
+
+
+/* 8.22 */
+private function f_bit4oct(template (omit) octetstring os) return BIT1
+{
+	if (istemplatekind(os, "omit")) {
+		return '0'B;
+	} else {
+		return '1'B;
+	}
+}
+template (value) FullyQualifiedTEID
+ts_GTP2C_FTEID(integer if_type, OCT4 teid, template (omit) OCT4 v4_addr := omit,
+		template (omit) OCT16 v6_addr := omit) := {
+	elementIdentifier := '57'O,
+	lengthIndicator := 0, /* overwritten */
+	instance := '0000'B,
+	spare := '0000'B,
+	interfaceType := if_type,
+	v6_Flag := f_bit4oct(v4_addr),
+	v4_Flag := f_bit4oct(v6_addr),
+	tEID_GRE_Key := teid,
+	iPv4_Address := v4_addr,
+	iPv6_Address := v6_addr,
+	additionalOctets := omit
+}
+template (present) FullyQualifiedTEID
+tr_GTP2C_FTEID(template (present) integer if_type, template (present) OCT4 teid,
+		template OCT4 v4_addr := omit,
+		template OCT16 v6_addr := omit) := {
+	elementIdentifier := '57'O,
+	lengthIndicator := ?,
+	instance := ?,
+	spare := '0000'B,
+	interfaceType := if_type,
+	v6_Flag := ?,
+	v4_Flag := ?,
+	tEID_GRE_Key := teid,
+	iPv4_Address := v4_addr,
+	iPv6_Address := v6_addr,
+	additionalOctets := omit
+}
+
+
+
+template (value) PDU_GTPCv2 ts_PDU_GTP2C(template (omit) OCT4 teid, template (value) OCT3 seq,
+					 template (value) OCT1 msg_type,
+					 template (value) GTPCv2_PDUs pdus,
+					 template (omit) PDU_GTPCv2 piggyback := omit) := {
+	spare := '000'B,
+	t_Bit := fs_GTP2C_t_bit(teid),
+	p_Bit := fs_GTP2C_p_bit(piggyback),
+	version := '010'B,
+	messageType := msg_type,
+	lengthf := 0, /* overwritten */
+	tEID := teid,
+	sequenceNumber := seq,
+	spare3 := '00'O,
+	gtpcv2_pdu := pdus,
+	piggybackPDU_GTPCv2 := piggyback
+}
+
+
+template (present) PDU_GTPCv2
+tr_GTP2C_CreateSessionReq(template (present) hexstring imsi) := tr_PDU_GTP2C('00000000'O, {
+	createSessionRequest := {
+		iMSI := tr_GTP2C_Imsi(imsi),
+		mSISDN := *,
+		mEI := *,
+		userLocationInfo := ?,
+		servingNetwork := ?,
+		rAT_Type := tr_GTP2C_RatType(6),
+		indication := *,
+		fullyQualifiedTEID := ?,
+		accessPointName := tr_GTP2C_APN('012a'O), // '*'
+		selectionMode := ?,
+		pDN_Type := ?,
+		pDN_AddressAllocation := ?,
+		maxAPN_Restriction := ?,
+		ambr := *,
+		linkedEPS_Bearer_ID := omit,
+		trustedWLANModeIndication := omit,
+		protocolConfigOptions := omit,
+		bearerContextGrouped := ?,
+		traceInformation := *,
+		recovery := omit,
+		csid := omit,
+		uE_TimeZone := ?,
+		user_CSG_Information := omit,
+		chargingCharacteristics := ?,
+		lDN := omit,
+		signallingPriorityIndication := *,
+		iP_Addr := omit,
+		portNumber := omit,
+		aPCO := omit,
+		trustedWLANAccessNetworkIdentifier := omit,
+		cNOperatorSelectionEntity := omit,
+		presenceReportingAreaInformation := omit,
+		overloadControlInformationGrouped := omit,
+		originationTimeStamp := *,
+		maximumWaitTime := *,
+		wLANLocationTimestamp := omit,
+		nBIFOMContainer := omit,
+		remoteUEContextGrouped := *,
+		nodeIdentifier := *,
+		extendedProtocolConfigOptions := omit,
+		servingPLMNRateControl := omit,
+		counter := omit,
+		privateExtension := omit
+	}});
+
+template (value) PDU_GTPCv2
+ts_GTP2C_CreateSessionResp(template (value) FullyQualifiedTEID_List fteids,
+			   template (value) PDN_AddressAllocation addr) :=
+ts_PDU_GTP2C('00000000'O, '000000'O, '20'O, {
+	createSessionResponse := {
+		cause := ts_GTP2C_Cause(int2oct(16, 1), '0'B),
+		changeReportingAction := omit,
+		cSG_InformationReportingAction := omit,
+		heNBInformationReporting := omit,
+		fullyQualifiedTEID := fteids,
+		pDN_AddressAllocation := addr,
+		aPN_Restriction := omit,
+		ambr := omit,
+		linkedEPS_Bearer_ID := omit,
+		protocolConfigOptions := omit,
+		bearerContextGrouped := omit,
+		recovery := omit,
+		chargingGatewayName := omit,
+		chargingGatewayAddress := omit,
+		csid := omit,
+		lDN := omit,
+		pGW_Back_OffTime := omit,
+		aPCO := omit,
+		trustedWLANIPv4Parameters := omit,
+		indicationFlags := omit,
+		presenceReportingAreaAction := omit,
+		loadControlInformationGrouped := omit,
+		overloadControlInformationGrouped := omit,
+		nBIFOMContainer := omit,
+		pDNConnectionChargingID := omit,
+		extendedProtocolConfigOptions := omit,
+		privateExtension := omit
+	}});
+
+
+
+}