diff --git a/lapd/LAPD_Primitives.ttcn b/lapd/LAPD_Primitives.ttcn
new file mode 100644
index 000000000..e6c8f3609
--- /dev/null
+++ b/lapd/LAPD_Primitives.ttcn
@@ -0,0 +1,112 @@
+module LAPD_Primitives {
+
+import from LAPD_Types all;
+
+type enumerated PrimOperation {
+	REQUEST,
+	RESPONSE,
+	INDICATION,
+	CONFIRM
+};
+
+type record LAPD_DL_Prim {
+	LapdTei			tei,
+	LapdSapi		sapi,
+	LAPD_DL			primitive,
+	PrimOperation		operation
+}
+type union LAPD_DL {
+	LapdDlEstablish		dl_establish,
+	LapdDlRelease		dl_release,
+	LapdDlData		dl_data,
+	LapdDlUnitData		dl_unitdata
+};
+type record LapdDlEstablish {
+};
+type record LapdDlRelease {
+};
+type record LapdDlData {
+	octetstring payload
+};
+type record LapdDlUnitData {
+	octetstring payload
+};
+
+type record LAPD_MDL_Prim {
+	LAPD_MDL		primitive,
+	PrimOperation		operation
+}
+type union LAPD_MDL {
+	LapdMdlAssign		mdl_assign,
+	LapdMdlRemove		mdl_remove,
+	LapdMdlError		mdl_error,
+	LapdMdlUnitData		mdl_unitdata,
+	LapdMdlXid		mdl_xid
+};
+type record LapdMdlAssign {
+	LapdTei			tei
+	//ces
+};
+type record LapdMdlRemove {
+	LapdTei			tei
+	//ces
+};
+type record LapdMdlError {
+	charstring		reason
+};
+type record LapdMdlUnitData {
+	octetstring		lm_pdu
+};
+type record LapdMdlXid {
+	octetstring		cm_pdu
+};
+
+type record LAPD_PH_Prim {
+	LAPD_PH			primitive,
+	PrimOperation		operation
+}
+type union LAPD_PH {
+	LapdPhData		ph_data,
+	LapdPhActivate		ph_activate,
+	LapdPhDeactivate	ph_deactivate
+};
+type record LapdPhData {
+	// priority
+	octetstring		data
+};
+type record LapdPhActivate {
+}
+type record LapdPhDeactivate {
+}
+
+type record LAPD_MPH_Prim {
+	Lapd_MPH		primitive,
+	PrimOperation		operation
+};
+type union Lapd_MPH {
+	LapdMphActivate		mph_activate,
+	LapdMphDeactivate	mph_deactivate,
+	LapdMphInformation	mph_information
+};
+type record LapdMphActivate {
+};
+type record LapdMphDeactivate {
+};
+type record LapdMphInformation {
+	// connected/disconnected
+};
+
+type union LAPD_Primitive {
+	LAPD_DL_Prim		dl,
+	LAPD_MDL_Prim		mdl,
+	LAPD_PH_Prim		ph,
+	LAPD_MPH_Prim		mph
+};
+
+external function f_enc_LAPD_Primitive(in LAPD_Primitive inp) return octetstring
+	with { extension "prototype(convert) encode(JSON)" }
+external function f_dec_LAPD_Primitive(in octetstring inp) return LAPD_Primitive
+	with { extension "prototype(convert) decode(JSON)" }
+
+
+} with { encode "JSON" }
diff --git a/lapd/LAPD_Tests.ttcn b/lapd/LAPD_Tests.ttcn
new file mode 100644
index 000000000..74e95c5f8
--- /dev/null
+++ b/lapd/LAPD_Tests.ttcn
@@ -0,0 +1,17 @@
+module LAPD_Tests {
+
+import from LAPD_Types all;
+
+type component test_CT {
+};
+
+
+testcase TC_selftest() runs on test_CT {
+	var LapdAddressField addr;
+
+	addr := { sapi := 62, c_r := true, ea0 := false, tei := 55, ea1 := true };
+	log(enc_LapdAddressField(addr));
+}
+
+
+}
diff --git a/lapd/RLAPD_CodecPort.ttcn b/lapd/RLAPD_CodecPort.ttcn
new file mode 100644
index 000000000..e9f4c6327
--- /dev/null
+++ b/lapd/RLAPD_CodecPort.ttcn
@@ -0,0 +1,64 @@
+module RLAPD_CodecPort {
+
+/* Simple RLAPD Codec Port, translating between raw TCP octetstring payload
+ * towards the IPL4asp port provider, and RLAPD primitives
+ * which carry the decoded RLAPD data types as payload.
+ *
+ * (C) 2020 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.
+ */
+
+
+import from IPL4asp_PortType all;
+import from IPL4asp_Types all;
+import from LAPD_Primitives all;
+
+type record RLAPD_RecvFrom {
+	ConnectionId	connId,
+	LAPD_Primitive	msg
+}
+
+type record RLAPD_Send {
+	ConnectionId	connId,
+	LAPD_Primitive	msg
+}
+
+template (value) RLAPD_Send ts_RLAPD_Send(ConnectionId conn_id, template (value) LAPD_Primitive msg) := {
+	connId := conn_id,
+	msg := msg
+}
+
+template RLAPD_RecvFrom tr_RLAPD_Recv(template ConnectionId conn_id, template LAPD_Primitive msg) := {
+	connId := conn_id,
+	msg := msg
+}
+
+private function IPL4_to_RLAPD_RecvFrom(in ASP_RecvFrom pin, out RLAPD_RecvFrom pout) {
+	pout.connId := pin.connId;
+	pout.msg := f_dec_LAPD_Primitive(pin.msg);
+} with { extension "prototype(fast)" }
+
+private function RLAPD_to_IPL4_Send(in RLAPD_Send pin, out ASP_Send pout) {
+	pout.connId := pin.connId;
+	pout.proto := { sctp := {} };
+	pout.msg := f_enc_LAPD_Primitive(pin.msg);
+} with { extension "prototype(fast)" }
+
+type port RLAPD_CODEC_PT message {
+	out	RLAPD_Send;
+	in	RLAPD_RecvFrom,
+		ASP_ConnId_ReadyToRelease,
+		ASP_Event;
+} with { extension "user IPL4asp_PT
+	out(RLAPD_Send -> ASP_Send: function(RLAPD_to_IPL4_Send))
+	in(ASP_RecvFrom -> RLAPD_RecvFrom: function(IPL4_to_RLAPD_RecvFrom);
+	   ASP_ConnId_ReadyToRelease -> ASP_ConnId_ReadyToRelease: simple;
+	   ASP_Event -> ASP_Event: simple)"
+}
+
+
+
+}
diff --git a/lapd/RLAPD_CodecPort_CtrlFunct.ttcn b/lapd/RLAPD_CodecPort_CtrlFunct.ttcn
new file mode 100644
index 000000000..a0280fb2b
--- /dev/null
+++ b/lapd/RLAPD_CodecPort_CtrlFunct.ttcn
@@ -0,0 +1,52 @@
+module RLAPD_CodecPort_CtrlFunct {
+
+  import from RLAPD_CodecPort all;
+  import from IPL4asp_Types all;
+
+  external function f_IPL4_listen(
+    inout RLAPD_CODEC_PT portRef,
+    in HostName locName,
+    in PortNumber locPort,
+    in ProtoTuple proto,
+    in OptionList options := {}
+  ) return Result;
+
+  external function f_IPL4_connect(
+    inout RLAPD_CODEC_PT portRef,
+    in HostName remName,
+    in PortNumber remPort,
+    in HostName locName,
+    in PortNumber locPort,
+    in ConnectionId connId,
+    in ProtoTuple proto,
+    in OptionList options := {}
+  ) return Result;
+
+  external function f_IPL4_close(
+    inout RLAPD_CODEC_PT portRef,
+    in ConnectionId id,
+    in ProtoTuple proto := { unspecified := {} }
+  ) return Result;
+
+  external function f_IPL4_setUserData(
+    inout RLAPD_CODEC_PT portRef,
+    in ConnectionId id,
+    in UserData userData
+  ) return Result;
+
+  external function f_IPL4_getUserData(
+    inout RLAPD_CODEC_PT portRef,
+    in ConnectionId id,
+    out UserData userData
+  ) return Result;
+
+  external function f_IPL4_setGetMsgLen(
+    inout RLAPD_CODEC_PT portRef,
+    in ConnectionId id,
+    inout f_IPL4_getMsgLen f,
+    in ro_integer msgLenArgs
+  );
+
+
+}
+
diff --git a/lapd/RLAPD_CodecPort_CtrlFunctDef.cc b/lapd/RLAPD_CodecPort_CtrlFunctDef.cc
new file mode 100644
index 000000000..8c1efe9a1
--- /dev/null
+++ b/lapd/RLAPD_CodecPort_CtrlFunctDef.cc
@@ -0,0 +1,66 @@
+#include "IPL4asp_PortType.hh"
+#include "RLAPD_CodecPort.hh"
+#include "IPL4asp_PT.hh"
+
+namespace RLAPD__CodecPort__CtrlFunct {
+
+  IPL4asp__Types::Result f__IPL4__listen(
+    RLAPD__CodecPort::RLAPD__CODEC__PT& portRef,
+    const IPL4asp__Types::HostName& locName,
+    const IPL4asp__Types::PortNumber& locPort,
+    const IPL4asp__Types::ProtoTuple& proto,
+    const IPL4asp__Types::OptionList& options)
+  {
+    return f__IPL4__PROVIDER__listen(portRef, locName, locPort, proto, options);
+  }
+  
+  IPL4asp__Types::Result f__IPL4__connect(
+    RLAPD__CodecPort::RLAPD__CODEC__PT& portRef,
+    const IPL4asp__Types::HostName& remName,
+    const IPL4asp__Types::PortNumber& remPort,
+    const IPL4asp__Types::HostName& locName,
+    const IPL4asp__Types::PortNumber& locPort,
+    const IPL4asp__Types::ConnectionId& connId,
+    const IPL4asp__Types::ProtoTuple& proto,
+    const IPL4asp__Types::OptionList& options)
+  {
+    return f__IPL4__PROVIDER__connect(portRef, remName, remPort,
+                                      locName, locPort, connId, proto, options);
+  }
+
+  IPL4asp__Types::Result f__IPL4__close(
+    RLAPD__CodecPort::RLAPD__CODEC__PT& portRef, 
+    const IPL4asp__Types::ConnectionId& connId, 
+    const IPL4asp__Types::ProtoTuple& proto)
+  {
+      return f__IPL4__PROVIDER__close(portRef, connId, proto);
+  }
+
+  IPL4asp__Types::Result f__IPL4__setUserData(
+    RLAPD__CodecPort::RLAPD__CODEC__PT& portRef,
+    const IPL4asp__Types::ConnectionId& connId,
+    const IPL4asp__Types::UserData& userData)
+  {
+    return f__IPL4__PROVIDER__setUserData(portRef, connId, userData);
+  }
+  
+  IPL4asp__Types::Result f__IPL4__getUserData(
+    RLAPD__CodecPort::RLAPD__CODEC__PT& portRef,
+    const IPL4asp__Types::ConnectionId& connId,
+    IPL4asp__Types::UserData& userData)
+  {
+    return f__IPL4__PROVIDER__getUserData(portRef, connId, userData);
+  }
+
+  void f__IPL4__setGetMsgLen(
+    RLAPD__CodecPort::RLAPD__CODEC__PT& portRef,
+    const IPL4asp__Types::ConnectionId& connId,
+    Socket__API__Definitions::f__getMsgLen& f,
+    const Socket__API__Definitions::ro__integer& msgLenArgs)
+  {
+    return f__IPL4__PROVIDER__setGetMsgLen(portRef, connId, f, msgLenArgs);
+  }
+
+
+}
+
diff --git a/lapd/gen_links.sh b/lapd/gen_links.sh
new file mode 100755
index 000000000..ecdf2e455
--- /dev/null
+++ b/lapd/gen_links.sh
@@ -0,0 +1,23 @@
+#!/bin/sh
+
+BASEDIR=../deps
+
+. ../gen_links.sh.inc
+
+DIR=$BASEDIR/titan.Libraries.TCCUsefulFunctions/src
+FILES="TCCInterface_Functions.ttcn TCCConversion_Functions.ttcn TCCConversion.cc TCCInterface.cc TCCInterface_ip.h"
+gen_links $DIR $FILES
+
+DIR=$BASEDIR/titan.TestPorts.Common_Components.Socket-API/src
+FILES="Socket_API_Definitions.ttcn"
+gen_links $DIR $FILES
+
+DIR=$BASEDIR/titan.TestPorts.IPL4asp/src
+FILES="IPL4asp_Functions.ttcn  IPL4asp_PT.cc  IPL4asp_PT.hh IPL4asp_PortType.ttcn  IPL4asp_Types.ttcn  IPL4asp_discovery.cc IPL4asp_protocol_L234.hh"
+gen_links $DIR $FILES
+
+DIR=../library
+FILES="Misc_Helpers.ttcn General_Types.ttcn Osmocom_Types.ttcn LAPD_Types.ttcn "
+gen_links $DIR $FILES
+
+ignore_pp_results
diff --git a/lapd/regen_makefile.sh b/lapd/regen_makefile.sh
new file mode 100755
index 000000000..6f8af367c
--- /dev/null
+++ b/lapd/regen_makefile.sh
@@ -0,0 +1,6 @@
+#!/bin/bash
+
+FILES="*.ttcn IPL4asp_PT.cc IPL4asp_discovery.cc TCCConversion.cc TCCInterface.cc "
+FILES+="RLAPD_CodecPort_CtrlFunctDef.cc "
+
+../regen-makefile.sh LAPD_Tests.ttcn $FILES
diff --git a/library/LAPD_Types.ttcn b/library/LAPD_Types.ttcn
new file mode 100644
index 000000000..6e6cc7b99
--- /dev/null
+++ b/library/LAPD_Types.ttcn
@@ -0,0 +1,413 @@
+/* LAPDm definitions according to ITU-T Q.921
+ * (C) 2017-2020 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
+ */
+
+module LAPD_Types {
+
+import from General_Types all;
+import from Osmocom_Types all;
+
+type uint6_t LapdSapi;
+type uint7_t LapdTei;
+type BIT2 LapdSBits;
+type BIT3 LapdUBits;
+type BIT2 LapdU2Bits;
+
+/* Section 3.3.2 / Table 1*/
+const boolean cr_UO_CMD := false;
+const boolean cr_UO_RSP := true;
+const boolean cr_UT_CMD := true;
+const boolean cr_UT_RSP := false;
+
+/* Figure 5 */
+type record LapdAddressField {
+	LapdSapi	sapi,
+	boolean		c_r,
+	boolean		ea0 (false),
+	LapdTei		tei,
+	boolean		ea1 (true)
+} with { variant "FIELDORDER(msb)" };
+
+template (present) LapdAddressField
+tr_LapdAddr(template (present) LapdTei tei := ?,
+	    template (present) LapdSapi sapi := ?,
+	    template (present) boolean c_r) := {
+	sapi := sapi,
+	c_r := c_r,
+	ea0 := false,
+	tei := tei,
+	ea1 := true
+};
+
+template (value) LapdAddressField
+ts_LapdAddr(template (value) LapdTei tei,
+	     template (value) LapdSapi sapi, boolean c_r) := {
+	sapi := sapi,
+	c_r := c_r,
+	ea0 := false,
+	tei := tei,
+	ea1 := true
+};
+
+/* Table 4 */
+type record LapdCtrlI {
+	uint7_t		n_s,
+	BIT1		spare ('0'B),
+	uint7_t		n_r,
+	boolean		p
+} with { variant "FIELDORDER(msb)" };
+
+type record LapdCtrlS {
+	BIT4		reserved ('0000'B),
+	LapdSBits	s,
+	BIT2		spare ('01'B),
+	uint8_t		n_r,
+	boolean		p_f
+} with { variant "FIELDORDER(msb)" };
+
+type record LapdCtrlU {
+	LapdUBits	u,
+	boolean		p_f,
+	LapdU2Bits	u2,
+	BIT2		spare ('11'B)
+} with { variant "FIELDORDER(msb)" };
+
+type union LapdCtrl {
+	LapdCtrlS	s,
+	LapdCtrlU	u,
+	LapdCtrlI	i,
+	uint8_t		other
+} with { variant "TAG(u, spare = '11'B;
+		      s, spare = '01'B;
+		      i, spare = '0'B;
+		      other, OTHERWISE)" };
+		/*      )" }; */
+
+
+template (present) LapdCtrl tr_LapdCtrlU := {
+	u := { u := ?, p_f := ?, u2 := ?, spare := '11'B }
+};
+
+template (present) LapdCtrl tr_LapdCtrlS := {
+	s := { reserved := '0000'B, s := ?, spare := '01'B, n_r := ?, p_f := ? }
+};
+
+template (present) LapdCtrl
+tr_LapdCtrlI(template (present) uint7_t nr, template (present) uint7_t ns,
+	     template (present) boolean p) := {
+	i := { n_s := ns, spare := '0'B, n_r := nr, p := p }
+};
+template (value) LapdCtrl
+ts_LapdCtrlI(uint7_t nr, uint7_t ns, boolean p) := {
+	i := { n_s := ns, spare := '0'B, n_r := nr, p := p }
+};
+
+template (present) LapdCtrl
+tr_LapdCtrlRR(template (present) uint7_t nr, template (present) boolean pf)
+modifies tr_LapdCtrlS := {
+	s := { s := '00'B, n_r := nr, p_f := pf }
+};
+template (value) LapdCtrl ts_LapdCtrlRR(uint7_t nr, boolean pf) := {
+	s := { reserved := '0000'B, s := '00'B, spare := '01'B, n_r := nr, p_f := pf }
+};
+
+template (present) LapdCtrl
+tr_LapdCtrlRNR(template (present) uint7_t nr, template (present) boolean pf)
+modifies tr_LapdCtrlS := {
+	s := { s := '01'B, n_r := nr, p_f := pf }
+};
+
+template (present) LapdCtrl
+tr_LapdCtrlREJ(template (present) uint7_t nr, template (present) boolean pf)
+modifies tr_LapdCtrlS := {
+	s := { s := '10'B, n_r := nr, p_f := pf }
+};
+template (value) LapdCtrl
+ts_LapdCtrlREJ(uint7_t nr, boolean pf)  := {
+	s := { reserved := '0000'B, s := '10'B, spare := '01'B, n_r := nr, p_f := pf }
+};
+
+template (present) LapdCtrl
+tr_LapdCtrlSABM(template (present) boolean p) := {
+	u := { u := '001'B, p_f := p, u2 := '11'B, spare := '11'B }
+};
+template (value) LapdCtrl
+ts_LapdCtrlSABM(boolean p) := {
+	u := { u := '001'B, p_f := p, u2 := '11'B, spare := '11'B }
+};
+
+template (present) LapdCtrl
+tr_LapdCtrlDM(template (present) boolean f) := {
+	u := { u := '000'B, p_f := f, u2 := '11'B, spare := '11'B }
+};
+template (value) LapdCtrl
+ts_LapdCtrlDM(boolean f) := {
+	u := { u := '000'B, p_f := f, u2 := '11'B, spare := '11'B }
+};
+
+template (present) LapdCtrl
+tr_LapdCtrlUI(template (present) boolean p := false) := {
+	u := { u := '000'B, p_f := p, u2 := '00'B, spare := '11'B }
+};
+template (value) LapdCtrl
+ts_LapdCtrlUI(boolean p := false) := {
+	u := { u := '000'B, p_f := p, u2 := '00'B, spare := '11'B }
+};
+
+template (present) LapdCtrl
+tr_LapdCtrlDISC(template (present) boolean p) := {
+	u := { u := '010'B, p_f := p, u2 := '00'B, spare := '11'B }
+};
+template (value) LapdCtrl
+ts_LapdCtrlDISC(boolean p) := {
+	u := { u := '010'B, p_f := p, u2 := '00'B, spare := '11'B }
+};
+
+template (present) LapdCtrl
+tr_LapdCtrlUA(template (present) boolean f) modifies tr_LapdCtrlU := {
+	u := { u := '011'B, p_f := f, u2 := '00'B, spare := '11'B }
+};
+template (value) LapdCtrl
+ts_LapdCtrlUA(boolean f) := {
+	u := { u := '011'B, p_f := f, u2 := '00'B, spare := '11'B }
+};
+
+template (present) LapdCtrl
+tr_LapdCtrlFRMR(template (present) boolean f) modifies tr_LapdCtrlU := {
+	u := { u := '100'B, p_f := f, u2 := '01'B, spare := '11'B }
+};
+template (value) LapdCtrl
+ts_LapdCtrlFRMR(boolean f) := {
+	u := { u := '100'B, p_f := f, u2 := '01'B, spare := '11'B }
+};
+
+template (present) LapdCtrl
+tr_LapdCtrlXID(template (present) boolean p_f) modifies tr_LapdCtrlU := {
+	u := { u := '101'B, p_f := p_f, u2 := '11'B, spare := '11'B }
+};
+template (value) LapdCtrl
+ts_LapdCtrlXID(boolean p_f) := {
+	u := { u := '101'B, p_f := p_f, u2 := '11'B, spare := '11'B }
+};
+
+
+external function dec_LapdAddressField(in octetstring stream) return LapdAddressField
+	with { extension "prototype(convert) decode(RAW)" };
+external function enc_LapdAddressField(in LapdAddressField f) return octetstring
+	with { extension "prototype(convert) encode(RAW)" };
+
+external function dec_LapdCtrl(in octetstring stream) return LapdCtrl
+	with { extension "prototype(convert) decode(RAW)" };
+
+external function dec_LapdCtrlU(in octetstring stream) return LapdCtrlU
+	with { extension "prototype(convert) decode(RAW)" };
+
+
+type record LapdFrame {
+	LapdAddressField	addr,
+	LapdCtrl		ctrl,
+	octetstring		payload	// zero-length in Frame A 
+} with { variant "FIELDORDER(msb)" };
+
+external function enc_LapdFrame(in LapdFrame si) return octetstring
+	with { extension "prototype(convert) encode(RAW)" };
+external function dec_LapdFrame(in octetstring stream) return LapdFrame
+	with { extension "prototype(convert) decode(RAW)" };
+
+template (value) LapdFrame
+ts_LAPD_SABM(LapdTei tei, LapdSapi sapi, boolean c_r, boolean p, octetstring l3) := {
+	addr := ts_LapdAddr(tei, sapi, c_r),
+	ctrl := ts_LapdCtrlSABM(p),
+	payload := l3
+}
+template (present) LapdFrame
+tr_LAPD_SABM(template (present) LapdTei tei, template (present) LapdSapi sapi,
+	     template (present) boolean c_r, template (present) boolean p,
+	     template (present) octetstring l3) := {
+	addr := tr_LapdAddr(tei, sapi, c_r),
+	ctrl := tr_LapdCtrlSABM(p),
+	payload := l3
+}
+
+template (value) LapdFrame
+ts_LAPD_UA(LapdTei tei, LapdSapi sapi, boolean c_r, boolean f, octetstring l3) := {
+	addr := ts_LapdAddr(tei, sapi, c_r),
+	ctrl := ts_LapdCtrlUA(f),
+	payload := l3
+}
+template (present) LapdFrame
+tr_LAPD_UA(template (present) LapdTei tei, template (present) LapdSapi sapi,
+		     template (present) boolean c_r, template (present) boolean f,
+		     template (present) octetstring l3) := {
+	addr := tr_LapdAddr(tei, sapi, c_r),
+	ctrl := tr_LapdCtrlUA(f),
+	payload := l3
+}
+
+template (value) LapdFrame
+ts_LAPD_DM(LapdTei tei, LapdSapi sapi, boolean c_r, boolean f) := {
+	addr := ts_LapdAddr(tei, sapi, c_r),
+	ctrl := ts_LapdCtrlDM(f),
+	payload := ''O
+}
+template (present) LapdFrame
+tr_LAPD_DM(template (present) LapdTei tei, template (present) LapdSapi sapi,
+	   template (present) boolean c_r, template (present) boolean f) := {
+	addr := tr_LapdAddr(tei, sapi, c_r),
+	ctrl := tr_LapdCtrlDM(f),
+	payload := ''O
+}
+
+template (value) LapdFrame
+ts_LAPD_DISC(LapdTei tei, LapdSapi sapi, boolean c_r, boolean p) := {
+	addr := ts_LapdAddr(tei, sapi, c_r),
+	ctrl := ts_LapdCtrlDISC(p),
+	payload := ''O
+}
+template (present) LapdFrame
+tr_LAPD_DISC(template (present) LapdTei tei, template (present) LapdSapi sapi,
+	     template (present) boolean c_r, template (present) boolean p) := {
+	addr := tr_LapdAddr(tei, sapi, c_r),
+	ctrl := tr_LapdCtrlDISC(p),
+	payload := ''O
+}
+
+template (value) LapdFrame
+ts_LAPD_UI(LapdTei tei, LapdSapi sapi, boolean c_r, octetstring l3) := {
+	addr := ts_LapdAddr(tei, sapi, c_r),
+	ctrl := ts_LapdCtrlUI,
+	payload := l3
+}
+template (present) LapdFrame
+tr_LAPD_UI(template (present) LapdTei tei, template (present) LapdSapi sapi,
+	   template (present) boolean c_r, template (present) octetstring l3) := {
+	addr := tr_LapdAddr(tei, sapi, c_r),
+	ctrl := tr_LapdCtrlUI,
+	payload := l3
+}
+
+template (value) LapdFrame
+ts_LAPD_I(LapdTei tei, LapdSapi sapi, boolean c_r, boolean p, uint7_t nr,
+	  uint7_t ns, octetstring l3, boolean m := false) := {
+	addr := ts_LapdAddr(tei, sapi, c_r),
+	ctrl := ts_LapdCtrlI(nr, ns, p),
+	payload := l3
+}
+template (present) LapdFrame
+tr_LAPD_I(template (present) LapdTei tei, template (present) LapdSapi sapi,
+	  template (present) boolean c_r, template (present) boolean p,
+	  template (present) uint7_t nr, template (present) uint7_t ns,
+	  template (present) octetstring l3, template (present) boolean m := false) := {
+	addr := tr_LapdAddr(tei, sapi, c_r),
+	ctrl := tr_LapdCtrlI(nr, ns, p),
+	payload := l3
+}
+
+template (value) LapdFrame
+ts_LAPD_RR(LapdTei tei, LapdSapi sapi, boolean c_r, boolean p, uint7_t nr) := {
+	addr := ts_LapdAddr(tei, sapi, c_r),
+	ctrl := ts_LapdCtrlRR(nr, p),
+	payload := ''O
+}
+template (present) LapdFrame
+tr_LAPD_RR(template (present) LapdTei tei, template (present) LapdSapi sapi,
+	   template (present) boolean c_r, template (present) boolean p,
+	   template (present) uint7_t nr) := {
+	addr := tr_LapdAddr(tei, sapi, c_r),
+	ctrl := tr_LapdCtrlRR(nr, p),
+	payload := ''O
+}
+
+template (value) LapdFrame ts_LAPD_REJ(LapdTei tei, LapdSapi sapi, boolean c_r,
+					boolean p, uint7_t nr) := {
+	addr := ts_LapdAddr(tei, sapi, c_r),
+	ctrl := ts_LapdCtrlREJ(nr, p),
+	payload := ''O
+}
+template (present) LapdFrame
+tr_LAPD_REJ(template (present) LapdTei tei, template (present) LapdSapi sapi,
+	     template (present) boolean c_r, template (present) boolean p,
+	     template (present) uint7_t nr) := {
+	addr := tr_LapdAddr(tei, sapi, c_r),
+	ctrl := tr_LapdCtrlREJ(nr, p),
+	payload := ''O
+}
+
+
+/* Table 8/Q.921 */
+type enumerated TeiMgmtMsgType {
+	IDENTITY_REQUEST	('00000001'B),
+	IDENTITY_ASSIGNED	('00000010'B),
+	IDENTITY_DENIED		('00000011'B),
+	IDENTITY_CHECK_REQ	('00000100'B),
+	IDENTITY_CHECK_RESP	('00000101'B),
+	IDENTITY_REMOVE		('00000110'B),
+	IDENTITY_VERIFY		('00000111'B)
+} with { variant "FIELDLENGTH(8)" };
+type record TeiMgmtMsg {
+	BIT8		me_id ('00001111'B), /* management entity identifier */
+	uint16_t	ri,	/* reference number */
+	TeiMgmtMsgType	msg_type,
+	uint7_t		ai,
+	BIT1		e
+};
+
+template (value) TeiMgmtMsg ts_TEI(TeiMgmtMsgType msgt, uint16_t ri, uint7_t ai) := {
+	me_id := '00001111'B,
+	ri := ri,
+	msg_type := msgt,
+	ai := ai,
+	e := '1'B
+}
+
+external function enc_TeiMgmtMsg(in TeiMgmtMsg si) return octetstring
+	with { extension "prototype(convert) encode(RAW)" };
+external function dec_TeiMgmtMsg(in octetstring stream) return TeiMgmtMsg
+	with { extension "prototype(convert) decode(RAW)" };
+
+template (value) TeiMgmtMsg
+ts_TEI_IdRequest(uint16_t ri, uint7_t ai) := ts_TEI(IDENTITY_REQUEST, ri, ai);
+
+template (value) TeiMgmtMsg
+ts_TEI_IdAssigned(uint16_t ri, uint7_t ai) := ts_TEI(IDENTITY_ASSIGNED, ri, ai);
+
+template (value) TeiMgmtMsg
+ts_TEI_IdDenied(uint16_t ri, uint7_t ai) := ts_TEI(IDENTITY_DENIED, ri, ai);
+
+template (value) TeiMgmtMsg
+ts_TEI_IdCheckReq(uint16_t ri, uint7_t ai) := ts_TEI(IDENTITY_CHECK_REQ, ri, ai);
+
+template (value) TeiMgmtMsg
+ts_TEI_IdCheckResp(uint16_t ri, uint7_t ai) := ts_TEI(IDENTITY_CHECK_RESP, ri, ai);
+
+template (value) TeiMgmtMsg
+ts_TEI_IdRemove(uint16_t ri, uint7_t ai) := ts_TEI(IDENTITY_REMOVE, ri, ai);
+
+template (value) TeiMgmtMsg
+ts_TEI_IdVerify(uint16_t ri, uint7_t ai) := ts_TEI(IDENTITY_VERIFY, ri, ai);
+
+
+/* Q.921bis Name:ID_Rmv */
+template (present) LapdFrame
+tr_ID_Rmv(template (present) LapdTei tei) := {
+	addr := ts_LapdAddr(tei := 127, sapi := 63, c_r := true),
+	ctrl := ts_LapdCtrlUI(p := false)
+}
+
+/* Q.921bis Name:ID_Ver */
+template (present) LapdFrame
+tr_ID_Ver(template (present) LapdTei tei) := {
+	addr := ts_LapdAddr(tei := 127, sapi := 63, c_r := true),
+	ctrl := ts_LapdCtrlUI(p := false)
+}
+
+
+
+
+} with { encode "RAW"; /*variant "FIELDORDER(msb)" */}