RAN_Emulation: Modularize protocol support

The RAN_Emulation currently unconditionally provides BSSAP and MGCP support.
Let's re-structure the code so that support for those protocols is now
possible to enable/disable at compile time.

This patch is in preparation of introducing RANAP support in RAN_Emulation.

Change-Id: Id53ba3ff05f9946230e0e4a759245de14a0f9fbd
Related: OS#2856

12 files changed, 214 insertions, 139 deletions

diff --git a/bsc-nat/BSC_MS_ConnectionHandler.ttcn b/bsc-nat/BSC_MS_ConnectionHandler.ttcn
index 63d0451c..e52b678f 100644
--- a/bsc-nat/BSC_MS_ConnectionHandler.ttcn
+++ b/bsc-nat/BSC_MS_ConnectionHandler.ttcn
@@ -53,6 +53,7 @@ const RanOps BSC_MS_RanOps := {
 	unitdata_cb := refers(UnitdataCallback),
 	decode_dtap := false,
 	role_ms := true,
+	protocol := RAN_PROTOCOL_BSSAP,
 	sccp_addr_local := omit,
 	sccp_addr_peer := omit
 }
diff --git a/bsc-nat/MSC_ConnectionHandler.ttcn b/bsc-nat/MSC_ConnectionHandler.ttcn
index 383b67b1..8635a296 100644
--- a/bsc-nat/MSC_ConnectionHandler.ttcn
+++ b/bsc-nat/MSC_ConnectionHandler.ttcn
@@ -59,6 +59,7 @@ const RanOps MSC_RanOps := {
 	unitdata_cb := refers(UnitdataCallback),
 	decode_dtap := false,
 	role_ms := false,
+	protocol := RAN_PROTOCOL_BSSAP,
 	sccp_addr_local := omit,
 	sccp_addr_peer := omit
 }
diff --git a/bsc-nat/gen_links.sh b/bsc-nat/gen_links.sh
index e54eec48..16e32b78 100755
--- a/bsc-nat/gen_links.sh
+++ b/bsc-nat/gen_links.sh
@@ -47,7 +47,7 @@ FILES="RTP_EncDec.cc RTP_Types.ttcn"
 gen_links $DIR $FILES
 
 DIR=../library
-FILES="Misc_Helpers.ttcn General_Types.ttcn Osmocom_Types.ttcn GSM_Types.ttcn IPA_Types.ttcn IPA_CodecPort.ttcn IPA_CodecPort_CtrlFunct.ttcn IPA_CodecPort_CtrlFunctDef.cc IPA_Emulation.ttcnpp L3_Templates.ttcn BSSMAP_Templates.ttcn RAN_Emulation.ttcn MGCP_Types.ttcn MGCP_Templates.ttcn MGCP_CodecPort.ttcn MGCP_CodecPort_CtrlFunct.ttcn MGCP_CodecPort_CtrlFunctDef.cc Osmocom_CTRL_Types.ttcn Osmocom_CTRL_Functions.ttcn BSSAP_CodecPort.ttcn"
+FILES="Misc_Helpers.ttcn General_Types.ttcn Osmocom_Types.ttcn GSM_Types.ttcn IPA_Types.ttcn IPA_CodecPort.ttcn IPA_CodecPort_CtrlFunct.ttcn IPA_CodecPort_CtrlFunctDef.cc IPA_Emulation.ttcnpp L3_Templates.ttcn BSSMAP_Templates.ttcn RAN_Emulation.ttcnpp MGCP_Types.ttcn MGCP_Templates.ttcn MGCP_CodecPort.ttcn MGCP_CodecPort_CtrlFunct.ttcn MGCP_CodecPort_CtrlFunctDef.cc Osmocom_CTRL_Types.ttcn Osmocom_CTRL_Functions.ttcn BSSAP_CodecPort.ttcn"
 gen_links $DIR $FILES
 
 ignore_pp_results
diff --git a/bsc-nat/regen_makefile.sh b/bsc-nat/regen_makefile.sh
index c5fe64c4..f49df7e2 100755
--- a/bsc-nat/regen_makefile.sh
+++ b/bsc-nat/regen_makefile.sh
@@ -4,6 +4,6 @@ MAIN=BSCNAT_Tests.ttcn
 
 FILES="*.ttcn *.ttcnpp SCCP_EncDec.cc IPA_CodecPort_CtrlFunctDef.cc IPL4asp_PT.cc IPL4asp_discovery.cc TCCConversion.cc TCCInterface.cc RTP_EncDec.cc SDP_EncDec.cc *.c MGCP_CodecPort_CtrlFunctDef.cc"
 
-export CPPFLAGS_TTCN3="-DIPA_EMULATION_SCCP -DIPA_EMULATION_MGCP -DUSE_MTP3_DISTRIBUTOR"
+export CPPFLAGS_TTCN3="-DIPA_EMULATION_SCCP -DIPA_EMULATION_MGCP -DRAN_EMULATION_BSSAP -DRAN_EMULATION_MGCP -DUSE_MTP3_DISTRIBUTOR"
 
 ../regen-makefile.sh $MAIN $FILES
diff --git a/bsc/MSC_ConnectionHandler.ttcn b/bsc/MSC_ConnectionHandler.ttcn
index 36e554df..520cc3ea 100644
--- a/bsc/MSC_ConnectionHandler.ttcn
+++ b/bsc/MSC_ConnectionHandler.ttcn
@@ -376,6 +376,7 @@ const RanOps MSC_RanOps := {
 	unitdata_cb := refers(UnitdataCallback),
 	decode_dtap := false,
 	role_ms := false,
+	protocol := RAN_PROTOCOL_BSSAP,
 	sccp_addr_local := omit,
 	sccp_addr_peer := omit
 }
diff --git a/bsc/gen_links.sh b/bsc/gen_links.sh
index d8393c32..a4f09f4d 100755
--- a/bsc/gen_links.sh
+++ b/bsc/gen_links.sh
@@ -67,7 +67,7 @@ FILES="TELNETasp_PT.cc  TELNETasp_PT.hh  TELNETasp_PortType.ttcn"
 gen_links $DIR $FILES
 
 DIR=../library
-FILES="Misc_Helpers.ttcn General_Types.ttcn Osmocom_Types.ttcn GSM_Types.ttcn Osmocom_VTY_Functions.ttcn Native_Functions.ttcn Native_FunctionDefs.cc IPA_Types.ttcn IPA_CodecPort.ttcn IPA_CodecPort_CtrlFunct.ttcn IPA_CodecPort_CtrlFunctDef.cc IPA_Emulation.ttcnpp L3_Templates.ttcn BSSMAP_Templates.ttcn RAN_Emulation.ttcn RLCMAC_CSN1_Types.ttcn GSM_RR_Types.ttcn RSL_Types.ttcn RSL_Emulation.ttcn MGCP_Emulation.ttcn MGCP_Types.ttcn MGCP_Templates.ttcn MGCP_CodecPort.ttcn MGCP_CodecPort_CtrlFunct.ttcn MGCP_CodecPort_CtrlFunctDef.cc BSSAP_CodecPort.ttcn RAN_Adapter.ttcn Osmocom_CTRL_Types.ttcn Osmocom_CTRL_Functions.ttcn Osmocom_CTRL_Adapter.ttcn RTP_CodecPort.ttcn RTP_CodecPort_CtrlFunct.ttcn RTP_CodecPort_CtrlFunctDef.cc RTP_Emulation.ttcn IuUP_Types.ttcn IuUP_EncDec.cc IuUP_Emulation.ttcn SCCP_Templates.ttcn IPA_Testing.ttcn"
+FILES="Misc_Helpers.ttcn General_Types.ttcn Osmocom_Types.ttcn GSM_Types.ttcn Osmocom_VTY_Functions.ttcn Native_Functions.ttcn Native_FunctionDefs.cc IPA_Types.ttcn IPA_CodecPort.ttcn IPA_CodecPort_CtrlFunct.ttcn IPA_CodecPort_CtrlFunctDef.cc IPA_Emulation.ttcnpp L3_Templates.ttcn BSSMAP_Templates.ttcn RAN_Emulation.ttcnpp RLCMAC_CSN1_Types.ttcn GSM_RR_Types.ttcn RSL_Types.ttcn RSL_Emulation.ttcn MGCP_Emulation.ttcn MGCP_Types.ttcn MGCP_Templates.ttcn MGCP_CodecPort.ttcn MGCP_CodecPort_CtrlFunct.ttcn MGCP_CodecPort_CtrlFunctDef.cc BSSAP_CodecPort.ttcn RAN_Adapter.ttcnpp Osmocom_CTRL_Types.ttcn Osmocom_CTRL_Functions.ttcn Osmocom_CTRL_Adapter.ttcn RTP_CodecPort.ttcn RTP_CodecPort_CtrlFunct.ttcn RTP_CodecPort_CtrlFunctDef.cc RTP_Emulation.ttcn IuUP_Types.ttcn IuUP_EncDec.cc IuUP_Emulation.ttcn SCCP_Templates.ttcn IPA_Testing.ttcn"
 gen_links $DIR $FILES
 
 ignore_pp_results
diff --git a/bsc/regen_makefile.sh b/bsc/regen_makefile.sh
index 08629d20..06fa8121 100755
--- a/bsc/regen_makefile.sh
+++ b/bsc/regen_makefile.sh
@@ -4,6 +4,6 @@ MAIN=BSC_Tests.ttcn
 
 FILES="*.ttcn *.ttcnpp IPA_CodecPort_CtrlFunctDef.cc IPL4asp_PT.cc IPL4asp_discovery.cc TCCConversion.cc TCCInterface.cc SCTPasp_PT.cc RTP_EncDec.cc SDP_EncDec.cc RTP_CodecPort_CtrlFunctDef.cc MGCP_CodecPort_CtrlFunctDef.cc IuUP_EncDec.cc Native_FunctionDefs.cc TELNETasp_PT.cc *.c"
 
-export CPPFLAGS_TTCN3="-DIPA_EMULATION_RSL -DIPA_EMULATION_MGCP -DIPA_EMULATION_SCCP -DUSE_MTP3_DISTRIBUTOR"
+export CPPFLAGS_TTCN3="-DIPA_EMULATION_RSL -DIPA_EMULATION_MGCP -DIPA_EMULATION_SCCP -DRAN_EMULATION_BSSAP -DRAN_EMULATION_MGCP -DUSE_MTP3_DISTRIBUTOR"
 
 ../regen-makefile.sh $MAIN $FILES
diff --git a/library/RAN_Adapter.ttcn b/library/RAN_Adapter.ttcnpp
index 294f747b..43b4988a 100644
--- a/library/RAN_Adapter.ttcn
+++ b/library/RAN_Adapter.ttcnpp
@@ -88,6 +88,7 @@ function f_bssap_init(inout RAN_Adapter ba, in RAN_Configuration cfg, charstring
 		ba.vc_RAN := RAN_Emulation_CT.create(id & "-RAN");
 	}
 	select (cfg.transport) {
+#ifdef RAN_EMULATION_BSSAP
 	case (BSSAP_TRANSPORT_AoIP) {
 		ba.vc_M3UA := M3UA_CT.create(id & "-M3UA");
 		map(ba.vc_M3UA:SCTP_PORT, system:sctp);
@@ -128,6 +129,7 @@ function f_bssap_init(inout RAN_Adapter ba, in RAN_Configuration cfg, charstring
 		ba.vc_WAIT.done;
 		disconnect(ba.vc_IPA:IPA_SP_PORT, ba.vc_WAIT:IPA_SP_PORT);
 		}
+#endif
 	case else {
 		setverdict(fail, "Unsuppored RAN_Transport");
 		mtc.stop;
@@ -139,8 +141,10 @@ function f_bssap_init(inout RAN_Adapter ba, in RAN_Configuration cfg, charstring
 		T.start;
 		//T.timeout;
 		log("Connecting BSSMAP Emulation to SCCP_SP_PORT and starting emulation");
+#if RAN_EMULATION_BSSAP
 		/* connect BSSNAP component to upper side of SCCP */
 		connect(ba.vc_RAN:BSSAP, ba.vc_SCCP:SCCP_SP_PORT);
+#endif
 		if (cfg.transport == BSSAP_TRANSPORT_SCCPlite_SERVER or
 		    cfg.transport == BSSAP_TRANSPORT_SCCPlite_CLIENT) {
 			/* connect IPA MGCP port with BSSMAP MGCP port */
diff --git a/library/RAN_Emulation.ttcn b/library/RAN_Emulation.ttcnpp
index 72e2733f..e0911331 100644
--- a/library/RAN_Emulation.ttcn
+++ b/library/RAN_Emulation.ttcnpp
@@ -22,7 +22,7 @@ module RAN_Emulation {
  * Inbound Unit Data messages (such as are dispatched to the RanOps.unitdata_cb() callback,
  * which is registered with an argument to the main() function below.
  *
- * (C) 2017-2018 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2017-2019 by Harald Welte <laforge@gnumonks.org>
  * All rights reserved.
  *
  * Released under the terms of GNU General Public License, Version 2 or
@@ -34,13 +34,19 @@ import from General_Types all;
 import from Osmocom_Types all;
 import from SCCP_Emulation all;
 import from SCCPasp_Types all;
+import from IPA_Emulation all;
+import from MobileL3_Types all;
+
+#ifdef RAN_EMULATION_BSSAP
 import from BSSAP_Types all;
 import from BSSAP_CodecPort all;
 import from BSSMAP_Templates all;
+#endif
+
+#ifdef RAN_EMULATION_MGCP
 import from MGCP_Types all;
 import from MGCP_Templates all;
-import from IPA_Emulation all;
-import from MobileL3_Types all;
+#endif
 
 /* General "base class" component definition, of which specific implementations
  * derive themselves by means of the "extends" feature */
@@ -61,12 +67,6 @@ type enumerated RAN_Conn_Prim {
 	MSC_CONN_PRIM_CONF_IND
 }
 
-type record BSSAP_Conn_Req {
-	SCCP_PAR_Address	addr_peer,
-	SCCP_PAR_Address	addr_own,
-	PDU_BSSAP		bssap
-}
-
 /* similar to PDU_BSSAP with DTAP, but DTAP is already decoded! */
 type record PDU_DTAP_MO {
 	OCT1			dlci optional,
@@ -102,23 +102,22 @@ template PDU_DTAP_MO tr_PDU_DTAP_MO(template PDU_ML3_MS_NW dtap, template OCT1 d
 	dtap := dtap
 }
 
-template BSSAP_Conn_Req ts_BSSAP_Conn_Req(SCCP_PAR_Address peer, SCCP_PAR_Address own, PDU_BSSAP bssap) := {
-	addr_peer := peer,
-	addr_own := own,
-	bssap := bssap
-};
-
-
 /* port between individual per-connection components and this dispatcher */
 type port RAN_Conn_PT message {
-		/* BSSAP or direct DTAP messages from/to clients */
-	inout	PDU_BSSAP, PDU_DTAP_MO, PDU_DTAP_MT,
-		/* misc indications / requests between SCCP and client */
-		RAN_Conn_Prim,
+	inout
+#ifdef RAN_EMULATION_BSSAP
+		PDU_BSSAP,
 		/* Client requests us to create SCCP Connection */
 		BSSAP_Conn_Req,
+#endif
+#ifdef RAN_EMULATION_MGCP
 		/* MGCP, only used for IPA SCCPlite (MGCP in IPA mux) */
-		MgcpCommand, MgcpResponse;
+		MgcpCommand, MgcpResponse,
+#endif
+		/* direct DTAP messages from/to clients */
+		PDU_DTAP_MO, PDU_DTAP_MT,
+		/* misc indications / requests between SCCP and client */
+		RAN_Conn_Prim;
 } with { extension "internal" };
 
 
@@ -127,8 +126,10 @@ type record ConnectionData {
 	/* reference to the instance of the per-connection component */
 	RAN_ConnHdlr	comp_ref,
 	integer		sccp_conn_id,
+#ifdef RAN_EMULATION_MGCP
 	/* most recent MGCP transaction ID (Used on MSC side) */
 	MgcpTransId	mgcp_trans_id optional,
+#endif
 	/* CIC that has been used for voice of this channel (BSC side) */
 	integer		cic optional,
 	/* array of N(SD) values for MO DTAP messages, indexed by discriminator */
@@ -142,12 +143,16 @@ type record ImsiMapping {
 }
 
 type component RAN_Emulation_CT {
-	/* SCCP port on the bottom side, using ASP primitives */
+	/* SCCP ports on the bottom side, using ASP primitives */
+#ifdef RAN_EMULATION_BSSAP
 	port BSSAP_CODEC_PT BSSAP;
+#endif
 	/* BSSAP port to the per-connection clients */
 	port RAN_Conn_PT CLIENT;
+#ifdef RAN_EMULATION_MGCP
 	/* MGCP port */
 	port IPA_MGCP_PT MGCP;
+#endif
 
 	/* use 16 as this is also the number of SCCP connections that SCCP_Emulation can handle */
 	var ConnectionData ConnectionTable[16];
@@ -212,6 +217,8 @@ runs on RAN_Emulation_CT return RAN_ConnHdlr {
 	mtc.stop;
 }
 
+
+#ifdef RAN_EMULATION_MGCP
 /* resolve component reference by CIC */
 private function f_comp_by_mgcp_tid(MgcpTransId tid)
 runs on RAN_Emulation_CT return RAN_ConnHdlr {
@@ -237,6 +244,7 @@ runs on RAN_Emulation_CT {
 	setverdict(fail, "RAN Connection table not found by component ", client);
 	mtc.stop;
 }
+#endif
 
 private function f_comp_by_cic(integer cic)
 runs on RAN_Emulation_CT return RAN_ConnHdlr {
@@ -303,7 +311,9 @@ runs on RAN_Emulation_CT {
 	for (var integer i := 0; i < sizeof(ConnectionTable); i := i+1) {
 		ConnectionTable[i].comp_ref := null;
 		ConnectionTable[i].sccp_conn_id := -1;
+#ifdef RAN_EMULATION_MGCP
 		ConnectionTable[i].mgcp_trans_id := omit;
+#endif
 		ConnectionTable[i].cic := omit;
 		ConnectionTable[i].n_sd := { 0, 0, 0, 0 };
 	}
@@ -354,6 +364,18 @@ runs on RAN_Emulation_CT return RAN_ConnHdlr {
 	return null;
 }
 
+#ifdef RAN_EMULATION_BSSAP
+type record BSSAP_Conn_Req {
+	SCCP_PAR_Address	addr_peer,
+	SCCP_PAR_Address	addr_own,
+	PDU_BSSAP		bssap
+}
+template BSSAP_Conn_Req ts_BSSAP_Conn_Req(SCCP_PAR_Address peer, SCCP_PAR_Address own, PDU_BSSAP bssap) := {
+	addr_peer := peer,
+	addr_own := own,
+	bssap := bssap
+};
+
 /* handle (optional) userData portion of various primitives and dispatch it to the client */
 private function f_handle_userData(RAN_ConnHdlr client, PDU_BSSAP bssap)
 runs on RAN_Emulation_CT {
@@ -420,11 +442,65 @@ runs on RAN_Emulation_CT return template PDU_BSSAP {
 	return g_ran_ops.unitdata_cb.apply(bssap);
 }
 
+private function f_bssap_wait_for_reset() runs on RAN_Emulation_CT {
+	var BSSAP_N_UNITDATA_ind ud_ind;
+	timer T := 20.0;
+
+	T.start;
+	alt {
+	[] BSSAP.receive(tr_BSSAP_UNITDATA_ind(?, ?, tr_BSSMAP_Reset)) -> value ud_ind {
+		BSSAP.send(ts_BSSAP_UNITDATA_req(ud_ind.callingAddress, ud_ind.calledAddress,
+			   ts_BSSMAP_ResetAck));
+		}
+	[] as_reset_ack();
+	[] BSSAP.receive {
+		repeat;
+		}
+	[] T.timeout {
+		setverdict(fail, "Timeout waiting for BSSAP RESET");
+		mtc.stop;
+		}
+	}
+}
+
+function f_bssap_reset(SCCP_PAR_Address peer, SCCP_PAR_Address own) runs on RAN_Emulation_CT {
+	timer T := 5.0;
+
+	BSSAP.send(ts_BSSAP_UNITDATA_req(peer, own, ts_BSSMAP_Reset(0)));
+	T.start;
+	alt {
+	[] BSSAP.receive(tr_BSSAP_UNITDATA_ind(own, peer, tr_BSSMAP_ResetAck)) {
+		log("Received RESET-ACK in response to RESET, we're ready to go!");
+		}
+	[] as_reset_ack();
+	[] BSSAP.receive { repeat };
+	[] T.timeout {
+		setverdict(fail, "Timeout waiting for RESET-ACK after sending RESET");
+		mtc.stop;
+		}
+	}
+}
+
+private function f_bssap_l3_is_rr(PDU_BSSAP bssap) return boolean {
+	var template octetstring l3 := f_bssap_extract_l3(bssap);
+	return f_L3_is_rr(l3);
+}
+#endif
+
+
+
+type enumerated RanProtocol {
+	RAN_PROTOCOL_BSSAP
+}
+
 type record RanOps {
-	BssmapCreateCallback create_cb,
-	BssmapUnitdataCallback unitdata_cb,
+#ifdef RAN_EMULATION_BSSAP
+	BssmapCreateCallback create_cb optional,
+	BssmapUnitdataCallback unitdata_cb optional,
+#endif
 	boolean decode_dtap,
 	boolean role_ms,
+	RanProtocol protocol,
 	/* needed for performing BSSMAP RESET */
 	SCCP_PAR_Address sccp_addr_local optional,
 	SCCP_PAR_Address sccp_addr_peer optional
@@ -432,6 +508,21 @@ type record RanOps {
 
 template BIT4 t_ML3_DISC_CC_MM_SS := ('0011'B, '0101'B, '1011'B);
 
+private function f_L3_is_rr(template octetstring l3) return boolean {
+	if (not isvalue(l3)) {
+		return false;
+	}
+	var octetstring l3v := valueof(l3);
+	if (lengthof(l3v) < 1) {
+		return false;
+	}
+	/* lower 4 bits of first octet are protocol discriminator */
+	if ((oct2bit(l3v[0]) and4b '00001111'B) == '00000110'B) {
+		return true;
+	}
+	return false;
+}
+
 /* patch N(SD) into enc_l3, according to 24.007 11.2.3.2 */
 function f_ML3_patch_seq(inout ConnectionData cd, in PDU_ML3_MS_NW dtap, inout octetstring enc_l3) {
 	var uint2_t seq_nr;
@@ -456,103 +547,32 @@ function f_ML3_patch_seq(inout ConnectionData cd, in PDU_ML3_MS_NW dtap, inout o
 	log("patched enc_l3: ", enc_l3);
 }
 
-private function f_bssap_l3_is_rr(PDU_BSSAP bssap) return boolean {
-	var template octetstring l3 := f_bssap_extract_l3(bssap);
-	if (not isvalue(l3)) {
-		return false;
-	}
-	var octetstring l3v := valueof(l3);
-	if (lengthof(l3v) < 1) {
-		return false;
-	}
-	/* lower 4 bits of first octet are protocol discriminator */
-	if ((oct2bit(l3v[0]) and4b '00001111'B) == '00000110'B) {
-		return true;
-	}
-	return false;
-}
-
 private altstep as_reset_ack() runs on RAN_Emulation_CT {
+#ifdef RAN_EMULATION_BSSAP
 	var BSSAP_N_UNITDATA_ind ud_ind;
+#endif
+#ifdef RAN_EMULATION_BSSAP
 	[] BSSAP.receive(tr_BSSAP_UNITDATA_ind(?, ?, tr_BSSMAP_Reset)) -> value ud_ind {
 		log("Respoding to inbound RESET with RESET-ACK");
 		BSSAP.send(ts_BSSAP_UNITDATA_req(ud_ind.callingAddress, ud_ind.calledAddress,
 			   ts_BSSMAP_ResetAck));
 		repeat;
 	}
+#endif
 }
 
 
-private function f_bssap_wait_for_reset() runs on RAN_Emulation_CT {
-	var BSSAP_N_UNITDATA_ind ud_ind;
-	timer T := 20.0;
-
-	T.start;
-	alt {
-	[] BSSAP.receive(tr_BSSAP_UNITDATA_ind(?, ?, tr_BSSMAP_Reset)) -> value ud_ind {
-		BSSAP.send(ts_BSSAP_UNITDATA_req(ud_ind.callingAddress, ud_ind.calledAddress,
-			   ts_BSSMAP_ResetAck));
-		}
-	[] as_reset_ack();
-	[] BSSAP.receive {
-		repeat;
-		}
-	[] T.timeout {
-		setverdict(fail, "Timeout waiting for BSSAP RESET");
-		mtc.stop;
-		}
-	}
-}
-
-function f_bssap_reset(SCCP_PAR_Address peer, SCCP_PAR_Address own) runs on RAN_Emulation_CT {
-	timer T := 5.0;
-
-	BSSAP.send(ts_BSSAP_UNITDATA_req(peer, own, ts_BSSMAP_Reset(0)));
-	T.start;
-	alt {
-	[] BSSAP.receive(tr_BSSAP_UNITDATA_ind(own, peer, tr_BSSMAP_ResetAck)) {
-		log("Received RESET-ACK in response to RESET, we're ready to go!");
-		}
-	[] as_reset_ack();
-	[] BSSAP.receive { repeat };
-	[] T.timeout {
-		setverdict(fail, "Timeout waiting for RESET-ACK after sending RESET");
-		mtc.stop;
-		}
-	}
-}
-
-function main(RanOps ops, charstring id) runs on RAN_Emulation_CT {
-
-	g_ran_id := id;
-	g_ran_ops := ops;
-	f_conn_table_init();
-	f_expect_table_init();
-
-	if (isvalue(ops.sccp_addr_peer) and isvalue(ops.sccp_addr_local)) {
-		f_sleep(1.0);	/* HACK to wait for M3UA/ASP to be ACTIVE */
-		f_bssap_reset(ops.sccp_addr_peer, ops.sccp_addr_local);
-	}
-
-	while (true) {
+private altstep as_main_bssap() runs on RAN_Emulation_CT {
+#ifdef RAN_EMULATION_BSSAP
 		var BSSAP_N_UNITDATA_ind ud_ind;
 		var BSSAP_N_CONNECT_ind conn_ind;
 		var BSSAP_N_CONNECT_cfm conn_cfm;
 		var BSSAP_N_DATA_ind data_ind;
 		var BSSAP_N_DISCONNECT_ind disc_ind;
 		var BSSAP_Conn_Req creq;
-		var RAN_ConnHdlr vc_conn;
 		var PDU_BSSAP bssap;
-		var PDU_DTAP_MO dtap_mo;
-		var PDU_DTAP_MT dtap_mt;
-		var MgcpCommand mgcp_req;
-		var MgcpResponse mgcp_resp;
-		var RAN_ConnHdlr vc_hdlr;
-		var octetstring l3_info;
-		var hexstring imsi;
-		var OCT4 tmsi;
+		var RAN_ConnHdlr vc_conn;
 
-		alt {
 		/* SCCP -> Client: UNIT-DATA (connectionless SCCP) from a BSC */
 		[] BSSAP.receive(BSSAP_N_UNITDATA_ind:?) -> value ud_ind {
 			/* Connectionless Procedures like RESET */
@@ -563,10 +583,9 @@ function main(RanOps ops, charstring id) runs on RAN_Emulation_CT {
 								ud_ind.calledAddress, resp));
 			}
 			}
-
 		/* SCCP -> Client: new connection from BSC */
 		[] BSSAP.receive(BSSAP_N_CONNECT_ind:?) -> value conn_ind {
-			vc_conn := ops.create_cb.apply(conn_ind, id);
+			vc_conn := g_ran_ops.create_cb.apply(conn_ind, g_ran_id);
 			/* store mapping between client components and SCCP connectionId */
 			f_conn_table_add(vc_conn, conn_ind.connectionId);
 			/* handle user payload */
@@ -574,7 +593,6 @@ function main(RanOps ops, charstring id) runs on RAN_Emulation_CT {
 			/* confirm connection establishment */
 			BSSAP.send(ts_BSSAP_CONNECT_res(conn_ind.connectionId, omit));
 			}
-
 		/* SCCP -> Client: connection-oriented data in existing connection */
 		[] BSSAP.receive(BSSAP_N_DATA_ind:?) -> value data_ind {
 			vc_conn := f_comp_by_conn_id(data_ind.connectionId);
@@ -582,7 +600,6 @@ function main(RanOps ops, charstring id) runs on RAN_Emulation_CT {
 				f_handle_userData(vc_conn, data_ind.userData);
 			}
 			}
-
 		/* SCCP -> Client: disconnect of an existing connection */
 		[] BSSAP.receive(BSSAP_N_DISCONNECT_ind:?) -> value disc_ind {
 			vc_conn := f_comp_by_conn_id(disc_ind.connectionId);
@@ -595,7 +612,6 @@ function main(RanOps ops, charstring id) runs on RAN_Emulation_CT {
 			f_conn_table_del(disc_ind.connectionId);
 			/* TOOD: return confirm to other side? */
 			}
-
 		/* SCCP -> Client: connection confirm for outbound connection */
 		[] BSSAP.receive(BSSAP_N_CONNECT_cfm:?) -> value conn_cfm {
 			vc_conn := f_comp_by_conn_id(conn_cfm.connectionId);
@@ -606,6 +622,11 @@ function main(RanOps ops, charstring id) runs on RAN_Emulation_CT {
 				f_handle_userData(vc_conn, conn_cfm.userData);
 			}
 			}
+		[] CLIENT.receive(PDU_BSSAP:?) -> value bssap sender vc_conn {
+			var integer conn_id := f_conn_id_by_comp(vc_conn);
+			/* send it to dispatcher */
+			BSSAP.send(ts_BSSAP_DATA_req(conn_id, bssap));
+			}
 
 		/* Disconnect request client -> SCCP */
 		[] CLIENT.receive(RAN_Conn_Prim:MSC_CONN_PRIM_DISC_REQ) -> sender vc_conn {
@@ -644,33 +665,16 @@ function main(RanOps ops, charstring id) runs on RAN_Emulation_CT {
 			}
 
 			}
+#else
+		[false] CLIENT.receive(false) {}
+#endif
+}
 
-		[] CLIENT.receive(PDU_BSSAP:?) -> value bssap sender vc_conn {
-			var integer conn_id := f_conn_id_by_comp(vc_conn);
-			/* send it to dispatcher */
-			BSSAP.send(ts_BSSAP_DATA_req(conn_id, bssap));
-			}
-
-		[g_ran_ops.role_ms] CLIENT.receive(PDU_DTAP_MO:?) -> value dtap_mo sender vc_conn {
-			var integer idx := f_idx_by_comp(vc_conn);
-			/* convert from decoded DTAP to encoded DTAP */
-			var octetstring l3_enc := enc_PDU_ML3_MS_NW(dtap_mo.dtap);
-			/* patch correct L3 send sequence number N(SD) into l3_enc */
-			if (dtap_mo.skip_seq_patching == false) {
-				f_ML3_patch_seq(ConnectionTable[idx], dtap_mo.dtap, l3_enc);
-			}
-			bssap := valueof(ts_BSSAP_DTAP(l3_enc, dtap_mo.dlci));
-			BSSAP.send(ts_BSSAP_DATA_req(ConnectionTable[idx].sccp_conn_id, bssap));
-			}
-
-		[not g_ran_ops.role_ms] CLIENT.receive(PDU_DTAP_MT:?) -> value dtap_mt sender vc_conn {
-			var integer conn_id := f_conn_id_by_comp(vc_conn);
-			/* convert from decoded DTAP to encoded DTAP */
-			var octetstring l3_enc := enc_PDU_ML3_NW_MS(dtap_mt.dtap);
-			bssap := valueof(ts_BSSAP_DTAP(l3_enc, dtap_mo.dlci));
-			BSSAP.send(ts_BSSAP_DATA_req(conn_id, bssap));
-			}
-
+private altstep as_main_mgcp() runs on RAN_Emulation_CT {
+#ifdef RAN_EMULATION_MGCP
+		var MgcpCommand mgcp_req;
+		var MgcpResponse mgcp_resp;
+		var RAN_ConnHdlr vc_conn;
 
 		/* Handling of MGCP in IPA SCCPLite case.  This predates 3GPP AoIP
 		 * and uses a MGCP session in parallel to BSSAP.  BSSAP uses CIC
@@ -710,7 +714,68 @@ function main(RanOps ops, charstring id) runs on RAN_Emulation_CT {
 			vc_conn := f_comp_by_mgcp_tid(mgcp_resp.line.trans_id);
 			CLIENT.send(mgcp_resp) to vc_conn;
 			}
+#else
+		[false] CLIENT.receive {}
+#endif
+}
+
+/* send a raw (encoded) L3 message over given SCCP connection */
+private function f_xmit_raw_l3(integer sccp_conn_id, OCT1 dlci, octetstring l3_enc) runs on RAN_Emulation_CT
+{
+	select (g_ran_ops.protocol) {
+#ifdef RAN_EMULATION_BSSAP
+	case (RAN_PROTOCOL_BSSAP) {
+		var PDU_BSSAP bssap;
+		bssap := valueof(ts_BSSAP_DTAP(l3_enc, dlci));
+		BSSAP.send(ts_BSSAP_DATA_req(sccp_conn_id, bssap));
+		}
+#endif
+	}
+}
+
+function main(RanOps ops, charstring id) runs on RAN_Emulation_CT {
+
+	g_ran_id := id;
+	g_ran_ops := ops;
+	f_conn_table_init();
+	f_expect_table_init();
+
+	if (isvalue(ops.sccp_addr_peer) and isvalue(ops.sccp_addr_local)) {
+		f_sleep(1.0);	/* HACK to wait for M3UA/ASP to be ACTIVE */
+		f_bssap_reset(ops.sccp_addr_peer, ops.sccp_addr_local);
+	}
+
+	while (true) {
+		var RAN_ConnHdlr vc_conn;
+		var PDU_DTAP_MO dtap_mo;
+		var PDU_DTAP_MT dtap_mt;
+		var RAN_ConnHdlr vc_hdlr;
+		var octetstring l3_info;
+		var hexstring imsi;
+		var OCT4 tmsi;
+
+		alt {
+		[g_ran_ops.protocol == RAN_PROTOCOL_BSSAP] as_main_bssap();
+
+		[g_ran_ops.role_ms] CLIENT.receive(PDU_DTAP_MO:?) -> value dtap_mo sender vc_conn {
+			var integer idx := f_idx_by_comp(vc_conn);
+			/* convert from decoded DTAP to encoded DTAP */
+			var octetstring l3_enc := enc_PDU_ML3_MS_NW(dtap_mo.dtap);
+			/* patch correct L3 send sequence number N(SD) into l3_enc */
+			if (dtap_mo.skip_seq_patching == false) {
+				f_ML3_patch_seq(ConnectionTable[idx], dtap_mo.dtap, l3_enc);
+			}
+			f_xmit_raw_l3(ConnectionTable[idx].sccp_conn_id, dtap_mo.dlci, l3_enc);
+			}
+
+		[not g_ran_ops.role_ms] CLIENT.receive(PDU_DTAP_MT:?) -> value dtap_mt sender vc_conn {
+			var integer idx := f_idx_by_comp(vc_conn);
+			/* convert from decoded DTAP to encoded DTAP */
+			var octetstring l3_enc := enc_PDU_ML3_NW_MS(dtap_mt.dtap);
+			f_xmit_raw_l3(ConnectionTable[idx].sccp_conn_id, dtap_mt.dlci, l3_enc);
+			}
 
+		[] as_main_mgcp();
 
 		[] PROC.getcall(RAN_register:{?,?}) -> param(l3_info, vc_hdlr) {
 			f_create_expect(l3_info, vc_hdlr);
@@ -727,11 +792,13 @@ function main(RanOps ops, charstring id) runs on RAN_Emulation_CT {
 	}
 }
 
+#ifdef RAN_EMULATION_MGCP
 private function f_mgcp_ep_extract_cic(charstring inp) return integer {
 	var charstring local_part := regexp(inp, "(*)@*", 0);
 	return hex2int(str2hex(local_part));
 
 }
+#endif
 
 /***********************************************************************
  * "Expect" Handling (mapping for expected incoming SCCP connections)
diff --git a/msc/BSC_ConnectionHandler.ttcn b/msc/BSC_ConnectionHandler.ttcn
index e408f829..11baf2ab 100644
--- a/msc/BSC_ConnectionHandler.ttcn
+++ b/msc/BSC_ConnectionHandler.ttcn
@@ -180,6 +180,7 @@ const RanOps BSC_RanOps := {
 	unitdata_cb := refers(BscUnitdataCallback),
 	decode_dtap := true,
 	role_ms := true,
+	protocol := RAN_PROTOCOL_BSSAP,
 	sccp_addr_local := omit,
 	sccp_addr_peer := omit
 }
diff --git a/msc/gen_links.sh b/msc/gen_links.sh
index a29118a8..e4e142ba 100755
--- a/msc/gen_links.sh
+++ b/msc/gen_links.sh
@@ -89,7 +89,7 @@ DIR=../library
 FILES="Misc_Helpers.ttcn General_Types.ttcn GSM_Types.ttcn Osmocom_Types.ttcn MNCC_Types.ttcn MNCC_EncDec.cc MNCC_CodecPort.ttcn mncc.h MNCC_Emulation.ttcn Osmocom_VTY_Functions.ttcn Native_Functions.ttcn Native_FunctionDefs.cc "
 FILES+="IPA_Types.ttcn IPA_Emulation.ttcnpp IPA_CodecPort.ttcn IPA_CodecPort_CtrlFunct.ttcn IPA_CodecPort_CtrlFunctDef.cc GSUP_Types.ttcn GSUP_Emulation.ttcn "
 FILES+="Osmocom_CTRL_Types.ttcn Osmocom_CTRL_Functions.ttcn Osmocom_CTRL_Adapter.ttcn L3_Templates.ttcn L3_Common.ttcn "
-FILES+="RAN_Emulation.ttcn BSSAP_CodecPort.ttcn BSSMAP_Templates.ttcn RAN_Adapter.ttcn MGCP_Types.ttcn MGCP_Templates.ttcn MGCP_CodecPort_CtrlFunct.ttcn MGCP_Emulation.ttcn "
+FILES+="RAN_Emulation.ttcnpp BSSAP_CodecPort.ttcn BSSMAP_Templates.ttcn RAN_Adapter.ttcnpp MGCP_Types.ttcn MGCP_Templates.ttcn MGCP_CodecPort_CtrlFunct.ttcn MGCP_Emulation.ttcn "
 FILES+="RTP_CodecPort.ttcn RTP_CodecPort_CtrlFunctDef.cc "
 FILES+="MGCP_CodecPort.ttcn MGCP_CodecPort_CtrlFunctDef.cc "
 FILES+="SMPP_CodecPort.ttcn SMPP_CodecPort_CtrlFunct.ttcn SMPP_CodecPort_CtrlFunctDef.cc SMPP_Emulation.ttcn SMPP_Templates.ttcn "
diff --git a/msc/regen_makefile.sh b/msc/regen_makefile.sh
index 5645fdde..091faf82 100755
--- a/msc/regen_makefile.sh
+++ b/msc/regen_makefile.sh
@@ -2,6 +2,6 @@
 
 FILES="*.ttcn *.ttcnpp SCCP_EncDec.cc  SCTPasp_PT.cc  TCCConversion.cc TCCInterface.cc UD_PT.cc MNCC_EncDec.cc IPL4asp_PT.cc IPL4asp_discovery.cc SDP_EncDec.cc RTP_EncDec.cc IPA_CodecPort_CtrlFunctDef.cc RTP_CodecPort_CtrlFunctDef.cc MGCP_CodecPort_CtrlFunctDef.cc TELNETasp_PT.cc Native_FunctionDefs.cc SMPP_EncDec.cc SMPP_CodecPort_CtrlFunctDef.cc MAP_EncDec.cc SS_EncDec.cc TCCEncoding.cc SGsAP_CodecPort_CtrlFunctDef.cc *.c *.asn"
 
-export CPPFLAGS_TTCN3="-DIPA_EMULATION_MGCP -DIPA_EMULATION_GSUP -DIPA_EMULATION_SCCP -DUSE_MTP3_DISTRIBUTOR"
+export CPPFLAGS_TTCN3="-DIPA_EMULATION_MGCP -DIPA_EMULATION_GSUP -DIPA_EMULATION_SCCP -DRAN_EMULATION_BSSAP -DRAN_EMULATION_MGCP -DUSE_MTP3_DISTRIBUTOR"
 
 ../regen-makefile.sh MSC_Tests.ttcn $FILES