mgw/MGCP_Test.ttcn

/* MGW (Media Gateway) test suite in TTCN-3
 * (C) 2017-2018 Harald Welte <laforge@gnumonks.org>
 * (C) 2018-2019 sysmocom - s.f.m.c. GmbH
 * 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 MGCP_Test {
	import from Osmocom_Types all;
	import from MGCP_Types all;
	import from MGCP_Templates all;
	import from SDP_Types all;
	import from MGCP_CodecPort all;
	import from MGCP_CodecPort_CtrlFunct all;
	import from RTP_CodecPort all;
	import from RTP_CodecPort_CtrlFunct all;
	import from RTP_Emulation all;
	import from IuUP_Emulation all;
	import from OSMUX_Types all;
	import from OSMUX_CodecPort all;
	import from OSMUX_CodecPort_CtrlFunct all;
	import from OSMUX_Emulation all;
	import from AMR_Types all;
	import from IPL4asp_Types all;
	import from General_Types all;
	import from Native_Functions all;
	import from IPCP_Types all;
	import from IP_Types all;
	import from Osmocom_VTY_Functions all;
	import from TELNETasp_PortType all;
	import from StatsD_Types all;
	import from StatsD_CodecPort all;
	import from StatsD_CodecPort_CtrlFunct all;
	import from StatsD_Checker all;
	import from Osmocom_CTRL_Functions all;
	import from Osmocom_CTRL_Types all;
	import from Osmocom_CTRL_Adapter all;

	const charstring c_mgw_domain := "mgw";
	const charstring c_mgw_ep_rtpbridge := "rtpbridge/";

	/* any variables declared in the component will be available to
	 * all functions that 'run on' the named component, similar to
	 * class members in C++ */
	type component dummy_CT extends StatsD_ConnHdlr, CTRL_Adapter_CT {
		port MGCP_CODEC_PT MGCP;
		var boolean initialized := false;
		var ConnectionId g_mgcp_conn_id := -1;
		var integer g_trans_id;

		var RTP_Emulation_CT vc_RTPEM[3];
		port RTPEM_CTRL_PT RTPEM[3];

		var OSMUX_Emulation_CT vc_OsmuxEM;
		port OsmuxEM_CTRL_PT OsmuxEM;

		port TELNETasp_PT MGWVTY;

		var StatsD_Checker_CT vc_STATSD;
	};

	function get_next_trans_id() runs on dummy_CT return MgcpTransId {
		var MgcpTransId tid := int2str(g_trans_id);
		g_trans_id := g_trans_id + 1;
		return tid;
	}

	/* all parameters declared here can be modified / overridden by
	 * the config file in the [MODULE_PARAMETERS] section. If no
	 * config file is used or the file doesn't specify them, the
	 * default values assigned below are used */
	modulepar {
		PortNumber mp_local_udp_port := 2727;
		charstring mp_local_ipv4 := "127.0.0.1";
		charstring mp_local_ipv6 := "::1";
		PortNumber mp_remote_udp_port := 2427;
		charstring mp_remote_ipv4 := "127.0.0.1";
		charstring mp_remote_ipv6 := "::1";
		PortNumber mp_local_rtp_port_base := 10000;
		PortNumber mp_local_osmux_port := 1985;
		PortNumber mp_mgw_statsd_port := 8125;
		PortNumber mp_mgw_ctrl_port := 4267;
		/* Maximum number of available endpoints in osmo-mgw.cfg ("number endpoints"): */
		integer	mp_num_endpoints := 300;
	}

	private function f_vty_enable_osmux(boolean osmux_on) runs on dummy_CT {
		/* Turn on conversion mode */
		f_vty_enter_config(MGWVTY);
		f_vty_transceive(MGWVTY, "mgcp");
		if (osmux_on) {
			f_vty_transceive(MGWVTY, "osmux on");
		} else {
			f_vty_transceive(MGWVTY, "osmux off");
		}
		f_vty_transceive(MGWVTY, "exit");
		f_vty_transceive(MGWVTY, "exit");

	}

	private function f_init_vty(boolean osmux_on) runs on dummy_CT {
		map(self:MGWVTY, system:MGWVTY);
		f_vty_set_prompts(MGWVTY);
		f_vty_transceive(MGWVTY, "enable");

		f_vty_enable_osmux(osmux_on);
	}

	private function f_rtpem_init(inout RTP_Emulation_CT comp_ref, integer i)
	runs on dummy_CT {
		comp_ref := RTP_Emulation_CT.create("RTPEM" & int2str(i));
		map(comp_ref:RTP, system:RTP);
		map(comp_ref:RTCP, system:RTCP);
		comp_ref.start(RTP_Emulation.f_main());
	}

	private function f_osmuxem_init(inout OSMUX_Emulation_CT comp_ref)
	runs on dummy_CT {
		comp_ref := OSMUX_Emulation_CT.create("OsmuxEM");
		map(comp_ref:OSMUX, system:OSMUX);
		comp_ref.start(OSMUX_Emulation.f_main());
	}

	/* initialization function, called by each test case at the
	 * beginning, but 'initialized' variable ensures its body is
	 * only executed once */
	private function f_init(template MgcpEndpoint ep := omit, boolean osmux_on := false) runs on dummy_CT {
		var Result res;
		var uint32_t ssrc;

		if (initialized == false) {
			initialized := true;

			/* some random number for the initial transaction id */
			g_trans_id := float2int(rnd()*65535.0);
			map(self:MGCP, system:MGCP_CODEC_PT);
			/* connect the MGCP test port using the given
			 * source/destionation ip/port and store the connection id in g_mgcp_conn_id
			 * */
			res := MGCP_CodecPort_CtrlFunct.f_IPL4_connect(MGCP, mp_remote_ipv4, mp_remote_udp_port, mp_local_ipv4, mp_local_udp_port, 0, { udp := {} });
			if (not ispresent(res.connId)) {
				setverdict(fail, "Could not connect MGCP, check your configuration");
				mtc.stop;
			}
			g_mgcp_conn_id := res.connId;

			for (var integer i := 0; i < sizeof(vc_RTPEM); i := i+1) {
				f_rtpem_init(vc_RTPEM[i], i);
				connect(vc_RTPEM[i]:CTRL, self:RTPEM[i]);
			}
			if (osmux_on) {
				f_osmuxem_init(vc_OsmuxEM);
				connect(vc_OsmuxEM:CTRL, self:OsmuxEM);
			}

			f_init_statsd("VirtCallAgent", vc_STATSD, mp_local_ipv4, mp_mgw_statsd_port);
			connect(self:STATSD_PROC, vc_STATSD:STATSD_PROC);

			f_statsd_reset();
		}

		f_ipa_ctrl_start_client(mp_remote_ipv4, mp_mgw_ctrl_port);

		if (isvalue(ep)) {
			/* do a DLCX on all connections of the EP */
			f_dlcx_ignore(valueof(ep));
		}

		f_init_vty(osmux_on);
	}

	testcase TC_selftest() runs on dummy_CT {
		const charstring c_auep := "AUEP 158663169 ds/e1-1/2@172.16.6.66 MGCP 1.0\r\n";
		const charstring c_mdcx3 := "MDCX 18983215 " & c_mgw_ep_rtpbridge & "1@" & c_mgw_domain & " MGCP 1.0\r\n";
		const charstring c_mdcx3_ret := "200 18983215 OK\r\n" &
						"I: 1\n" &
						"\n" &
						"v=0\r\n" &
						"o=- 1 23 IN IP4 0.0.0.0\r\n" &
						"s=-\r\n" &
						"c=IN IP4 0.0.0.0\r\n" &
						"t=0 0\r\n" &
						"m=audio 0 RTP/AVP 126\r\n" &
						"a=rtpmap:126 AMR/8000\r\n" &
						"a=ptime:20\r\n";
		const charstring c_mdcx4 :=	"MDCX 18983216 " & c_mgw_ep_rtpbridge & "1@" & c_mgw_domain & " MGCP 1.0\r\n" &
						"M: sendrecv\r" &
						"C: 2\r\n" &
						"I: 1\r\n" &
						"L: p:20, a:AMR, nt:IN\r\n" &
						"\n" &
						"v=0\r\n" &
						"o=- 1 23 IN IP4 0.0.0.0\r\n" &
						"s=-\r\n" &
						"c=IN IP4 0.0.0.0\r\n" &
						"t=0 0\r\n" &
						"m=audio 4441 RTP/AVP 99\r\n" &
						"a=rtpmap:99 AMR/8000\r\n" &
						"a=ptime:40\r\n";
		const charstring c_crcx510_ret := "510 23 FAIL\r\n"

		log(c_auep);
		log(dec_MgcpCommand(c_auep));

		log(c_mdcx3);
		log(dec_MgcpCommand(c_mdcx3));

		log(c_mdcx3_ret);
		log(dec_MgcpResponse(c_mdcx3_ret));

		log(c_mdcx4);
		log(dec_MgcpCommand(c_mdcx4));

		log(ts_CRCX("23", c_mgw_ep_rtpbridge & "42@" & c_mgw_domain, "sendrecv", '1234'H));
		log(enc_MgcpCommand(valueof(ts_CRCX("23", c_mgw_ep_rtpbridge & "42@" & c_mgw_domain, "sendrecv", '1234'H))));

		log(c_crcx510_ret);
		log(dec_MgcpResponse(c_crcx510_ret));
		log(dec_MgcpMessage(c_crcx510_ret));

		/* We didn't encounter any DTE, so pass the test */
		setverdict(pass);
	}

	/* CRCX test ideas:
	 * x without mandatory CallId
	 * - with forbidden parameters (e.g. Capabilities, PackageList, ...
	 * - CRCX with remote session description and without
	 *
	 * general ideas:
	 * x packetization != 20ms
	 * x invalid mode
	 * x unsupported mode (517)
	 * x bidirectional mode before RemoteConnDesc: 527
	 * - invalid codec
	 * x retransmission of same transaction
	 * - unsupported LocalConnectionOptions ("b", "a", "e", "gc", "s", "r", "k", ..)
	 */

	/* build a receive template for receiving a MGCP message. You
	 * pass the MGCP response template in, and it will generate an
	 * MGCP_RecvFrom template that can match the primitives arriving on the
	 * MGCP_CodecPort */
	function tr_MGCP_RecvFrom_R(template MgcpResponse resp) runs on dummy_CT return template MGCP_RecvFrom {
		var template MGCP_RecvFrom mrf := {
			connId := g_mgcp_conn_id,
			remName := mp_remote_ipv4,
			remPort := mp_remote_udp_port,
			locName := mp_local_ipv4,
			locPort := mp_local_udp_port,
			msg := { response := resp }
		}
		return mrf;
	}

	/* Send a MGCP request + receive a (matching!) response */
	function mgcp_transceive_mgw(template MgcpCommand cmd, template MgcpResponse resp := ?) runs on dummy_CT return MgcpResponse {
		var MgcpMessage msg := { command := valueof(cmd) };
		resp.line.trans_id := cmd.line.trans_id;
		var template MGCP_RecvFrom mrt := tr_MGCP_RecvFrom_R(resp);
		var MGCP_RecvFrom mrf;
		timer T := 5.0;

		MGCP.send(t_MGCP_Send(g_mgcp_conn_id, msg));
		T.start;
		alt {
			[] MGCP.receive(mrt) -> value mrf { }
			[] MGCP.receive(tr_MGCP_RecvFrom_R(?)) {
				setverdict(fail, "Response didn't match template");
				mtc.stop;
				}
			[] MGCP.receive { repeat; }
			[] T.timeout {
				setverdict(fail, "Timeout waiting for response to ", cmd);
				mtc.stop;
				}
		}
		T.stop;

		if (isbound(mrf) and isbound(mrf.msg) and ischosen(mrf.msg.response)) {
			return mrf.msg.response;
		} else {
			var MgcpResponse r := { line := { code := "999", trans_id := valueof(cmd.line.trans_id) } };
			return r;
		}
	}

	function extract_conn_id(MgcpResponse resp) return MgcpConnectionId {
		var integer i;
		for (i := 0; i < lengthof(resp.params); i := i + 1) {
			var MgcpParameter par := resp.params[i];
			if (par.code == "I") {
				return str2hex(par.val);
			}
		}
		setverdict(fail, "Could not find conn id for MgcpReponse");
		mtc.stop;
		return '00000000'H;
	}

	function f_dlcx(MgcpEndpoint ep, template MgcpResponseCode ret_code, template charstring ret_val,
			template MgcpCallId call_id := omit,
			template MgcpConnectionId conn_id := omit) runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var template MgcpResponse rtmpl := {
			line := {
				code := ret_code,
				string := ret_val
			},
			params := *,
			sdp := *
		};
		cmd := ts_DLCX(get_next_trans_id(), ep, call_id, conn_id);
		resp := mgcp_transceive_mgw(cmd, rtmpl);
	}

	/* Send DLCX and expect OK response */
	function f_dlcx_ok(MgcpEndpoint ep, template MgcpCallId call_id := omit,
			   template MgcpConnectionId conn_id := omit) runs on dummy_CT {
		f_dlcx(ep, ("200","250"), "OK", call_id, conn_id);
	}

	/* Send DLCX and accept any response */
	function f_dlcx_ignore(MgcpEndpoint ep, template MgcpCallId call_id := omit,
				template MgcpConnectionId conn_id := omit) runs on dummy_CT {
		f_dlcx(ep, ?, *, call_id, conn_id);
	}

	type record HostPort {
		charstring hostname,
		integer portnr optional
	}
	type record RtpOsmuxFlowData {
		boolean local_cid_sent, /* whther non wildcarded CID was already sent to MGW */
		MgcpOsmuxCID local_cid optional,
		MgcpOsmuxCID remote_cid optional,
		OsmuxemConfig cfg optional
	}
	type record RtpCodecDescr {
		uint7_t pt,
		charstring codec,
		charstring fmtp optional
	}
	type record RtpFlowData {
		HostPort em,	/* emulation side */
		HostPort mgw,	/* mgw side */
		MgcpConnectionId mgcp_conn_id optional,
		record of RtpCodecDescr codec_descr,
		RtpemConfig rtp_cfg optional,
		RtpOsmuxFlowData osmux
	}

	template RtpFlowData t_RtpFlow(charstring host_a, charstring host_b, uint7_t pt,
				       charstring codec, template charstring fmtp := omit) := {
		em := {
			hostname := host_a,
			portnr := omit
		},
		mgw := {
			hostname := host_b,
			portnr := omit
		},
		codec_descr := {{
			pt := pt,
			codec := codec,
			fmtp := fmtp
		}},
		osmux:= {
			local_cid_sent := false,
			local_cid := omit,
			remote_cid := omit,
			cfg := omit
		}
	}

	/* To be used with f_flow_create/modify... functions */
	function f_gen_sdp(RtpFlowData flow) runs on dummy_CT return SDP_Message {
		var template SDP_Message sdp;
		var SDP_fmt_list fmt_list := {};
		var SDP_attribute_list attributes := {};

		/* Add SDP RTMAP attributes (codec type, referenced by PT) */
		for (var integer i := 0; i < lengthof(flow.codec_descr); i := i + 1) {
			attributes := attributes & { valueof(ts_SDP_rtpmap(flow.codec_descr[i].pt,
				      flow.codec_descr[i].codec)) };
		}

		/* Add SDP PTIME attribute, regardless of which codec, the packet intervall remains the same */
		attributes := attributes & { valueof(ts_SDP_ptime(20)) };

		/* Add SDP FMTP attributes (codec parameters for each codec, referenced by PT) */
		for (var integer i := 0; i < lengthof(flow.codec_descr); i := i + 1) {
			if (isvalue(flow.codec_descr[i].fmtp) and flow.codec_descr[i].fmtp != "") {
				attributes := attributes & { valueof(ts_SDP_fmtp(flow.codec_descr[i].pt,
							     flow.codec_descr[i].fmtp)) };
			}
		}

		/* Final step: Generate SDP */
		for (var integer i := 0; i < lengthof(flow.codec_descr); i := i + 1) {
			fmt_list := fmt_list & {int2str(flow.codec_descr[i].pt)};
		}
		sdp := ts_SDP(flow.em.hostname, flow.em.hostname, "23", "42", flow.em.portnr, fmt_list, attributes);

		return valueof(sdp);
	}

	/* Generate a valid RTP emulation config from the payload type numbers configured in the flow description and
	 * the the default configuration of the RTP emulation module. */
	function f_gen_rtpem_config_from_flow(RtpFlowData flow) return RtpemConfig {
		var RtpemConfig rtp_cfg := c_RtpemDefaultCfg;

		for (var integer i := 0; i < lengthof(flow.codec_descr); i := i + 1) {
			var RtpemConfigPayload tx_cfg_payload;
			var RtpemConfigPayload rx_cfg_payload;

			tx_cfg_payload.payload_type := flow.codec_descr[i].pt;
			tx_cfg_payload.fixed_payload := c_RtpemDefaultCfg.tx_payloads[0].fixed_payload;
			rx_cfg_payload.payload_type := flow.codec_descr[i].pt;
			rx_cfg_payload.fixed_payload := c_RtpemDefaultCfg.rx_payloads[0].fixed_payload;

			rtp_cfg.tx_payloads := rtp_cfg.tx_payloads & {tx_cfg_payload};
			rtp_cfg.rx_payloads := rtp_cfg.rx_payloads & {rx_cfg_payload};
		}

		return rtp_cfg;
	}

	/* Create an RTP flow (bidirectional, or receive-only) */
	function f_flow_create(RTPEM_CTRL_PT pt, MgcpEndpoint ep, MgcpCallId call_id, charstring mode, inout RtpFlowData flow,
				boolean one_phase := true)
	runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;

		/* bind local RTP emulation socket */
		f_rtpem_bind(pt, flow.em.hostname, flow.em.portnr);

		/* configure rtp-emulation */
		if (ispresent(flow.rtp_cfg)) {
			f_rtpem_configure(pt, flow.rtp_cfg);
		} else {
			f_rtpem_configure(pt, f_gen_rtpem_config_from_flow(flow));
		}

		if (one_phase) {
			/* Connect flow to MGW using a CRCX that also contains an SDP
			 * part that tells the MGW where we are listening for RTP streams
			 * that come from the MGW. We get a fully working connection in
			 * one go. */

			cmd := ts_CRCX(get_next_trans_id(), ep, mode, call_id);
			cmd.sdp := f_gen_sdp(flow);

			resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);
			flow.mgcp_conn_id := extract_conn_id(resp);
			/* extract port number from response */
			flow.mgw.portnr :=
				resp.sdp.media_list[0].media_field.ports.port_number;
		} else {
			/* Create a half-open connection only. We do not tell the MGW
			 * where it can send RTP streams to us. This means this
			 * connection will only be able to receive but can not send
			 * data back to us. In order to turn the connection in a fully
			 * bi-directional one, a separate MDCX is needed. */

			cmd := ts_CRCX(get_next_trans_id(), ep, mode, call_id);
			resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);
			flow.mgcp_conn_id := extract_conn_id(resp);
			/* extract MGW-side port number from response */
			flow.mgw.portnr :=
				resp.sdp.media_list[0].media_field.ports.port_number;
		}
		/* finally, connect the emulation-side RTP socket to the MGW */
		f_rtpem_connect(pt, flow.mgw.hostname, flow.mgw.portnr);
	}

	/* Create an Osmux flow (bidirectional, or receive-only) */
	function f_flow_create_osmux(OsmuxEM_CTRL_PT pt, MgcpEndpoint ep, MgcpCallId call_id, charstring mode, inout RtpFlowData flow,
				boolean one_phase := true)
	runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var OsmuxTxHandle tx_hdl;
		var OsmuxRxHandle rx_hdl;
		var charstring cid_response;
		var OsmuxCID cid_resp_parsed

		/* bind local Osmux emulation socket */
		f_osmuxem_bind(pt, flow.em.hostname, flow.em.portnr);

		/* configure osmux-emulation */
		if (ispresent(flow.osmux.cfg)) {
			f_osmuxem_configure(pt, flow.osmux.cfg);
		} else {
			var OsmuxemConfig osmux_cfg := c_OsmuxemDefaultCfg;
			f_osmuxem_configure(pt, osmux_cfg);
			flow.osmux.cfg := osmux_cfg
		}

		if (one_phase) {
			/* Connect flow to MGW using a CRCX that also contains an SDP
			 * part that tells the MGW where we are listening for Osmux streams
			 * that come from the MGW. We get a fully working connection in
			 * one go. */
			if (flow.osmux.local_cid != -1) {
				/* We may still want to negotiate osmux CID later at MDCX */
				rx_hdl := c_OsmuxemDefaultRxHandle;
				rx_hdl.cid := flow.osmux.local_cid;
				f_osmuxem_register_rxhandle(pt, rx_hdl);
				flow.osmux.local_cid_sent := true;
			}
			cmd := ts_CRCX_osmux(get_next_trans_id(), ep, mode, call_id, flow.osmux.local_cid);
			cmd.sdp := f_gen_sdp(flow);
  			resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK_osmux);
			flow.mgcp_conn_id := extract_conn_id(resp);
			/* extract port number from response */
			flow.mgw.portnr :=
				resp.sdp.media_list[0].media_field.ports.port_number;
		} else {
			/* Create a half-open connection only. We do not tell the MGW
			 * where it can send Osmux streams to us. This means this
			 * connection will only be able to receive but can not send
			 * data back to us. In order to turn the connection in a fully
			 * bi-directional one, a separate MDCX is needed. */

			cmd := ts_CRCX_osmux(get_next_trans_id(), ep, mode, call_id, flow.osmux.local_cid);
			resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK_osmux);

			flow.mgcp_conn_id := extract_conn_id(resp);
			/* extract MGW-side port number from response */
			flow.mgw.portnr :=
				resp.sdp.media_list[0].media_field.ports.port_number;
		}

		/* extract Osmux CID we got assigned by the MGW */
		var MgcpMessage resp_msg := {
			response := resp
		}

		if (f_mgcp_find_param(resp_msg, "X-OSMUX", cid_response) == false) {
			setverdict(fail, "No Osmux CID in MGCP response", resp);
			mtc.stop;
		}

		/* Make sure response is no wildcard */
		flow.osmux.remote_cid := f_mgcp_osmux_cid_decode(cid_response);
		if (flow.osmux.remote_cid == -1) {
			setverdict(fail, "Osmux CID in MGCP response contains unexpected wildcard");
			mtc.stop;
		}
		tx_hdl := valueof(t_TxHandleAMR590(flow.osmux.remote_cid));
		f_osmuxem_register_txhandle(pt, tx_hdl);

		/* finally, connect the emulation-side RTP socket to the MGW */
		f_osmuxem_connect(pt, flow.mgw.hostname, flow.mgw.portnr);
	}

	/* Modify an existing RTP flow */
	function f_flow_modify(RTPEM_CTRL_PT pt, MgcpEndpoint ep, MgcpCallId call_id, charstring mode, inout RtpFlowData flow)
	runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;

		/* rebind local RTP emulation socket to the new address */
		f_rtpem_bind(pt, flow.em.hostname, flow.em.portnr);

		/* reconfigure rtp-emulation */
		if (ispresent(flow.rtp_cfg)) {
			f_rtpem_configure(pt, flow.rtp_cfg);
		} else {
			f_rtpem_configure(pt, f_gen_rtpem_config_from_flow(flow));
		}

		/* connect MGW side RTP socket to the emulation-side RTP socket using SDP */
		cmd := ts_MDCX(get_next_trans_id(), ep, mode, call_id, flow.mgcp_conn_id);
		cmd.sdp := f_gen_sdp(flow);
		resp := mgcp_transceive_mgw(cmd, tr_MDCX_ACK);

		/* extract MGW-side port number from response. (usually this
		 * will not change, but thats is up to the MGW) */
		flow.mgw.portnr :=
			resp.sdp.media_list[0].media_field.ports.port_number;

		/* reconnect the emulation-side RTP socket to the MGW */
		f_rtpem_connect(pt, flow.mgw.hostname, flow.mgw.portnr);
	}

	/* Modify an existing Osmux flow */
	function f_flow_modify_osmux(OsmuxEM_CTRL_PT pt, MgcpEndpoint ep, MgcpCallId call_id, charstring mode, inout RtpFlowData flow)
	runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var OsmuxRxHandle rx_hdl;
		var charstring cid_response;
		var OsmuxCID cid_resp_parsed

		/* rebind local Osmux emulation socket to the new address */
		f_osmuxem_bind(pt, flow.em.hostname, flow.em.portnr);

		/* configure osmux-emulation */
		if (ispresent(flow.osmux.cfg)) {
			f_osmuxem_configure(pt, flow.osmux.cfg);
		} else {
			var OsmuxemConfig osmux_cfg := c_OsmuxemDefaultCfg;
			f_osmuxem_configure(pt, osmux_cfg);
		}

		/* We didn't send a non-wildcarded Osmux CID yet. If caller wants to submit it, register handler */
		if (flow.osmux.local_cid_sent == false and flow.osmux.local_cid != -1) {
			rx_hdl := c_OsmuxemDefaultRxHandle;
			rx_hdl.cid := flow.osmux.local_cid;
			f_osmuxem_register_rxhandle(pt, rx_hdl);
			flow.osmux.local_cid_sent := true;
		}

		/* connect MGW side Osmux socket to the emulation-side Osmux socket using SDP */
		cmd := ts_MDCX_osmux(get_next_trans_id(), ep, mode, call_id, flow.mgcp_conn_id, flow.osmux.local_cid);
		cmd.sdp := f_gen_sdp(flow);
		resp := mgcp_transceive_mgw(cmd, tr_MDCX_ACK);

		/* extract MGW-side port number from response. (usually this
		 * will not change, but thats is up to the MGW) */
		flow.mgw.portnr :=
			resp.sdp.media_list[0].media_field.ports.port_number;

		/* extract Osmux CID we got assigned by the MGW */
		var MgcpMessage resp_msg := {
			response := resp
		}

		if (f_mgcp_find_param(resp_msg, "X-OSMUX", cid_response) == false) {
			setverdict(fail, "No Osmux CID in MGCP response", resp);
			mtc.stop;
		}

		/* Make sure response is no wildcard */
		cid_resp_parsed := f_mgcp_osmux_cid_decode(cid_response);
		if (cid_resp_parsed == -1) {
			setverdict(fail, "Osmux CID in MGCP response contains unexpected wildcard");
			mtc.stop;
		}
		if (cid_resp_parsed != flow.osmux.remote_cid) {
			setverdict(fail, "Osmux CID in MGCP MDCX response changed from prev value");
			mtc.stop;
		}

		/* reconnect the emulation-side Osmux socket to the MGW */
		f_osmuxem_connect(pt, flow.mgw.hostname, flow.mgw.portnr);
	}

	/* Delete an existing RTP flow */
	function f_flow_delete(RTPEM_CTRL_PT pt, template MgcpEndpoint ep := omit, template MgcpCallId call_id := omit)
	runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;

		/* Switch off RTP flow */
		f_rtpem_mode(pt, RTPEM_MODE_NONE);

		/* Delete connection on MGW (if needed) */
		if (isvalue(call_id) and isvalue(ep)) {
			f_sleep(0.1);
			f_dlcx_ok(valueof(ep), call_id);
		}
	}

	/* Delete an existing Osmux flow */
	function f_flow_delete_osmux(OsmuxEM_CTRL_PT pt, template MgcpEndpoint ep := omit, template MgcpCallId call_id := omit)
	runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;

		/* Switch off Osmux flow */
		f_osmuxem_mode(pt, OSMUXEM_MODE_NONE);

		/* Delete connection on MGW (if needed) */
		if (isvalue(call_id) and isvalue(ep)) {
			f_sleep(0.1);
			f_dlcx_ok(valueof(ep), call_id);
		}
	}

	function f_crcx(charstring ep_prefix) runs on dummy_CT {
		var MgcpEndpoint ep := ep_prefix & "2@" & c_mgw_domain;
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpCallId call_id := '1234'H;

		f_init(ep);

		/* create the connection on the MGW */
		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);
		extract_conn_id(resp);

		/* clean-up */
		f_dlcx_ok(ep, call_id);
	}

	function f_crcx_no_lco(charstring ep_prefix) runs on dummy_CT {
		var MgcpEndpoint ep := ep_prefix & "2@" & c_mgw_domain;
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpCallId call_id := '1234'H;

		f_init(ep);

		/* create the connection on the MGW */
		cmd := ts_CRCX_no_lco(get_next_trans_id(), ep, "recvonly", call_id);
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);
		extract_conn_id(resp);

		/* clean-up */
		f_dlcx_ok(ep, call_id);

		/* See also OS#2658: Even when we omit the LCO information, we
		   expect the MGW to pick a sane payload type for us. This
		   payload type should be visible in the SDP of the response. */
		if (resp.sdp.media_list[0].media_field.fmts[0] != "0") {
			setverdict(fail, "SDP contains unexpected codec");
			mtc.stop;
		}

		/* See also OS#2658: We also expect the MGW to assign a port
		   number to us. */
		if (isbound(resp.sdp.media_list[0].media_field.ports.port_number) == false) {
			setverdict(fail, "SDP does not contain a port number");
			mtc.stop;
		}
	}

	function f_crcx_osmux(charstring ep_prefix, MgcpOsmuxCID osmux_cid, boolean run_init := true) runs on dummy_CT {
		var MgcpEndpoint ep := ep_prefix & "2@" & c_mgw_domain;
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpCallId call_id := '1234'H;
		var charstring cid_response;

		if (run_init) {
			f_init(ep, true);
		}

		/* create the connection on the MGW */
		cmd := ts_CRCX_osmux(get_next_trans_id(), ep, "recvonly", call_id, osmux_cid);
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK_osmux);
		extract_conn_id(resp);

		/* extract Osmux CID we got assigned by the MGW */
		var MgcpMessage resp_msg := {
			response := resp
		}

		if (f_mgcp_find_param(resp_msg, "X-OSMUX", cid_response) == false) {
			setverdict(fail, "No Osmux CID in MGCP response", resp);
			mtc.stop;
		}

		/* Make sure response is no wildcard */
		if (f_mgcp_osmux_cid_decode(cid_response) == -1) {
			setverdict(fail, "Osmux CID in MGCP response contains unexpected wildcard");
			mtc.stop;
		}

		/* clean-up */
		f_dlcx_ok(ep, call_id);
	}

	/* test valid CRCX without SDP */
	testcase TC_crcx() runs on dummy_CT {
		f_crcx(c_mgw_ep_rtpbridge);
		setverdict(pass);
	}

	/* test valid CRCX without SDP and LCO */
	testcase TC_crcx_no_lco() runs on dummy_CT {
		f_crcx_no_lco(c_mgw_ep_rtpbridge);
		setverdict(pass);
	}

	/* test valid CRCX without SDP (older method without endpoint prefix) */
	testcase TC_crcx_noprefix() runs on dummy_CT {
		f_crcx("");
		setverdict(pass);
	}

	/* test CRCX with unsupported mode, expect 517 */
	testcase TC_crcx_unsupp_mode() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var MgcpCallId call_id := '1233'H;
		var template MgcpResponse rtmpl := tr_MgcpResp_Err("517");

		f_init(ep);

		cmd := ts_CRCX(get_next_trans_id(), ep, "netwtest", call_id);
		resp := mgcp_transceive_mgw(cmd, rtmpl);
		setverdict(pass);
	}

	/* Test CRCX with X-Osmo-IGN, using same message as SYS#5063 to make sure it doesn't cause a crash. */
	testcase TC_crcx_osmo_ign() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := "7@" & c_mgw_domain;
		var MgcpCallId call_id := '3'H;

		f_init(ep);

		/* CRCX 1 7@mgw MGCP 1.0
		C: 3
		L: p:20, a:GSM-EFR, nt:IN
		M: recvonly
		X-Osmo-IGN: C
		*/

		cmd := ts_CRCX(get_next_trans_id(), ep, "netwtest", call_id);
		cmd.params := {ts_MgcpParCallId(call_id),
			       t_MgcpParLocConnOpt("p:20, a:GSM-EFR, nt:IN"),
			       t_MgcpParConnMode("recvonly"),
			       t_MgcpParOsmoIGN("C")};
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);
		extract_conn_id(resp);

		/* clean-up */
		f_dlcx_ok(ep, call_id);
		setverdict(pass);
	}

	/* test CRCX with early bi-directional mode, expect 527 as
	 * bi-diretional media can only  be established once both local and
	 * remote side are specified, see MGCP RFC */
	testcase TC_crcx_early_bidir_mode() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var MgcpCallId call_id := '1232'H;
		var template MgcpResponse rtmpl := tr_MgcpResp_Err("527");

		f_init(ep);

		cmd := ts_CRCX(get_next_trans_id(), ep, "sendrecv", call_id);
		resp := mgcp_transceive_mgw(cmd, rtmpl);
		setverdict(pass);
	}

	/* test CRCX with unsupported Parameters */
	testcase TC_crcx_unsupp_param() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var MgcpCallId call_id := '1231'H;
		var template MgcpResponse rtmpl := tr_MgcpResp_Err("539");

		f_init(ep);

		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
		/* osmo-bsc_mgcp/mgw doesn't implement notifications */
		f_mgcp_par_append(cmd.params, MgcpParameter:{ "N", "foobar" });

		resp := mgcp_transceive_mgw(cmd, rtmpl);
		setverdict(pass);
	}

	/* test CRCX with missing CallId */
	testcase TC_crcx_missing_callid() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var template MgcpResponse rtmpl := tr_MgcpResp_Err(("400","516"));

		f_init(ep);

		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", '1230'H);
		cmd.params := {
			t_MgcpParConnMode("recvonly"),
			t_MgcpParLocConnOpt("p:20")
		}
		resp := mgcp_transceive_mgw(cmd, rtmpl);
		setverdict(pass);

	}

	/* test CRCX with missing Mode */
	testcase TC_crcx_missing_mode() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var MgcpCallId call_id := '1229'H;
		var template MgcpResponse rtmpl := tr_MgcpResp_Err(("400","517"));

		f_init(ep);

		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
		cmd.params := {
			ts_MgcpParCallId(call_id),
			t_MgcpParLocConnOpt("p:20")
		}
		resp := mgcp_transceive_mgw(cmd, rtmpl);
		setverdict(pass);
	}

	/* test CRCX with unsupported packetization interval */
	testcase TC_crcx_unsupp_packet_intv() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var MgcpCallId call_id := '1228'H;
		var template MgcpResponse rtmpl := tr_MgcpResp_Err("535");

		f_init(ep);

		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
		cmd.params[2] := t_MgcpParLocConnOpt("p:111");
		resp := mgcp_transceive_mgw(cmd, rtmpl);
		setverdict(pass);
	}

	/* test CRCX with illegal double presence of local connection option */
	testcase TC_crcx_illegal_double_lco() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var MgcpCallId call_id := '1227'H;
		var template MgcpResponse rtmpl := tr_MgcpResp_Err("524");

		f_init(ep);

		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
		/* p:20 is permitted only once and not twice! */
		cmd.params[2] := t_MgcpParLocConnOpt("p:20, a:AMR, p:20");
		resp := mgcp_transceive_mgw(cmd, rtmpl);
		setverdict(pass);
	}

	/* test valid CRCX with valid SDP */
	testcase TC_crcx_sdp() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var MgcpCallId call_id := '1226'H;

		f_init(ep);

		cmd := ts_CRCX(get_next_trans_id(), ep, "sendrecv", call_id);
		cmd.sdp := ts_SDP("127.0.0.1", "127.0.0.2", "23", "42", 2344, { "98" },
				  { valueof(ts_SDP_rtpmap(98, "AMR/8000")),
				    valueof(ts_SDP_ptime(20)) });
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);

		/* clean-up */
		f_dlcx_ok(ep, call_id);

		setverdict(pass);
	}

	/* test valid wildcarded CRCX */
	testcase TC_crcx_wildcarded() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "*@" & c_mgw_domain;
		var MgcpCallId call_id := '1234'H;
		var MgcpEndpoint ep_assigned;
		f_init();

		/* create the connection on the MGW */
		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);
		extract_conn_id(resp);

		/* extract endpoint name we got assigned by the MGW */
		var MgcpMessage resp_msg := {
			response := resp
		}
		if (f_mgcp_find_param(resp_msg, "Z", ep_assigned) == false) {
			setverdict(fail, "No SpecificEndpointName in MGCP response", resp);
			mtc.stop;
		}

		/* clean-up */
		f_dlcx_ok(ep_assigned, call_id);

		setverdict(pass);
	}

	/* test valid wildcarded CRCX */
	type record of MgcpEndpoint MgcpEndpointList;
	testcase TC_crcx_wildcarded_exhaust() runs on dummy_CT {
		var integer i;
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "*@" & c_mgw_domain;
		var MgcpCallId call_id := '1234'H;
		var MgcpEndpoint ep_assigned;
		var MgcpEndpointList ep_assigned_li := {};
		f_init();

		/* Exhaust all endpoint resources on the virtual trunk */
		for (i := 0; i < mp_num_endpoints; i := i+1) {
			cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
			resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);

			/* Make sure we got a connection id */
			extract_conn_id(resp);

			var MgcpMessage resp_msg := {
			    response := resp
			}
			if (f_mgcp_find_param(resp_msg, "Z", ep_assigned) == false) {
				setverdict(fail, "No SpecificEndpointName in MGCP response", resp);
				mtc.stop;
			}
			ep_assigned_li := ep_assigned_li & {ep_assigned}
		}

		/* Try to allocate one more endpoint, which should fail */
		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
		var template MgcpResponse rtmpl := tr_MgcpResp_Err("403");
		resp := mgcp_transceive_mgw(cmd, rtmpl);
		setverdict(pass);

		/* clean-up */
		for (i := 0; i < mp_num_endpoints; i := i+1) {
		    f_dlcx_ok(ep_assigned_li[i], call_id);
		}
		setverdict(pass);
	}

	/* TODO: various SDP related bits */


	/* TODO: CRCX with X-Osmux */
	/* TODO: double CRCX without force_realloc */

	/* TODO: MDCX (various) */

	/* TODO: MDCX without CRCX first */
	testcase TC_mdcx_without_crcx() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "3@" & c_mgw_domain;
		var MgcpCallId call_id := '1225'H;
		var template MgcpResponse rtmpl := {
			line := {
				/* TODO: accept/enforce better error? */
				code := "400",
				string := ?
			},
			params:= { },
			sdp := omit
		};

		f_init(ep);

		cmd := ts_MDCX(get_next_trans_id(), ep, "sendrecv", call_id, call_id);
		cmd.sdp := ts_SDP("127.0.0.1", "127.0.0.2", "23", "42", 2344, { "98" },
				  { valueof(ts_SDP_rtpmap(98, "AMR/8000")),
				    valueof(ts_SDP_ptime(20)) });
		resp := mgcp_transceive_mgw(cmd, rtmpl);
		setverdict(pass);
	}

	/* DLCX without CRCX first */
	testcase TC_dlcx_without_crcx() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "4@" & c_mgw_domain;
		var template MgcpResponse rtmpl := {
			line := {
				code := ("400", "515"),
				string := ?
			},
			params:= { },
			sdp := omit
		};

		f_init(ep);

		cmd := ts_DLCX(get_next_trans_id(), ep, '41234'H);
		resp := mgcp_transceive_mgw(cmd, rtmpl);
		setverdict(pass);
	}

	/* DLCX to non existing endpoint */
	testcase TC_dlcx_non_existant_ep() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var charstring non_existant_ep := hex2str(int2hex(mp_num_endpoints + 1, 4))
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & non_existant_ep & "@" & c_mgw_domain;
		var template MgcpResponse rtmpl := {
			line := {
				code := ("500"),
				string := ?
			},
			params:= { },
			sdp := omit
		};

		f_init(ep);

		cmd := ts_DLCX(get_next_trans_id(), ep, '41234'H);
		resp := mgcp_transceive_mgw(cmd, rtmpl);
		setverdict(pass);
	}

	/* test valid wildcarded MDCX */
	testcase TC_mdcx_wildcarded() runs on dummy_CT {
		 /* Note: A wildcarded MDCX is not allowed, so we expect the
		  * MGW to reject this request */
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "*@" & c_mgw_domain;
		var MgcpCallId call_id := '1225'H;
		var template MgcpResponse rtmpl := {
			line := {
				/* TODO: accept/enforce better error? */
				code := "507",
				string := ?
			},
			params:= { },
			sdp := omit
		};

		f_init(ep);

		cmd := ts_MDCX(get_next_trans_id(), ep, "sendrecv", call_id, call_id);
		cmd.sdp := ts_SDP("127.0.0.1", "127.0.0.2", "23", "42", 2344, { "98" },
				  { valueof(ts_SDP_rtpmap(98, "AMR/8000")),
				    valueof(ts_SDP_ptime(20)) });
		resp := mgcp_transceive_mgw(cmd, rtmpl);
		setverdict(pass);
	}

	/* test valid wildcarded DLCX */
	testcase TC_dlcx_wildcarded() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "*@" & c_mgw_domain;
		var integer i;
		var MgcpCallId call_id := '1234'H;
		var StatsDExpects expect;
		f_init(ep);

		/* Allocate a few endpoints */
		for (i := 0; i < mp_num_endpoints; i := i+1) {
			cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
			resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);
		}

		/* Wait until the stats items have seteled and then check if we get the expected number (all) of
		 * occupied endpoints */
		f_sleep(1.0)
		expect := {
			{ name := "TTCN3.trunk.virtual-0.common.endpoints.used", mtype := "g", min := mp_num_endpoints, max := mp_num_endpoints}
		};
		f_statsd_expect(expect);

		/* Send wildcarded DLCX */
		var template MgcpResponse rtmpl := {
			line := {
				code := "200",
				string := ?
			},
			params:= { },
			sdp := omit
		};
		cmd := ts_DLCX(get_next_trans_id(), ep);
		mgcp_transceive_mgw(cmd, rtmpl);

		/* Query a the statsd once to ensure that intermediate results are pulled from the
		 * pipeline. The second query (below) will return the actual result. */
		expect := {
			{ name := "TTCN3.trunk.virtual-0.common.endpoints.used", mtype := "g", min := 0, max := mp_num_endpoints}
		};
		f_statsd_expect(expect);

		/* The second query must resturn a result with 0 endpoints in use. */
		expect := {
			{ name := "TTCN3.trunk.virtual-0.common.endpoints.used", mtype := "g", min := 0, max := 0}
		};
		f_statsd_expect(expect);

		setverdict(pass);
	}

	/* Test (valid) CRCX followed by (valid) DLCX containig EP+CallId+ConnId */
	testcase TC_crcx_and_dlcx_ep_callid_connid() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "5@" & c_mgw_domain;
		var MgcpCallId call_id := '51234'H;

		f_init(ep);

		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);

		f_dlcx_ok(ep, call_id, extract_conn_id(resp));

		setverdict(pass);
	}

	/* test valid CRCX without SDP */
	testcase TC_crcx_osmux_wildcard() runs on dummy_CT {
		f_crcx_osmux(c_mgw_ep_rtpbridge, -1);
		setverdict(pass);
	}

	/* test valid CRCX without SDP */
	testcase TC_crcx_osmux_fixed() runs on dummy_CT {
		f_crcx_osmux(c_mgw_ep_rtpbridge, 2);
		setverdict(pass);
	}

	/* test valid CRCX without SDP, twice, to make sure CID is freed fine during first step. */
	testcase TC_crcx_osmux_fixed_twice() runs on dummy_CT {
		f_crcx_osmux(c_mgw_ep_rtpbridge, 3, true);
		f_crcx_osmux(c_mgw_ep_rtpbridge, 3, false);
		setverdict(pass);
	}

	/* test Creating 257 concurrent osmux conns. It should fail since maximum is 256. */
	testcase TC_crcx_osmux_257() runs on dummy_CT {
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "*@" & c_mgw_domain;
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var charstring cid_response;
		var integer i;

		f_init(ep, true);

		for (i := 0; i < 256; i := i + 1) {

			cmd := ts_CRCX_osmux(get_next_trans_id(), ep, "recvonly", int2hex(i, 4), -1);
			resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK_osmux);
			extract_conn_id(resp);

			/* extract Osmux CID we got assigned by the MGW */
			var MgcpMessage resp_msg := {
				response := resp
			}

			if (f_mgcp_find_param(resp_msg, "X-OSMUX", cid_response) == false) {
				setverdict(fail, "No Osmux CID in MGCP response", resp);
				mtc.stop;
			}

			/* Make sure response is no wildcard */
			if (f_mgcp_osmux_cid_decode(cid_response) == -1) {
				setverdict(fail, "Osmux CID in MGCP response contains unexpected wildcard");
				mtc.stop;
			}
		}

		/* Now conn num 257, it should fail due to all Osmux conns already allocated: */
		cmd := ts_CRCX_osmux(get_next_trans_id(), ep, "recvonly", int2hex(i, 4), -1);
		resp := mgcp_transceive_mgw(cmd, tr_MgcpResp_Err("400"));

		setverdict(pass);

		/* Clean up */
		for (i := 0; i < 256; i := i + 1) {
			f_dlcx_ok(ep, int2hex(i, 4));
		}
	}

	/* Create one half open connection in receive-only mode. The MGW must accept
	 * the packets but must not send any. */
	testcase TC_one_crcx_receive_only_osmux() runs on dummy_CT {
		var RtpFlowData flow;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "1@" & c_mgw_domain;
		var MgcpCallId call_id := '1225'H;
		var OsmuxemStats stats;
		var OsmuxTxHandle tx_hdl;

		f_init(ep, true);
		flow := valueof(t_RtpFlow(mp_local_ipv4, mp_remote_ipv4, 112, "AMR/8000/1"));
		flow.em.portnr := mp_local_osmux_port;
		flow.osmux.local_cid := -1;
		f_flow_create_osmux(OsmuxEM, ep, call_id, "recvonly", flow, false);

		/* create a transmitter not yet known by MGW */
		tx_hdl := valueof(t_TxHandleAMR590(2));
		f_osmuxem_register_txhandle(OsmuxEM, tx_hdl);

		f_osmuxem_mode(OsmuxEM, OSMUXEM_MODE_TXONLY);
		f_sleep(1.0);
		f_flow_delete_osmux(OsmuxEM, ep, call_id);

		stats := f_osmuxem_stats_get(OsmuxEM);

		if (stats.num_pkts_tx < 40 / flow.osmux.cfg.batch_size) {
			setverdict(fail);
		}
		if (stats.bytes_payload_tx < stats.num_pkts_tx * f_amrft_payload_len(tx_hdl.amr_ft) * flow.osmux.cfg.batch_size) {
			setverdict(fail);
		}

		f_osmuxem_stats_err_check(stats);

		setverdict(pass);
	}

	/* Create one connection in loopback mode, test if the Osmux packets are
	 * actually reflected */
	testcase TC_one_crcx_loopback_osmux() runs on dummy_CT {
		var RtpFlowData flow;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "1@" & c_mgw_domain;
		var MgcpCallId call_id := '1225'H;
		var OsmuxemStats stats;
		var OsmuxTxHandle tx_hdl;

		f_init(ep, true);
		flow := valueof(t_RtpFlow(mp_local_ipv4, mp_remote_ipv4, 111, "GSM-HR-08/8000/1"));
		flow.em.portnr := mp_local_osmux_port;
		flow.osmux.local_cid := 2;
		f_flow_create_osmux(OsmuxEM, ep, call_id, "loopback", flow);

		f_osmuxem_mode(OsmuxEM, OSMUXEM_MODE_BIDIR);
		f_sleep(1.0);

		/* Switch off both Tx, wait to receive delayed frames from MGW */
		f_osmuxem_mode(OsmuxEM, OSMUXEM_MODE_RXONLY);
		f_sleep(0.1);
		f_flow_delete_osmux(OsmuxEM, ep, call_id);

		stats := f_osmuxem_stats_get(OsmuxEM);

		if (stats.num_pkts_tx != stats.num_pkts_rx) {
			setverdict(fail);
		}
		if (stats.bytes_payload_tx != stats.bytes_payload_rx) {
			setverdict(fail);
		}

		f_osmuxem_stats_err_check(stats);

		setverdict(pass);
	}

	/* Cross-compare two osmuxem-statistics. The transmission statistics on the a side
	 * must match the reception statistics on the other side and vice versa. The
	 * user may also supply a tolerance value (number of packets) when deviations
	 * are acceptable */
	function f_rtp_osmux_stats_compare(RtpemStats a, OsmuxemStats b, integer batch_size, integer tolerance := 0) return boolean {
		var integer plen;

		log("stats A: ", a);
		log("stats B: ", b);
		log("tolerance: ", tolerance, " packets");
		log("batch_size: ", batch_size, " packets");

		var integer tolerance_batch := tolerance + (batch_size - tolerance mod batch_size);

		if (f_osmuxem_stats_compare_value(a.num_pkts_tx, b.num_pkts_rx * batch_size, tolerance_batch) == false) {
			return false;
		}

		if (f_osmuxem_stats_compare_value(a.num_pkts_rx / batch_size, b.num_pkts_tx, tolerance_batch) == false) {
			return false;
		}

		if(a.num_pkts_tx > 0) {
			plen := a.bytes_payload_tx / a.num_pkts_tx;
		} else {
			plen := 0;
		}

		/* Each RTP pcket payload contains 2 extra bytes due to AMR ToC at start */
		if (f_osmuxem_stats_compare_value(a.bytes_payload_tx, b.bytes_payload_rx + a.num_pkts_tx * 2, tolerance_batch * plen) == false) {
			log("incorrect payload A->B: " , a.bytes_payload_tx, " vs ", b.bytes_payload_rx + a.num_pkts_rx * 2);
			return false;
		}

		if (f_osmuxem_stats_compare_value(a.bytes_payload_rx, b.bytes_payload_tx + b.num_pkts_tx * 2 * batch_size, tolerance_batch * plen) == false) {
			log("incorrect payload B->A: " ,  b.bytes_payload_tx + b.num_pkts_tx * 2 * batch_size, " vs ", a.bytes_payload_rx);
			return false;
		}

		return true;
	}

	function f_TC_two_crcx_and_rtp_osmux(boolean bidir, boolean rtp_amr_oa,
					     charstring local_ip_rtp, charstring remote_ip_rtp,
					     charstring local_ip_osmux, charstring remote_ip_osmux) runs on dummy_CT {
		var RtpFlowData flow[2];
		var RtpemStats stats_rtp;
		var OsmuxemStats stats_osmux;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var MgcpCallId call_id := '1226'H;
		var integer tolerance := 0;

		var octetstring amr_payload;
		var charstring fmtp;

		f_init(ep, true);

		var AMRFT cmr := AMR_FT_0;
		var AMRFT ft := AMR_FT_2;
		if (rtp_amr_oa) {
			fmtp := "octet-align=1";
			var RTP_AMR_Hdr amr_oa_hdr := valueof(ts_RTP_AMR_Hdr(enum2int(cmr), enum2int(ft)));
			amr_payload := enc_RTP_AMR_Hdr(amr_oa_hdr) &
				       f_osmux_gen_expected_rx_rtp_payload(enum2int(ft), c_OsmuxemDefaultCfg.tx_fixed_payload);
		} else {
			fmtp := "octet-align=0";
			/* Convert OA to BWE: */
			var RTP_AMR_BWE_Hdr amr_bwe_hdr := valueof(ts_RTP_AMR_BWE_Hdr(enum2int(cmr), enum2int(ft)));
			var bitstring amr_bwe_hdr_bits := substr(oct2bit(enc_RTP_AMR_BWE_Hdr(amr_bwe_hdr)), 0 , 10);
			var bitstring amr_data_bits := oct2bit(f_osmux_gen_expected_rx_rtp_payload(enum2int(ft), c_OsmuxemDefaultCfg.tx_fixed_payload));
			var bitstring amr_payload_bits := amr_bwe_hdr_bits & substr(amr_data_bits, 0, f_amrft_payload_bits_len(enum2int(ft)));
			amr_payload := bit2oct(f_pad_bit(amr_payload_bits, (lengthof(amr_payload_bits)+7)/8*8, '0'B));
		};

		/* from us to MGW */
		flow[0] := valueof(t_RtpFlow(local_ip_rtp, remote_ip_rtp, 112, "AMR/8000", fmtp));
		flow[0].rtp_cfg := c_RtpemDefaultCfg
		flow[0].rtp_cfg.rx_payloads[0].payload_type := flow[0].codec_descr[0].pt;
		flow[0].rtp_cfg.rx_payloads[0].fixed_payload := amr_payload;
		flow[0].rtp_cfg.tx_payloads[0].payload_type := flow[0].codec_descr[0].pt;
		flow[0].rtp_cfg.tx_payloads[0].fixed_payload := amr_payload;
		/* bind local RTP emulation sockets */
		flow[0].em.portnr := 10000;
		f_flow_create(RTPEM[0], ep, call_id, "sendrecv", flow[0]);

		/* from MGW back to us */
		flow[1] := valueof(t_RtpFlow(local_ip_osmux, remote_ip_osmux, 110, "AMR/8000"));
		flow[1].em.portnr := mp_local_osmux_port;
		flow[1].osmux.local_cid := 2;
		flow[1].osmux.cfg := c_OsmuxemDefaultCfg;
		f_flow_create_osmux(OsmuxEM, ep, call_id, "sendrecv", flow[1]);

		if (bidir) {
				f_rtpem_mode(RTPEM[0], RTPEM_MODE_BIDIR);
				f_osmuxem_mode(OsmuxEM, OSMUXEM_MODE_BIDIR);

				/* Note: When we test bidirectional we may
				 * loose packets during switch off because
				 * both ends are transmitting and we only
				 * can switch them off one by one. */
				tolerance := 3;
		} else {
				f_rtpem_mode(RTPEM[0], RTPEM_MODE_RXONLY);
				f_osmuxem_mode(OsmuxEM, OSMUXEM_MODE_TXONLY);
		}

		f_sleep(1.0);

		/* Switch off both Tx, wait to receive delayed frames from MGW */
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_RXONLY);
		f_osmuxem_mode(OsmuxEM, OSMUXEM_MODE_RXONLY);
		f_sleep(0.1);

		f_flow_delete_osmux(OsmuxEM, ep, call_id);
		f_flow_delete(RTPEM[1]);

		stats_rtp := f_rtpem_stats_get(RTPEM[0]);
		stats_osmux := f_osmuxem_stats_get(OsmuxEM);
		if (not f_rtp_osmux_stats_compare(stats_rtp, stats_osmux, flow[1].osmux.cfg.batch_size,  tolerance)) {
			setverdict(fail, "RTP and Osmux endpoint statistics don't match");
			mtc.stop;
		}

		f_rtpem_stats_err_check(stats_rtp);
		f_osmuxem_stats_err_check(stats_osmux);

		setverdict(pass);
	}

	/* create one RTP and one OSmux emulations; create two connections on MGW EP, exchange some data */
	testcase TC_two_crcx_and_rtp_osmux() runs on dummy_CT {
		 f_TC_two_crcx_and_rtp_osmux(false, true, mp_local_ipv4, mp_remote_ipv4,
					     mp_local_ipv4, mp_remote_ipv4);
	}

	/* create one RTP and one OSmux emulations; create two connections on MGW EP,
	 * exchange some data in both directions */
	testcase TC_two_crcx_and_rtp_osmux_bidir() runs on dummy_CT {
		 f_TC_two_crcx_and_rtp_osmux(true, true, mp_local_ipv4, mp_remote_ipv4,
					     mp_local_ipv4, mp_remote_ipv4);
	}

	/* create one RTP and one OSmux emulations; create two connections on MGW EP,
	 * exchange some data in both directions. RTP side is configured to
	 * rx/rx AMR in bandwidth-efficient mode. */
	testcase TC_two_crcx_and_rtp_osmux_bidir_amr_bwe() runs on dummy_CT {
		 f_TC_two_crcx_and_rtp_osmux(true, false, mp_local_ipv4, mp_remote_ipv4,
					     mp_local_ipv4, mp_remote_ipv4);
	}


	/* Same as TC_two_crcx_and_rtp_osmux_bidir, but using IPv6 */
	testcase TC_two_crcx_and_rtp_osmux_bidir_ipv6() runs on dummy_CT {
		 f_TC_two_crcx_and_rtp_osmux(true, true, mp_local_ipv6, mp_remote_ipv6,
					     mp_local_ipv6, mp_remote_ipv6);
	}
	/* Same as TC_two_crcx_and_rtp_osmux_bidir, but using IPv4 (RTP) and IPv6 (Osmux) */
	testcase TC_two_crcx_and_rtp_osmux_bidir_ipv4_ipv6() runs on dummy_CT {
		 f_TC_two_crcx_and_rtp_osmux(true, true, mp_local_ipv4, mp_remote_ipv4,
					     mp_local_ipv6, mp_remote_ipv6);
	}
	/* Same as TC_two_crcx_and_rtp_osmux_bidir, but using IPv6 (RTP) and IPv4 (Osmux) */
	testcase TC_two_crcx_and_rtp_osmux_bidir_ipv6_ipv4() runs on dummy_CT {
		 f_TC_two_crcx_and_rtp_osmux(true, true, mp_local_ipv6, mp_remote_ipv6,
					     mp_local_ipv4, mp_remote_ipv4);
	}


	function f_two_crcx_mdcx_and_rtp_osmux(boolean crcx_osmux_wildcard,
					       charstring local_ip_rtp, charstring remote_ip_rtp,
					       charstring local_ip_osmux, charstring remote_ip_osmux) runs on dummy_CT {
		var RtpFlowData flow[2];
		var RtpemStats stats_rtp;
		var OsmuxemStats stats_osmux;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var MgcpCallId call_id := '1227'H;
		var integer num_pkts_tx[2], num_pkts_rx[2];
		var integer temp;

		f_init(ep, true);

		/* Create the first connection in receive only mode */
		flow[0] := valueof(t_RtpFlow(local_ip_rtp, remote_ip_rtp, 112, "AMR/8000"));
		flow[0].rtp_cfg := c_RtpemDefaultCfg
		flow[0].rtp_cfg.rx_payloads[0].payload_type := flow[0].codec_descr[0].pt;
		flow[0].rtp_cfg.tx_payloads[0].payload_type := flow[0].codec_descr[0].pt;
		/* 0014 is the ToC (CMR=AMR4.75) in front of AMR Payload in RTP Payload */
		flow[0].rtp_cfg.rx_payloads[0].fixed_payload := '0014'O & f_osmux_gen_expected_rx_rtp_payload(2 /* AMR_FT_2, 5.90 */, c_OsmuxemDefaultCfg.tx_fixed_payload);
		flow[0].rtp_cfg.tx_payloads[0].fixed_payload := flow[0].rtp_cfg.rx_payloads[0].fixed_payload;
		/* bind local RTP emulation sockets */
		flow[0].em.portnr := 10000;
		f_flow_create(RTPEM[0], ep, call_id, "recvonly", flow[0], true);


		/* Create the second connection. This connection will be also
		 * in receive only mode */
		flow[1] := valueof(t_RtpFlow(local_ip_osmux, remote_ip_osmux, 110, "AMR/8000"));
		flow[1].em.portnr := mp_local_osmux_port;
		if (crcx_osmux_wildcard) {
			flow[1].osmux.local_cid := -1;
		} else {
			flow[1].osmux.local_cid := 2;
		}
		flow[1].osmux.cfg := c_OsmuxemDefaultCfg;
		f_flow_create_osmux(OsmuxEM, ep, call_id, "recvonly", flow[1], true);


		/* The first leg starts transmitting */
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_TXONLY);
		f_sleep(0.5);
		stats_rtp := f_rtpem_stats_get(RTPEM[0]);
		if (stats_rtp.num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from RTP MGW on recvonly connection");
			mtc.stop;
		}
		stats_osmux := f_osmuxem_stats_get(OsmuxEM);
		if (stats_osmux.num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from Osmux MGW on recvonly connection");
			mtc.stop;
		}

		/* The second leg starts transmitting a little later */
		f_osmuxem_mode(OsmuxEM, OSMUXEM_MODE_TXONLY);
		f_sleep(1.0);
		stats_rtp := f_rtpem_stats_get(RTPEM[0]);
		if (stats_rtp.num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from RTP MGW on recvonly connection");
			mtc.stop;
		}
		stats_osmux := f_osmuxem_stats_get(OsmuxEM);
		if (stats_osmux.num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from Osmux MGW on recvonly connection");
			mtc.stop;
		}

		/* The first leg will now be switched into bidirectional
		 * mode, but we do not expect any data comming back yet. */
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_BIDIR);
		f_flow_modify(RTPEM[0], ep, call_id, "sendrecv", flow[0]);
		/* At this point in time, flow[1](Osmux)->MGW->flow[0](RTP) is active,
		 * hence if local CID was provided during CRCX we should already be seeing packets
		 * flowing in one direction, aka stats_rtp.num_pkts_rx sould be >0 after a while: */
		f_sleep(0.5);
		stats_rtp := f_rtpem_stats_get(RTPEM[0]);
		if (stats_rtp.num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from RTP MGW on recvonly connection");
			mtc.stop;
		}
		if (not crcx_osmux_wildcard and stats_rtp.num_pkts_rx == 0) {
			setverdict(fail, "received 0 packets Osmux->MGW->RTP");
			mtc.stop;
		}

		stats_osmux := f_osmuxem_stats_get(OsmuxEM);
		if (stats_osmux.num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from Osmux MGW on recvonly connection");
			mtc.stop;
		}
		if (stats_osmux.num_pkts_rx > 0) {
			setverdict(fail, "received unexpected ", stats_osmux.num_pkts_rx, " packets RTP->MGW->Osmux");
			mtc.stop;
		}

		/* When the second leg is switched into bidirectional mode
		 * as well, then the MGW will connect the two together and
		 * we should see RTP streams passing through from both ends. */
		f_osmuxem_mode(OsmuxEM, OSMUXEM_MODE_BIDIR);
		if (crcx_osmux_wildcard) {
			/* We set now the local CID in MDCX: */
			flow[1].osmux.local_cid := 2;
		}
		f_flow_modify_osmux(OsmuxEM, ep, call_id, "sendrecv", flow[1]);
		stats_rtp := f_rtpem_stats_get(RTPEM[0]);
		stats_osmux := f_osmuxem_stats_get(OsmuxEM);
		num_pkts_tx[0] := stats_rtp.num_pkts_tx;
		num_pkts_tx[1] := stats_osmux.num_pkts_tx;
		num_pkts_rx[0] := stats_rtp.num_pkts_rx;
		num_pkts_rx[1] := stats_osmux.num_pkts_rx;
		f_sleep(2.0);

		stats_rtp := f_rtpem_stats_get(RTPEM[0]);
		stats_osmux := f_osmuxem_stats_get(OsmuxEM);

		temp := (stats_rtp.num_pkts_tx - num_pkts_tx[0]) -
			(stats_osmux.num_pkts_rx - num_pkts_rx[1]) * flow[1].osmux.cfg.batch_size;
		if (temp > 3 * flow[1].osmux.cfg.batch_size or temp < -3 * flow[1].osmux.cfg.batch_size) {
			log("stats_rtp: ", stats_rtp);
			log("stats_osmux: ", stats_osmux);
			log("old_rtp_tx: ", num_pkts_tx[0]);
			setverdict(fail, "RTP-Tx vs OSmux-Rx number of packets not within normal parameters (" & int2str(temp) & ")");
			mtc.stop;
		}

		temp := (stats_osmux.num_pkts_tx - num_pkts_tx[1]) -
			((stats_rtp.num_pkts_rx -  num_pkts_rx[0])/ flow[1].osmux.cfg.batch_size);
		if (temp > 3 or temp < -3) {
			log("stats_rtp: ", stats_rtp);
			log("stats_osmux: ", stats_osmux);
			log("old_osmux_tx: ", num_pkts_tx[1]);
			setverdict(fail, "Osmux-Tx vs RTP-Rx number of packets not within normal parameters (" & int2str(temp) & ")");
			mtc.stop;
		}

		f_rtpem_stats_err_check(stats_rtp);
		f_osmuxem_stats_err_check(stats_osmux);

		/* Tear down */
		f_flow_delete(RTPEM[0]);
		f_flow_delete_osmux(OsmuxEM, ep, call_id);
		setverdict(pass);
	}

	/*  create one RTP and one OSmux emulations and pass data in both
	    directions. Create CRCX with wildcard Osmux CID and set it later
	    during MDCX. This is similar to how MSC sets up the call in AoIP. */
	testcase TC_two_crcx_mdcx_and_rtp_osmux_wildcard() runs on dummy_CT {
		f_two_crcx_mdcx_and_rtp_osmux(true, mp_local_ipv4, mp_remote_ipv4,
					      mp_local_ipv4, mp_remote_ipv4);
	}

	/*  create one RTP and one OSmux emulations and pass data in both
	    directions. Create CRCX with fixed Osmux CID and keep it during
	    MDCX. This is similar to how BSC sets up the call in AoIP. */
	testcase TC_two_crcx_mdcx_and_rtp_osmux_fixed() runs on dummy_CT {
		f_two_crcx_mdcx_and_rtp_osmux(false, mp_local_ipv4, mp_remote_ipv4,
					      mp_local_ipv4, mp_remote_ipv4);
	}

	/*  Same as TC_two_crcx_mdcx_and_rtp_osmux_wildcard, but using IPv6. */
	testcase TC_two_crcx_mdcx_and_rtp_osmux_ipv6() runs on dummy_CT {
		f_two_crcx_mdcx_and_rtp_osmux(false, mp_local_ipv6, mp_remote_ipv6,
					      mp_local_ipv6, mp_remote_ipv6);
	}
	/*  Same as TC_two_crcx_mdcx_and_rtp_osmux_wildcard, but using IPv4 (RTP) and IPv6 (Osmux). */
	testcase TC_two_crcx_mdcx_and_rtp_osmux_ipv4_ipv6() runs on dummy_CT {
		f_two_crcx_mdcx_and_rtp_osmux(false, mp_local_ipv4, mp_remote_ipv4,
					      mp_local_ipv6, mp_remote_ipv6);
	}
	/*  Same as TC_two_crcx_mdcx_and_rtp_osmux_wildcard, but using IPv6 (RTP) and IPv4 (Osmux). */
	testcase TC_two_crcx_mdcx_and_rtp_osmux_ipv6_ipv4() runs on dummy_CT {
		f_two_crcx_mdcx_and_rtp_osmux(false, mp_local_ipv6, mp_remote_ipv6,
					      mp_local_ipv4, mp_remote_ipv4);
	}

	function f_crcx_and_dlcx_ep_callid_connid(MgcpEndpoint ep, MgcpCallId call_id) runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;

		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);

		f_dlcx_ok(ep, call_id, extract_conn_id(resp));

		setverdict(pass);
	}

	testcase TC_crcx_dlcx_30ep() runs on dummy_CT {
		var MgcpEndpoint ep;
		var MgcpCallId call_id;
		var integer ep_nr;

		f_init();

		for (ep_nr := 1; ep_nr < 30; ep_nr := ep_nr+1) {
			if(ep_nr > 15) {
				ep := c_mgw_ep_rtpbridge & hex2str(int2hex(ep_nr, 2)) & "@" & c_mgw_domain;
			} else {
				ep := c_mgw_ep_rtpbridge & hex2str(int2hex(ep_nr, 1)) & "@" & c_mgw_domain;
			}
			call_id := int2hex(ep_nr, 2) & '1234'H;
			f_crcx_and_dlcx_ep_callid_connid(ep, call_id);
		}
	}

	/* Test (valid) CRCX followed by (valid) DLCX containing EP+CallId */
	testcase TC_crcx_and_dlcx_ep_callid() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "5@" & c_mgw_domain;
		var MgcpCallId call_id := '51233'H;

		f_init(ep);

		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);

		f_dlcx_ok(ep, call_id);

		setverdict(pass);
	}

	/* Test (valid) CRCX followed by (valid) DLCX containing EP */
	testcase TC_crcx_and_dlcx_ep() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "5@" & c_mgw_domain;
		var MgcpCallId call_id := '51232'H;

		f_init(ep);

		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);

		f_dlcx_ok(ep);

		setverdict(pass);
	}


	/* CRCX + DLCX of valid endpoint but invalid call-id */
	testcase TC_crcx_and_dlcx_ep_callid_inval() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "5@" & c_mgw_domain;
		var MgcpCallId call_id := '51231'H;

		f_init(ep);

		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);

		f_dlcx(ep, "516", *, 'ffff'H);

		setverdict(pass);
	}


	/* CRCX + DLCX of valid endpoint and call-id but invalid conn-id */
	testcase TC_crcx_and_dlcx_ep_callid_connid_inval() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "5@" & c_mgw_domain;
		var MgcpCallId call_id := '51230'H;

		f_init(ep);

		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);

		f_dlcx(ep, "515", *, call_id, 'ffff'H);

		setverdict(pass);
	}


	/* TODO: Double-DLCX (retransmission) */
	testcase TC_crcx_and_dlcx_retrans() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "5@" & c_mgw_domain;
		var MgcpCallId call_id := '51229'H;
		var template MgcpResponse rtmpl := {
			line := {
				code := "200",
				string := "OK"
			},
			params:= { },
			sdp := omit
		};

		f_init(ep);

		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);

		cmd := ts_DLCX(get_next_trans_id(), ep, call_id);
		resp := mgcp_transceive_mgw(cmd, rtmpl);
		resp := mgcp_transceive_mgw(cmd, rtmpl);

		setverdict(pass);
	}

	/* transmit RTP streams between two RTP Emulations back-to-back; expect no loss */
	testcase TC_rtpem_selftest() runs on dummy_CT {
		var RtpemStats stats[2];
		var integer local_port := 10000;
		var integer local_port2 := 20000;

		f_init();

		f_rtpem_bind(RTPEM[0], "127.0.0.1", local_port);
		f_rtpem_bind(RTPEM[1], "127.0.0.2", local_port2);

		f_rtpem_connect(RTPEM[0], "127.0.0.2", local_port2);
		f_rtpem_connect(RTPEM[1], "127.0.0.1", local_port);

		log("=== starting");
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_BIDIR);
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_BIDIR);

		f_sleep(5.0);

		log("=== stopping");
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_RXONLY);
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_RXONLY);
		f_sleep(0.5);
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_NONE);
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_NONE);

		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		if (not f_rtpem_stats_compare(stats[0], stats[1])) {
			setverdict(fail, "RTP endpoint statistics don't match");
			mtc.stop;
		}
		setverdict(pass);
	}

	/* Create one half open connection in receive-only mode. The MGW must accept
	 * the packets but must not send any. */
	testcase TC_one_crcx_receive_only_rtp() runs on dummy_CT {
		var RtpFlowData flow;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "1@" & c_mgw_domain;
		var MgcpCallId call_id := '1225'H;
		var RtpemStats stats;

		f_init(ep);
		flow := valueof(t_RtpFlow(mp_local_ipv4, mp_remote_ipv4, 112, "AMR/8000/1"));
		flow.em.portnr := 10000;
		f_flow_create(RTPEM[0], ep, call_id, "recvonly", flow, true);

		f_rtpem_mode(RTPEM[0], RTPEM_MODE_TXONLY);
		f_sleep(1.0);
		f_flow_delete(RTPEM[0], ep, call_id);

		stats := f_rtpem_stats_get(RTPEM[0]);

		/* Make sure that at least some amount of RTP packets/bytes
		 * have has been transmitted. The compare values for
		 * stats.num_pkts_tx and stats.bytes_payload_tx are determined
		 * using a testrun and the results were devided by 2, so even
		 * in load situations we should reach the minimum amount of
		 * required packets/bytes */

		if (stats.num_pkts_tx < 24) {
			setverdict(fail);
		}
		if (stats.bytes_payload_tx < 96) {
			setverdict(fail);
		}

		f_rtpem_stats_err_check(stats);

		setverdict(pass);
	}

	/* Create one connection in loopback mode, test if the RTP packets are
	 * actually reflected */
	function f_TC_one_crcx_loopback_rtp(charstring local_ip, charstring remote_ip, boolean one_phase := true) runs on dummy_CT {
		var RtpFlowData flow;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "1@" & c_mgw_domain;
		var MgcpCallId call_id := '1225'H;
		var RtpemStats stats;

		f_init(ep);
		flow := valueof(t_RtpFlow(local_ip, remote_ip, 111, "GSM-HR-08/8000/1"));
		flow.em.portnr := 10000;
		f_flow_create(RTPEM[0], ep, call_id, "loopback", flow, one_phase := one_phase);

		f_rtpem_mode(RTPEM[0], RTPEM_MODE_BIDIR);
		f_sleep(1.0);
		f_flow_delete(RTPEM[0], ep, call_id);

		stats := f_rtpem_stats_get(RTPEM[0]);

		if (stats.num_pkts_tx != stats.num_pkts_rx) {
			setverdict(fail);
		}
		if (stats.bytes_payload_tx != stats.bytes_payload_rx) {
			setverdict(fail);
		}

		f_rtpem_stats_err_check(stats);

		setverdict(pass);
	}

	/* Create one connection in loopback mode, test if the RTP packets are
	 * actually reflected */
	testcase TC_one_crcx_loopback_rtp() runs on dummy_CT {
		 f_TC_one_crcx_loopback_rtp(mp_local_ipv4, mp_remote_ipv4, one_phase := true)
	}
	testcase TC_one_crcx_loopback_rtp_ipv6() runs on dummy_CT {
		 f_TC_one_crcx_loopback_rtp(mp_local_ipv6, mp_remote_ipv6, one_phase := true)
	}

	/* Same as above, but we will intenionally not tell the MGW where to
	 * send the outgoing traffic. The connection is still created in
	 * loopback mode, so the MGW should take the originating address from
	 * the incoming RTP packet and send it back to the source */
	testcase TC_one_crcx_loopback_rtp_implicit() runs on dummy_CT {
		 f_TC_one_crcx_loopback_rtp(mp_local_ipv6, mp_remote_ipv6, one_phase := false)
	}


	function f_TC_two_crcx_and_rtp(boolean bidir, charstring codec_name_a, integer pt_a,
					charstring codec_name_b, integer pt_b) runs on dummy_CT {
		var RtpFlowData flow[2];
		var RtpemStats stats[2];
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var MgcpCallId call_id := '1226'H;
		var integer tolerance := 0;

		f_init(ep);

		/* from us to MGW */
		flow[0] := valueof(t_RtpFlow(mp_local_ipv4, mp_remote_ipv4, pt_a, codec_name_a));
		/* bind local RTP emulation sockets */
		flow[0].em.portnr := 10000;
		f_flow_create(RTPEM[0], ep, call_id, "sendrecv", flow[0]);

		/* from MGW back to us */
		flow[1] := valueof(t_RtpFlow(mp_local_ipv4, mp_remote_ipv4, pt_b, codec_name_b));
		flow[1].em.portnr := 20000;
		f_flow_create(RTPEM[1], ep, call_id, "sendrecv", flow[1]);

		if (bidir) {
				f_rtpem_mode(RTPEM[0], RTPEM_MODE_BIDIR);
				f_rtpem_mode(RTPEM[1], RTPEM_MODE_BIDIR);

				/* Note: When we test bidirectional we may
				 * loose packets during switch off because
				 * both ends are transmitting and we only
				 * can switch them off one by one. */
				tolerance := 3;
		} else {
				f_rtpem_mode(RTPEM[0], RTPEM_MODE_RXONLY);
				f_rtpem_mode(RTPEM[1], RTPEM_MODE_TXONLY);
		}

		f_sleep(1.0);

		f_flow_delete(RTPEM[1]);
		f_flow_delete(RTPEM[0], ep, call_id);

		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		if (not f_rtpem_stats_compare(stats[0], stats[1], tolerance)) {
			setverdict(fail, "RTP endpoint statistics don't match");
			mtc.stop;
		}

		f_rtpem_stats_err_check(stats[0]);
		f_rtpem_stats_err_check(stats[1]);

		setverdict(pass);
	}

	/* create two local RTP emulations; create two connections on MGW EP, exchange some data */
	testcase TC_two_crcx_and_rtp() runs on dummy_CT {
		 f_TC_two_crcx_and_rtp(false, "AMR/8000", 98, "AMR/8000", 98);
	}

	/* create two local RTP emulations; create two connections on MGW EP,
	 * exchange some data in both directions */
	testcase TC_two_crcx_and_rtp_bidir() runs on dummy_CT {
		 f_TC_two_crcx_and_rtp(true, "AMR/8000", 98, "AMR/8000", 98);
	}

	/* same as TC_two_crcx_and_rtp, but with different PT number on both ends */
	testcase TC_two_crcx_diff_pt_and_rtp() runs on dummy_CT {
		 f_TC_two_crcx_and_rtp(false, "AMR/8000", 98, "AMR/8000", 112);
	}

	/* same as TC_two_crcx_and_rtp, but with different PT number on both ends */
	testcase TC_two_crcx_diff_pt_and_rtp_bidir() runs on dummy_CT {
		 f_TC_two_crcx_and_rtp(true, "AMR/8000", 98, "AMR/8000", 112);
	}

	/* create two local RTP emulations and pass data in both directions */
	function f_tc_two_crcx_mdcx_and_rtp(charstring local_ip_a, charstring remote_ip_a,
					    charstring local_ip_b, charstring remote_ip_b,
					    uint7_t payload_type := 3,
					    charstring codec_name := "GSM/8000/1") runs on dummy_CT {
		var RtpFlowData flow[2];
		var RtpemStats stats[2];
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var MgcpCallId call_id := '1227'H;
		var integer num_pkts_tx[2];
		var integer temp;

		f_init(ep);

		/* Create the first connection in receive only mode */
		flow[0] := valueof(t_RtpFlow(local_ip_a, remote_ip_a, payload_type, codec_name));
		flow[0].em.portnr := 10000;
		f_flow_create(RTPEM[0], ep, call_id, "recvonly", flow[0], true);

		/* Create the second connection. This connection will be also
		 * in receive only mode */
		flow[1] := valueof(t_RtpFlow(local_ip_b, remote_ip_b, payload_type, codec_name));
		flow[1].em.portnr := 20000;
		f_flow_create(RTPEM[1], ep, call_id, "recvonly", flow[1], true);

		/* The first leg starts transmitting */
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_TXONLY);
		f_sleep(0.5);
		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		if (stats[0].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 0");
			mtc.stop;
		}
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		if (stats[1].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 1");
			mtc.stop;
		}

		/* The second leg starts transmitting a little later */
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_TXONLY);
		f_sleep(1.0);
		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		if (stats[0].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 0");
			mtc.stop;
		}
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		if (stats[1].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 1");
			mtc.stop;
		}

		/* The first leg will now be switched into bidirectional
		 * mode, but we do not expect any data comming back yet. */
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_BIDIR);
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		num_pkts_tx[1] := stats[1].num_pkts_tx;
		f_flow_modify(RTPEM[0], ep, call_id, "sendrecv", flow[0]);
		f_sleep(0.5);
		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		if (stats[0].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 0");
			mtc.stop;
		}
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		if (stats[1].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 1");
			mtc.stop;
		}

		/* When the second leg is switched into bidirectional mode
		 * as well, then the MGW will connect the two together and
		 * we should see RTP streams passing through from both ends. */
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_BIDIR);
		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		num_pkts_tx[0] := stats[0].num_pkts_tx;
		f_flow_modify(RTPEM[1], ep, call_id, "sendrecv", flow[1]);
		f_sleep(2.0);

		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		stats[1] := f_rtpem_stats_get(RTPEM[1]);

		temp := stats[0].num_pkts_tx - num_pkts_tx[0] - stats[1].num_pkts_rx;
		if (temp > 3 or temp < -3) {
			setverdict(fail, "number of packets not within normal parameters:", temp);
			mtc.stop;
		}

		temp := stats[1].num_pkts_tx - num_pkts_tx[1] - stats[0].num_pkts_rx;
		if (temp > 3 or temp < -3) {
			setverdict(fail, "number of packets not within normal parameters:", temp);
			mtc.stop;
		}

		f_rtpem_stats_err_check(stats[0]);
		f_rtpem_stats_err_check(stats[1]);

		/* Tear down */
		f_flow_delete(RTPEM[0]);
		f_flow_delete(RTPEM[1], ep, call_id);
		setverdict(pass);
	}

	testcase TC_two_crcx_mdcx_and_rtp() runs on dummy_CT {
		f_tc_two_crcx_mdcx_and_rtp(mp_local_ipv4, mp_remote_ipv4,
					   mp_local_ipv4, mp_remote_ipv4);
	}

	testcase TC_two_crcx_mdcx_and_rtp_ipv6() runs on dummy_CT {
		f_tc_two_crcx_mdcx_and_rtp(mp_local_ipv6, mp_remote_ipv6,
					   mp_local_ipv6, mp_remote_ipv6);
	}

	testcase TC_two_crcx_mdcx_and_rtp_ipv4_ipv6() runs on dummy_CT {
		f_tc_two_crcx_mdcx_and_rtp(mp_local_ipv4, mp_remote_ipv4,
					   mp_local_ipv6, mp_remote_ipv6);
	}

	testcase TC_two_crcx_mdcx_and_rtp_clearmode() runs on dummy_CT {
		f_tc_two_crcx_mdcx_and_rtp(mp_local_ipv4, mp_remote_ipv4,
					   mp_local_ipv4, mp_remote_ipv4,
					   120, /* 3GPP TS 48.103 table 5.4.2.2.1 */
					   "CLEARMODE/8000");
	}

	/* Test what happens when two RTP streams from different sources target
	 * a single connection. Is the unsolicited stream properly ignored? */
	testcase TC_two_crcx_and_unsolicited_rtp() runs on dummy_CT {
		var RtpFlowData flow[2];
		var RtpemStats stats[2];
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var MgcpCallId call_id := '1234321326'H;
		var integer unsolicited_port := 10002;

		f_init(ep);

		/* from us to MGW */
		flow[0] := valueof(t_RtpFlow(mp_local_ipv4, mp_remote_ipv4, 98, "AMR/8000"));
		/* bind local RTP emulation sockets */
		flow[0].em.portnr := 10000;
		f_flow_create(RTPEM[0], ep, call_id, "sendrecv", flow[0]);

		/* from MGW back to us */
		flow[1] := valueof(t_RtpFlow(mp_local_ipv4, mp_remote_ipv4, 98, "AMR/8000"));
		flow[1].em.portnr := 20000;
		f_flow_create(RTPEM[1], ep, call_id, "sendrecv", flow[1]);

		f_rtpem_mode(RTPEM[1], RTPEM_MODE_RXONLY);
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_TXONLY);

		f_sleep(0.5);

		/* Start inserting unsolicited RTP packets */
		f_rtpem_bind(RTPEM[2], mp_local_ipv4, unsolicited_port);
		f_rtpem_connect(RTPEM[2], mp_remote_ipv4, flow[0].mgw.portnr);
		f_rtpem_mode(RTPEM[2], RTPEM_MODE_TXONLY);

		f_sleep(0.5);

		/* Stop transmitting packets and tear down the flows */
		f_rtpem_mode(RTPEM[2], RTPEM_MODE_NONE);
		f_flow_delete(RTPEM[0]);
		f_flow_delete(RTPEM[1], ep, call_id);

		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		if (not f_rtpem_stats_compare(stats[0], stats[1])) {
			setverdict(fail, "RTP endpoint statistics don't match");
			mtc.stop;
		}

		f_rtpem_stats_err_check(stats[0]);
		f_rtpem_stats_err_check(stats[0]);

		setverdict(pass);
	}

	/* Test a handover situation. We first create two connections transmit
	 * some data bidirectionally. Then we will simulate a handover situation. */
	testcase TC_two_crcx_and_one_mdcx_rtp_ho() runs on dummy_CT {
		var RtpFlowData flow[2];
		var RtpemStats stats[3];
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "4@" & c_mgw_domain;
		var MgcpCallId call_id := '76338'H;
		var integer port_old;

		f_init(ep);

		/* First connection (BTS) */
		flow[0] := valueof(t_RtpFlow(mp_local_ipv4, mp_remote_ipv4, 110, "GSM-EFR/8000"));
		/* bind local RTP emulation sockets */
		flow[0].em.portnr := 10000;
		f_flow_create(RTPEM[0], ep, call_id, "sendrecv", flow[0]);

		/* Second connection (PBX) */
		flow[1] := valueof(t_RtpFlow(mp_local_ipv4, mp_remote_ipv4, 110, "GSM-EFR/8000"));
		flow[1].em.portnr := 20000;
		f_flow_create(RTPEM[1], ep, call_id, "sendrecv", flow[1]);

		/* Normal rtp flow for one second */
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_BIDIR);
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_BIDIR);
		f_sleep(1.0);

		/* Now switch the flow over to a new port (BTS) */
		port_old := flow[0].em.portnr;
		flow[0].em.portnr := 10002;
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_RXONLY);
		f_flow_modify(RTPEM[0], ep, call_id, "sendrecv", flow[0]);
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_BIDIR);

		/* When handing over a call, the old source may still keep
		 * transmitting for a while. We simulate this by injecting
		 * some unsolicited packets on the behalf of the old source,
		 * (old remote port) */
		f_rtpem_bind(RTPEM[2], mp_local_ipv4, port_old);
		f_rtpem_connect(RTPEM[2], mp_remote_ipv4, flow[0].mgw.portnr);
		f_rtpem_mode(RTPEM[2], RTPEM_MODE_TXONLY);
		f_sleep(1.0);
		f_rtpem_mode(RTPEM[2], RTPEM_MODE_NONE);
		f_sleep(1.0);

		/* Terminate call */
		f_flow_delete(RTPEM[0]);
		f_flow_delete(RTPEM[1], ep, call_id);

		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		if (not f_rtpem_stats_compare(stats[0], stats[1], 5)) {
			setverdict(fail, "RTP endpoint statistics don't match");
			mtc.stop;
		}
		stats[2] := f_rtpem_stats_get(RTPEM[2]);
		if (stats[2].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets on old leg after handover");
			mtc.stop;
		}

		f_rtpem_stats_err_check(stats[0]);
		f_rtpem_stats_err_check(stats[1]);
		f_rtpem_stats_err_check(stats[2]);

		setverdict(pass);
	}


	/* create two local RTP emulations; create two connections on MGW EP, see if
	 * exchanged data is converted between ts101318 and rfc5993 */
	function f_ts101318_rfc5993_rtp_conversion(octetstring pl0, octetstring pl1, charstring fmtp0, charstring fmtp1) runs on dummy_CT {
		var RtpFlowData flow[2];
		var RtpemStats stats[2];
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var MgcpCallId call_id := '1226'H;

		f_init(ep);

		/* Turn on conversion mode */
		f_vty_enter_config(MGWVTY);
		f_vty_transceive(MGWVTY, "mgcp");
		f_vty_transceive(MGWVTY, "rtp-patch rfc5993hr");

		/* Connection #0 (Bidirectional) */
		flow[0] := valueof(t_RtpFlow(mp_local_ipv4, mp_remote_ipv4, 111, "GSM-HR-08/8000", fmtp0));
		/* bind local RTP emulation sockets */
		flow[0].em.portnr := 10000;
		flow[0].rtp_cfg := c_RtpemDefaultCfg;
		flow[0].rtp_cfg.rx_payloads[0].payload_type := flow[0].codec_descr[0].pt;
		flow[0].rtp_cfg.tx_payloads[0].payload_type := flow[0].codec_descr[0].pt;
		flow[0].rtp_cfg.rx_payloads[0].fixed_payload := pl0;
		flow[0].rtp_cfg.tx_payloads[0].fixed_payload := pl0;
		f_flow_create(RTPEM[0], ep, call_id, "sendrecv", flow[0]);

		/* Connection #1 (Bidirectional) */
		flow[1] := valueof(t_RtpFlow(mp_local_ipv4, mp_remote_ipv4, 111, "GSM-HR-08/8000", fmtp1));
		flow[1].em.portnr := 20000;
		flow[1].rtp_cfg	:= c_RtpemDefaultCfg;
		flow[1].rtp_cfg.rx_payloads[0].payload_type := flow[1].codec_descr[0].pt;
		flow[1].rtp_cfg.tx_payloads[0].payload_type := flow[1].codec_descr[0].pt;
		flow[1].rtp_cfg.rx_payloads[0].fixed_payload := pl1;
		flow[1].rtp_cfg.tx_payloads[0].fixed_payload := pl1;
		f_flow_create(RTPEM[1], ep, call_id, "sendrecv", flow[1]);

		/* Send RTP packets to connection #0, receive on connection #1 */
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_RXONLY);
		f_sleep(0.5);
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_TXONLY);
		f_sleep(1.0);
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_NONE);
		f_sleep(0.5);
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_NONE);

		/* Send RTP packets to connection #1, receive on connection #0 */
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_RXONLY);
		f_sleep(0.5);
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_TXONLY);
		f_sleep(1.0);
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_NONE);
		f_sleep(0.5);
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_NONE);

		/* Remove RTP flows and check statistics */
		f_flow_delete(RTPEM[0]);
		f_flow_delete(RTPEM[1], ep, call_id);

		/* Check for errors */
		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		f_rtpem_stats_err_check(stats[0]);
		f_rtpem_stats_err_check(stats[1]);

		/* Turn off conversion mode */
		f_vty_transceive(MGWVTY, "no rtp-patch rfc5993hr");

		setverdict(pass);
	}

	const octetstring rtp_hr_gsm_ts101318 := '0b11b3eede60be4e3ec68838c7b5'O;
	const octetstring rtp_hr_gsm_rfc5993 := '000b11b3eede60be4e3ec68838c7b5'O;

	testcase TC_ts101318_rfc5993_rtp_conversion() runs on dummy_CT {
		f_ts101318_rfc5993_rtp_conversion(rtp_hr_gsm_ts101318, rtp_hr_gsm_rfc5993, "", "");
	}

	testcase TC_ts101318_rfc5993_rtp_conversion_fmtp() runs on dummy_CT {
		f_ts101318_rfc5993_rtp_conversion(rtp_hr_gsm_ts101318, rtp_hr_gsm_rfc5993, "gsm-hr-format=ts101318", "gsm-hr-format=rfc5993");
	}

	/* create two local RTP emulations; create two connections on MGW EP, see if
	 * exchanged data is converted between AMR octet-aligned and bandwidth
	 * efficient-mode */
	function f_TC_amr_x_x_rtp_conversion(charstring fmtp0, octetstring pl0,
					     charstring fmtp1a, octetstring pl1a,
					     charstring fmtp1b, octetstring pl1b) runs on dummy_CT {
		var RtpFlowData flow[2];
		var RtpemStats stats[2];
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var MgcpCallId call_id := '1226'H;

		f_init(ep);

		/* Connection #0 (Bidirectional) */
		flow[0] := valueof(t_RtpFlow(mp_local_ipv4, mp_remote_ipv4, 96, "AMR/8000", fmtp0));
		/* bind local RTP emulation sockets */
		flow[0].em.portnr := 10000;
		flow[0].rtp_cfg := c_RtpemDefaultCfg;
		flow[0].rtp_cfg.rx_payloads[0].payload_type := flow[0].codec_descr[0].pt;
		flow[0].rtp_cfg.tx_payloads[0].payload_type := flow[0].codec_descr[0].pt;
		flow[0].rtp_cfg.rx_payloads[0].fixed_payload := pl0;
		flow[0].rtp_cfg.tx_payloads[0].fixed_payload := pl0;
		f_flow_create(RTPEM[0], ep, call_id, "sendrecv", flow[0]);

		/* Connection #1 (Bidirectional) */
		flow[1] := valueof(t_RtpFlow(mp_local_ipv4, mp_remote_ipv4, 112, "AMR/8000", fmtp1a));
		flow[1].em.portnr := 20000;
		flow[1].rtp_cfg	:= c_RtpemDefaultCfg;
		flow[1].rtp_cfg.rx_payloads := {};
		flow[1].rtp_cfg.tx_payloads := {};
		if (pl1a != ''O) {
			flow[1].rtp_cfg.rx_payloads := flow[1].rtp_cfg.rx_payloads & {{112, pl1a}};
			flow[1].rtp_cfg.tx_payloads := flow[1].rtp_cfg.tx_payloads & {{112, pl1a}};
		}

		/* The second fmtp parameter is to simulate a call agent that offers the transmission both modes. */
		if (fmtp1b != "") {
			flow[1].codec_descr := flow[1].codec_descr & {{113, "AMR/8000", fmtp1b}};
			if (pl1b != ''O) {
				flow[1].rtp_cfg.rx_payloads := flow[1].rtp_cfg.rx_payloads & {{113, pl1b}};
				flow[1].rtp_cfg.tx_payloads := flow[1].rtp_cfg.tx_payloads & {{113, pl1b}};
			}
		}

		f_flow_create(RTPEM[1], ep, call_id, "sendrecv", flow[1]);

		/* Send RTP packets to connection #0, receive on connection #1 */
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_RXONLY);
		f_sleep(0.5);
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_TXONLY);
		f_sleep(1.0);
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_NONE);
		f_sleep(0.5);
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_NONE);

		/* Send RTP packets to connection #1, receive on connection #0 */
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_RXONLY);
		f_sleep(0.5);
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_TXONLY);
		f_sleep(1.0);
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_NONE);
		f_sleep(0.5);
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_NONE);

		/* Remove RTP flows and check statistics */
		f_flow_delete(RTPEM[0]);
		f_flow_delete(RTPEM[1], ep, call_id);

		/* Check for errors */
		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		f_rtpem_stats_err_check(stats[0]);
		f_rtpem_stats_err_check(stats[1]);

		setverdict(pass);
	}

	/* Note: The hexstrings used with the f_TC_amr_x_x_rtp_conversion test
	 * functions are real world AMR RTP payloads including AMR header. The
	 * payloads were extracted from a trace with known good payloads. */

	const octetstring rtp_amr_5_90k_oa := '2014e959f35fdfe5e9667ffbc088818088'O;
	const octetstring rtp_amr_5_90k_bwe := '217a567cd7f7f97a599ffef022206022'O;
	const octetstring rtp_amr_5_15k_oa := '100c4e9ba850e30d5d53d04de41e7c'O;
	const octetstring rtp_amr_5_15k_bwe := '10d3a6ea1438c35754f41379079f'O;

	/* Only one codec on each side */
	testcase TC_amr_oa_bwe_rtp_conversion() runs on dummy_CT {
		f_TC_amr_x_x_rtp_conversion("octet-align=1", rtp_amr_5_90k_oa, "octet-align=0", rtp_amr_5_90k_bwe, "", ''O);
	}
	testcase TC_amr_oa_oa_rtp_conversion() runs on dummy_CT {
		f_TC_amr_x_x_rtp_conversion("octet-align=1", rtp_amr_5_15k_oa, "octet-align=1", rtp_amr_5_15k_oa, "", ''O);
	}
	testcase TC_amr_bwe_bwe_rtp_conversion() runs on dummy_CT {
		f_TC_amr_x_x_rtp_conversion("octet-align=0", rtp_amr_5_15k_bwe, "octet-align=0", rtp_amr_5_15k_bwe, "", ''O);
	}

	/* Only one codec on one side, two codecs (compatibility) on other side. The payloads are the same on both
	 * sides, so the expectation is that conversion must not be performed. Each test is done with both formats in
	 * two different configurations.*/
	testcase TC_amr_oa_oa_no_bwe_rtp_conversion() runs on dummy_CT {
		f_TC_amr_x_x_rtp_conversion("octet-align=1", rtp_amr_5_15k_oa,
					    "octet-align=1", rtp_amr_5_15k_oa,
					    "octet-align=0", ''O); /* We expect to see NO bandwidth efficient packets! */
	}
	testcase TC_amr_oa_no_bwe_oa_rtp_conversion() runs on dummy_CT {
		/* (Same as above but flipped on the opposite side) */
		f_TC_amr_x_x_rtp_conversion("octet-align=1", rtp_amr_5_15k_oa,
					    "octet-align=0", ''O, /* We expect to see NO bandwidth efficient packets! */
					    "octet-align=1", rtp_amr_5_15k_oa);
	}
	testcase TC_amr_bwe_bwe_no_oa_rtp_conversion() runs on dummy_CT {
		f_TC_amr_x_x_rtp_conversion("octet-align=0", rtp_amr_5_15k_bwe,
					    "octet-align=0", rtp_amr_5_15k_bwe,
					    "octet-align=1", ''O); /* We expect to see NO octet aligned packets! */
	}
	testcase TC_amr_bwe_no_oa_bwe_rtp_conversion() runs on dummy_CT {
		/* (Same as above but flipped on the opposite side) */
		f_TC_amr_x_x_rtp_conversion("octet-align=0", rtp_amr_5_15k_bwe,
					    "octet-align=1", ''O, /* We expect to see NO octet aligned packets! */
					    "octet-align=0", rtp_amr_5_15k_bwe);
	}

	/* TODO: Double-DLCX (no retransmission) */



	/* TODO: AUEP (various) */
	/* TODO: RSIP (various) */
	/* TODO: RQNT (various) */
	/* TODO: EPCF (various) */
	/* TODO: AUCX (various) */
	/* TODO: invalid verb (various) */


	testcase TC_conn_timeout() runs on dummy_CT {
		var RtpFlowData flow;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "1@" & c_mgw_domain;
		var MgcpCallId call_id := '1225'H;
		var MGCP_RecvFrom mrf;

		f_init(ep);
		log("Setting conn-timeout to 1s");
		f_vty_config(MGWVTY, "mgcp", "conn-timeout 1"); /* reset in f_init_vty() */

		log("Sending RTP data for 1.5s");
		flow := valueof(t_RtpFlow(mp_local_ipv4, mp_remote_ipv4, 111, "GSM-HR-08/8000/1"));
		flow.em.portnr := 10000;
		f_flow_create(RTPEM[0], ep, call_id, "loopback", flow);
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_BIDIR);
		f_sleep(1.5);

		log("Stopping for 0.5s and resuming");
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_NONE);
		f_sleep(0.5);
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_BIDIR);
		f_sleep(0.1);

		log("Stopping for 1.5s, expecting to run into timeout");
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_NONE);
		f_sleep(1.5);

		log("Resuming should fail now");
		f_rtpem_conn_refuse_expect(RTPEM[0]);
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_BIDIR);
		f_sleep(0.2);
		f_rtpem_conn_refuse_verify(RTPEM[0]);

		setverdict(pass);
	}

	/* Test (valid) CRCX followed by (valid) DLCX containing EP (E1) */
	testcase TC_e1_crcx_and_dlcx_ep() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := "ds/e1-1/s-1/su16-0@" & c_mgw_domain;
		var MgcpCallId call_id := '8376F297'H;

		f_init(ep);

		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);

		f_dlcx_ok(ep);

		setverdict(pass);
	}

	/* Test what happens when overlapping endpoints are selected (E1) */
	testcase TC_e1_crcx_with_overlap() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep_1 := "ds/e1-1/s-1/su8-0@" & c_mgw_domain;
		var MgcpEndpoint ep_2 := "ds/e1-1/s-1/su16-0@" & c_mgw_domain;
		var MgcpCallId call_id_1 := '8376F297'H;
		var MgcpCallId call_id_2 := '837AF2A7'H;

		f_init();

		/* ep_1 and ep_2 are overlapping, selecting both one after
		 * another should work fine: */
		cmd := ts_CRCX(get_next_trans_id(), ep_1, "recvonly", call_id_1);
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);
		f_dlcx_ok(ep_1);
		cmd := ts_CRCX(get_next_trans_id(), ep_2, "recvonly", call_id_2);
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);
		f_dlcx_ok(ep_2);

		/* When ep_1 is serving a call we can not select ep_2 becaus
		 * it is overlapping with ep_1 */
		cmd := ts_CRCX(get_next_trans_id(), ep_1, "recvonly", call_id_1);
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);
		cmd := ts_CRCX(get_next_trans_id(), ep_2, "recvonly", call_id_2);
		resp := mgcp_transceive_mgw(cmd, ?);
		if (resp.line.code != "501") {
			setverdict(fail, "unexpected CRCX returncode, CRCX should fail!");
		}
		f_dlcx_ok(ep_1);

		setverdict(pass);
	}

	/* Create one connection in loopback mode, test if the RTP packets are
	 * actually reflected */
	testcase TC_e1_crcx_loopback() runs on dummy_CT {
		var RtpFlowData flow;
		var MgcpEndpoint ep := "ds/e1-1/s-1/su16-0@" & c_mgw_domain;
		var MgcpCallId call_id := '12250989'H;
		var RtpemStats stats;

		f_init(ep);
		flow := valueof(t_RtpFlow(mp_local_ipv4, mp_remote_ipv4, 111, "GSM-HR-08/8000/1"));
		flow.em.portnr := 10000;
		f_flow_create(RTPEM[0], ep, call_id, "loopback", flow);

		f_rtpem_mode(RTPEM[0], RTPEM_MODE_BIDIR);
		f_sleep(1.0);
		f_flow_delete(RTPEM[0], ep, call_id);

		stats := f_rtpem_stats_get(RTPEM[0]);

		if (stats.num_pkts_tx != stats.num_pkts_rx) {
			setverdict(fail);
		}
		if (stats.bytes_payload_tx != stats.bytes_payload_rx) {
			setverdict(fail);
		}

		f_rtpem_stats_err_check(stats);

		setverdict(pass);
	}

	/* test valid wildcarded DLCX on an E1 trunk */
	testcase TC_e1_dlcx_wildcarded() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpEndpoint ep;
		var MgcpCallId call_id := '8376F297'H;
		var integer n_e1_ts := 4;
		var StatsDExpects expect;

		f_init();

		/* Open a few E1 timeslots */
		for (var integer i := 0; i < n_e1_ts; i := i+1) {
			ep := "ds/e1-1/s-" & int2str(i+1) & "/su16-0@" & c_mgw_domain;
			cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
			mgcp_transceive_mgw(cmd, tr_CRCX_ACK);
			ep := "ds/e1-1/s-" & int2str(i+1) & "/su16-2@" & c_mgw_domain;
			cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
			mgcp_transceive_mgw(cmd, tr_CRCX_ACK);
			ep := "ds/e1-1/s-" & int2str(i+1) & "/su16-4@" & c_mgw_domain;
			cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
			mgcp_transceive_mgw(cmd, tr_CRCX_ACK);
			ep := "ds/e1-1/s-" & int2str(i+1) & "/su16-6@" & c_mgw_domain;
			cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
			mgcp_transceive_mgw(cmd, tr_CRCX_ACK);
		}

		/* Wait until the stats items have seteled and then check if we get the expected number (all) of
		 * occupied endpoints */
		f_sleep(1.0)
		expect := {
			{ name := "TTCN3.trunk.e1-1.common.endpoints.used", mtype := "g", min := n_e1_ts * 4, max := n_e1_ts * 4}
		};
		f_statsd_expect(expect);

		/* Send wildcarded DLCX */
		var template MgcpResponse rtmpl := {
			line := {
				code := "200",
				string := ?
			},
			params:= { },
			sdp := omit
		};
		ep := "ds/e1-1/*@" & c_mgw_domain;
		cmd := ts_DLCX(get_next_trans_id(), ep);
		mgcp_transceive_mgw(cmd, rtmpl);

		/* Query a the statsd once to ensure that intermediate results are pulled from the
		 * pipeline. The second query (below) will return the actual result. */
		expect := {
			{ name := "TTCN3.trunk.e1-1.common.endpoints.used", mtype := "g", min := 0, max := n_e1_ts * 4}
		};
		f_statsd_expect(expect);

		/* The second query must resturn a result with 0 endpoints in use. */
		expect := {
			{ name := "TTCN3.trunk.e1-1.common.endpoints.used", mtype := "g", min := 0, max := 0}
		};
		f_statsd_expect(expect);

		setverdict(pass);
	}

	/* test valid CRCX then MDCX with IPv4 address, MGW provides a local IPv4 too */
	testcase TC_crcx_mdcx_ip4() runs on dummy_CT {
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpCallId call_id := '1234'H;
		var MgcpConnectionId conn_id;

		f_init(ep);

		/* create the connection on the MGW */
		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);
		conn_id := extract_conn_id(resp);

		cmd := ts_MDCX(get_next_trans_id(), ep, "sendrecv", call_id, conn_id);
		cmd.sdp := ts_SDP("127.0.0.2", "127.0.0.1", "23", "42", 2344, { "98" },
				  { valueof(ts_SDP_rtpmap(98, "AMR/8000")),
				    valueof(ts_SDP_ptime(20)) });
		resp := mgcp_transceive_mgw(cmd, tr_MDCX_ACK);

		if (not ispresent(resp.sdp) or not ispresent(resp.sdp.connection)) {
			setverdict(fail, "No RemoteConnection info found in MDCX ACK!");
		}
		if (not match(resp.sdp.connection, ts_SDP_connection_IP("127.0.0.1", "IP4"))) {
			setverdict(fail, "Wrong RemoteConnection in MDCX ACK!", resp.sdp.connection);
		}

		/* clean-up */
		f_dlcx_ok(ep, call_id);
		setverdict(pass);
	}

	/* test valid CRCX then MDCX with IPv6 address, MGW provides a local IPv6 too */
	testcase TC_crcx_mdcx_ip6() runs on dummy_CT {
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpCallId call_id := '1234'H;
		var MgcpConnectionId conn_id;

		f_init(ep);

		/* create the connection on the MGW */
		cmd := ts_CRCX(get_next_trans_id(), ep, "recvonly", call_id);
		resp := mgcp_transceive_mgw(cmd, tr_CRCX_ACK);
		conn_id := extract_conn_id(resp);

		cmd := ts_MDCX(get_next_trans_id(), ep, "sendrecv", call_id, conn_id);
		cmd.sdp := ts_SDP("::2", "::1", "23", "42", 2344, { "98" },
				  { valueof(ts_SDP_rtpmap(98, "AMR/8000")),
				    valueof(ts_SDP_ptime(20)) });
		resp := mgcp_transceive_mgw(cmd, tr_MDCX_ACK);

		if (not ispresent(resp.sdp) or not ispresent(resp.sdp.connection)) {
			setverdict(fail, "No RemoteConnection info found in MDCX ACK!");
		}
		if (not match(resp.sdp.connection, ts_SDP_connection_IP("::1", "IP6"))) {
			setverdict(fail, "Wrong RemoteConnection in MDCX ACK!", resp.sdp.connection);
		}

		/* clean-up */
		f_dlcx_ok(ep, call_id);
		setverdict(pass);
	}

	/* create two local RTP+IuUP emulations and pass data in both directions */
	function f_tc_two_crcx_mdcx_and_iuup(charstring local_ip_a, charstring remote_ip_a,
					    IuUP_RabFlowCombinationList rfcl_a,
					    charstring local_ip_b, charstring remote_ip_b) runs on dummy_CT {
		var RtpFlowData flow[2];
		var RtpemStats stats[2];
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var MgcpCallId call_id := '1227'H;
		var integer num_pkts_tx[2];
		var integer temp;

		f_init(ep);

		/* Create the first connection in receive only mode (RNC side, IuUP-Init active) */
		flow[0] := valueof(t_RtpFlow(local_ip_a, remote_ip_a, 96, "VND.3GPP.IUFP/16000"));
		flow[0].em.portnr := 10000;
		flow[0].rtp_cfg := c_RtpemDefaultCfg;
		flow[0].rtp_cfg.rx_payloads[0].payload_type := flow[0].codec_descr[0].pt;
		flow[0].rtp_cfg.tx_payloads[0].payload_type := flow[0].codec_descr[0].pt;
		flow[0].rtp_cfg.iuup_mode := true;
		flow[0].rtp_cfg.iuup_cfg.active_init := true;
		flow[0].rtp_cfg.iuup_cfg.rab_flow_combs := rfcl_a;
		f_flow_create(RTPEM[0], ep, call_id, "recvonly", flow[0], true);
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_RXONLY);

		/* Create the second connection. This connection will be also
		 * in receive only mode (CN side, IuUP-Init passive) */
		flow[1] := valueof(t_RtpFlow(local_ip_b, remote_ip_b, 96, "VND.3GPP.IUFP/16000"));
		flow[1].em.portnr := 20000;
		flow[1].rtp_cfg := c_RtpemDefaultCfg;
		flow[1].rtp_cfg.rx_payloads[0].payload_type := flow[1].codec_descr[0].pt;
		flow[1].rtp_cfg.tx_payloads[0].payload_type := flow[1].codec_descr[0].pt;
		flow[1].rtp_cfg.iuup_mode := true;
		flow[1].rtp_cfg.iuup_cfg.active_init := false;
		f_flow_create(RTPEM[1], ep, call_id, "recvonly", flow[1], true);
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_RXONLY);

		/* The first leg starts transmitting */
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_TXONLY);
		f_sleep(0.5);
		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		if (stats[0].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 0");
			mtc.stop;
		}
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		if (stats[1].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 1");
			mtc.stop;
		}

		/* The second leg starts transmitting a little later */
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_TXONLY);
		f_sleep(1.0);
		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		if (stats[0].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 0");
			mtc.stop;
		}
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		if (stats[1].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 1");
			mtc.stop;
		}

		/* The first leg will now be switched into bidirectional
		 * mode, but we do not expect any data coming back yet. */
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_BIDIR);
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		num_pkts_tx[1] := stats[1].num_pkts_tx;
		f_flow_modify(RTPEM[0], ep, call_id, "sendrecv", flow[0]);
		f_sleep(0.5);
		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		if (stats[0].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 0");
			mtc.stop;
		}
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		if (stats[1].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 1");
			mtc.stop;
		}

		/* When the second leg is switched into bidirectional mode
		 * as well, then the MGW will connect the two together and
		 * we should see RTP streams passing through from both ends. */
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_BIDIR);
		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		num_pkts_tx[0] := stats[0].num_pkts_tx;
		f_flow_modify(RTPEM[1], ep, call_id, "sendrecv", flow[1]);
		f_sleep(2.0);

		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		stats[1] := f_rtpem_stats_get(RTPEM[1]);

		temp := stats[0].num_pkts_tx - num_pkts_tx[0] - stats[1].num_pkts_rx;
		if (temp > 3 or temp < -3) {
			setverdict(fail, "number of packets not within normal parameters:", temp);
			mtc.stop;
		}

		temp := stats[1].num_pkts_tx - num_pkts_tx[1] - stats[0].num_pkts_rx;
		if (temp > 3 or temp < -3) {
			setverdict(fail, "number of packets not within normal parameters:", temp);
			mtc.stop;
		}

		f_rtpem_stats_err_check(stats[0]);
		f_rtpem_stats_err_check(stats[1]);

		/* Tear down */
		f_flow_delete(RTPEM[0]);
		f_flow_delete(RTPEM[1], ep, call_id);
		setverdict(pass);
	}
	testcase TC_two_crcx_mdcx_and_iuup() runs on dummy_CT {
		var template (value) IuUP_RabFlowCombinationList rfcl := {
			t_IuUP_RFC_AMR_12_2(0),
			t_IuUP_RFC_AMR_SID(1),
			t_IuUP_RFC_AMR_NO_DATA(2)
		};
		f_tc_two_crcx_mdcx_and_iuup(mp_local_ipv4, mp_remote_ipv4, valueof(rfcl),
					   mp_local_ipv4, mp_remote_ipv4);
	}
	/* Same as TC_two_crcx_mdcx_and_iuup, but passing unordered RFCI list (ID != position) */
	testcase TC_two_crcx_mdcx_and_iuup_rfci_unordered() runs on dummy_CT {
		var template (value) IuUP_RabFlowCombinationList rfcl := {
			t_IuUP_RFC_AMR_12_2(1),
			t_IuUP_RFC_AMR_SID(2),
			t_IuUP_RFC_AMR_NO_DATA(0)
		};
		f_tc_two_crcx_mdcx_and_iuup(mp_local_ipv4, mp_remote_ipv4, valueof(rfcl),
					   mp_local_ipv4, mp_remote_ipv4);
	}

	/* create two local emulations (1 RTP, 1 RTP+IuUP) and pass data in both directions */
	function f_tc_two_crcx_mdcx_and_iuup_rtp(charstring local_ip_a, charstring remote_ip_a,
					    IuUP_RabFlowCombinationList rfcl_a,
					    charstring local_ip_b, charstring remote_ip_b) runs on dummy_CT {
		var RtpFlowData flow[2];
		var RtpemStats stats[2];
		var MgcpResponse resp;
		var MgcpEndpoint ep := c_mgw_ep_rtpbridge & "2@" & c_mgw_domain;
		var MgcpCallId call_id := '1227'H;
		var integer num_pkts_tx[2];
		var integer temp;

		f_init(ep);

		/* Create the first connection in receive only mode (RNC side, IuUP-Init active) */
		flow[0] := valueof(t_RtpFlow(local_ip_a, remote_ip_a, 96, "VND.3GPP.IUFP/16000"));
		flow[0].em.portnr := 10000;
		flow[0].rtp_cfg := c_RtpemDefaultCfg;
		flow[0].rtp_cfg.tx_payloads[0].payload_type := flow[0].codec_descr[0].pt;
		flow[0].rtp_cfg.rx_payloads[0].payload_type := flow[0].codec_descr[0].pt;
		flow[0].rtp_cfg.tx_payloads[0].fixed_payload := '4f28959ffeb80181f5c4e83d176c897b4a4e333298333419a493ca63ded6e0'O;
		/* flow[1].rtp_cfg.rx_payloads[0].fixed_payload converted AMR-BE-RTP->AMR-IUUP*/
		flow[0].rtp_cfg.rx_payloads[0].fixed_payload := '08556d944c71a1a081e7ead204244480000ecd82b81118000097c4794e7740'O;
		flow[0].rtp_cfg.iuup_mode := true;
		flow[0].rtp_cfg.iuup_cfg.active_init := true;
		flow[0].rtp_cfg.iuup_cfg.rab_flow_combs := rfcl_a;
		f_flow_create(RTPEM[0], ep, call_id, "recvonly", flow[0], true);
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_RXONLY);

		/* Create the second connection. This connection will be also
		 * in receive only mode (CN side, regular RTP) */
		flow[1] := valueof(t_RtpFlow(local_ip_b, remote_ip_b, 112, "AMR/8000"));
		flow[1].em.portnr := 20000;
		flow[1].rtp_cfg := c_RtpemDefaultCfg;
		flow[1].rtp_cfg.tx_payloads[0].payload_type := flow[1].codec_descr[0].pt;
		flow[1].rtp_cfg.rx_payloads[0].payload_type := flow[1].codec_descr[0].pt;
		flow[1].rtp_cfg.tx_payloads[0].fixed_payload := '0382155b65131c68682079fab4810911200003b360ae0446000025f11e539dd0'O;
		/* flow[0].rtp_cfg.rx_payloads[0].fixed_payload converted AMR-IuUP->AMR-BE-RTP*/
		flow[1].rtp_cfg.rx_payloads[0].fixed_payload := 'f3d3ca2567ffae00607d713a0f45db225ed2938ccca60ccd066924f298f7b5b8'O;
		flow[1].rtp_cfg.iuup_mode := false;
		f_flow_create(RTPEM[1], ep, call_id, "recvonly", flow[1], true);
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_RXONLY);

		/* The first leg starts transmitting */
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_TXONLY);
		f_sleep(0.5);
		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		if (stats[0].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 0");
			mtc.stop;
		}
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		if (stats[1].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 1");
			mtc.stop;
		}

		/* The second leg starts transmitting a little later */
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_TXONLY);
		f_sleep(1.0);
		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		if (stats[0].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 0");
			mtc.stop;
		}
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		if (stats[1].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 1");
			mtc.stop;
		}

		/* The first leg will now be switched into bidirectional
		 * mode, but we do not expect any data coming back yet. */
		f_rtpem_mode(RTPEM[0], RTPEM_MODE_BIDIR);
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		num_pkts_tx[1] := stats[1].num_pkts_tx;
		f_flow_modify(RTPEM[0], ep, call_id, "sendrecv", flow[0]);
		f_sleep(0.5);
		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		if (stats[0].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 0");
			mtc.stop;
		}
		stats[1] := f_rtpem_stats_get(RTPEM[1]);
		if (stats[1].num_pkts_rx_err_disabled != 0) {
			setverdict(fail, "received packets from MGW on recvonly connection 1");
			mtc.stop;
		}

		/* When the second leg is switched into bidirectional mode
		 * as well, then the MGW will connect the two together and
		 * we should see RTP streams passing through from both ends. */
		f_rtpem_mode(RTPEM[1], RTPEM_MODE_BIDIR);
		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		num_pkts_tx[0] := stats[0].num_pkts_tx;
		f_flow_modify(RTPEM[1], ep, call_id, "sendrecv", flow[1]);
		f_sleep(2.0);

		stats[0] := f_rtpem_stats_get(RTPEM[0]);
		stats[1] := f_rtpem_stats_get(RTPEM[1]);

		temp := stats[0].num_pkts_tx - num_pkts_tx[0] - stats[1].num_pkts_rx;
		if (temp > 3 or temp < -3) {
			setverdict(fail, "number of packets not within normal parameters:", temp);
			mtc.stop;
		}

		temp := stats[1].num_pkts_tx - num_pkts_tx[1] - stats[0].num_pkts_rx;
		if (temp > 3 or temp < -3) {
			setverdict(fail, "number of packets not within normal parameters:", temp);
			mtc.stop;
		}

		f_rtpem_stats_err_check(stats[0]);
		f_rtpem_stats_err_check(stats[1]);

		/* Tear down */
		f_flow_delete(RTPEM[0]);
		f_flow_delete(RTPEM[1], ep, call_id);
		setverdict(pass);
	}
	testcase TC_two_crcx_mdcx_and_iuup_rtp() runs on dummy_CT {
		var template (value) IuUP_RabFlowCombinationList rfcl := {
			t_IuUP_RFC_AMR_12_2(0),
			t_IuUP_RFC_AMR_SID(1),
			t_IuUP_RFC_AMR_NO_DATA(2)
		};
		f_tc_two_crcx_mdcx_and_iuup_rtp(mp_local_ipv4, mp_remote_ipv4, valueof(rfcl),
					   mp_local_ipv4, mp_remote_ipv4);
	}
	/* Same as TC_two_crcx_mdcTC_two_crcx_mdcx_and_iuup_rtpx_and_iuup, but passing unordered RFCI list (ID != position) */
	testcase TC_two_crcx_mdcx_and_iuup_rtp_rfci_unordered() runs on dummy_CT {
		var template (value) IuUP_RabFlowCombinationList rfcl := {
			t_IuUP_RFC_AMR_12_2(1),
			t_IuUP_RFC_AMR_SID(2),
			t_IuUP_RFC_AMR_NO_DATA(0)
		};
		f_tc_two_crcx_mdcx_and_iuup_rtp(mp_local_ipv4, mp_remote_ipv4, valueof(rfcl),
					   mp_local_ipv4, mp_remote_ipv4);
	}

	control {
		execute(TC_selftest());
		execute(TC_crcx());
		execute(TC_crcx_no_lco());
		execute(TC_crcx_noprefix());
		execute(TC_crcx_unsupp_mode());
		execute(TC_crcx_osmo_ign());
		execute(TC_crcx_early_bidir_mode());
		execute(TC_crcx_unsupp_param());
		execute(TC_crcx_missing_callid());
		execute(TC_crcx_missing_mode());
		execute(TC_crcx_unsupp_packet_intv());
		execute(TC_crcx_illegal_double_lco());
		execute(TC_crcx_sdp());
		execute(TC_crcx_wildcarded());
		execute(TC_crcx_wildcarded_exhaust());
		execute(TC_mdcx_without_crcx());
		execute(TC_dlcx_without_crcx());
		execute(TC_dlcx_non_existant_ep());
		execute(TC_mdcx_wildcarded());
		execute(TC_dlcx_wildcarded());
		execute(TC_crcx_and_dlcx_ep_callid_connid());
		execute(TC_crcx_and_dlcx_ep_callid());
		execute(TC_crcx_and_dlcx_ep());
		execute(TC_crcx_and_dlcx_ep_callid_inval());
		execute(TC_crcx_and_dlcx_ep_callid_connid_inval());
		execute(TC_crcx_and_dlcx_retrans());

		execute(TC_crcx_osmux_wildcard());
		execute(TC_crcx_osmux_fixed());
		execute(TC_crcx_osmux_fixed_twice());
		execute(TC_crcx_osmux_257());
		execute(TC_one_crcx_receive_only_osmux());
		execute(TC_one_crcx_loopback_osmux());
		execute(TC_two_crcx_and_rtp_osmux());
		execute(TC_two_crcx_and_rtp_osmux_bidir());
		execute(TC_two_crcx_and_rtp_osmux_bidir_amr_bwe());
		execute(TC_two_crcx_mdcx_and_rtp_osmux_wildcard());
		execute(TC_two_crcx_mdcx_and_rtp_osmux_fixed());

		execute(TC_crcx_dlcx_30ep());

		execute(TC_rtpem_selftest());

		execute(TC_one_crcx_receive_only_rtp());
		execute(TC_one_crcx_loopback_rtp());
		execute(TC_one_crcx_loopback_rtp_ipv6());
		execute(TC_two_crcx_and_rtp());
		execute(TC_two_crcx_and_rtp_bidir());
		execute(TC_two_crcx_diff_pt_and_rtp());
		execute(TC_two_crcx_diff_pt_and_rtp_bidir());
		execute(TC_two_crcx_mdcx_and_rtp());
		execute(TC_two_crcx_and_unsolicited_rtp());
		execute(TC_two_crcx_and_one_mdcx_rtp_ho());
		execute(TC_ts101318_rfc5993_rtp_conversion());
		execute(TC_ts101318_rfc5993_rtp_conversion_fmtp());
		execute(TC_amr_oa_bwe_rtp_conversion());
		execute(TC_amr_oa_oa_rtp_conversion());
		execute(TC_amr_bwe_bwe_rtp_conversion());
		execute(TC_amr_oa_oa_no_bwe_rtp_conversion());
		execute(TC_amr_oa_no_bwe_oa_rtp_conversion());
		execute(TC_amr_bwe_bwe_no_oa_rtp_conversion());
		execute(TC_amr_bwe_no_oa_bwe_rtp_conversion());

		execute(TC_conn_timeout());

		execute(TC_e1_crcx_and_dlcx_ep());
		execute(TC_e1_crcx_with_overlap());
		execute(TC_e1_crcx_loopback());
		execute(TC_e1_dlcx_wildcarded());

		execute(TC_crcx_mdcx_ip4());
		execute(TC_crcx_mdcx_ip6());
		execute(TC_two_crcx_mdcx_and_rtp_ipv4_ipv6());
		execute(TC_two_crcx_mdcx_and_rtp_ipv6());
		execute(TC_two_crcx_and_rtp_osmux_bidir_ipv6());
		execute(TC_two_crcx_and_rtp_osmux_bidir_ipv4_ipv6());
		execute(TC_two_crcx_and_rtp_osmux_bidir_ipv6_ipv4());
		execute(TC_two_crcx_mdcx_and_rtp_osmux_ipv6());
		execute(TC_two_crcx_mdcx_and_rtp_osmux_ipv4_ipv6());
		execute(TC_two_crcx_mdcx_and_rtp_osmux_ipv6_ipv4());

		execute(TC_two_crcx_mdcx_and_iuup());
		execute(TC_two_crcx_mdcx_and_iuup_rfci_unordered());
		execute(TC_two_crcx_mdcx_and_iuup_rtp());
		execute(TC_two_crcx_mdcx_and_iuup_rtp_rfci_unordered());

		execute(TC_two_crcx_mdcx_and_rtp_clearmode());

		/* Note: This testcase will trigger an OSMO_ASSERT() bug in
		 * older versions of osmo-mgw. This eventually leads into
		 * a failure of all subsequent testcases, so it is important
		 * not to add new testcaes after this one. */
		execute(TC_one_crcx_loopback_rtp_implicit());
	}
}