mgw/MGCP_Test.ttcn

module MGCP_Test {
	import from Osmocom_Types all;
	import from MGCP_Types 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_Endpoint all;
	import from IPL4asp_Types all;

	/* 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 {
		port MGCP_CODEC_PT MGCP;
		port RTP_CODEC_PT RTP;
		var boolean initialized := false;
		var ConnectionId g_mgcp_conn_id := -1;
		var integer g_trans_id;

		var RtpEndpoint	g_rtp_ep[2];
	};

	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_ip := "127.0.0.1";
		PortNumber mp_remote_udp_port := 2427;
		charstring mp_remote_ip := "127.0.0.1";
		PortNumber mp_local_rtp_port_base := 10000;
	}

	/* 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) 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_ip, mp_remote_udp_port, mp_local_ip, mp_local_udp_port, 0, { udp := {} });
			g_mgcp_conn_id := res.connId;

			map(self:RTP, system:RTP_CODEC_PT);
			ssrc := float2int(rnd()*4294967296.0);
			rtp_endpoint_init(g_rtp_ep[0], mp_local_ip, mp_local_rtp_port_base, ssrc);
			rtp_endpoint_bind(RTP, g_rtp_ep[0]);
			rtp_endpoint_init(g_rtp_ep[1], mp_local_ip, mp_local_rtp_port_base+2, ssrc);
			rtp_endpoint_bind(RTP, g_rtp_ep[1]);
		}

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

	/* 3.2.2.6 Connection Mode (sendonly, recvonly, sendrecv, confrnce, inactive, loopback,
	 * conttest, netwloop, netwtest) */
	template MgcpParameter t_MgcpParConnMode(template MgcpConnectionMode mode) := { "M", mode };

	/* 3.2.2.2 CallId: maximum 32 hex chars */
	template MgcpParameter ts_MgcpParCallId(MgcpCallId cid) := {
		code := "C",
		val := hex2str(cid)
	};

	/* 3.2.2.18 RequestIdentifier: Maximum 32 hex chars */
	template MgcpParameter ts_MgcpParReqId(MgcpRequestId rid) := {
		code := "X",
		val := hex2str(rid)
	};

	/* 3.2.2.10: LocalConnectionOptions (codec, packetization, bandwidth, ToS, eco, gain, silence, ...) */
	template MgcpParameter t_MgcpParLocConnOpt(template charstring lco) := { "L", lco };

	/* 3.2.2.5: ConnectionId: maximum 32 hex chars */
	template MgcpParameter ts_MgcpParConnectionId(MgcpConnectionId cid) := {
		code := "I",
		val := hex2str(cid)
	};

	/* osmo-bsc_mgcp implements L/C/M/X only, osmo-mgw adds 'I' */
	/* SDP: osmo-bsc_mgcp implements Tx of v,o,s,c,t,m,a */

	template MgcpResponse tr_MgcpResp_Err(template MgcpResponseCode code) := {
		line := {
			code := code,
			trans_id := ?,
			string := ?
		},
		params := {},
		sdp := omit
	}

	template MgcpCommandLine t_MgcpCmdLine(template charstring verb, template MgcpTransId trans_id, template charstring ep) := {
		verb := verb,
		trans_id := trans_id,
		ep := ep,
		ver := "1.0"
	};

	template MgcpCommand ts_CRCX(MgcpTransId trans_id, charstring ep, MgcpConnectionMode mode, MgcpCallId call_id, template SDP_Message sdp := omit) := {
		line := t_MgcpCmdLine("CRCX", trans_id, ep),
		params := {
			t_MgcpParConnMode(mode),
			ts_MgcpParCallId(call_id),
			//t_MgcpParReqId(omit),
			t_MgcpParLocConnOpt("p: 20")
		},
		sdp := sdp
	}

	template MgcpResponse tr_CRCX_ACK := {
		line := {
			code := "200",
			string := "OK"
		},
		params:= { { "I", ? }, *},
		sdp := ?
	}

	template MgcpCommand ts_MDCX(MgcpTransId trans_id, charstring ep, MgcpConnectionMode mode, MgcpCallId call_id, template SDP_Message sdp := omit) := {
		line := t_MgcpCmdLine("MDCX", trans_id, ep),
		params := {
			t_MgcpParConnMode(mode),
			ts_MgcpParCallId(call_id),
			//t_MgcpParReqId(omit),
			t_MgcpParLocConnOpt("p: 20")
		},
		sdp := sdp
	}

	/* have a function that generates a template, rather than a template in order to handle
	 * optional parameters */
	function ts_DLCX(MgcpTransId trans_id, charstring ep, template MgcpCallId call_id := omit,
			 template MgcpConnectionId conn_id := omit) return template MgcpCommand {
		var template MgcpCommand cmd;
		cmd.line := t_MgcpCmdLine("DLCX", trans_id, ep);
		cmd.params := {};
		cmd.sdp := omit;
		if (isvalue(call_id)) {
			f_mgcp_par_append(cmd.params, ts_MgcpParCallId(valueof(call_id)));
			if (isvalue(conn_id)) {
				f_mgcp_par_append(cmd.params, ts_MgcpParConnectionId(valueof(conn_id)));
			}
		}
		return cmd;
	}

	/* SDP Templates */
	template SDP_Origin ts_SDP_origin(charstring addr, charstring session_id,
					  charstring session_version := "1",
					  charstring addr_type := "IP4",
					  charstring user_name := "-") := {
		user_name := user_name,
		session_id := session_id,
		session_version := session_version,
		net_type := "IN",
		addr_type := addr_type,
		addr := addr
	}

	template SDP_connection ts_SDP_connection_IP(charstring addr, charstring addr_type := "IP4",
						     template integer ttl := omit,
						     template integer num_of_addr := omit) :={
		net_type := "IN",
		addr_type := addr_type,
		conn_addr := {
			addr := addr,
			ttl := ttl,
			num_of_addr := num_of_addr
		}
	}

	template SDP_time ts_SDP_time(charstring beg, charstring end) := {
		time_field := {
			start_time := beg,
			stop_time := end
		},
		time_repeat := omit
	}

	template SDP_media_desc ts_SDP_media_desc(integer port_number, SDP_fmt_list fmts,
						  SDP_attribute_list attributes) := {
		media_field := {
			media := "audio",
			ports := {
				port_number := port_number,
				num_of_ports := omit
			},
			transport := "ARTP/AVP",
			fmts := fmts
		},
		information := omit,
		connections := omit,
		bandwidth := omit,
		key := omit,
		attributes := attributes
	}

	/* master template for generating SDP based in template arguments */
	template SDP_Message ts_SDP(charstring local_addr, charstring remote_addr,
				    charstring session_id, charstring session_version,
				    integer rtp_port, SDP_fmt_list fmts,
				    SDP_attribute_list attributes) := {
		protocol_version := 0,
		origin := ts_SDP_origin(local_addr, session_id, session_version),
		session_name := "-",
		information := omit,
		uri := omit,
		emails := omit,
		phone_numbers := omit,
		connection := ts_SDP_connection_IP(remote_addr),
		bandwidth := omit,
		times := { ts_SDP_time("0","0") },
		timezone_adjustments := omit,
		key := omit,
		attributes := omit,
		media_list := { ts_SDP_media_desc(rtp_port, fmts, attributes) }
	}

	template SDP_attribute ts_SDP_rtpmap(integer fmt, charstring val) := {
		rtpmap := {
			attr_value := int2str(fmt) & " " & val
		}
	}
	template SDP_attribute ts_SDP_ptime(integer p) := {
		ptime := {
			attr_value := int2str(p)
		}
	}

	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 1@mgw 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 1@mgw 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", "42@mgw", "sendrecv", '1234'H));
		log(enc_MgcpCommand(valueof(ts_CRCX("23", "42@mgw", "sendrecv", '1234'H))));

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

	/* CRCX test ideas:
	 * - without mandatory CallId
	 * - without mandatory ConnectionId
	 * - with forbidden parameters (e.g. Capabilities, PackageList, ...
	 * - CRCX with remote session description and without
	 *
	 * general ideas:
	 * - packetization != 20ms
	 * - invalid mode
	 * x unsupported mode (517)
	 * x bidirectional mode before RemoteConnDesc: 527
	 * - invalid codec
	 * - 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_ip,
			remPort := mp_remote_udp_port,
			locName := mp_local_ip,
			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); }
			[] MGCP.receive { repeat; }
			[] T.timeout { setverdict(fail); }
		}
		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);
		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", "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);
	}

	/* test valid CRCX without SDP */
	testcase TC_crcx() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := "2@mgw";
		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);

		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 := "2@mgw";
		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 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 := "2@mgw";
		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);
	}

	function f_mgcp_par_append(inout template MgcpParameterList list, template MgcpParameter par) {
		var integer len := lengthof(list);
		list[len] := par;
	}

	/* test CRCX with unsupported Parameters */
	testcase TC_crcx_unsupp_param() runs on dummy_CT {
		var template MgcpCommand cmd;
		var MgcpResponse resp;
		var MgcpEndpoint ep := "2@mgw";
		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 := "2@mgw";
		var template MgcpResponse rtmpl := tr_MgcpResp_Err("400");

		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 := "2@mgw";
		var MgcpCallId call_id := '1229'H;
		var template MgcpResponse rtmpl := tr_MgcpResp_Err("400");

		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 := "2@mgw";
		var MgcpCallId call_id := '1228'H;
		var template MgcpResponse rtmpl := tr_MgcpResp_Err("532");

		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 := "2@mgw";
		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 := "2@mgw";
		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);
		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 := "3@mgw";
		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);
		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 := "4@mgw";
		var template MgcpResponse rtmpl := {
			line := {
				/* TODO: accept/enforce better error? */
				code := "400",
				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) 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 := "5@mgw";
		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 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 := "5@mgw";
		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);

		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 := "5@mgw";
		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);

		setverdict(pass);
	}


	/* TODO: DLCX of valid endpoint but invalid call-id */
	/* TODO: Double-DLCX (retransmission) */
	/* TODO: Double-DLCX (no retransmission) */



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

	control {
		execute(TC_selftest());
		execute(TC_crcx());
		execute(TC_crcx_unsupp_mode());
		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_mdcx_without_crcx());
		execute(TC_dlcx_without_crcx());
		execute(TC_crcx_and_dlcx_ep_callid_connid());
		execute(TC_crcx_and_dlcx_ep_callid());
		execute(TC_crcx_and_dlcx_ep());
	}
}