bsc: inter-BSC HO: add TC_ho_out_of_this_bsc, TC_ho_into_this_bsc
Add f_gen_handover_req() like f_gen_ass_req(), to match AoIP or SCCPlite
requirements.
For incoming HO, MSC_ConnHdlr needs to know the SCCP addresses to expect the
incoming SCCP Connection from MSC to BSC. Add 'handover' section to
TestHdlrParams, and pass in the addresses from test_CT via that.
In osmo-bsc.cfg, add a remote neighbor config, so that the VTY command
'handover any to arfcn 123 bsic any' can trigger an outgoing inter-BSC HO.
Add various BSSMAP handover templates to BSSMAP_Templates.ttcn.
Add RR Ho Command template to L3_Templates.ttcn.
Move ts_BSSAP_Conn_Req() from msc/BSC_ConnectionHandler.ttcn to
library/BSSMAP_Emulation.ttcn, so we can also model an SCCP Connection Request
in BSC_Tests.ttcn (this time from MSC to BSC).
Add the two new tests to bsc/expected-results.xml.
Related: OS#2283
Change-Id: Id22852d4be7f127d827e7a8beeec55db27c07f03
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index 9a43ead..4a34310 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -33,6 +33,8 @@
import from RSL_Types all;
import from RSL_Emulation all;
import from MGCP_Emulation all;
+import from MGCP_Templates all;
+import from MGCP_Types all;
import from Osmocom_CTRL_Functions all;
import from Osmocom_CTRL_Types all;
@@ -43,12 +45,15 @@
import from MobileL3_CommonIE_Types all;
import from MobileL3_Types all;
+import from MobileL3_RRM_Types all;
import from L3_Templates all;
import from GSM_RR_Types all;
import from SCCP_Templates all;
import from BSSMAP_Templates all;
+import from SCCPasp_Types all;
+
const integer NUM_BTS := 3;
const float T3101_MAX := 12.0;
@@ -572,6 +577,19 @@
return ass_cmd;
}
+function f_gen_handover_req() return PDU_BSSAP {
+ var PDU_BSSAP ho_req;
+ if (mp_bssap_cfg.transport == BSSAP_TRANSPORT_AoIP) {
+ var BSSMAP_IE_AoIP_TransportLayerAddress tla :=
+ valueof(ts_BSSMAP_IE_AoIP_TLA4('01020304'O, 2342));
+ ho_req := valueof(ts_BSSMAP_HandoverRequest(omit, tla));
+ } else {
+ var BSSMAP_IE_CircuitIdentityCode cic := valueof(ts_BSSMAP_IE_CIC(0,1));
+ ho_req := valueof(ts_BSSMAP_HandoverRequest(cic, omit));
+ }
+ return ho_req;
+}
+
/* generate an assignment complete template for either AoIP or SCCPlite */
function f_gen_exp_compl() return template PDU_BSSAP {
var template PDU_BSSAP exp_compl;
@@ -2083,6 +2101,10 @@
vc_conn.done;
}
+/***********************************************************************
+ * Handover
+ ***********************************************************************/
+
/* execute a "bts <0-255> trx <0-255> timeslot <0-7> " command on given Dchan */
private function f_vty_ts_action(charstring suffix, integer bts_nr, integer trx_nr, integer ts_nr)
runs on test_CT {
@@ -2165,6 +2187,158 @@
vc_conn.done;
}
+private function f_tc_ho_out_of_this_bsc(charstring id) runs on MSC_ConnHdlr {
+ g_pars := valueof(t_def_TestHdlrPars);
+
+ var PDU_BSSAP ass_req := f_gen_ass_req();
+ ass_req.pdu.bssmap.assignmentRequest.channelType := valueof(ts_BSSMAP_IE_ChannelType);
+ ass_req.pdu.bssmap.assignmentRequest.codecList := valueof(ts_BSSMAP_IE_CodecList({ts_CodecFR}));
+ var template PDU_BSSAP exp_compl := f_gen_exp_compl();
+ f_establish_fully(ass_req, exp_compl);
+
+ f_vty_transceive(BSCVTY, "handover any to arfcn 123 bsic any");
+
+ BSSAP.receive(tr_BSSMAP_HandoverRequired);
+
+ f_sleep(0.5);
+ /* The MSC negotiates Handover Request and Handover Request Ack with
+ * the other BSS and comes back with a BSSMAP Handover Command
+ * containing an RR Handover Command coming from the target BSS... */
+
+ var PDU_ML3_NW_MS rr_ho_cmd := valueof(ts_RR_HandoverCommand);
+ log("Remote cell's RR Handover Command passed through as L3 Info: ", rr_ho_cmd);
+ var octetstring rr_ho_cmd_enc := enc_PDU_ML3_NW_MS(rr_ho_cmd);
+ log("Remote cell's RR Handover Command passed through as L3 Info, encoded: ", rr_ho_cmd_enc);
+ BSSAP.send(ts_BSSMAP_HandoverCommand(rr_ho_cmd_enc));
+
+ /* expect the Handover Command to go out on RR */
+ var RSL_Message rsl_ho_cmd
+ RSL.receive(tr_RSL_DATA_REQ(g_chan_nr, ?, ?)) -> value rsl_ho_cmd;
+ log("RSL Data Req went out to first BTS: ", rsl_ho_cmd);
+ var RSL_IE_Body rsl_ho_cmd_l3;
+ if (not f_rsl_find_ie(rsl_ho_cmd, RSL_IE_L3_INFO, rsl_ho_cmd_l3)) {
+ log("RSL message contains no L3 Info IE, expected RR Handover Command");
+ setverdict(fail);
+ } else {
+ log("Found L3 Info: ", rsl_ho_cmd_l3);
+ if (rsl_ho_cmd_l3.l3_info.payload != rr_ho_cmd_enc) {
+ log("FAIL: the BSC sent out a different L3 Info, not matching the RR Handover Command the other BSS forwarded.");
+ setverdict(fail);
+ } else {
+ log("Success: the BSC sent out the same RR Handover Command the other BSS forwarded.");
+ setverdict(pass);
+ }
+ }
+
+ /* When the other BSS has reported a completed handover, this side is
+ * torn down. */
+
+ var myBSSMAP_Cause cause_val := GSM0808_CAUSE_HANDOVER_SUCCESSFUL;
+ var BssmapCause cause := enum2int(cause_val);
+ BSSAP.send(ts_BSSMAP_ClearCommand(cause));
+
+ /* Expecting MGCP to DLCX the endpoint's two connections: towards BTS and towards MSC */
+ var MgcpCommand mgcp;
+ interleave {
+ [] BSSAP.receive(tr_BSSMAP_ClearComplete);
+ [] MGCP.receive(tr_DLCX()) -> value mgcp {
+ log("Got first DLCX: ", mgcp);
+ }
+ [] MGCP.receive(tr_DLCX()) -> value mgcp {
+ log("Got second DLCX: ", mgcp);
+ }
+ }
+ setverdict(pass);
+ f_sleep(1.0);
+}
+testcase TC_ho_out_of_this_bsc() runs on test_CT {
+ var MSC_ConnHdlr vc_conn;
+
+ f_init(1, true);
+ f_sleep(1.0);
+
+ vc_conn := f_start_handler(refers(f_tc_ho_out_of_this_bsc));
+ vc_conn.done;
+}
+
+private function f_tc_ho_into_this_bsc(charstring id) runs on MSC_ConnHdlr {
+ /* Hack: the proper way would be to wait for the BSSMAP Handover Request ACK and extract the
+ * actual assigned chan_nr from its L3 (RR Handover Command) message. But osmo-bsc starts acting
+ * on the lchan even before we get a chance to evaluate the BSSMAP Handover Request ACK. So we
+ * need to assume that osmo-bsc will activate TS 1 and already set up this lchan's RSL emulation
+ * before we get started. */
+ var RslChannelNr new_chan_nr := valueof(t_RslChanNr0(1, RSL_CHAN_NR_Bm_ACCH));
+ f_rslem_register(0, new_chan_nr);
+ g_chan_nr := new_chan_nr;
+ f_sleep(1.0);
+
+ f_create_mgcp_expect(ExpectCriteria:{omit,omit,omit});
+ f_MscConnHdlr_init(g_pars.media_nr, "127.0.0.2", "127.0.0.3", FR_AMR);
+ activate(as_Media());
+
+ BSSAP.send(ts_BSSAP_Conn_Req(g_pars.handover.sccp_addr_bsc, g_pars.handover.sccp_addr_msc,
+ f_gen_handover_req()));
+ BSSAP.receive(BSSAP_Conn_Prim:MSC_CONN_PRIM_CONF_IND);
+
+ /* The RSL Emulation magically accepts the Chan Activ behind the scenes. */
+
+ var PDU_BSSAP rx_bssap;
+ var octetstring ho_command_str;
+
+ BSSAP.receive(tr_BSSMAP_HandoverRequestAcknowledge(?)) -> value rx_bssap;
+
+ ho_command_str := rx_bssap.pdu.bssmap.handoverRequestAck.layer3Information.layer3info;
+ log("Received L3 Info in HO Request Ack: ", ho_command_str);
+ var PDU_ML3_NW_MS ho_command := dec_PDU_ML3_NW_MS(ho_command_str);
+ log("L3 Info in HO Request Ack is ", ho_command);
+
+ var GsmArfcn arfcn;
+ var RslChannelNr actual_new_chan_nr;
+ f_ChDesc2RslChanNr(ho_command.msgs.rrm.handoverCommand.channelDescription2,
+ actual_new_chan_nr, arfcn);
+
+ if (actual_new_chan_nr != new_chan_nr) {
+ log("ERROR: osmo-bsc assigned a different lchan than we assumed above -- this test will fail now.",
+ " Assumed: ", new_chan_nr, " Assigned: ", actual_new_chan_nr);
+ setverdict(fail);
+ return;
+ }
+ log("Handover Command chan_nr is", actual_new_chan_nr);
+
+ /* Now the MSC forwards the RR Handover Command to the other BSC, which
+ * tells the MS to handover to the new lchan. Here comes the new MS on
+ * the new lchan with a Handover RACH: */
+
+ /* send handover detect */
+
+ RSL.send(ts_RSL_HANDO_DET(new_chan_nr));
+
+ BSSAP.receive(tr_BSSMAP_HandoverDetect);
+
+ /* send handover complete over the new channel */
+
+ var PDU_ML3_MS_NW l3_tx := valueof(ts_RRM_HandoverComplete('00'O));
+ RSL.send(ts_RSL_EST_IND(new_chan_nr, valueof(ts_RslLinkID_DCCH(0)),
+ enc_PDU_ML3_MS_NW(l3_tx)));
+
+ BSSAP.receive(tr_BSSMAP_HandoverComplete);
+ setverdict(pass);
+}
+testcase TC_ho_into_this_bsc() runs on test_CT {
+ var MSC_ConnHdlr vc_conn;
+ var TestHdlrParams pars := valueof(t_def_TestHdlrPars);
+
+ f_init(1, true);
+ f_sleep(1.0);
+
+ pars.handover.sccp_addr_msc := g_bssap.sccp_addr_own;
+ pars.handover.sccp_addr_bsc := g_bssap.sccp_addr_peer;
+
+ vc_conn := f_start_handler(refers(f_tc_ho_into_this_bsc), pars);
+ vc_conn.done;
+}
+
+
/* OS#3041: Open and close N connections in a normal fashion, and expect no
* BSSMAP Reset just because of that. */
testcase TC_bssap_rlsd_does_not_cause_bssmap_reset() runs on test_CT {
@@ -2648,7 +2822,10 @@
execute( TC_unsol_ho_fail() );
execute( TC_err_82_short_msg() );
execute( TC_err_84_unknown_msg() );
+
execute( TC_ho_int() );
+ execute( TC_ho_out_of_this_bsc() );
+ execute( TC_ho_into_this_bsc() );
execute( TC_bssap_rlsd_does_not_cause_bssmap_reset() );
execute( TC_bssmap_clear_does_not_cause_bssmap_reset() );