fixeria has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-ttcn3-hacks/+/27986 )

Change subject: BTS_Tests: fix expectations in TC_speech_no_rtp_tch[fh] ......................................................................

BTS_Tests: fix expectations in TC_speech_no_rtp_tch[fh]

On receipt of a FACCH block, trxcon generates not only a DATA.ind, but also one or two artificial TRAFFIC.ind with BFI. These BFIs have CRC != 0 indicating their nature, so my initial assumption about CRC being 0 was incorrect.

Instead of checking CRC, let's count received dummy FACCH frammes. This patch makes both TC_speech_no_rtp_tch[fh] pass.

Change-Id: Ic680002f60e598cfeeb448c517581b3506355e5b Related: SYS#5919 Fixes: OS#4823 --- M bts/BTS_Tests.ttcn 1 file changed, 27 insertions(+), 12 deletions(-)

git pull ssh://gerrit.osmocom.org:29418/osmo-ttcn3-hacks refs/changes/86/27986/1

diff --git a/bts/BTS_Tests.ttcn b/bts/BTS_Tests.ttcn index 06fe43b..4bcb90b 100644 --- a/bts/BTS_Tests.ttcn +++ b/bts/BTS_Tests.ttcn @@ -7893,10 +7893,12 @@ Misc_Helpers.f_shutdown(__BFILE__, __LINE__); }

+/* Verify that we get dummy FACCH blocks on Downlink in the absence of RTP frames */ private function f_TC_speech_no_rtp(charstring id) runs on ConnHdlr { - var template L1ctlDlMessage tr_bad_frame; + var integer facch_count := 0; + var integer facch_count_exp; var L1ctlDlMessage l1_dl; - timer T := 8.0; + timer T := 2.0;

f_l1_tune(L1CTL); RSL.clear; @@ -7907,27 +7909,40 @@ f_sleep(2.0); /* ... so let's give the L1 some time to stabilize */ L1CTL.clear;

- /* A universal template for bad Downlink frame: {DATA,TRAFFIC}.ind */ - tr_bad_frame := tr_L1CTL_TRAFFIC_IND(g_chan_nr, tr_RslLinkID_DCCH(0)); - tr_bad_frame.header.msg_type := (L1CTL_DATA_IND, L1CTL_TRAFFIC_IND); - tr_bad_frame.dl_info.fire_crc := (1..255); /* != 0 */ - tr_bad_frame.payload := ?; - T.start; alt { - /* OS#4823: DATA.ind or TRAFFIC.ind with bad CRC most likely means that - * the IUT is sending *dummy bursts*, so the L1 fails to decode them. */ - [] L1CTL.receive(tr_bad_frame) -> value l1_dl { - setverdict(fail, "Received {DATA,TRAFFIC}.ind with bad CRC: ", l1_dl); + /* Expect dummy FACCH frames with LAPDm func=UI */ + [] L1CTL.receive(tr_L1CTL_DATA_IND(g_chan_nr, tr_RslLinkID_DCCH(0))) -> value l1_dl { + var octetstring payload := l1_dl.payload.data_ind.payload; + /* XXX: TITAN does not support match(payload, '0303012b?#19'O) */ + if (substr(payload, 0, 4) != '0303012B'O) { + setverdict(fail, "Unexpected FACCH payload := ", payload); + Misc_Helpers.f_shutdown(__BFILE__, __LINE__); + } + log("Rx FACCH frame: ", payload); + facch_count := facch_count + 1; + repeat; } [] as_l1_sacch(); [] L1CTL.receive { repeat; } [] T.timeout { /* We're done, break the loop */ + log("Rx ", facch_count, " dummy FACCH blocks"); setverdict(pass); } }

+ /* Expect a certain number of FACCH frames depending on the channel rate */ + if (match(g_chan_nr, t_RslChanNr_Bm(?))) { + facch_count_exp := 90; /* ~50 FACCH/F blocks/s, so at least 90 in 2s */ + } else { + facch_count_exp := 40; /* ~25 FACCH/H blocks/s, so at least 40 in 2s */ + } + if (facch_count < facch_count_exp) { + setverdict(fail, "Expected at least ", facch_count_exp, " DL FACCH frames, ", + "but received ", facch_count); + } + f_rsl_chan_deact(); f_L1CTL_DM_REL_REQ(L1CTL, g_chan_nr); }