Delay ImmAss(PCH, PktDlAss) if waiting for PKT_CTRL_ACK answering UL_ACK_NACK (FinACK=1)
In that state (ul_tbf=TBF_ST_FINISHED), we are unable to reach the MS to
assign a new DL TBF.
* MS Is not available in CCCH because it's attached the PDCH.
* MS won't be able to PKT_CTRL_ACK a PktDlAss on PACCH, because next
thing it will do is to PKT_CTRL_ACK the UL_ACK_NACK(FINACK=1) we
already polled it for, and immediatelly after that it will release the
UL TBF on its side and go back to packet idle mode.
Hence, we must wait for MS to send the PKT_CTRL_ACK to us in order to be
able to assign the DL TBF in PCH (CCCH).
Related: OS#5700
Change-Id: I7a30db9cc7dae70e04054f1a4dba004bd1780d4a
diff --git a/tests/tbf/TbfTest.cpp b/tests/tbf/TbfTest.cpp
index 43ea8c7..91d1f07 100644
--- a/tests/tbf/TbfTest.cpp
+++ b/tests/tbf/TbfTest.cpp
@@ -1715,7 +1715,6 @@
ms = bts_ms_by_imsi(bts, imsi);
OSMO_ASSERT(ms != NULL);
- OSMO_ASSERT(ms_dl_tbf(ms) != NULL);
if (imsi[0] != '\0') {
ms2 = bts_ms_by_tlli(bts, tlli, GSM_RESERVED_TMSI);
@@ -1779,6 +1778,38 @@
TALLOC_FREE(the_pcu);
}
+static void test_tbf_single_phase2()
+{
+ the_pcu = prepare_pcu();
+ struct gprs_rlcmac_bts *bts = bts_alloc(the_pcu, 0);
+ int ts_no = 7;
+ uint32_t fn = DUMMY_FN; /* 17,25,9 */
+ uint32_t tlli = 0xf1223344;
+ const char *imsi = "0011223344";
+ uint16_t qta = 31;
+ gprs_rlcmac_ul_tbf *ul_tbf;
+
+ fprintf(stderr, "=== start %s ===\n", __func__);
+
+ setup_bts(bts, ts_no);
+
+ ul_tbf = establish_ul_tbf_single_phase(bts, ts_no, tlli, &fn, qta);
+
+ print_ta_tlli(ul_tbf, true);
+ /* PCU sends CTRL ACK/NCK with FINAL_ACK=1, hence TBF is not in state FINISHED */
+ request_dl_rlc_block(bts, ul_tbf->trx->trx_no, ts_no, &fn);
+ OSMO_ASSERT(ul_tbf->state_is(TBF_ST_FINISHED));
+ /* Now data is sent but no DL TBF is created because MS is not reachable for DL Assignment */
+ send_dl_data(bts, tlli, imsi, (const uint8_t *)"TEST", 4);
+
+ /* After MS CTRL ACKs the FINAL_ACK=1 then it releases the TBF and goes
+ * to packet-idle mode. Hence PCU will trigger ImmAss(PktDlAss) on PCH. */
+ send_control_ack(ul_tbf);
+
+ fprintf(stderr, "=== end %s ===\n", __func__);
+ TALLOC_FREE(the_pcu);
+}
+
static void test_tbf_egprs_two_phase_puan(void)
{
the_pcu = prepare_pcu();
@@ -3363,6 +3394,7 @@
test_tbf_exhaustion();
test_tbf_dl_llc_loss();
test_tbf_single_phase();
+ test_tbf_single_phase2();
test_tbf_two_phase();
test_tbf_ra_update_rach();
test_tbf_dl_flow_and_rach_two_phase();