BSC_Tests: fix a race condition in TC_chan_rel_conn_fail

Change-Id: Ic8ee641c19f47442538eaba2b120736bec793c70
Fixes: OS#5823
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index 4753ae9..501b3e9 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -1976,6 +1976,10 @@
 
 	dt := f_est_dchan('23'O, 23, '00010203040506'O);
 
+	/* Sending CONN FAIL IND immediately may trigger a race condition.
+	 * Give the BSC some time to process a new SCCP connection (OS#5823). */
+	f_sleep(0.2);
+
 	/* simulate CONN FAIL IND */
 	f_ipa_tx(ts_RSL_CONN_FAIL_IND(dt.rsl_chan_nr, RSL_ERR_RADIO_LINK_FAIL));
 	/* TODO: different cause values? */