diff --git a/tests/alloc/AllocTest.cpp b/tests/alloc/AllocTest.cpp
index 66bc84f..b6f263f 100644
--- a/tests/alloc/AllocTest.cpp
+++ b/tests/alloc/AllocTest.cpp
@@ -38,13 +38,13 @@
 
 static gprs_rlcmac_tbf *tbf_alloc(struct gprs_rlcmac_bts *bts,
 		GprsMs *ms, gprs_rlcmac_tbf_direction dir,
-		uint8_t tfi, uint8_t trx,
+		uint8_t use_trx,
 		uint8_t ms_class, uint8_t single_slot)
 {
 	if (dir == GPRS_RLCMAC_UL_TBF)
-		return tbf_alloc_ul_tbf(bts, ms, tfi, trx, ms_class, single_slot);
+		return tbf_alloc_ul_tbf(bts, ms, use_trx, ms_class, single_slot);
 	else
-		return tbf_alloc_dl_tbf(bts, ms, tfi, trx, ms_class, single_slot);
+		return tbf_alloc_dl_tbf(bts, ms, use_trx, ms_class, single_slot);
 }
 
 static void check_tfi_usage(BTS *the_bts)
@@ -133,9 +133,7 @@
 	 * least this part is working okay.
 	 */
 	for (int i = 0; i < count; ++i) {
-		tfi = the_bts.tfi_find_free(dir, &used_trx, 0);
-		OSMO_ASSERT(tfi >= 0);
-		tbfs[i] = tbf_alloc(bts, NULL, dir, tfi, used_trx, 0, 0);
+		tbfs[i] = tbf_alloc(bts, NULL, dir, -1, 0, 0);
 		OSMO_ASSERT(tbfs[i] != NULL);
 		tfi = the_bts.tfi_find_free(dir, &tmp_trx, used_trx);
 		OSMO_ASSERT(tbfs[i]->tfi() != tfi);
@@ -151,16 +149,13 @@
 		OSMO_ASSERT(tfi < 0);
 		break;
 	}
-	OSMO_ASSERT(!tbf_alloc(bts, NULL, dir, tfi, used_trx, 0, 0));
+	OSMO_ASSERT(!tbf_alloc(bts, NULL, dir, -1, 0, 0));
 
 	for (size_t i = 0; i < ARRAY_SIZE(tbfs); ++i)
 		if (tbfs[i])
 			tbf_free(tbfs[i]);
 
-	tfi = the_bts.tfi_find_free(dir, &used_trx, 0);
-	OSMO_ASSERT(tfi >= 0);
-
-	tbfs[tfi] = tbf_alloc(bts, NULL, dir, tfi, used_trx, 0, 0);
+	tbfs[tfi] = tbf_alloc(bts, NULL, dir, -1, 0, 0);
 	OSMO_ASSERT(tbfs[tfi]);
 	tbf_free(tbfs[tfi]);
 }
@@ -198,7 +193,6 @@
 		BTS the_bts;
 		struct gprs_rlcmac_bts *bts;
 		struct gprs_rlcmac_trx *trx;
-		int tfi;
 		uint8_t trx_no;
 
 		gprs_rlcmac_tbf *ul_tbf, *dl_tbf;
@@ -213,16 +207,15 @@
 		trx->pdch[6].enable();
 		trx->pdch[7].enable();
 
-		tfi = the_bts.tfi_find_free(GPRS_RLCMAC_UL_TBF, &trx_no, -1);
-		OSMO_ASSERT(tfi >= 0);
-		ul_tbf = tbf_alloc_ul_tbf(bts, NULL, tfi, trx_no, ms_class, 1);
+		ul_tbf = tbf_alloc_ul_tbf(bts, NULL, -1, ms_class, 1);
 		OSMO_ASSERT(ul_tbf);
+		OSMO_ASSERT(ul_tbf->ms());
+		OSMO_ASSERT(ul_tbf->ms()->current_trx());
+		trx_no = ul_tbf->ms()->current_trx()->trx_no;
 		dump_assignment(ul_tbf, "UL");
 
 		/* assume final ack has not been sent */
-		tfi = the_bts.tfi_find_free(GPRS_RLCMAC_UL_TBF, &trx_no, -1);
-		OSMO_ASSERT(tfi >= 0);
-		dl_tbf = tbf_alloc_dl_tbf(bts, ul_tbf->ms(), tfi, trx_no, ms_class, 0);
+		dl_tbf = tbf_alloc_dl_tbf(bts, ul_tbf->ms(), trx_no, ms_class, 0);
 		OSMO_ASSERT(dl_tbf);
 		dump_assignment(dl_tbf, "DL");
 
@@ -241,7 +234,6 @@
 		BTS the_bts;
 		struct gprs_rlcmac_bts *bts;
 		struct gprs_rlcmac_trx *trx;
-		int tfi;
 		uint8_t trx_no;
 
 		gprs_rlcmac_ul_tbf *ul_tbf;
@@ -257,16 +249,15 @@
 		trx->pdch[6].enable();
 		trx->pdch[7].enable();
 
-		tfi = the_bts.tfi_find_free(GPRS_RLCMAC_UL_TBF, &trx_no, -1);
-		OSMO_ASSERT(tfi >= 0);
-		dl_tbf = tbf_alloc_dl_tbf(bts, NULL, tfi, trx_no, ms_class, 1);
+		dl_tbf = tbf_alloc_dl_tbf(bts, NULL, -1, ms_class, 1);
 		dl_tbf->update_ms(0x23, GPRS_RLCMAC_DL_TBF);
 		OSMO_ASSERT(dl_tbf);
+		OSMO_ASSERT(dl_tbf->ms());
+		OSMO_ASSERT(dl_tbf->ms()->current_trx());
+		trx_no = dl_tbf->ms()->current_trx()->trx_no;
 		dump_assignment(dl_tbf, "DL");
 
-		tfi = the_bts.tfi_find_free(GPRS_RLCMAC_UL_TBF, &trx_no, -1);
-		OSMO_ASSERT(tfi >= 0);
-		ul_tbf = tbf_alloc_ul_tbf(bts, dl_tbf->ms(), tfi, trx_no, ms_class, 0);
+		ul_tbf = tbf_alloc_ul_tbf(bts, dl_tbf->ms(), trx_no, ms_class, 0);
 		ul_tbf->update_ms(0x23, GPRS_RLCMAC_UL_TBF);
 		ul_tbf->m_contention_resolution_done = 1;
 		OSMO_ASSERT(ul_tbf);
@@ -308,14 +299,15 @@
 
 		tfi = the_bts.tfi_find_free(GPRS_RLCMAC_UL_TBF, &trx_no, -1);
 		OSMO_ASSERT(tfi >= 0);
-		ul_tbf = tbf_alloc_ul_tbf(bts, NULL, tfi, trx_no, ms_class, 0);
+		ul_tbf = tbf_alloc_ul_tbf(bts, NULL, .1, ms_class, 0);
 		OSMO_ASSERT(ul_tbf);
+		OSMO_ASSERT(ul_tbf->ms());
+		OSMO_ASSERT(ul_tbf->ms()->current_trx());
+		trx_no = ul_tbf->ms()->current_trx()->trx_no;
 		dump_assignment(ul_tbf, "UL");
 
 		/* assume final ack has not been sent */
-		tfi = the_bts.tfi_find_free(GPRS_RLCMAC_UL_TBF, &trx_no, -1);
-		OSMO_ASSERT(tfi >= 0);
-		dl_tbf = tbf_alloc_dl_tbf(bts, ul_tbf->ms(), tfi, trx_no, ms_class, 0);
+		dl_tbf = tbf_alloc_dl_tbf(bts, ul_tbf->ms(), trx_no, ms_class, 0);
 		OSMO_ASSERT(dl_tbf);
 		dump_assignment(dl_tbf, "DL");
 
@@ -353,7 +345,6 @@
 		BTS the_bts;
 		struct gprs_rlcmac_bts *bts;
 		struct gprs_rlcmac_trx *trx;
-		int tfi;
 		uint8_t trx_no;
 
 		gprs_rlcmac_tbf *ul_tbf, *dl_tbf;
@@ -371,16 +362,14 @@
 		ENABLE_PDCH(6, ts6, trx);
 		ENABLE_PDCH(7, ts7, trx);
 
-		tfi = the_bts.tfi_find_free(GPRS_RLCMAC_UL_TBF, &trx_no, -1);
-
-		OSMO_ASSERT(tfi >= 0);
-		ul_tbf = tbf_alloc_ul_tbf(bts, NULL, tfi, trx_no, ms_class, 1);
+		ul_tbf = tbf_alloc_ul_tbf(bts, NULL, -1, ms_class, 1);
+		OSMO_ASSERT(ul_tbf->ms());
+		OSMO_ASSERT(ul_tbf->ms()->current_trx());
+		trx_no = ul_tbf->ms()->current_trx()->trx_no;
 		OSMO_ASSERT(ul_tbf);
 
 		/* assume final ack has not been sent */
-		tfi = the_bts.tfi_find_free(GPRS_RLCMAC_UL_TBF, &trx_no, -1);
-		OSMO_ASSERT(tfi >= 0);
-		dl_tbf = tbf_alloc_dl_tbf(bts, ul_tbf->ms(), tfi, trx_no, ms_class, 0);
+		dl_tbf = tbf_alloc_dl_tbf(bts, ul_tbf->ms(), trx_no, ms_class, 0);
 		OSMO_ASSERT(dl_tbf);
 
 		/* verify that both are on the same ts */
@@ -399,7 +388,6 @@
 		BTS the_bts;
 		struct gprs_rlcmac_bts *bts;
 		struct gprs_rlcmac_trx *trx;
-		int tfi;
 		uint8_t trx_no;
 
 		gprs_rlcmac_ul_tbf *ul_tbf;
@@ -418,15 +406,14 @@
 		ENABLE_PDCH(6, ts6, trx);
 		ENABLE_PDCH(7, ts7, trx);
 
-		tfi = the_bts.tfi_find_free(GPRS_RLCMAC_UL_TBF, &trx_no, -1);
-		OSMO_ASSERT(tfi >= 0);
-		dl_tbf = tbf_alloc_dl_tbf(bts, NULL, tfi, trx_no, ms_class, 1);
+		dl_tbf = tbf_alloc_dl_tbf(bts, NULL, -1, ms_class, 1);
 		OSMO_ASSERT(dl_tbf);
+		OSMO_ASSERT(dl_tbf->ms());
+		OSMO_ASSERT(dl_tbf->ms()->current_trx());
+		trx_no = dl_tbf->ms()->current_trx()->trx_no;
 		dl_tbf->update_ms(0x23, GPRS_RLCMAC_DL_TBF);
 
-		tfi = the_bts.tfi_find_free(GPRS_RLCMAC_UL_TBF, &trx_no, -1);
-		OSMO_ASSERT(tfi >= 0);
-		ul_tbf = tbf_alloc_ul_tbf(bts, dl_tbf->ms(), tfi, trx_no, ms_class, 0);
+		ul_tbf = tbf_alloc_ul_tbf(bts, dl_tbf->ms(), trx_no, ms_class, 0);
 		OSMO_ASSERT(ul_tbf);
 		ul_tbf->update_ms(0x23, GPRS_RLCMAC_UL_TBF);
 		ul_tbf->m_contention_resolution_done = 1;
@@ -472,7 +459,8 @@
 
 typedef int (*algo_t)(struct gprs_rlcmac_bts *bts,
 		struct GprsMs *ms,
-		struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single);
+		struct gprs_rlcmac_tbf *tbf, uint32_t cust, uint8_t single,
+		int use_trx);
 
 static char get_dir_char(uint8_t mask, uint8_t tx, uint8_t rx)
 {
@@ -495,30 +483,28 @@
 	enum test_mode mode)
 {
 	struct gprs_rlcmac_bts *bts;
-	int tfi;
-	uint8_t trx_no;
+	uint8_t trx_no = -1;
 
 	bts = the_bts->bts_data();
 
 	gprs_rlcmac_tbf *tbf = NULL;
 
+	if (ms && ms->current_trx())
+		trx_no = ms->current_trx()->trx_no;
+
 	/* Allocate what is needed first */
 	switch (mode) {
 	case TEST_MODE_UL_ONLY:
 	case TEST_MODE_DL_AFTER_UL:
 	case TEST_MODE_UL_AND_DL:
-		tfi = the_bts->tfi_find_free(GPRS_RLCMAC_UL_TBF, &trx_no, -1);
-		if (tfi < 0)
-			return NULL;
-		tbf = tbf_alloc_ul_tbf(bts, ms, tfi, trx_no, ms_class, 0);
+		tbf = tbf_alloc_ul_tbf(bts, ms, trx_no, ms_class, 0);
 		if (tbf == NULL)
 			return NULL;
 		break;
 	case TEST_MODE_DL_ONLY:
 	case TEST_MODE_UL_AFTER_DL:
 	case TEST_MODE_DL_AND_UL:
-		tfi = the_bts->tfi_find_free(GPRS_RLCMAC_DL_TBF, &trx_no, -1);
-		tbf = tbf_alloc_dl_tbf(bts, ms, tfi, trx_no, ms_class, 0);
+		tbf = tbf_alloc_dl_tbf(bts, ms, trx_no, ms_class, 0);
 		if (tbf == NULL)
 			return NULL;
 	}
diff --git a/tests/alloc/AllocTest.err b/tests/alloc/AllocTest.err
index 2dc99fe..d848aff 100644
--- a/tests/alloc/AllocTest.err
+++ b/tests/alloc/AllocTest.err
@@ -1,36 +1,55 @@
 No TFI available.
 No TFI available.
-- Failed to allocate a TS, no USF available
 No TFI available.
-No TFI available.
+- Failed to allocate a TFI
 - Failed to allocate a TS, no USF available
 No TFI available.
 No TFI available.
 No TFI available.
+- Failed to allocate a TFI
+- Failed to allocate a TS, no USF available
 No TFI available.
 No TFI available.
+- Failed to allocate a TFI
 No TFI available.
 No TFI available.
+- Failed to allocate a TFI
 No TFI available.
 No TFI available.
+- Failed to allocate a TFI
 No TFI available.
 No TFI available.
+- Failed to allocate a TFI
 No TFI available.
 No TFI available.
+- Failed to allocate a TFI
 No TFI available.
 No TFI available.
+- Failed to allocate a TFI
 No TFI available.
 No TFI available.
+- Failed to allocate a TFI
 No TFI available.
 No TFI available.
+- Failed to allocate a TFI
 No TFI available.
 No TFI available.
+- Failed to allocate a TFI
 No TFI available.
 No TFI available.
+- Failed to allocate a TFI
 No TFI available.
 No TFI available.
+- Failed to allocate a TFI
 No TFI available.
 No TFI available.
+- Failed to allocate a TFI
 No TFI available.
 No TFI available.
+- Failed to allocate a TFI
 No TFI available.
+No TFI available.
+- Failed to allocate a TFI
+No TFI available.
+No TFI available.
+- Failed to allocate a TFI