diff --git a/pcu/PCU_Tests.ttcn b/pcu/PCU_Tests.ttcn
index 9829edb..a6d3559 100644
--- a/pcu/PCU_Tests.ttcn
+++ b/pcu/PCU_Tests.ttcn
@@ -446,7 +446,7 @@
 	BSSGP[0].receive(tr_BSSGP_UL_UD(ms.tlli, mp_gb_cfg.bvc[0].cell_id));
 
 	/* Now SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Wait timer X2002 and DL block is available after CCCH IMM ASS: */
@@ -1059,7 +1059,7 @@
 	f_bssgp_client_llgmm_assign(TLLI_UNUSED, ms.tlli);
 
 	/* SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Wait timer X2002 and DL block is available after CCCH IMM ASS: */
@@ -1102,7 +1102,7 @@
 	f_bssgp_client_llgmm_assign(TLLI_UNUSED, ms.tlli);
 
 	/* SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, ms_racap));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, ms_racap, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Wait timer X2002 and DL block is available after CCCH IMM ASS */
@@ -1332,7 +1332,7 @@
 	f_bssgp_client_llgmm_assign(TLLI_UNUSED, ms.tlli);
 
 	/* SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, bssgp_ms_racap_egprs_def));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, bssgp_ms_racap_egprs_def, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Wait timer X2002 and DL block is available after CCCH IMM ASS: */
@@ -1726,7 +1726,7 @@
 	f_bssgp_client_llgmm_assign(TLLI_UNUSED, ms.tlli);
 
 	/* SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data1));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data1, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Wait timer X2002 and DL block is available after CCCH IMM ASS: */
@@ -1827,7 +1827,7 @@
 	f_bssgp_client_llgmm_assign(TLLI_UNUSED, ms.tlli);
 
 	/* SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data1));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data1, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Wait timer X2002 and DL block is available after CCCH IMM ASS: */
@@ -1906,7 +1906,7 @@
 	f_bssgp_client_llgmm_assign(TLLI_UNUSED, ms.tlli);
 
 	/* SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Wait timer X2002 and DL block is available after CCCH IMM ASS: */
@@ -1980,7 +1980,7 @@
 	f_bssgp_client_llgmm_assign(TLLI_UNUSED, ms.tlli);
 
 	/* SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data1));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data1, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Wait timer X2002 and DL block is available after CCCH IMM ASS: */
@@ -2053,7 +2053,7 @@
 	}
 
 	/* after T_3195 timeout, TBF is released */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data2));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data2, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Wait timer X2002 and DL block is available after CCCH IMM ASS: */
@@ -2118,7 +2118,7 @@
 	}
 
 	/* SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Wait timer X2002 and DL block is available after CCCH IMM ASS: */
@@ -2434,7 +2434,7 @@
 	BSSGP[0].receive(tr_BSSGP_UL_UD(ms.tlli, mp_gb_cfg.bvc[0].cell_id));
 
 	/* Now SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Wait timer X2002 and DL block is available after CCCH IMM ASS: */
@@ -2624,7 +2624,7 @@
 	f_bssgp_client_llgmm_assign(TLLI_UNUSED, ms.tlli);
 
 	/* SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, ms_racap));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, ms_racap, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Wait timer X2002 and DL block is available after CCCH IMM ASS: */
@@ -2779,7 +2779,7 @@
 	f_bssgp_client_llgmm_assign(TLLI_UNUSED, ms.tlli);
 
 	/* SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Wait timer X2002 and DL block is available after CCCH IMM ASS: */
@@ -2830,7 +2830,7 @@
 	f_bssgp_client_llgmm_assign(TLLI_UNUSED, ms.tlli);
 
 	/* SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Wait timer X2002 and DL block is available after CCCH IMM ASS */
@@ -3027,7 +3027,7 @@
 	f_bssgp_client_llgmm_assign(TLLI_UNUSED, ms.tlli);
 
 	/* SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data1));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data1, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Wait timer X2002 and DL block is available after CCCH IMM ASS: */
@@ -3126,7 +3126,7 @@
 
 	/* SGSN sends some low prio DL data, PCU will page on CCCH (PCH) */
 	for (var integer i := 0; i < 10; i := i + 1) {
-		BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data_sapi_other));
+		BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data_sapi_other, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	}
 	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data_sapi2));
 	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data_sapi7));
@@ -3644,7 +3644,7 @@
 	f_bssgp_client_llgmm_assign(TLLI_UNUSED, ms.tlli);
 
 	/* SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, racap_tmpl));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, racap_tmpl, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Wait timer X2002 and DL block is available after CCCH IMM ASS: */
@@ -4150,7 +4150,7 @@
 	f_bssgp_client_llgmm_assign(TLLI_UNUSED, ms.tlli);
 
 	/* SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, ms_racap));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, ms_racap, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	f_ms_exp_dl_tbf_ass_ccch(ms);
 
 	/* Wait timer X2002 and DL block is available after CCCH IMM ASS */
@@ -4242,7 +4242,7 @@
 	/* 1 UL block should be received in SGSN */
 	BSSGP[0].receive(tr_BSSGP_UL_UD(ms.tlli, mp_gb_cfg.bvc[0].cell_id));
 	/* Now SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, imsi := ts_BSSGP_IMSI(ms.imsi)));
 
 	/* UL ACK/NACK sets poll+rrbp requesting PACKET CONTROL ACK */
 	f_ms_tx_ul_block(ms, ts_RLCMAC_CTRL_ACK(ms.tlli), sched_fn);
@@ -4309,7 +4309,7 @@
 	/* 1 UL block should be received in SGSN */
 	BSSGP[0].receive(tr_BSSGP_UL_UD(ms.tlli, mp_gb_cfg.bvc[0].cell_id));
 	/* Now SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, imsi := ts_BSSGP_IMSI(ms.imsi)));
 
 	/* UL ACK/NACK sets poll+rrbp requesting PACKET CONTROL ACK */
 	f_ms_tx_ul_block(ms, ts_RLCMAC_CTRL_ACK(ms.tlli), sched_fn);
@@ -4389,7 +4389,7 @@
 	/* 1 UL block should be received in SGSN */
 	BSSGP[0].receive(tr_BSSGP_UL_UD(ms.tlli, mp_gb_cfg.bvc[0].cell_id));
 	/* Now SGSN sends some DL data, PCU will page on CCCH (PCH) */
-	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data));
+	BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, imsi := ts_BSSGP_IMSI(ms.imsi)));
 
 	/* UL ACK/NACK sets poll+rrbp requesting PACKET CONTROL ACK */
 	f_ms_tx_ul_block(ms, ts_RLCMAC_CTRL_ACK(ms.tlli), sched_fn);
@@ -7354,9 +7354,9 @@
 	/* SGSN sends some DL data, PCU will page on CCCH (PCH) */
 	var octetstring data := f_rnd_octstring(1400);
 	if (egprs) {
-		BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, bssgp_ms_racap_egprs));
+		BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, bssgp_ms_racap_egprs, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	} else {
-		BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, bssgp_ms_racap_gprs));
+		BSSGP[0].send(ts_BSSGP_DL_UD(ms.tlli, data, bssgp_ms_racap_gprs, imsi := ts_BSSGP_IMSI(ms.imsi)));
 	}
 	f_ms_exp_dl_tbf_ass_ccch(ms);