diff --git a/fr-net/FRNET_Tests.ttcn b/fr-net/FRNET_Tests.ttcn
index bc6e513..c3ec468 100644
--- a/fr-net/FRNET_Tests.ttcn
+++ b/fr-net/FRNET_Tests.ttcn
@@ -6,6 +6,8 @@
 
 import from NS_Emulation all;
 import from BSSGP_Emulation all;
+import from LLC_Types all;
+import from LLC_Templates all;
 
 modulepar {
 	integer mp_num_bvc := 10;
@@ -69,7 +71,19 @@
 
 
 private function CreateCallback(BssgpBvci bvci, BssgpCellId cell_id, OCT4 tlli, BssgpDecoded dec) runs on BSSGP_BVC_CT {
-	/* simply ignore any inbound traffic for now */
+	if (ischosen(dec.bssgp.pDU_BSSGP_UL_UNITDATA)) {
+		var PDU_LLC llc_rx := dec_PDU_LLC(dec.bssgp.pDU_BSSGP_UL_UNITDATA.lLC_PDU.lLC_PDU)
+		select (llc_rx) {
+		case (tr_LLC_UI(sapi := '0010'B)) {
+			//log("BVCI=", bvci, ", CellId=", cell_id, ", TLLI=", tlli, ", BSSGP=", dec);
+			/* mirror back as DL-UNITDATA */
+			BVC.send(ts_ptp_BnsUdReq(ts_BSSGP_DL_UD(tlli, dec.bssgp.pDU_BSSGP_UL_UNITDATA.lLC_PDU.lLC_PDU), bvci, oct2int(tlli)));
+			}
+		case else {
+			/* simply ignore any inbound traffic for now */
+			}
+		}
+	}
 }
 
 private function f_init_gb(inout GbInstance gb, charstring id, integer offset) runs on test_CT {