diff --git a/library/GTPv2_Emulation.ttcn b/library/GTPv2_Emulation.ttcn
index eb2b977..240cce4 100644
--- a/library/GTPv2_Emulation.ttcn
+++ b/library/GTPv2_Emulation.ttcn
@@ -560,7 +560,12 @@
 	/* route inbound GTP2-C based on TEID, SEQ or IMSI */
 	[] GTP2C.receive(Gtp2cUnitdata:?) -> value g2c_ud {
 		var template hexstring imsi_t := f_gtp2c_extract_imsi(g2c_ud.gtpc);
-		if (isvalue(imsi_t) and f_imsi_known(valueof(imsi_t))) {
+		/* if this is a response, route by SEQ: */
+		if (match(g2c_ud.gtpc, tr_PDU_GTP2C_msgtypes(gtp2_responses))
+			  and f_seq_known(g2c_ud.gtpc.sequenceNumber)) {
+			vc_conn := f_comp_by_seq(g2c_ud.gtpc.sequenceNumber);
+			CLIENT.send(g2c_ud.gtpc) to vc_conn;
+		}else if (isvalue(imsi_t) and f_imsi_known(valueof(imsi_t))) {
 			vc_conn := f_comp_by_imsi(valueof(imsi_t));
 			CLIENT.send(g2c_ud.gtpc) to vc_conn;
 		} else if ((ispresent(g2c_ud.gtpc.tEID) and g2c_ud.gtpc.tEID != '00000000'O)
@@ -571,13 +576,11 @@
 			   and f_teid_known('00000000'O)) {
 			vc_conn := f_comp_by_teid(g2c_ud.gtpc.tEID);
 			CLIENT.send(g2c_ud.gtpc) to vc_conn;
-		/* if this is a response, route by SEQ: */
-		} else if (match(g2c_ud.gtpc, tr_PDU_GTP2C_msgtypes(gtp2_responses))
-			   and f_seq_known(g2c_ud.gtpc.sequenceNumber)) {
-			vc_conn := f_comp_by_seq(g2c_ud.gtpc.sequenceNumber);
-			CLIENT.send(g2c_ud.gtpc) to vc_conn;
 		} else {
 			SendToUdMsgTable(g2c_ud);
+			if (not ispresent(g2c_ud.gtpc.tEID) or g2c_ud.gtpc.tEID == '00000000'O) {
+				TEID0.send(g2c_ud.gtpc);
+			}
 		}
 
 		/* remove sequence number if response was received */