diff --git a/gbproxy/GBProxy_Tests.ttcn b/gbproxy/GBProxy_Tests.ttcn
index c496ca8ac..dd33106cd 100644
--- a/gbproxy/GBProxy_Tests.ttcn
+++ b/gbproxy/GBProxy_Tests.ttcn
@@ -337,6 +337,8 @@ type component test_CT extends CTRL_Adapter_CT {
 	var GbInstances g_pcu;
 	var GbInstances g_sgsn;
 
+	port NS_CTRL_PT NS_CTRL;
+
 	port BSSGP_CT_PROC_PT PROC;
 
 	port BSSGP_BVC_MGMT_PT SGSN_MGMT;
@@ -1130,6 +1132,53 @@ testcase TC_ul_unitdata() runs on test_CT
 	f_cleanup();
 }
 
+
+/* send uplink-unitdata of a variety of different sizes; expect it to show up on the only connected SGSN */
+private function f_TC_ul_unitdata_pool_failure(charstring id) runs on BSSGP_ConnHdlr {
+	var integer ran_idx := 0;
+	var BssgpBvcConfig bvcc := g_pars.pcu[ran_idx].cfg.bvc[0];
+	var integer i;
+
+	/* All data should arrive at the one SGSN that is still up */
+	g_pars.sgsn_idx := 0;
+
+	for (i := 0; i < max_fr_info_size-4; i := i+4) {
+		var octetstring payload := f_rnd_octstring(i);
+		var template (value) PDU_BSSGP pdu_tx := ts_BSSGP_UL_UD(g_pars.tlli, bvcc.cell_id, payload);
+		/* we cannot use pdu_tx as there are some subtle differences in the length field :/ */
+		var template (present) PDU_BSSGP pdu_rx := tr_BSSGP_UL_UD(g_pars.tlli, bvcc.cell_id, payload);
+
+		log("UL-UNITDATA(payload_size=", i);
+		f_pcu2sgsn(pdu_tx, pdu_rx);
+	}
+	setverdict(pass);
+}
+
+testcase TC_ul_unitdata_pool_failure() runs on test_CT
+{
+	var integer i;
+	var integer j;
+
+	f_init(60.0);
+
+	for (i := 1; i < lengthof(mp_nsconfig_sgsn); i := i+1) {
+		connect(self:NS_CTRL, g_sgsn[i].vc_NS:NS_CTRL);
+		for (j := 0; j < lengthof(mp_nsconfig_sgsn[i].nsvc); j := j+1) {
+			var uint16_t nsvci := mp_nsconfig_sgsn[i].nsvc[j].nsvci;
+			var NsDisableVcRequest tx_disar;
+			tx_disar.nsvci := nsvci;
+			NS_CTRL.send(tx_disar);
+		}
+		disconnect(self:NS_CTRL, g_sgsn[i].vc_NS:NS_CTRL);
+	}
+	/* Wait until gbproxy notices that the NSVCs are down */
+	f_sleep(15.0);
+
+	f_start_handlers(refers(f_TC_ul_unitdata_pool_failure), testcasename(), 1);
+	/* TODO: start multiple handlers (UEs) on various cells on same and other NSEs */
+	f_cleanup();
+}
+
 /* send downlink-unitdata of a variety of different sizes; expect it to show up on PCU */
 private function f_TC_dl_unitdata(charstring id) runs on BSSGP_ConnHdlr {
 	var integer i;
@@ -3461,6 +3510,7 @@ testcase TC_status_ptp_dl_bvci() runs on GlobalTest_CT
 control {
 	execute( TC_BVC_bringup() );
 	execute( TC_ul_unitdata() );
+	execute( TC_ul_unitdata_pool_failure() );
 	execute( TC_dl_unitdata() );
 	execute( TC_ra_capability() );
 	execute( TC_ra_capability_upd() );
diff --git a/gbproxy/osmo-gbproxy.cfg b/gbproxy/osmo-gbproxy.cfg
index dab4ef354..d26956705 100644
--- a/gbproxy/osmo-gbproxy.cfg
+++ b/gbproxy/osmo-gbproxy.cfg
@@ -42,6 +42,6 @@ ns
  timer tns-block-retries 3
  timer tns-reset 3
  timer tns-reset-retries 3
- timer tns-test 30
- timer tns-alive 3
- timer tns-alive-retries 10
+ timer tns-test 5
+ timer tns-alive 2
+ timer tns-alive-retries 3