diff --git a/Makefile b/Makefile
index 1813bc5..fda0ea1 100644
--- a/Makefile
+++ b/Makefile
@@ -8,7 +8,6 @@ LDFLAGS = -X github.com/free5gc/version.BUILD_TIME=$(BUILD_TIME) \
 
 n3iwue: clean
 	@echo "Start building $(@F)...."
-	go mod tidy
 	CGO_ENABLED=0 go build -gcflags "$(GCFLAGS)" -ldflags "$(LDFLAGS)" -o $(ROOT_PATH)/$@ $(@F).go
 
 debug: GCFLAGS += -N -l
diff --git a/config/n3ue.yaml b/config/n3ue.yaml
index 2abe8ca..0fda7eb 100644
--- a/config/n3ue.yaml
+++ b/config/n3ue.yaml
@@ -35,7 +35,7 @@ configuration:
             SQN: 16f3b3f71005
             AMF: 8000
             OP: b672047e003bb952dca6cb8af0e5b779
-            OPC: df0c67868fa25f748b7044c6e7c245b8
+            OPC: df0c67868fa25f748b7044c6e7c245b8 # not support
 logger:
     N3UE: # the kind of log output
         debugLevel: trace # how detailed to output, value: trace, debug, info, warn, error, fatal, panic
diff --git a/internal/gre/gre.go b/internal/gre/gre.go
index 5dc07c9..dfe513f 100644
--- a/internal/gre/gre.go
+++ b/internal/gre/gre.go
@@ -21,7 +21,7 @@ func SetupGreTunnel(greIfaceName, parentIfaceName string, ueTunnelAddr, n3iwfTun
 	)
 
 	if qoSInfo != nil {
-		greKeyField |= (uint32(qoSInfo.QfiList[0]) & 0x3F) << 24
+		greKeyField |= (uint32(qoSInfo.MaxQFI()) & 0x3F) << 24
 	}
 
 	if parent, err = netlink.LinkByName(parentIfaceName); err != nil {
diff --git a/internal/qos/qos.go b/internal/qos/qos.go
index 2242cc7..1924d1a 100644
--- a/internal/qos/qos.go
+++ b/internal/qos/qos.go
@@ -35,3 +35,11 @@ func Parse5GQoSInfoNotify(n *message.Notification) (info *PDUQoSInfo, err error)
 
 	return
 }
+
+func (pduQosInfo PDUQoSInfo) MaxQFI() uint8 {
+	var maxQfi uint8 = 0
+	for _, qfi := range pduQosInfo.QfiList {
+		maxQfi = max(maxQfi, qfi)
+	}
+	return maxQfi
+}
diff --git a/pkg/procedure/Procedure.go b/pkg/procedure/Procedure.go
index d9ef801..4ca0b68 100644
--- a/pkg/procedure/Procedure.go
+++ b/pkg/procedure/Procedure.go
@@ -65,13 +65,20 @@ func StartProcedure() {
 				}
 			case context.PduSessionCreated:
 				AppLog.Info("PduSession Created")
-				if err := TestConnectivity("8.8.8.8"); err != nil {
-					AppLog.Errorf("ping fail : %+v", err)
+
+				pingDest := "1.1.1.1"
+				if err := TestConnectivity(pingDest); err != nil {
+					AppLog.Errorf("ping fail %s: %+v", pingDest, err)
 				} else {
-					logger.NASLog.Infof("ULCount=%x, DLCount=%x",
-						n3ueSelf.RanUeContext.ULCount.Get(),
-						n3ueSelf.RanUeContext.DLCount.Get())
-					AppLog.Info("Keep connection with N3IWF until receive SIGINT or SIGTERM")
+					pingDest = "8.8.8.8"
+					if err := TestConnectivity(pingDest); err != nil {
+						AppLog.Errorf("ping fail %s: %+v", pingDest, err)
+					} else {
+						logger.NASLog.Infof("ULCount=%x, DLCount=%x",
+							n3ueSelf.RanUeContext.ULCount.Get(),
+							n3ueSelf.RanUeContext.DLCount.Get())
+						AppLog.Info("Keep connection with N3IWF until receive SIGINT or SIGTERM")
+					}
 				}
 			}
 		}