diff --git a/ie/dl-buffering-suggested-packet-count.go b/ie/dl-buffering-suggested-packet-count.go
index 166086ce..287b02ba 100644
--- a/ie/dl-buffering-suggested-packet-count.go
+++ b/ie/dl-buffering-suggested-packet-count.go
@@ -36,7 +36,7 @@ func (i *IE) DLBufferingSuggestedPacketCount() (uint16, error) {
 
 		return 0, io.ErrUnexpectedEOF
 	case UpdateBARWithinSessionReportResponse:
-		ies, err := i.CreateBAR()
+		ies, err := i.UpdateBAR()
 		if err != nil {
 			return 0, err
 		}
diff --git a/ie/ethertype.go b/ie/ethertype.go
index 73e1f842..1d1f918b 100644
--- a/ie/ethertype.go
+++ b/ie/ethertype.go
@@ -29,7 +29,7 @@ func (i *IE) Ethertype() (uint16, error) {
 			return 0, err
 		}
 		for _, x := range ies {
-			if x.Type == EthernetPacketFilter {
+			if x.Type == Ethertype {
 				return x.Ethertype()
 			}
 		}
diff --git a/ie/ie_uint16_test.go b/ie/ie_uint16_test.go
new file mode 100644
index 00000000..0a0b8871
--- /dev/null
+++ b/ie/ie_uint16_test.go
@@ -0,0 +1,308 @@
+// Copyright 2019-2020 go-pfcp authors. All rights reserved.
+// Use of this source code is governed by a MIT-style license that can be
+// found in the LICENSE file.
+
+package ie_test
+
+import (
+	"net"
+	"testing"
+	"time"
+
+	"github.com/google/go-cmp/cmp"
+	"github.com/wmnsk/go-pfcp/ie"
+)
+
+func TestUint16IEs(t *testing.T) {
+	cases := []struct {
+		description string
+		structured  *ie.IE
+		decoded     uint16
+		decoderFunc func(*ie.IE) (uint16, error)
+	}{
+		{
+			description: "AdditionalUsageReportsInformation",
+			structured:  ie.NewAdditionalUsageReportsInformation(0x00ff),
+			decoded:     0x00ff,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.AdditionalUsageReportsInformation() },
+		}, {
+			description: "DLBufferingSuggestedPacketCount",
+			structured:  ie.NewDLBufferingSuggestedPacketCount(0xffff),
+			decoded:     0xffff,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.DLBufferingSuggestedPacketCount() },
+		}, {
+			description: "DLBufferingSuggestedPacketCount/UpdateBARWithinSessionReportResponse",
+			structured: ie.NewUpdateBARWithinSessionReportResponse(
+				ie.NewBARID(0xff),
+				ie.NewDownlinkDataNotificationDelay(100*time.Millisecond),
+				ie.NewDLBufferingDuration(30*time.Second),
+				ie.NewDLBufferingSuggestedPacketCount(0xffff),
+				ie.NewSuggestedBufferingPacketsCount(0x01),
+			),
+			decoded:     0xffff,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.DLBufferingSuggestedPacketCount() },
+		}, {
+			description: "DLDataPacketsSize",
+			structured:  ie.NewDLDataPacketsSize(0xffff),
+			decoded:     0xffff,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.DLDataPacketsSize() },
+		}, {
+			description: "DLDataPacketsSize/DownlinkDataReport",
+			structured: ie.NewDownlinkDataReport(
+				ie.NewPDRID(0xffff),
+				ie.NewDLDataPacketsSize(0xffff),
+			),
+			decoded:     0xffff,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.DLDataPacketsSize() },
+		}, {
+			description: "Ethertype",
+			structured:  ie.NewEthertype(0xffff),
+			decoded:     0xffff,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.Ethertype() },
+		}, {
+			description: "Ethertype/PDI",
+			structured: ie.NewPDI(
+				ie.NewSourceInterface(ie.SrcInterfaceAccess),
+				ie.NewEthertype(0xffff),
+			),
+			decoded:     0xffff,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.Ethertype() },
+		}, {
+			description: "Ethertype/EthernetPacketFilter",
+			structured: ie.NewEthernetPacketFilter(
+				ie.NewEthernetFilterID(0xffffffff),
+				ie.NewEthertype(0xffff),
+			),
+			decoded:     0xffff,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.Ethertype() },
+		}, {
+			description: "MARID",
+			structured:  ie.NewMARID(0x1111),
+			decoded:     0x1111,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.MARID() },
+		}, {
+			description: "MARID/CreatePDR",
+			structured: ie.NewCreatePDR(
+				ie.NewPDRID(0xffff),
+				ie.NewMARID(0x1111),
+			),
+			decoded:     0x1111,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.MARID() },
+		}, {
+			description: "MARID/CreateMAR",
+			structured: ie.NewCreateMAR(
+				ie.NewMARID(0x1111),
+				ie.NewSteeringFunctionality(ie.SteeringFunctionalityATSSSLL),
+			),
+			decoded:     0x1111,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.MARID() },
+		}, {
+			description: "MARID/RemoveMAR",
+			structured: ie.NewRemoveMAR(
+				ie.NewMARID(0x1111),
+			),
+			decoded:     0x1111,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.MARID() },
+		}, {
+			description: "MARID/UpdateMAR",
+			structured: ie.NewUpdateMAR(
+				ie.NewMARID(0x1111),
+				ie.NewSteeringFunctionality(ie.SteeringFunctionalityATSSSLL),
+			),
+			decoded:     0x1111,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.MARID() },
+		}, {
+			description: "NumberOfReports",
+			structured:  ie.NewNumberOfReports(0x1111),
+			decoded:     0x1111,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.NumberOfReports() },
+		}, {
+			description: "NumberOfReports/CreateURR",
+			structured: ie.NewCreateURR(
+				ie.NewURRID(0xffffffff),
+				ie.NewNumberOfReports(0x1111),
+			),
+			decoded:     0x1111,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.NumberOfReports() },
+		}, {
+			description: "NumberOfReports/UpdateURR",
+			structured: ie.NewUpdateURR(
+				ie.NewURRID(0xffffffff),
+				ie.NewNumberOfReports(0x1111),
+			),
+			decoded:     0x1111,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.NumberOfReports() },
+		}, {
+			description: "OffendingIE",
+			structured:  ie.NewOffendingIE(ie.Cause),
+			decoded:     ie.Cause,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.OffendingIE() },
+		}, {
+			description: "PDRID",
+			structured:  ie.NewPDRID(0xffff),
+			decoded:     0xffff,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.PDRID() },
+		}, {
+			description: "PDRID/CreatePDR",
+			structured: ie.NewCreatePDR(
+				ie.NewPDRID(0xffff),
+				ie.NewPrecedence(0x11111111),
+			),
+			decoded:     0xffff,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.PDRID() },
+		}, {
+			description: "PDRID/UpdatePDR",
+			structured: ie.NewUpdatePDR(
+				ie.NewPDRID(0xffff),
+				ie.NewPrecedence(0x11111111),
+			),
+			decoded:     0xffff,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.PDRID() },
+		}, {
+			description: "PDRID/RemovePDR",
+			structured: ie.NewRemovePDR(
+				ie.NewPDRID(0xffff),
+			),
+			decoded:     0xffff,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.PDRID() },
+		}, {
+			description: "PDRID/CreatedPDR",
+			structured: ie.NewCreatedPDR(
+				ie.NewPDRID(0xffff),
+				ie.NewFTEID(0x11111111, net.ParseIP("127.0.0.1"), nil, nil),
+			),
+			decoded:     0xffff,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.PDRID() },
+		}, {
+			description: "PDRID/ApplicationDetectionInformation",
+			structured: ie.NewApplicationDetectionInformation(
+				ie.NewApplicationID("https://github.com/wmnsk/go-pfcp/"),
+				ie.NewPDRID(0xffff),
+			),
+			decoded:     0xffff,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.PDRID() },
+		}, {
+			description: "PDRID/UsageReportWithinSessionReportRequest",
+			structured: ie.NewUsageReportWithinSessionReportRequest(
+				ie.NewURRID(0xffffffff),
+				ie.NewApplicationDetectionInformation(
+					ie.NewApplicationID("https://github.com/wmnsk/go-pfcp/"),
+					ie.NewPDRID(0xffff),
+				),
+			),
+			decoded:     0xffff,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.PDRID() },
+		}, {
+			description: "PDRID/DownlinkDataReport",
+			structured: ie.NewDownlinkDataReport(
+				ie.NewPDRID(0xffff),
+				ie.NewDownlinkDataServiceInformation(true, true, 0xff, 0xff),
+			),
+			decoded:     0xffff,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.PDRID() },
+		}, {
+			description: "PDRID/UpdatedPDR",
+			structured: ie.NewUpdatedPDR(
+				ie.NewPDRID(0xffff),
+				ie.NewFTEID(0x11111111, net.ParseIP("127.0.0.1"), nil, nil),
+			),
+			decoded:     0xffff,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.PDRID() },
+		}, {
+			description: "ReportingTriggers",
+			structured:  ie.NewReportingTriggers(0x1122),
+			decoded:     0x1122,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.ReportingTriggers() },
+		}, {
+			description: "ReportingTriggers/CreateURR",
+			structured: ie.NewCreateURR(
+				ie.NewURRID(0xffffffff),
+				ie.NewReportingTriggers(0x1122),
+			),
+			decoded:     0x1122,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.ReportingTriggers() },
+		}, {
+			description: "ReportingTriggers/UpdateURR",
+			structured: ie.NewUpdateURR(
+				ie.NewURRID(0xffffffff),
+				ie.NewReportingTriggers(0x1122),
+			),
+			decoded:     0x1122,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.ReportingTriggers() },
+		}, {
+			description: "TransportLevelMarking",
+			structured:  ie.NewTransportLevelMarking(0x1111),
+			decoded:     0x1111,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.TransportLevelMarking() },
+		}, {
+			description: "TransportLevelMarking/ForwardingParameters",
+			structured: ie.NewForwardingParameters(
+				ie.NewDestinationInterface(ie.DstInterfaceAccess),
+				ie.NewTransportLevelMarking(0x1111),
+			),
+			decoded:     0x1111,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.TransportLevelMarking() },
+		}, {
+			description: "TransportLevelMarking/UpdateForwardingParameters",
+			structured: ie.NewUpdateForwardingParameters(
+				ie.NewDestinationInterface(ie.DstInterfaceAccess),
+				ie.NewTransportLevelMarking(0x1111),
+			),
+			decoded:     0x1111,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.TransportLevelMarking() },
+		}, {
+			description: "TransportLevelMarking/DuplicatingParameters",
+			structured: ie.NewDuplicatingParameters(
+				ie.NewDestinationInterface(ie.DstInterfaceAccess),
+				ie.NewTransportLevelMarking(0x1111),
+			),
+			decoded:     0x1111,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.TransportLevelMarking() },
+		}, {
+			description: "TransportLevelMarking/UpdateDuplicatingParameters",
+			structured: ie.NewUpdateDuplicatingParameters(
+				ie.NewDestinationInterface(ie.DstInterfaceAccess),
+				ie.NewTransportLevelMarking(0x1111),
+			),
+			decoded:     0x1111,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.TransportLevelMarking() },
+		}, {
+			description: "TransportLevelMarking/GTPUPathQoSControlInformation",
+			structured: ie.NewGTPUPathQoSControlInformation(
+				ie.NewRemoteGTPUPeer(0x0e, "127.0.0.1", "", ie.DstInterfaceAccess, "some.instance.example"),
+				ie.NewTransportLevelMarking(0x1111),
+			),
+			decoded:     0x1111,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.TransportLevelMarking() },
+		}, {
+			description: "TransportLevelMarking/GTPUPathQoSReport",
+			structured: ie.NewGTPUPathQoSReport(
+				ie.NewRemoteGTPUPeer(0x0e, "127.0.0.1", "", ie.DstInterfaceAccess, "some.instance.example"),
+				ie.NewTransportLevelMarking(0x1111),
+			),
+			decoded:     0x1111,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.TransportLevelMarking() },
+		}, {
+			description: "TransportLevelMarking/QoSInformationInGTPUPathQoSReport",
+			structured: ie.NewQoSInformationInGTPUPathQoSReport(
+				ie.NewAveragePacketDelay(10*time.Second),
+				ie.NewTransportLevelMarking(0x1111),
+			),
+			decoded:     0x1111,
+			decoderFunc: func(i *ie.IE) (uint16, error) { return i.TransportLevelMarking() },
+		},
+	}
+
+	for _, c := range cases {
+		t.Run(c.description, func(t *testing.T) {
+			got, err := c.decoderFunc(c.structured)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+			if diff := cmp.Diff(got, c.decoded); diff != "" {
+				t.Error(diff)
+			}
+		})
+	}
+}
diff --git a/ie/transport-level-marking.go b/ie/transport-level-marking.go
index d6471f7f..913130d2 100644
--- a/ie/transport-level-marking.go
+++ b/ie/transport-level-marking.go
@@ -83,7 +83,7 @@ func (i *IE) TransportLevelMarking() (uint16, error) {
 			return 0, err
 		}
 		for _, x := range ies {
-			if x.Type == QoSInformationInGTPUPathQoSReport {
+			if x.Type == TransportLevelMarking {
 				return x.TransportLevelMarking()
 			}
 		}