diff --git a/internal/pkg/core/device_handler_test.go b/internal/pkg/core/device_handler_test.go
new file mode 100644
index 0000000..70b92bb
--- /dev/null
+++ b/internal/pkg/core/device_handler_test.go
@@ -0,0 +1,1184 @@
+/*
+ * Copyright 2020-present Open Networking Foundation
+
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+
+ * http://www.apache.org/licenses/LICENSE-2.0
+
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//Package core provides the utility for olt devices, flows and statistics
+package core
+
+import (
+	"context"
+	"net"
+	"reflect"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/golang/protobuf/ptypes"
+	"github.com/golang/protobuf/ptypes/any"
+	"github.com/opencord/voltha-lib-go/v3/pkg/db"
+	fu "github.com/opencord/voltha-lib-go/v3/pkg/flows"
+	"github.com/opencord/voltha-lib-go/v3/pkg/log"
+	"github.com/opencord/voltha-lib-go/v3/pkg/pmmetrics"
+	ponrmgr "github.com/opencord/voltha-lib-go/v3/pkg/ponresourcemanager"
+	"github.com/opencord/voltha-openolt-adapter/internal/pkg/config"
+	"github.com/opencord/voltha-openolt-adapter/internal/pkg/olterrors"
+	"github.com/opencord/voltha-openolt-adapter/internal/pkg/resourcemanager"
+	"github.com/opencord/voltha-openolt-adapter/pkg/mocks"
+	ic "github.com/opencord/voltha-protos/v3/go/inter_container"
+	of "github.com/opencord/voltha-protos/v3/go/openflow_13"
+	ofp "github.com/opencord/voltha-protos/v3/go/openflow_13"
+	oop "github.com/opencord/voltha-protos/v3/go/openolt"
+	"github.com/opencord/voltha-protos/v3/go/voltha"
+)
+
+func newMockCoreProxy() *mocks.MockCoreProxy {
+	mcp := mocks.MockCoreProxy{
+		Devices:     make(map[string]*voltha.Device),
+		DevicePorts: make(map[string][]*voltha.Port),
+	}
+	var pm []*voltha.PmConfig
+	mcp.Devices["olt"] = &voltha.Device{
+		Id:           "olt",
+		Root:         true,
+		ParentId:     "logical_device",
+		ParentPortNo: 1,
+		ProxyAddress: &voltha.Device_ProxyAddress{
+			DeviceId:       "olt",
+			DeviceType:     "onu",
+			ChannelId:      1,
+			ChannelGroupId: 1,
+		},
+		ConnectStatus: 1,
+		PmConfigs: &voltha.PmConfigs{
+			DefaultFreq:  10,
+			Id:           "olt",
+			FreqOverride: false,
+			Grouped:      false,
+			Metrics:      pm,
+		},
+	}
+	mcp.DevicePorts["olt"] = []*voltha.Port{
+		{PortNo: 1, Label: "pon"},
+		{PortNo: 2, Label: "nni"},
+	}
+
+	mcp.Devices["onu1"] = &voltha.Device{
+		Id:           "1",
+		Root:         false,
+		ParentId:     "olt",
+		ParentPortNo: 1,
+
+		OperStatus: 4,
+		ProxyAddress: &voltha.Device_ProxyAddress{
+			OnuId:          1,
+			ChannelId:      1,
+			ChannelGroupId: 1,
+		},
+		ConnectStatus: 1,
+		PmConfigs: &voltha.PmConfigs{
+			DefaultFreq:  10,
+			Id:           "olt",
+			FreqOverride: false,
+			Grouped:      false,
+			Metrics:      pm,
+		},
+	}
+	mcp.DevicePorts["onu1"] = []*voltha.Port{
+		{PortNo: 1, Label: "pon"},
+		{PortNo: 2, Label: "uni"},
+	}
+
+	mcp.Devices["onu2"] = &voltha.Device{
+		Id:         "2",
+		Root:       false,
+		ParentId:   "olt",
+		OperStatus: 2,
+
+		ParentPortNo: 1,
+
+		ProxyAddress: &voltha.Device_ProxyAddress{
+			OnuId:          2,
+			ChannelId:      1,
+			ChannelGroupId: 1,
+		},
+		ConnectStatus: 1,
+		PmConfigs: &voltha.PmConfigs{
+			DefaultFreq:  10,
+			Id:           "olt",
+			FreqOverride: false,
+			Grouped:      false,
+			Metrics:      pm,
+		},
+	}
+	mcp.DevicePorts["onu2"] = []*voltha.Port{
+		{PortNo: 1, Label: "pon"},
+		{PortNo: 2, Label: "uni"},
+	}
+	return &mcp
+}
+
+func newMockDeviceHandler() *DeviceHandler {
+	device := &voltha.Device{
+		Id:       "olt",
+		Root:     true,
+		ParentId: "logical_device",
+		ProxyAddress: &voltha.Device_ProxyAddress{
+			DeviceId:       "olt",
+			DeviceType:     "onu",
+			ChannelId:      1,
+			ChannelGroupId: 1,
+		},
+		ConnectStatus: 1,
+		MacAddress:    "08:00:27:1c:18:55",
+	}
+	cp := newMockCoreProxy()
+	ap := &mocks.MockAdapterProxy{}
+	ep := &mocks.MockEventProxy{}
+	cnf := &config.AdapterFlags{
+		InterfaceName: "enp0s3",
+		SrcMac:        "08:00:27:1c:18:9a",
+	}
+	openOLT := &OpenOLT{
+		coreProxy:    cp,
+		adapterProxy: ap,
+		eventProxy:   ep,
+		config:       cnf,
+	}
+	dh := NewDeviceHandler(cp, ap, ep, device, openOLT)
+	oopRanges := []*oop.DeviceInfo_DeviceResourceRanges{{
+		IntfIds:    []uint32{0, 1},
+		Technology: "xgs-pon",
+		Pools:      []*oop.DeviceInfo_DeviceResourceRanges_Pool{{}},
+	}}
+
+	deviceInf := &oop.DeviceInfo{Vendor: "openolt", Ranges: oopRanges, Model: "openolt", DeviceId: dh.device.Id, PonPorts: 2}
+	rsrMgr := resourcemanager.OpenOltResourceMgr{DeviceID: dh.device.Id, DeviceType: dh.device.Type, DevInfo: deviceInf,
+		KVStore: &db.Backend{
+			Client: &mocks.MockKVClient{},
+		}}
+	rsrMgr.AllocIDMgmtLock = make([]sync.RWMutex, deviceInf.PonPorts)
+	rsrMgr.GemPortIDMgmtLock = make([]sync.RWMutex, deviceInf.PonPorts)
+	rsrMgr.OnuIDMgmtLock = make([]sync.RWMutex, deviceInf.PonPorts)
+
+	dh.resourceMgr = &rsrMgr
+	dh.resourceMgr.ResourceMgrs = make(map[uint32]*ponrmgr.PONResourceManager)
+	ranges := make(map[string]interface{})
+	sharedIdxByType := make(map[string]string)
+	sharedIdxByType["ALLOC_ID"] = "ALLOC_ID"
+	sharedIdxByType["ONU_ID"] = "ONU_ID"
+	sharedIdxByType["GEMPORT_ID"] = "GEMPORT_ID"
+	sharedIdxByType["FLOW_ID"] = "FLOW_ID"
+	ranges["ONU_ID"] = uint32(0)
+	ranges["GEMPORT_ID"] = uint32(0)
+	ranges["ALLOC_ID"] = uint32(0)
+	ranges["FLOW_ID"] = uint32(0)
+	ranges["onu_id_shared"] = uint32(0)
+	ranges["alloc_id_shared"] = uint32(0)
+	ranges["gemport_id_shared"] = uint32(0)
+	ranges["flow_id_shared"] = uint32(0)
+
+	ponmgr := &ponrmgr.PONResourceManager{
+		DeviceID: "onu-1",
+		IntfIDs:  []uint32{0, 1},
+		KVStore: &db.Backend{
+			Client: &mocks.MockKVClient{},
+		},
+		PonResourceRanges: ranges,
+		SharedIdxByType:   sharedIdxByType,
+	}
+	dh.resourceMgr.ResourceMgrs[0] = ponmgr
+	dh.resourceMgr.ResourceMgrs[1] = ponmgr
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+	dh.flowMgr = NewFlowManager(ctx, dh, dh.resourceMgr)
+	dh.Client = &mocks.MockOpenoltClient{}
+	dh.eventMgr = &OpenOltEventMgr{eventProxy: &mocks.MockEventProxy{}, handler: dh}
+	dh.transitionMap = &TransitionMap{}
+	dh.portStats = &OpenOltStatisticsMgr{}
+
+	var pmNames = []string{
+		"rx_bytes",
+		"rx_packets",
+		"rx_mcast_packets",
+		"rx_bcast_packets",
+		"tx_bytes",
+		"tx_packets",
+		"tx_mcast_packets",
+		"tx_bcast_packets",
+	}
+
+	dh.metrics = pmmetrics.NewPmMetrics(device.Id, pmmetrics.Frequency(2), pmmetrics.FrequencyOverride(false), pmmetrics.Grouped(false), pmmetrics.Metrics(pmNames))
+	return dh
+}
+
+func negativeDeviceHandler() *DeviceHandler {
+	dh := newMockDeviceHandler()
+	device := dh.device
+	device.Id = ""
+	return dh
+}
+
+func Test_generateMacFromHost(t *testing.T) {
+
+	ctx := context.Background()
+	type args struct {
+		host string
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    string
+		wantErr bool
+	}{
+		{"generateMacFromHost-1", args{host: "localhost"}, "00:00:7f:00:00:01", false},
+		{"generateMacFromHost-2", args{host: "10.10.10.10"}, "00:00:0a:0a:0a:0a", false},
+		//{"generateMacFromHost-3", args{host: "google.com"}, "00:00:d8:3a:c8:8e", false},
+		{"generateMacFromHost-4", args{host: "testing3"}, "", true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := generateMacFromHost(ctx, tt.args.host)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("generateMacFromHost() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if got != tt.want {
+				t.Errorf("generateMacFromHost() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+func Test_macifyIP(t *testing.T) {
+	type args struct {
+		ip net.IP
+	}
+	tests := []struct {
+		name string
+		args args
+		want string
+	}{{
+		"macifyIP-1",
+		args{ip: net.ParseIP("10.10.10.10")},
+		"00:00:0a:0a:0a:0a",
+	},
+		{
+			"macifyIP-2",
+			args{ip: net.ParseIP("127.0.0.1")},
+			"00:00:7f:00:00:01",
+		},
+		{
+			"macifyIP-3",
+			args{ip: net.ParseIP("127.0.0.1/24")},
+			"",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := macifyIP(tt.args.ip); got != tt.want {
+				t.Errorf("macifyIP() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func sparseCompare(keys []string, spec, target interface{}) bool {
+	if spec == target {
+		return true
+	}
+	if spec == nil || target == nil {
+		return false
+	}
+	typeSpec := reflect.TypeOf(spec)
+	typeTarget := reflect.TypeOf(target)
+	if typeSpec != typeTarget {
+		return false
+	}
+
+	vSpec := reflect.ValueOf(spec)
+	vTarget := reflect.ValueOf(target)
+	if vSpec.Kind() == reflect.Ptr {
+		vSpec = vSpec.Elem()
+		vTarget = vTarget.Elem()
+	}
+
+	for _, key := range keys {
+		fSpec := vSpec.FieldByName(key)
+		fTarget := vTarget.FieldByName(key)
+		if !reflect.DeepEqual(fSpec.Interface(), fTarget.Interface()) {
+			return false
+		}
+	}
+	return true
+}
+
+func TestDeviceHandler_GetChildDevice(t *testing.T) {
+	ctx := context.Background()
+	dh1 := newMockDeviceHandler()
+	dh2 := negativeDeviceHandler()
+	type args struct {
+		parentPort uint32
+		onuID      uint32
+	}
+	tests := []struct {
+		name          string
+		devicehandler *DeviceHandler
+		args          args
+		want          *voltha.Device
+		errType       reflect.Type
+	}{
+		{"GetChildDevice-1", dh1,
+			args{parentPort: 1,
+				onuID: 1},
+			&voltha.Device{
+				Id:           "1",
+				ParentId:     "olt",
+				ParentPortNo: 1,
+			},
+			nil,
+		},
+		{"GetChildDevice-2", dh2,
+			args{parentPort: 1,
+				onuID: 1},
+			nil,
+			reflect.TypeOf(&olterrors.ErrNotFound{}),
+		},
+	}
+
+	/*
+	   --- FAIL: TestDeviceHandler_GetChildDevice/GetChildDevice-1 (0.00s)
+	       device_handler_test.go:309: GetportLabel() => want=(, <nil>) got=(id:"1" parent_id:"olt" parent_port_no:1 proxy_address:<channel_id:1 channel_group_id:1 onu_id:1 > oper_status:ACTIVE connect_status:UNREACHABLE ports:<port_no:1 label:"pon" > ports:<port_no:2 label:"uni" > pm_configs:<id:"olt" default_freq:10 > , <nil>)
+	   --- FAIL: TestDeviceHandler_GetChildDevice/GetChildDevice-2 (0.00s)
+	*/
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := tt.devicehandler.GetChildDevice(ctx, tt.args.parentPort, tt.args.onuID)
+			if reflect.TypeOf(err) != tt.errType || !sparseCompare([]string{"Id", "ParentId", "ParentPortNo"}, tt.want, got) {
+				t.Errorf("GetportLabel() => want=(%v, %v) got=(%v, %v)",
+					tt.want, tt.errType, got, reflect.TypeOf(err))
+				return
+			}
+			t.Log("onu device id", got)
+		})
+	}
+}
+
+func TestGetportLabel(t *testing.T) {
+	invalid := reflect.TypeOf(&olterrors.ErrInvalidValue{})
+	type args struct {
+		portNum  uint32
+		portType voltha.Port_PortType
+	}
+	tests := []struct {
+		name    string
+		args    args
+		want    string
+		errType reflect.Type
+	}{
+		{"GetportLabel-1", args{portNum: 0, portType: 0}, "", invalid},
+		{"GetportLabel-2", args{portNum: 1, portType: 1}, "nni-1", nil},
+		{"GetportLabel-3", args{portNum: 2, portType: 2}, "", invalid},
+		{"GetportLabel-4", args{portNum: 3, portType: 3}, "pon-3", nil},
+		{"GetportLabel-5", args{portNum: 4, portType: 4}, "", invalid},
+		{"GetportLabel-6", args{portNum: 5, portType: 5}, "", invalid},
+		{"GetportLabel-7", args{portNum: 6, portType: 6}, "", invalid},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := GetportLabel(tt.args.portNum, tt.args.portType)
+			if reflect.TypeOf(err) != tt.errType || got != tt.want {
+				t.Errorf("GetportLabel() => want=(%v, %v) got=(%v, %v)",
+					tt.want, tt.errType, got, reflect.TypeOf(err))
+			}
+
+		})
+	}
+}
+
+func TestDeviceHandler_ProcessInterAdapterMessage(t *testing.T) {
+	ctx := context.Background()
+	dh := newMockDeviceHandler()
+	proxyAddr := dh.device.ProxyAddress
+	body := &ic.InterAdapterOmciMessage{
+		Message:      []byte("asdfasdfasdfasdfas"),
+		ProxyAddress: proxyAddr,
+	}
+	body2 := &ic.InterAdapterOmciMessage{
+		Message: []byte("asdfasdfasdfasdfas"),
+		//ProxyAddress: &voltha.Device_ProxyAddress{},
+	}
+	body3 := &ic.InterAdapterTechProfileDownloadMessage{}
+	var marshalledData *any.Any
+	var err error
+
+	if marshalledData, err = ptypes.MarshalAny(body); err != nil {
+		logger.Errorw(ctx, "cannot-marshal-request", log.Fields{"error": err})
+	}
+
+	var marshalledData1 *any.Any
+
+	if marshalledData1, err = ptypes.MarshalAny(body2); err != nil {
+		logger.Errorw(ctx, "cannot-marshal-request", log.Fields{"error": err})
+	}
+	var marshalledData2 *any.Any
+
+	if marshalledData2, err = ptypes.MarshalAny(body3); err != nil {
+		logger.Errorw(ctx, "cannot-marshal-request", log.Fields{"error": err})
+	}
+	type args struct {
+		msg *ic.InterAdapterMessage
+	}
+	invalid := reflect.TypeOf(&olterrors.ErrInvalidValue{})
+	tests := []struct {
+		name    string
+		args    args
+		wantErr reflect.Type
+	}{
+		{"ProcessInterAdapterMessage-1", args{msg: &ic.InterAdapterMessage{
+			Header: &ic.InterAdapterHeader{
+				Id:   "012345",
+				Type: ic.InterAdapterMessageType_FLOW_REQUEST,
+			},
+			Body: marshalledData,
+		}}, invalid},
+		{"ProcessInterAdapterMessage-2", args{msg: &ic.InterAdapterMessage{
+			Header: &ic.InterAdapterHeader{
+				Id:   "012345",
+				Type: ic.InterAdapterMessageType_FLOW_RESPONSE,
+			},
+			Body: marshalledData1,
+		}}, invalid},
+		{"ProcessInterAdapterMessage-3", args{msg: &ic.InterAdapterMessage{
+			Header: &ic.InterAdapterHeader{
+				Id:   "012345",
+				Type: ic.InterAdapterMessageType_OMCI_REQUEST,
+			},
+			Body: marshalledData,
+		}}, reflect.TypeOf(&olterrors.ErrCommunication{})},
+		{"ProcessInterAdapterMessage-4", args{msg: &ic.InterAdapterMessage{
+			Header: &ic.InterAdapterHeader{
+				Id:   "012345",
+				Type: ic.InterAdapterMessageType_OMCI_RESPONSE,
+			}, Body: marshalledData,
+		}}, invalid},
+		{"ProcessInterAdapterMessage-5", args{msg: &ic.InterAdapterMessage{
+			Header: &ic.InterAdapterHeader{
+				Id:   "012345",
+				Type: ic.InterAdapterMessageType_METRICS_REQUEST,
+			}, Body: marshalledData1,
+		}}, invalid},
+		{"ProcessInterAdapterMessage-6", args{msg: &ic.InterAdapterMessage{
+			Header: &ic.InterAdapterHeader{
+				Id:   "012345",
+				Type: ic.InterAdapterMessageType_METRICS_RESPONSE,
+			}, Body: marshalledData,
+		}}, invalid},
+		/*
+			{"ProcessInterAdapterMessage-7", args{msg: &ic.InterAdapterMessage{
+				Header: &ic.InterAdapterHeader{
+					Id:   "012345",
+					Type: ic.InterAdapterMessageType_ONU_IND_REQUEST,
+				}, Body: marshalledData,
+			}}, nil},
+		*/
+		{"ProcessInterAdapterMessage-8", args{msg: &ic.InterAdapterMessage{
+			Header: &ic.InterAdapterHeader{
+				Id:   "012345",
+				Type: ic.InterAdapterMessageType_ONU_IND_RESPONSE,
+			}, Body: marshalledData,
+		}}, invalid},
+		{"ProcessInterAdapterMessage-9", args{msg: &ic.InterAdapterMessage{
+			Header: &ic.InterAdapterHeader{
+				Id:   "012345",
+				Type: ic.InterAdapterMessageType_TECH_PROFILE_DOWNLOAD_REQUEST,
+			}, Body: marshalledData,
+		}}, invalid},
+		{"ProcessInterAdapterMessage-10", args{msg: &ic.InterAdapterMessage{
+			Header: &ic.InterAdapterHeader{
+				Id:   "012345",
+				Type: ic.InterAdapterMessageType_DELETE_GEM_PORT_REQUEST,
+			}, Body: marshalledData2,
+		}}, invalid},
+		{"ProcessInterAdapterMessage-11", args{msg: &ic.InterAdapterMessage{
+			Header: &ic.InterAdapterHeader{
+				Id:   "012345",
+				Type: ic.InterAdapterMessageType_DELETE_TCONT_REQUEST,
+			}, Body: marshalledData2,
+		}}, invalid},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+
+			if err := dh.ProcessInterAdapterMessage(ctx, tt.args.msg); reflect.TypeOf(err) != tt.wantErr {
+				t.Errorf("DeviceHandler.ProcessInterAdapterMessage() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
+}
+
+func TestDeviceHandler_sendProxiedMessage(t *testing.T) {
+	ctx := context.Background()
+	dh1 := newMockDeviceHandler()
+	dh2 := negativeDeviceHandler()
+	device1 := &voltha.Device{
+		Id:       "onu1",
+		Root:     false,
+		ParentId: "logical_device",
+		ProxyAddress: &voltha.Device_ProxyAddress{
+			DeviceId:       "onu1",
+			DeviceType:     "onu",
+			ChannelId:      1,
+			ChannelGroupId: 1,
+		},
+		ConnectStatus: 1,
+	}
+	device2 := device1
+	device2.ConnectStatus = 2
+	iaomciMsg1 := &ic.InterAdapterOmciMessage{
+		ProxyAddress: &voltha.Device_ProxyAddress{
+			DeviceId:       "onu2",
+			DeviceType:     "onu",
+			ChannelId:      1,
+			ChannelGroupId: 1,
+			//OnuId:          2,
+		},
+		ConnectStatus: 1,
+	}
+	iaomciMsg2 := &ic.InterAdapterOmciMessage{
+		ProxyAddress: &voltha.Device_ProxyAddress{
+			DeviceId:       "onu3",
+			DeviceType:     "onu",
+			ChannelId:      1,
+			ChannelGroupId: 1,
+		},
+		ConnectStatus: 1,
+	}
+	type args struct {
+		onuDevice *voltha.Device
+		omciMsg   *ic.InterAdapterOmciMessage
+	}
+	tests := []struct {
+		name          string
+		devicehandler *DeviceHandler
+		args          args
+	}{
+		{"sendProxiedMessage-1", dh1, args{onuDevice: device1, omciMsg: &ic.InterAdapterOmciMessage{}}},
+		{"sendProxiedMessage-2", dh1, args{onuDevice: device2, omciMsg: &ic.InterAdapterOmciMessage{}}},
+		{"sendProxiedMessage-3", dh1, args{onuDevice: nil, omciMsg: iaomciMsg1}},
+		{"sendProxiedMessage-4", dh1, args{onuDevice: nil, omciMsg: iaomciMsg2}},
+		{"sendProxiedMessage-5", dh2, args{onuDevice: nil, omciMsg: iaomciMsg2}},
+		{"sendProxiedMessage-6", dh2, args{onuDevice: device1, omciMsg: &ic.InterAdapterOmciMessage{}}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_ = tt.devicehandler.sendProxiedMessage(ctx, tt.args.onuDevice, tt.args.omciMsg)
+			//TODO: actually verify test cases
+		})
+	}
+}
+
+func TestDeviceHandler_SendPacketInToCore(t *testing.T) {
+	dh1 := newMockDeviceHandler()
+	dh2 := negativeDeviceHandler()
+
+	type args struct {
+		logicalPort   uint32
+		packetPayload []byte
+	}
+	tests := []struct {
+		name          string
+		devicehandler *DeviceHandler
+		args          args
+	}{
+		{"SendPacketInToCore-1", dh1, args{logicalPort: 1, packetPayload: []byte("test1")}},
+		{"SendPacketInToCore-2", dh1, args{logicalPort: 1, packetPayload: []byte("")}},
+		{"SendPacketInToCore-3", dh2, args{logicalPort: 1, packetPayload: []byte("test1")}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_ = tt.devicehandler.SendPacketInToCore(context.Background(), tt.args.logicalPort, tt.args.packetPayload)
+			//TODO: actually verify test cases
+		})
+	}
+}
+
+func TestDeviceHandler_DisableDevice(t *testing.T) {
+	dh1 := newMockDeviceHandler()
+	dh2 := negativeDeviceHandler()
+	type args struct {
+		device *voltha.Device
+	}
+	tests := []struct {
+		name          string
+		devicehandler *DeviceHandler
+		args          args
+		wantErr       bool
+	}{
+		{"DisableDevice-1", dh1, args{device: dh1.device}, false},
+		{"DisableDevice-2", dh1, args{device: dh2.device}, true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if err := tt.devicehandler.DisableDevice(context.Background(), tt.args.device); (err != nil) != tt.wantErr {
+				t.Errorf("DeviceHandler.DisableDevice() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
+}
+
+func TestDeviceHandler_ReenableDevice(t *testing.T) {
+	dh1 := newMockDeviceHandler()
+	dh2 := negativeDeviceHandler()
+	type args struct {
+		device *voltha.Device
+	}
+	tests := []struct {
+		name          string
+		devicehandler *DeviceHandler
+		args          args
+		wantErr       bool
+	}{
+		{"ReenableDevice-1", dh1, args{device: dh1.device}, false},
+		{"ReenableDevice-2", dh1, args{device: &voltha.Device{}}, true},
+		{"ReenableDevice-3", dh2, args{device: dh1.device}, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			dh := tt.devicehandler
+			if err := dh.ReenableDevice(context.Background(), tt.args.device); (err != nil) != tt.wantErr {
+				t.Errorf("DeviceHandler.ReenableDevice() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
+}
+
+func TestDeviceHandler_RebootDevice(t *testing.T) {
+	dh1 := newMockDeviceHandler()
+	dh2 := newMockDeviceHandler()
+	type args struct {
+		device *voltha.Device
+	}
+	tests := []struct {
+		name          string
+		devicehandler *DeviceHandler
+		args          args
+	}{
+		// TODO: Add test cases.
+		{"RebootDevice-1", dh1, args{device: dh1.device}},
+		{"RebootDevice-2", dh1, args{device: dh2.device}},
+		{"RebootDevice-3", dh2, args{device: dh2.device}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+
+			if err := tt.devicehandler.RebootDevice(context.Background(), tt.args.device); err != nil {
+				t.Errorf("DeviceHandler.RebootDevice() error = %v", err)
+			}
+		})
+	}
+}
+
+func TestDeviceHandler_handleIndication(t *testing.T) {
+	dh1 := newMockDeviceHandler()
+	dh2 := negativeDeviceHandler()
+	dh3 := newMockDeviceHandler()
+	dh3.onus = sync.Map{}
+	dh3.onus.Store("onu1", NewOnuDevice("onu1", "onu1", "onu1", 1, 1, "onu1", false))
+	dh3.onus.Store("onu2", NewOnuDevice("onu2", "onu2", "onu2", 2, 2, "onu2", false))
+
+	type args struct {
+		indication *oop.Indication
+	}
+	tests := []struct {
+		name          string
+		deviceHandler *DeviceHandler
+		args          args
+	}{
+		// TODO: Add test cases.
+		{"handleIndication-1", dh1, args{indication: &oop.Indication{Data: &oop.Indication_OltInd{OltInd: &oop.OltIndication{OperState: "up"}}}}},
+		{"handleIndication-2", dh1, args{indication: &oop.Indication{Data: &oop.Indication_OltInd{OltInd: &oop.OltIndication{OperState: "down"}}}}},
+		{"handleIndication-3", dh1, args{indication: &oop.Indication{Data: &oop.Indication_IntfInd{IntfInd: &oop.IntfIndication{IntfId: 1, OperState: "up"}}}}},
+		{"handleIndication-4", dh1, args{indication: &oop.Indication{Data: &oop.Indication_IntfInd{IntfInd: &oop.IntfIndication{IntfId: 1, OperState: "down"}}}}},
+		{"handleIndication-5", dh1, args{indication: &oop.Indication{Data: &oop.Indication_IntfOperInd{IntfOperInd: &oop.IntfOperIndication{Type: "nni", IntfId: 1, OperState: "up"}}}}},
+		{"handleIndication-6", dh1, args{indication: &oop.Indication{Data: &oop.Indication_IntfOperInd{IntfOperInd: &oop.IntfOperIndication{Type: "pon", IntfId: 1, OperState: "up"}}}}},
+		{"handleIndication-7", dh1, args{indication: &oop.Indication{Data: &oop.Indication_OnuDiscInd{OnuDiscInd: &oop.OnuDiscIndication{IntfId: 1, SerialNumber: &oop.SerialNumber{VendorId: []byte("TWSH"), VendorSpecific: []byte("1234")}}}}}},
+		{"handleIndication-8", dh1, args{indication: &oop.Indication{Data: &oop.Indication_OnuInd{OnuInd: &oop.OnuIndication{IntfId: 1, OnuId: 1, OperState: "up", AdminState: "up"}}}}},
+		{"handleIndication-9", dh1, args{indication: &oop.Indication{Data: &oop.Indication_OnuInd{OnuInd: &oop.OnuIndication{IntfId: 1, OnuId: 1, OperState: "up", AdminState: "down"}}}}},
+		{"handleIndication-10", dh1, args{indication: &oop.Indication{Data: &oop.Indication_OnuInd{OnuInd: &oop.OnuIndication{IntfId: 1, OnuId: 1, OperState: "down", AdminState: "up"}}}}},
+		{"handleIndication-11", dh1, args{indication: &oop.Indication{Data: &oop.Indication_OnuInd{OnuInd: &oop.OnuIndication{IntfId: 1, OnuId: 1, OperState: "down", AdminState: "down"}}}}},
+		{"handleIndication-12", dh1, args{indication: &oop.Indication{Data: &oop.Indication_OmciInd{OmciInd: &oop.OmciIndication{IntfId: 1, OnuId: 1, Pkt: []byte("onu123-random value")}}}}},
+		{"handleIndication-13", dh1, args{indication: &oop.Indication{Data: &oop.Indication_PktInd{PktInd: &oop.PacketIndication{IntfType: "nni", IntfId: 1, GemportId: 1, FlowId: 1234, PortNo: 1}}}}},
+		{"handleIndication-14", dh1, args{indication: &oop.Indication{Data: &oop.Indication_PortStats{PortStats: &oop.PortStatistics{IntfId: 1, RxBytes: 100, RxPackets: 100, RxUcastPackets: 100, RxMcastPackets: 100, RxBcastPackets: 100, RxErrorPackets: 100, TxBytes: 100, TxPackets: 100, TxUcastPackets: 100, TxMcastPackets: 100, TxBcastPackets: 100, TxErrorPackets: 100, RxCrcErrors: 100, BipErrors: 100, Timestamp: 1000}}}}},
+		{"handleIndication-15", dh1, args{indication: &oop.Indication{Data: &oop.Indication_FlowStats{FlowStats: &oop.FlowStatistics{RxBytes: 100, RxPackets: 100, TxBytes: 100, TxPackets: 100, Timestamp: 1000}}}}},
+		{"handleIndication-16", dh1, args{indication: &oop.Indication{Data: &oop.Indication_AlarmInd{AlarmInd: &oop.AlarmIndication{}}}}},
+		{"handleIndication-17", dh1, args{indication: &oop.Indication{Data: &oop.Indication_PktInd{PktInd: &oop.PacketIndication{IntfType: "nni", FlowId: 1234, PortNo: 1}}}}},
+		{"handleIndication-18", dh1, args{indication: &oop.Indication{Data: &oop.Indication_PktInd{PktInd: &oop.PacketIndication{}}}}},
+
+		// Negative testcases
+		{"handleIndication-19", dh2, args{indication: &oop.Indication{Data: &oop.Indication_OltInd{OltInd: &oop.OltIndication{OperState: "up"}}}}},
+		{"handleIndication-20", dh2, args{indication: &oop.Indication{Data: &oop.Indication_OltInd{OltInd: &oop.OltIndication{OperState: "down"}}}}},
+		{"handleIndication-21", dh2, args{indication: &oop.Indication{Data: &oop.Indication_IntfInd{IntfInd: &oop.IntfIndication{IntfId: 1, OperState: "up"}}}}},
+		{"handleIndication-22", dh2, args{indication: &oop.Indication{Data: &oop.Indication_IntfInd{IntfInd: &oop.IntfIndication{IntfId: 1, OperState: "down"}}}}},
+		{"handleIndication-23", dh2, args{indication: &oop.Indication{Data: &oop.Indication_IntfOperInd{IntfOperInd: &oop.IntfOperIndication{Type: "nni", IntfId: 1, OperState: "up"}}}}},
+		{"handleIndication-24", dh2, args{indication: &oop.Indication{Data: &oop.Indication_IntfOperInd{IntfOperInd: &oop.IntfOperIndication{Type: "pon", IntfId: 1, OperState: "up"}}}}},
+		{"handleIndication-25", dh2, args{indication: &oop.Indication{Data: &oop.Indication_OnuDiscInd{OnuDiscInd: &oop.OnuDiscIndication{IntfId: 1, SerialNumber: &oop.SerialNumber{VendorId: []byte("TWSH"), VendorSpecific: []byte("1234")}}}}}},
+		{"handleIndication-26", dh2, args{indication: &oop.Indication{Data: &oop.Indication_OnuInd{OnuInd: &oop.OnuIndication{IntfId: 1, OnuId: 1, OperState: "up", AdminState: "up"}}}}},
+		{"handleIndication-27", dh2, args{indication: &oop.Indication{Data: &oop.Indication_OnuInd{OnuInd: &oop.OnuIndication{IntfId: 1, OnuId: 1, OperState: "up", AdminState: "down"}}}}},
+		{"handleIndication-28", dh2, args{indication: &oop.Indication{Data: &oop.Indication_OnuInd{OnuInd: &oop.OnuIndication{IntfId: 1, OnuId: 1, OperState: "down", AdminState: "up"}}}}},
+		{"handleIndication-29", dh2, args{indication: &oop.Indication{Data: &oop.Indication_OnuInd{OnuInd: &oop.OnuIndication{IntfId: 1, OnuId: 1, OperState: "down", AdminState: "down"}}}}},
+		{"handleIndication-30", dh2, args{indication: &oop.Indication{Data: &oop.Indication_OmciInd{OmciInd: &oop.OmciIndication{IntfId: 1, OnuId: 1, Pkt: []byte("onu123-random value")}}}}},
+		{"handleIndication-31", dh2, args{indication: &oop.Indication{Data: &oop.Indication_PktInd{PktInd: &oop.PacketIndication{IntfType: "nni", IntfId: 1, GemportId: 1, FlowId: 1234, PortNo: 1}}}}},
+		{"handleIndication-32", dh2, args{indication: &oop.Indication{Data: &oop.Indication_PortStats{PortStats: &oop.PortStatistics{IntfId: 1, RxBytes: 100, RxPackets: 100, RxUcastPackets: 100, RxMcastPackets: 100, RxBcastPackets: 100, RxErrorPackets: 100, TxBytes: 100, TxPackets: 100, TxUcastPackets: 100, TxMcastPackets: 100, TxBcastPackets: 100, TxErrorPackets: 100, RxCrcErrors: 100, BipErrors: 100, Timestamp: 1000}}}}},
+		{"handleIndication-33", dh2, args{indication: &oop.Indication{Data: &oop.Indication_FlowStats{FlowStats: &oop.FlowStatistics{RxBytes: 100, RxPackets: 100, TxBytes: 100, TxPackets: 100, Timestamp: 1000}}}}},
+		{"handleIndication-34", dh2, args{indication: &oop.Indication{Data: &oop.Indication_AlarmInd{AlarmInd: &oop.AlarmIndication{}}}}},
+		//
+		{"handleIndication-35", dh3, args{indication: &oop.Indication{Data: &oop.Indication_OnuInd{OnuInd: &oop.OnuIndication{IntfId: 1, OnuId: 1, OperState: "up", AdminState: "up"}}}}},
+		{"handleIndication-36", dh3, args{indication: &oop.Indication{Data: &oop.Indication_OnuInd{OnuInd: &oop.OnuIndication{IntfId: 1, OnuId: 1, OperState: "down", AdminState: "up"}}}}},
+		{"handleIndication-37", dh3, args{indication: &oop.Indication{Data: &oop.Indication_OnuInd{OnuInd: &oop.OnuIndication{IntfId: 1, OnuId: 1, OperState: "up", AdminState: "down"}}}}},
+		{"handleIndication-38", dh3, args{indication: &oop.Indication{Data: &oop.Indication_OnuInd{OnuInd: &oop.OnuIndication{IntfId: 1, OnuId: 1, OperState: "down", AdminState: "down"}}}}},
+		{"handleIndication-30", dh1, args{indication: &oop.Indication{Data: &oop.Indication_OmciInd{OmciInd: &oop.OmciIndication{IntfId: 1, OnuId: 4, Pkt: []byte("onu123-random value")}}}}},
+		{"handleIndication-30", dh2, args{indication: &oop.Indication{Data: &oop.Indication_OmciInd{OmciInd: &oop.OmciIndication{IntfId: 1, OnuId: 4, Pkt: []byte("onu123-random value")}}}}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			dh := tt.deviceHandler
+			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+			defer cancel()
+			dh.handleIndication(ctx, tt.args.indication)
+		})
+	}
+}
+
+func TestDeviceHandler_addPort(t *testing.T) {
+	dh1 := newMockDeviceHandler()
+	dh2 := negativeDeviceHandler()
+	type args struct {
+		intfID   uint32
+		portType voltha.Port_PortType
+		state    string
+	}
+	tests := []struct {
+		name          string
+		devicehandler *DeviceHandler
+		args          args
+	}{
+		// State up
+		{"addPort.1", dh1, args{intfID: 1, portType: voltha.Port_UNKNOWN, state: "up"}},
+		{"addPort.2", dh1, args{intfID: 1, portType: voltha.Port_VENET_OLT, state: "up"}},
+		{"addPort.3", dh1, args{intfID: 1, portType: voltha.Port_VENET_ONU, state: "up"}},
+		{"addPort.4", dh1, args{intfID: 1, portType: voltha.Port_ETHERNET_NNI, state: "up"}},
+		{"addPort.5", dh1, args{intfID: 1, portType: voltha.Port_ETHERNET_UNI, state: "up"}},
+		{"addPort.6", dh1, args{intfID: 1, portType: voltha.Port_PON_OLT, state: "up"}},
+		{"addPort.7", dh1, args{intfID: 1, portType: voltha.Port_PON_ONU, state: "up"}},
+		{"addPort.8", dh1, args{intfID: 1, portType: 8, state: "up"}},
+		// state discovery
+		{"addPort.9", dh1, args{intfID: 1, portType: voltha.Port_UNKNOWN, state: "down"}},
+		{"addPort.10", dh1, args{intfID: 1, portType: voltha.Port_VENET_OLT, state: "down"}},
+		{"addPort.11", dh1, args{intfID: 1, portType: voltha.Port_VENET_ONU, state: "down"}},
+		{"addPort.12", dh1, args{intfID: 1, portType: voltha.Port_ETHERNET_NNI, state: "down"}},
+		{"addPort.13", dh1, args{intfID: 1, portType: voltha.Port_ETHERNET_UNI, state: "down"}},
+		{"addPort.14", dh1, args{intfID: 1, portType: voltha.Port_PON_OLT, state: "down"}},
+		{"addPort.15", dh1, args{intfID: 1, portType: voltha.Port_PON_ONU, state: "down"}},
+		{"addPort.16", dh1, args{intfID: 1, portType: 8, state: "down"}},
+
+		{"addPort.17", dh2, args{intfID: 1, portType: voltha.Port_ETHERNET_NNI, state: "up"}},
+		{"addPort.18", dh2, args{intfID: 1, portType: voltha.Port_ETHERNET_UNI, state: "up"}},
+		{"addPort.19", dh2, args{intfID: 1, portType: voltha.Port_ETHERNET_NNI, state: "down"}},
+		{"addPort.20", dh2, args{intfID: 1, portType: voltha.Port_ETHERNET_UNI, state: "down"}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_ = tt.devicehandler.addPort(context.Background(), tt.args.intfID, tt.args.portType, tt.args.state)
+			//TODO: actually verify test cases
+		})
+	}
+}
+
+func Test_macAddressToUint32Array(t *testing.T) {
+	type args struct {
+		mac string
+	}
+	tests := []struct {
+		name string
+		args args
+		want []uint32
+	}{
+		// TODO: Add test cases.
+		{"macAddressToUint32Array-1", args{mac: "00:00:00:00:00:01"}, []uint32{0, 0, 0, 0, 0, 1}},
+		{"macAddressToUint32Array-2", args{mac: "0abcdef"}, []uint32{11259375}},
+		{"macAddressToUint32Array-3", args{mac: "testing"}, []uint32{1, 2, 3, 4, 5, 6}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := macAddressToUint32Array(tt.args.mac); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("macAddressToUint32Array() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestDeviceHandler_handleOltIndication(t *testing.T) {
+
+	type args struct {
+		oltIndication *oop.OltIndication
+	}
+	tests := []struct {
+		name string
+		args args
+	}{
+		{"handleOltIndication-1", args{oltIndication: &oop.OltIndication{OperState: "up"}}},
+		{"handleOltIndication-2", args{oltIndication: &oop.OltIndication{OperState: "down"}}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			dh := newMockDeviceHandler()
+			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+			defer cancel()
+			if err := dh.handleOltIndication(ctx, tt.args.oltIndication); err != nil {
+				t.Error(err)
+			}
+		})
+	}
+}
+
+func TestDeviceHandler_AdoptDevice(t *testing.T) {
+	dh1 := newMockDeviceHandler()
+	dh2 := negativeDeviceHandler()
+	type args struct {
+		device *voltha.Device
+	}
+	tests := []struct {
+		name          string
+		devicehandler *DeviceHandler
+		args          args
+	}{
+		// TODO: Add test cases.
+		{"AdoptDevice-1", dh1, args{device: dh1.device}},
+		{"AdoptDevice-2", dh2, args{device: dh2.device}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			//dh.doStateInit()
+			//	context.
+			//dh.AdoptDevice(tt.args.device)
+			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+			defer cancel()
+			if err := tt.devicehandler.postInit(ctx); err != nil {
+				t.Error(err)
+			}
+		})
+	}
+}
+
+func TestDeviceHandler_activateONU(t *testing.T) {
+	dh := newMockDeviceHandler()
+	dh1 := negativeDeviceHandler()
+	type args struct {
+		intfID       uint32
+		onuID        int64
+		serialNum    *oop.SerialNumber
+		serialNumber string
+	}
+	tests := []struct {
+		name          string
+		devicehandler *DeviceHandler
+		args          args
+	}{
+		{"activateONU-1", dh, args{intfID: 0, onuID: 1, serialNum: &oop.SerialNumber{VendorId: []byte("onu1")}}},
+		{"activateONU-2", dh, args{intfID: 1, onuID: 2, serialNum: &oop.SerialNumber{VendorId: []byte("onu2")}}},
+		{"activateONU-3", dh1, args{intfID: 0, onuID: 1, serialNum: &oop.SerialNumber{VendorId: []byte("onu1")}}},
+		{"activateONU-4", dh1, args{intfID: 1, onuID: 2, serialNum: &oop.SerialNumber{VendorId: []byte("onu2")}}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+			defer cancel()
+			_ = tt.devicehandler.activateONU(ctx, tt.args.intfID, tt.args.onuID, tt.args.serialNum, tt.args.serialNumber)
+			//TODO: actually verify test cases
+		})
+	}
+}
+
+func TestDeviceHandler_start(t *testing.T) {
+	dh := newMockDeviceHandler()
+	dh1 := negativeDeviceHandler()
+	dh.start(context.Background())
+	dh.stop(context.Background())
+
+	dh1.start(context.Background())
+	dh1.stop(context.Background())
+
+}
+
+func TestDeviceHandler_PacketOut(t *testing.T) {
+	dh1 := newMockDeviceHandler()
+	dh2 := negativeDeviceHandler()
+	acts := []*ofp.OfpAction{
+		fu.SetField(fu.Metadata_ofp(uint64(ofp.OfpInstructionType_OFPIT_WRITE_METADATA))),
+		fu.SetField(fu.VlanVid(uint32(ofp.OfpVlanId_OFPVID_PRESENT) | 101)),
+		fu.Output(1),
+	}
+	pktout := &ofp.OfpPacketOut{BufferId: 0, InPort: 1, Actions: acts, Data: []byte("AYDCAAAOAODsSE5TiMwCBwQA4OxITlIEBQUwLzUxBgIAFAgEMC81MQoJbG9jYWxob3N0EBwFAawbqqACAAAAoRAxLjMuNi4xLjQuMS40NDEz/gYAgMILAgD+GQCAwgkDAAAAAGQAAAAAAAAAAgICAgICAgL+GQCAwgoDAAAAAGQAAAAAAAAAAgICAgICAgIAAA==")}
+	type args struct {
+		egressPortNo int
+		packet       *of.OfpPacketOut
+	}
+	tests := []struct {
+		name          string
+		devicehandler *DeviceHandler
+		args          args
+		wantErr       bool
+	}{
+		// TODO: Add test cases.
+		//{"test1", args{egressPortNo: 0, packet: &ofp.OfpPacketOut{}}, true},
+		{"PacketOut-1", dh1, args{egressPortNo: 0, packet: pktout}, false},
+		{"PacketOut-2", dh2, args{egressPortNo: 1, packet: pktout}, false},
+		{"PacketOut-3", dh2, args{egressPortNo: 4112, packet: pktout}, false},
+		{"PacketOut-4", dh1, args{egressPortNo: 1048577, packet: pktout}, false},
+		{"PacketOut-5", dh2, args{egressPortNo: 1048576, packet: pktout}, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			dh := tt.devicehandler
+			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+			defer cancel()
+			if err := dh.PacketOut(ctx, tt.args.egressPortNo, tt.args.packet); (err != nil) != tt.wantErr {
+				t.Errorf("DeviceHandler.PacketOut() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
+}
+
+//
+func TestDeviceHandler_doStateUp(t *testing.T) {
+	dh1 := newMockDeviceHandler()
+	dh2 := newMockDeviceHandler()
+
+	dh2.device.Id = ""
+	dh3 := negativeDeviceHandler()
+
+	tests := []struct {
+		name          string
+		devicehandler *DeviceHandler
+		wantErr       bool
+	}{
+		{"dostateup-1", dh1, false},
+		{"dostateup-2", dh2, false},
+		{"dostateup-3", dh3, true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+			defer cancel()
+			if err := tt.devicehandler.doStateUp(ctx); (err != nil) != tt.wantErr {
+				t.Logf("DeviceHandler.doStateUp() error = %v, wantErr %v", err, tt.wantErr)
+			}
+			tt.devicehandler.stopCollector <- true //stop the stat collector invoked from doStateUp
+		})
+	}
+}
+func TestDeviceHandler_doStateDown(t *testing.T) {
+	dh1 := newMockDeviceHandler()
+	dh2 := negativeDeviceHandler()
+	dh3 := newMockDeviceHandler()
+	dh3.device.OperStatus = voltha.OperStatus_UNKNOWN
+	tests := []struct {
+		name          string
+		devicehandler *DeviceHandler
+		wantErr       bool
+	}{
+		{"dostatedown-1", dh1, false},
+		{"dostatedown-2", dh2, true},
+		{"dostatedown-2", dh3, true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+			defer cancel()
+			if err := tt.devicehandler.doStateDown(ctx); (err != nil) != tt.wantErr {
+				t.Logf("DeviceHandler.doStateDown() error = %v", err)
+				//TODO: should fail this test case (Errorf) if result is not as expected
+			}
+		})
+	}
+}
+
+func TestDeviceHandler_GetOfpDeviceInfo(t *testing.T) {
+	dh1 := newMockDeviceHandler()
+	dh2 := negativeDeviceHandler()
+	type args struct {
+		device *voltha.Device
+	}
+	tests := []struct {
+		name          string
+		devicehandler *DeviceHandler
+		args          args
+		wantErr       bool
+	}{
+		// TODO: Add test cases.
+		{"GetOfpDeviceInfo-1", dh1, args{dh1.device}, false},
+		{"GetOfpDeviceInfo-2", dh1, args{&voltha.Device{}}, false},
+		{"GetOfpDeviceInfo-3", dh2, args{dh1.device}, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			dh := tt.devicehandler
+			_, err := dh.GetOfpDeviceInfo(tt.args.device)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("DeviceHandler.GetOfpDeviceInfo() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+		})
+	}
+}
+
+func TestDeviceHandler_onuDiscIndication(t *testing.T) {
+
+	dh1 := newMockDeviceHandler()
+	dh1.discOnus = sync.Map{}
+	dh1.discOnus.Store("onu1", true)
+	dh1.discOnus.Store("onu2", false)
+	dh1.discOnus.Store("onu3", true)
+	dh1.discOnus.Store("onu4", true)
+	dh1.onus = sync.Map{}
+	dh1.onus.Store("onu3", NewOnuDevice("onu3", "onu3", "onu3", 3, 3, "onu3", true))
+	dh1.onus.Store("onu4", NewOnuDevice("onu4", "onu4", "onu4", 4, 4, "onu4", true))
+	dh2 := negativeDeviceHandler()
+	type args struct {
+		onuDiscInd *oop.OnuDiscIndication
+		sn         string
+	}
+	tests := []struct {
+		name          string
+		devicehandler *DeviceHandler
+		args          args
+	}{
+		// TODO: Add test cases.
+		{"onuDiscIndication-1", dh1, args{onuDiscInd: &oop.OnuDiscIndication{IntfId: 1, SerialNumber: &oop.SerialNumber{VendorId: []byte("TWSH"), VendorSpecific: []byte("1234")}}}},
+		{"onuDiscIndication-2", dh1, args{onuDiscInd: &oop.OnuDiscIndication{IntfId: 1, SerialNumber: &oop.SerialNumber{}}}},
+		{"onuDiscIndication-3", dh1, args{onuDiscInd: &oop.OnuDiscIndication{SerialNumber: &oop.SerialNumber{}}}},
+		{"onuDiscIndication-4", dh1, args{onuDiscInd: &oop.OnuDiscIndication{}}},
+		{"onuDiscIndication-5", dh1, args{onuDiscInd: &oop.OnuDiscIndication{IntfId: 1, SerialNumber: &oop.SerialNumber{VendorId: []byte("TWSH"), VendorSpecific: []byte("1234")}}, sn: "onu1"}},
+		{"onuDiscIndication-6", dh1, args{onuDiscInd: &oop.OnuDiscIndication{IntfId: 1, SerialNumber: &oop.SerialNumber{VendorId: []byte("TWSH"), VendorSpecific: []byte("1234")}}, sn: "onu2"}},
+		{"onuDiscIndication-7", dh1, args{onuDiscInd: &oop.OnuDiscIndication{IntfId: 3, SerialNumber: &oop.SerialNumber{VendorId: []byte("TWSH"), VendorSpecific: []byte("1234")}}, sn: "onu3"}},
+		{"onuDiscIndication-8", dh1, args{onuDiscInd: &oop.OnuDiscIndication{IntfId: 3, SerialNumber: &oop.SerialNumber{VendorId: []byte("TWSH"), VendorSpecific: []byte("1234")}}, sn: "onu4"}},
+		{"onuDiscIndication-9", dh2, args{onuDiscInd: &oop.OnuDiscIndication{IntfId: 1, SerialNumber: &oop.SerialNumber{VendorId: []byte("TWSH"), VendorSpecific: []byte("1234")}}}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+			defer cancel()
+			_ = tt.devicehandler.onuDiscIndication(ctx, tt.args.onuDiscInd, tt.args.sn)
+			//TODO: actually verify test cases
+		})
+	}
+}
+
+func TestDeviceHandler_populateDeviceInfo(t *testing.T) {
+	dh1 := newMockDeviceHandler()
+	dh2 := negativeDeviceHandler()
+	tests := []struct {
+		name          string
+		devicehandler *DeviceHandler
+
+		wantErr bool
+	}{
+		// TODO: Add test cases.
+		{"populateDeviceInfo-1", dh1, true},
+		{"populateDeviceInfo-2", dh1, true},
+		{"populateDeviceInfo-3", dh1, true},
+		{"populateDeviceInfo-4", dh1, true},
+		{"populateDeviceInfo-5", dh2, true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+
+			_, err := tt.devicehandler.populateDeviceInfo(context.Background())
+			if (err != nil) != tt.wantErr {
+				t.Errorf("DeviceHandler.populateDeviceInfo() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+
+		})
+	}
+}
+
+func TestDeviceHandler_readIndications(t *testing.T) {
+	dh1 := newMockDeviceHandler()
+	dh2 := newMockDeviceHandler()
+	dh3 := newMockDeviceHandler()
+	dh3.device.AdminState = voltha.AdminState_DISABLED
+	dh4 := negativeDeviceHandler()
+	tests := []struct {
+		name          string
+		devicehandler *DeviceHandler
+	}{
+		// TODO: Add test cases.
+		{"readIndications-1", dh1},
+		{"readIndications-2", dh2},
+		{"readIndications-3", dh2},
+		{"readIndications-4", dh2},
+		{"readIndications-5", dh2},
+		{"readIndications-6", dh3},
+		{"readIndications-7", dh3},
+		{"readIndications-8", dh4},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+			defer cancel()
+			_ = tt.devicehandler.readIndications(ctx)
+			// TODO: actually verify test cases
+		})
+	}
+}
+
+func Test_startCollector(t *testing.T) {
+	type args struct {
+		dh *DeviceHandler
+	}
+	dh := newMockDeviceHandler()
+	dh.coreProxy.(*mocks.MockCoreProxy).DevicePorts[dh.device.Id] = []*voltha.Port{
+		{PortNo: 1, Label: "pon", Type: voltha.Port_PON_OLT},
+		{PortNo: 1048577, Label: "nni", Type: voltha.Port_ETHERNET_NNI},
+		{PortNo: 1048578, Label: "nni", Type: voltha.Port_ETHERNET_NNI},
+	}
+	dh.portStats.NorthBoundPort = make(map[uint32]*NniPort)
+	dh.portStats.NorthBoundPort[1] = &NniPort{Name: "OLT-1"}
+	dh.portStats.NorthBoundPort[2] = &NniPort{Name: "OLT-1"}
+	dh.portStats.SouthBoundPort = make(map[uint32]*PonPort)
+	dh.portStats.Device = dh
+	for i := 0; i < 16; i++ {
+		dh.portStats.SouthBoundPort[uint32(i)] = &PonPort{DeviceID: "OLT-1"}
+	}
+	dh1 := newMockDeviceHandler()
+	dh1.coreProxy.(*mocks.MockCoreProxy).DevicePorts[dh.device.Id] = []*voltha.Port{}
+	tests := []struct {
+		name string
+		args args
+	}{
+		// TODO: Add test cases.
+		{"StartCollector-1", args{dh}},
+		{"StartCollector-2", args{dh1}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			go func() {
+				time.Sleep(1 * time.Second) // simulated wait time to stop startCollector
+				tt.args.dh.stopCollector <- true
+			}()
+			startCollector(context.Background(), tt.args.dh)
+		})
+	}
+}