diff --git a/x/wire/wire_test.go b/x/wire/wire_test.go
new file mode 100644
index 00000000..ef5b3c47
--- /dev/null
+++ b/x/wire/wire_test.go
@@ -0,0 +1,112 @@
+package wire
+
+import (
+	"context"
+	"io"
+	"testing"
+
+	wpb "github.com/openconfig/kne/proto/wire"
+	"google.golang.org/grpc/metadata"
+)
+
+type FakeStream struct {
+	incoming []*wpb.Packet
+	i        int
+	outgoing []*wpb.Packet
+}
+
+func NewFakeStream(packets []*wpb.Packet) *FakeStream {
+	return &FakeStream{incoming: packets, outgoing: []*wpb.Packet{}}
+}
+
+func (f *FakeStream) Recv() (*wpb.Packet, error) {
+	if f.i >= len(f.incoming) {
+		return nil, io.EOF
+	}
+	p := f.incoming[f.i]
+	f.i++
+	return p, nil
+}
+
+func (f *FakeStream) Send(p *wpb.Packet) error {
+	f.outgoing = append(f.outgoing, p)
+	return nil
+}
+
+type FakeReadWriter struct {
+	src [][]byte
+	i   int
+	dst [][]byte
+}
+
+func NewFakeReadWriter(b [][]byte) *FakeReadWriter {
+	return &FakeReadWriter{src: b, dst: [][]byte{}}
+}
+
+func (f *FakeReadWriter) Read() ([]byte, error) {
+	if f.i >= len(f.src) {
+		return nil, io.EOF
+	}
+	b := f.src[f.i]
+	f.i++
+	return b, nil
+}
+
+func (f *FakeReadWriter) Write(b []byte) error {
+	f.dst = append(f.dst, b)
+	return nil
+}
+
+func TestTransmit(t *testing.T) {
+	rwSrc := [][]byte{
+		[]byte("rwSrc1"),
+		[]byte("rwSrc2"),
+	}
+	rw := NewFakeReadWriter(rwSrc)
+	sSrc := []*wpb.Packet{
+		&wpb.Packet{Data: []byte("sSrc1")},
+		&wpb.Packet{Data: []byte("sSrc2")},
+		&wpb.Packet{Data: []byte("sSrc3")},
+	}
+	s := NewFakeStream(sSrc)
+	w := NewWire(rw)
+	if err := w.Transmit(context.Background(), s); err != nil {
+		t.Fatalf("wire.Transmit() unexpected error: %v", err)
+	}
+	if len(rw.dst) != len(s.incoming) {
+		t.Fatalf("Got %v []bytes written, want %v", len(rw.dst), len(s.incoming))
+	}
+	for i := range rw.dst {
+		if string(rw.dst[i]) != string(s.incoming[i].Data) {
+			t.Errorf("Got data at index %v: %v, want %v", i, string(rw.dst[i]), string(s.incoming[i].Data))
+		}
+	}
+	if len(s.outgoing) != len(rw.src) {
+		t.Fatalf("Got %v packets written, want %v", len(s.outgoing), len(rw.src))
+	}
+	for i := range s.outgoing {
+		if string(s.outgoing[i].Data) != string(rw.src[i]) {
+			t.Errorf("Got data at index %v: %v, want %v", i, string(s.outgoing[i].Data), string(rw.src[i]))
+		}
+	}
+}
+
+func TestPhysicalEndpoint(t *testing.T) {
+	pe := NewPhysicalEndpoint("dev1", "intf1")
+	ctx := pe.NewContext(context.Background())
+	md, ok := metadata.FromOutgoingContext(ctx)
+	if !ok {
+		t.Fatalf("Unable to get metadata from context")
+	}
+	ctx = metadata.NewIncomingContext(context.Background(), md)
+	ppe, err := ParsePhysicalEndpoint(ctx)
+	if err != nil {
+		t.Fatalf("ParsePhysicalEndpoint() unexpected error: %v", err)
+	}
+	if ppe.device != pe.device {
+		t.Errorf("ParsePhysicalEndpoint() got device %v, want device %v", ppe.device, pe.device)
+	}
+	if ppe.intf != pe.intf {
+		t.Errorf("ParsePhysicalEndpoint() got intf %v, want intf %v", ppe.intf, pe.intf)
+	}
+}