diff --git a/src/core/core_test.go b/src/core/core_test.go
index dd60af21..fcfe2e31 100644
--- a/src/core/core_test.go
+++ b/src/core/core_test.go
@@ -44,13 +44,11 @@ func CreateAndConnectTwo(t testing.TB, verbose bool) (nodeA *Core, nodeB *Core)
 	if err := nodeA.Start(GenerateConfig(), GetLoggerWithPrefix("A: ", verbose)); err != nil {
 		t.Fatal(err)
 	}
-	nodeA.SetMTU(1500)
 
 	nodeB = new(Core)
 	if err := nodeB.Start(GenerateConfig(), GetLoggerWithPrefix("B: ", verbose)); err != nil {
 		t.Fatal(err)
 	}
-	nodeB.SetMTU(1500)
 
 	u, err := url.Parse("tcp://" + nodeA.links.tcp.getAddr().String())
 	if err != nil {
@@ -94,7 +92,7 @@ func CreateEchoListener(t testing.TB, nodeA *Core, bufLen int, repeats int) chan
 		buf := make([]byte, bufLen)
 		res := make([]byte, bufLen)
 		for i := 0; i < repeats; i++ {
-			n, err := nodeA.Read(buf)
+			n, from, err := nodeA.ReadFrom(buf)
 			if err != nil {
 				t.Error(err)
 				return
@@ -106,7 +104,7 @@ func CreateEchoListener(t testing.TB, nodeA *Core, bufLen int, repeats int) chan
 			copy(res, buf)
 			copy(res[8:24], buf[24:40])
 			copy(res[24:40], buf[8:24])
-			_, err = nodeA.Write(res)
+			_, err = nodeA.WriteTo(res, from)
 			if err != nil {
 				t.Error(err)
 			}
@@ -141,12 +139,12 @@ func TestCore_Start_Transfer(t *testing.T) {
 	msg[0] = 0x60
 	copy(msg[8:24], nodeB.Address())
 	copy(msg[24:40], nodeA.Address())
-	_, err := nodeB.Write(msg)
+	_, err := nodeB.WriteTo(msg, nodeA.LocalAddr())
 	if err != nil {
 		t.Fatal(err)
 	}
 	buf := make([]byte, msgLen)
-	_, err = nodeB.Read(buf)
+	_, _, err = nodeB.ReadFrom(buf)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -179,12 +177,13 @@ func BenchmarkCore_Start_Transfer(b *testing.B) {
 	b.SetBytes(int64(msgLen))
 	b.ResetTimer()
 
+	addr := nodeA.LocalAddr()
 	for i := 0; i < b.N; i++ {
-		_, err := nodeB.Write(msg)
+		_, err := nodeB.WriteTo(msg, addr)
 		if err != nil {
 			b.Fatal(err)
 		}
-		_, err = nodeB.Read(buf)
+		_, _, err = nodeB.ReadFrom(buf)
 		if err != nil {
 			b.Fatal(err)
 		}