diff --git a/internal/test/integration_test.go b/internal/test/integration_test.go
index f9820f9..797bb78 100644
--- a/internal/test/integration_test.go
+++ b/internal/test/integration_test.go
@@ -310,27 +310,51 @@ func TestClosingStreamsFromProxy(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	// closing stream on server side
-	clientConn, _ := pxyClientD.Dial("", "")
-	clientConn.Write(make([]byte, 16))
-	serverConn, _ := pxyServerL.Accept()
-	serverConn.Close()
+	t.Run("closing from server", func(t *testing.T) {
+		clientConn, _ := pxyClientD.Dial("", "")
+		clientConn.Write(make([]byte, 16))
+		serverConn, _ := pxyServerL.Accept()
+		serverConn.Close()
 
-	time.Sleep(100 * time.Millisecond)
-	if _, err := clientConn.Read(make([]byte, 16)); err == nil {
-		t.Errorf("closing stream on server side is not reflected to the client: %v", err)
-	}
+		time.Sleep(100 * time.Millisecond)
+		if _, err := clientConn.Read(make([]byte, 16)); err == nil {
+			t.Errorf("closing stream on server side is not reflected to the client: %v", err)
+		}
+	})
 
-	// closing stream on client side
-	clientConn, _ = pxyClientD.Dial("", "")
-	clientConn.Write(make([]byte, 16))
-	serverConn, _ = pxyServerL.Accept()
-	clientConn.Close()
+	t.Run("closing from client", func(t *testing.T) {
+		// closing stream on client side
+		clientConn, _ := pxyClientD.Dial("", "")
+		clientConn.Write(make([]byte, 16))
+		serverConn, _ := pxyServerL.Accept()
+		clientConn.Close()
 
-	time.Sleep(100 * time.Millisecond)
-	if _, err := serverConn.Read(make([]byte, 16)); err == nil {
-		t.Errorf("closing stream on client side is not reflected to the server: %v", err)
-	}
+		time.Sleep(100 * time.Millisecond)
+		if _, err := serverConn.Read(make([]byte, 16)); err == nil {
+			t.Errorf("closing stream on client side is not reflected to the server: %v", err)
+		}
+	})
+
+	t.Run("send then close", func(t *testing.T) {
+		testData := make([]byte, 24*1024)
+		rand.Read(testData)
+		clientConn, _ := pxyClientD.Dial("", "")
+		go func() {
+			clientConn.Write(testData)
+			// TODO: this is time dependent. It could be due to the time it took for this
+			// connutil.StreamPipe's Close to be reflected on the copy function, instead of inherent bad sync
+			// in multiplexer
+			time.Sleep(10 * time.Millisecond)
+			clientConn.Close()
+		}()
+
+		readBuf := make([]byte, len(testData))
+		serverConn, _ := pxyServerL.Accept()
+		_, err := io.ReadFull(serverConn, readBuf)
+		if err != nil {
+			t.Errorf("failed to read data sent before closing: %v", err)
+		}
+	})
 }
 
 func BenchmarkThroughput(b *testing.B) {
@@ -357,39 +381,60 @@ func BenchmarkThroughput(b *testing.B) {
 			}
 
 			b.Run("single conn", func(b *testing.B) {
+				more := make(chan int, 100)
 				go func() {
+					writeBuf := make([]byte, bufSize+100)
 					serverConn, _ := pxyServerL.Accept()
-					io.Copy(ioutil.Discard, serverConn)
+					for {
+						serverConn.Write(writeBuf)
+						<-more
+					}
 				}()
 				clientConn, _ := pxyClientD.Dial("", "")
-				writeBuf := make([]byte, bufSize)
+				readBuf := make([]byte, bufSize)
+				clientConn.Write([]byte{1}) // to make server accept
 				b.ResetTimer()
 				for i := 0; i < b.N; i++ {
-					n, _ := clientConn.Write(writeBuf)
+					n, _ := clientConn.Read(readBuf)
 					b.SetBytes(int64(n))
+					more <- 0
 				}
 			})
 
-			b.Run("multi conn", func(b *testing.B) {
-				for i := 0; i < numConns; i++ {
-					go func() {
-						serverConn, _ := pxyServerL.Accept()
-						io.Copy(ioutil.Discard, serverConn)
-					}()
-				}
-				conns := make([]net.Conn, numConns)
-				for i := 0; i < numConns; i++ {
-					conns[i], _ = pxyClientD.Dial("", "")
-				}
-				writeBuf := make([]byte, bufSize)
-				b.ResetTimer()
-				b.RunParallel(func(pb *testing.PB) {
-					for pb.Next() {
-						n, _ := conns[rand.Intn(numConns)].Write(writeBuf)
-						b.SetBytes(int64(n))
+			/*
+				b.Run("multi conn", func(b *testing.B) {
+					var connsIds sync.Pool
+					conns := make([]net.Conn, numConns)
+					more := make([]chan int, numConns)
+					for i := 0; i < numConns; i++ {
+						conns[i], _ = pxyClientD.Dial("", "")
+						conns[i].Write([]byte{1}) // to make server accept
+						connsIds.Put(i)
+						moreChan := make(chan int, 100)
+						more[i] = moreChan
+						writeBuf := make([]byte, bufSize + 100)
+						go func() {
+							serverConn, _ := pxyServerL.Accept()
+							for {
+								serverConn.Write(writeBuf)
+								<- moreChan
+							}
+						}()
 					}
+					b.SetParallelism(numConns)
+					b.ResetTimer()
+					b.RunParallel(func(pb *testing.PB) {
+						buf := make([]byte, bufSize)
+						connNum := connsIds.Get().(int)
+						for pb.Next() {
+							n, _ := conns[connNum].Read(buf)
+							more[connNum] <- 0
+							b.SetBytes(int64(n))
+						}
+					})
 				})
-			})
+
+			*/
 		})
 	}