diff --git a/opennotrd/core/tcpforward_test.go b/opennotrd/core/tcpforward_test.go
index b642856..95c1d64 100644
--- a/opennotrd/core/tcpforward_test.go
+++ b/opennotrd/core/tcpforward_test.go
@@ -4,13 +4,20 @@ import (
 	"fmt"
 	"io"
 	"net"
+	"net/http"
+	_ "net/http/pprof"
 	"os"
+	"sync"
 	"testing"
 	"time"
 
 	"github.com/hashicorp/yamux"
 )
 
+func init() {
+	go http.ListenAndServe("127.0.0.1:6060", nil)
+}
+
 // client -----> tproxy | opennotr server <------ opennotr client
 
 var backendAddr = "127.0.0.1:8522"
@@ -37,30 +44,22 @@ func (c *mockConn) LocalAddr() net.Addr {
 	return c.addr
 }
 
-func (c *mockConn) Write(buf []byte) (int, error) {
-	fmt.Printf("receive %d bytes\n", len(buf))
-	return len(buf), nil
-}
-
-func runBackend(t *testing.T) {
+func runBackend() {
 	conn, err := net.Dial("tcp", serverAddr)
 	if err != nil {
-		t.Error(err)
-		return
+		panic(err)
 	}
 	defer conn.Close()
 	sess, err := yamux.Client(conn, nil)
 	if err != nil {
-		t.Error(err)
-		t.FailNow()
+		panic(err)
 	}
 	defer sess.Close()
 
 	for {
 		stream, err := sess.AcceptStream()
 		if err != nil {
-			t.Error(err)
-			t.FailNow()
+			panic(err)
 		}
 
 		go func() {
@@ -69,7 +68,7 @@ func runBackend(t *testing.T) {
 			for {
 				nr, err := stream.Read(buf)
 				if err != nil {
-					fmt.Println(err)
+					fmt.Println("read stream fail:", err)
 					break
 				}
 				stream.Write(buf[:nr])
@@ -78,7 +77,7 @@ func runBackend(t *testing.T) {
 	}
 }
 
-func runserver(t *testing.T, listener net.Listener) {
+func runserver(listener net.Listener) {
 	for {
 		conn, err := listener.Accept()
 		if err != nil {
@@ -88,18 +87,17 @@ func runserver(t *testing.T, listener net.Listener) {
 		go func() {
 			sess, err := yamux.Server(conn, nil)
 			if err != nil {
-				t.Error(err)
-				t.FailNow()
+				panic(err)
 			}
 
 			sessMgr := GetSessionManager()
 			sessMgr.AddSession(vip, &Session{conn: sess})
-			t.Log("add session: ", vip)
+			fmt.Println("add session: ", vip)
 		}()
 	}
 }
 
-func runtproxy(t *testing.T, tcpfw *TCPForward, listener net.Listener) {
+func runtproxy(tcpfw *TCPForward, listener net.Listener) {
 	for {
 		conn, err := listener.Accept()
 		if err != nil {
@@ -123,7 +121,7 @@ func TestTCPForward(t *testing.T) {
 		t.Error(err)
 		return
 	}
-	defer listener.Close()
+	// defer listener.Close()
 
 	srvlistener, err := net.Listen("tcp", serverAddr)
 	if err != nil {
@@ -132,10 +130,11 @@ func TestTCPForward(t *testing.T) {
 	}
 	defer srvlistener.Close()
 
-	go runBackend(t)
-	go runserver(t, srvlistener)
-	go runtproxy(t, tcpfw, listener)
-
+	go runBackend()
+	go runserver(srvlistener)
+	go runtproxy(tcpfw, listener)
+	// wait for session created
+	time.Sleep(time.Second * 1)
 	conn, err := net.Dial("tcp", tproxyAddr)
 	if err != nil {
 		t.FailNow()
@@ -143,11 +142,87 @@ func TestTCPForward(t *testing.T) {
 	defer conn.Close()
 
 	go func() {
-		for i := 0; i < 100; i++ {
+		defer conn.Close()
+		for i := 0; i < 10; i++ {
 			conn.Write([]byte("ping\n"))
 			time.Sleep(time.Second * 1)
 		}
+		fmt.Println("connection close")
 	}()
 
-	io.Copy(os.Stdout, conn)
+	buf := make([]byte, 128)
+	c := 0
+	for {
+		nr, err := conn.Read(buf)
+		if err != nil {
+			break
+		}
+		fmt.Printf("receive %d %s\n", c+1, string(buf[:nr]))
+		c += 1
+	}
+}
+
+func benchmark(t *testing.B, nconn int) {
+	// listen tproxy
+	tcpfw := NewTCPForward()
+	listener, err := tcpfw.Listen(tproxyAddr)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	// defer listener.Close()
+
+	srvlistener, err := net.Listen("tcp", serverAddr)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	defer srvlistener.Close()
+
+	go runBackend()
+	go runserver(srvlistener)
+	go runtproxy(tcpfw, listener)
+
+	// wait for session created
+	time.Sleep(time.Second * 1)
+	wg := sync.WaitGroup{}
+	wg.Add(nconn)
+	defer wg.Wait()
+	for i := 0; i < nconn; i++ {
+		go func() {
+			defer wg.Done()
+			conn, err := net.Dial("tcp", tproxyAddr)
+			if err != nil {
+				t.FailNow()
+			}
+			defer conn.Close()
+
+			go func() {
+				defer conn.Close()
+				for i := 0; i < 10; i++ {
+					conn.Write([]byte("ping\n"))
+					time.Sleep(time.Second * 1)
+				}
+			}()
+			fp, _ := os.Open(os.DevNull)
+			defer fp.Close()
+			io.Copy(fp, conn)
+		}()
+	}
+}
+
+func Benchmark1K(b *testing.B) {
+	benchmark(b, 1024)
+}
+
+func Benchmark2K(b *testing.B) {
+	benchmark(b, 1024*2)
+}
+
+func Benchmark4K(b *testing.B) {
+	benchmark(b, 1024*4)
+}
+
+func Benchmark8K(b *testing.B) {
+	benchmark(b, 1024*8)
 }