diff --git a/README.md b/README.md
index b15462c..bf285bf 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,7 @@ go-socks5
 [![License](https://img.shields.io/github/license/thinkgos/go-socks5)](https://github.com/thinkgos/go-socks5/raw/master/LICENSE)
 [![Tag](https://img.shields.io/github/v/tag/thinkgos/go-socks5)](https://github.com/thinkgos/go-socks5/tags)
 
-Provides the `socks5` package that implements a [SOCKS5 server](http://en.wikipedia.org/wiki/SOCKS).
+Provides the `socks5` package that implements a [SOCKS5](http://en.wikipedia.org/wiki/SOCKS).
 SOCKS (Secure Sockets) is used to route traffic between a client and server through
 an intermediate proxy layer. This can be used to bypass firewalls or NATs.
 
@@ -17,22 +17,24 @@ Feature
 =======
 
 The package has the following features:
-* Unit tests
-* "No Auth" mode
-* User/Password authentication optional user addr limit
-* Support for the CONNECT command
-* Support for the ASSOCIATE command
-* Rules to do granular filtering of commands
-* Custom DNS resolution
-* Custom goroutine pool
-* buffer pool design and optional custom buffer pool
-* Custom logger
+- Support client(**under ccsocks5 directory**) and server(**under root directory**)
+- Support TCP/UDP and IPv4/IPv6
+- Unit tests
+- "No Auth" mode
+- User/Password authentication optional user addr limit
+- Support for the CONNECT command
+- Support for the ASSOCIATE command
+- Rules to do granular filtering of commands
+- Custom DNS resolution
+- Custom goroutine pool
+- buffer pool design and optional custom buffer pool
+- Custom logger
 
 TODO
 ====
 
 The package still needs the following:
-* Support for the BIND command
+- Support for the BIND command
 
 Example
 =======
diff --git a/_testing/associate/main.go b/_example/associate/main.go
similarity index 100%
rename from _testing/associate/main.go
rename to _example/associate/main.go
diff --git a/_testing/connect/main.go b/_example/connect/main.go
similarity index 100%
rename from _testing/connect/main.go
rename to _example/connect/main.go
diff --git a/ccsocks5/client.go b/ccsocks5/client.go
index 8fe90bc..30edd8b 100644
--- a/ccsocks5/client.go
+++ b/ccsocks5/client.go
@@ -22,7 +22,8 @@ type Client struct {
 	bufferPool      bufferpool.BufPool
 }
 
-// NewClient This is just create a client, you need to use Dial to create conn.
+// NewClient This is just create a client.
+// you need to use Dial to create conn.
 func NewClient(proxyAddr string, opts ...Option) (*Client, error) {
 	c := &Client{
 		proxyAddr:       proxyAddr,
@@ -37,7 +38,9 @@ func NewClient(proxyAddr string, opts ...Option) (*Client, error) {
 
 // Close closes the connection.
 func (sf *Client) Close() (err error) {
-	err = sf.tcpConn.Close()
+	if sf.tcpConn != nil {
+		err = sf.tcpConn.Close()
+	}
 	if sf.Conn != nil {
 		err = sf.Conn.Close()
 	}
diff --git a/server.go b/server.go
index e96feef..910cba3 100644
--- a/server.go
+++ b/server.go
@@ -106,7 +106,7 @@ func (sf *Server) Serve(l net.Listener) error {
 		}
 		sf.submit(func() {
 			if err := sf.ServeConn(conn); err != nil {
-				sf.logger.Errorf("server conn %v", err)
+				sf.logger.Errorf("server: %v", err)
 			}
 		})
 	}
diff --git a/testing/socks5_test.go b/testing/socks5_test.go
new file mode 100644
index 0000000..b778679
--- /dev/null
+++ b/testing/socks5_test.go
@@ -0,0 +1,128 @@
+package testing
+
+import (
+	"io"
+	"log"
+	"net"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"golang.org/x/net/proxy"
+
+	"github.com/thinkgos/go-socks5"
+	"github.com/thinkgos/go-socks5/bufferpool"
+	"github.com/thinkgos/go-socks5/ccsocks5"
+)
+
+func Test_Socks5_Connect(t *testing.T) {
+	// Create a local listener
+	l, err := net.Listen("tcp", "127.0.0.1:0")
+	require.NoError(t, err)
+
+	go func() {
+		conn, err := l.Accept()
+		require.NoError(t, err)
+		defer conn.Close()
+
+		buf := make([]byte, 4)
+		_, err = io.ReadAtLeast(conn, buf, 4)
+		require.NoError(t, err)
+		assert.Equal(t, []byte("ping"), buf)
+
+		conn.Write([]byte("pong")) // nolint: errcheck
+	}()
+
+	// Create a socks server with UserPass auth.
+	cator := socks5.UserPassAuthenticator{Credentials: socks5.StaticCredentials{"user": "pass"}}
+	srv := socks5.NewServer(
+		socks5.WithAuthMethods([]socks5.Authenticator{cator}),
+		socks5.WithLogger(socks5.NewLogger(log.New(os.Stdout, "socks5: ", log.LstdFlags))),
+	)
+
+	// Start listening
+	go func() {
+		err := srv.ListenAndServe("tcp", "127.0.0.1:12389")
+		require.NoError(t, err)
+	}()
+	time.Sleep(10 * time.Millisecond)
+
+	// Get a local conn
+	client, err := ccsocks5.NewClient("127.0.0.1:12389",
+		ccsocks5.WithAuth(&proxy.Auth{User: "user", Password: "pass"}),
+		ccsocks5.WithBufferPool(bufferpool.NewPool(32*1024)),
+	)
+	require.NoError(t, err)
+
+	conn, err := client.Dial("tcp", l.Addr().String())
+	require.NoError(t, err)
+	defer conn.Close()
+	// Send all the bytes
+	conn.Write([]byte("ping")) // nolint: errcheck
+
+	out := make([]byte, 4)
+	conn.SetDeadline(time.Now().Add(time.Second)) // nolint: errcheck
+	_, err = io.ReadFull(conn, out)
+	conn.SetDeadline(time.Time{}) // nolint: errcheck
+	require.NoError(t, err)
+	assert.Equal(t, []byte("pong"), out)
+}
+
+func Test_socks5_Associate(t *testing.T) {
+	locIP := net.ParseIP("127.0.0.1")
+	// Create a local listener
+	lAddr := &net.UDPAddr{IP: locIP, Port: 12312}
+	l, err := net.ListenUDP("udp", lAddr)
+	require.NoError(t, err)
+	defer l.Close()
+
+	go func() {
+		buf := make([]byte, 2048)
+		for {
+			n, remote, err := l.ReadFrom(buf)
+			if err != nil {
+				return
+			}
+			require.Equal(t, []byte("ping"), buf[:n])
+
+			l.WriteTo([]byte("pong"), remote) // nolint: errcheck
+		}
+	}()
+
+	// Create a socks server
+	cator := socks5.UserPassAuthenticator{Credentials: socks5.StaticCredentials{"user": "pass"}}
+	proxySrv := socks5.NewServer(
+		socks5.WithAuthMethods([]socks5.Authenticator{cator}),
+		socks5.WithLogger(socks5.NewLogger(log.New(os.Stdout, "socks5: ", log.LstdFlags))),
+	)
+	// Start listening
+	go func() {
+		err := proxySrv.ListenAndServe("tcp", "127.0.0.1:12385")
+		require.NoError(t, err)
+	}()
+	time.Sleep(10 * time.Millisecond)
+
+	// Get a local conn
+	client, err := ccsocks5.NewClient(
+		"127.0.0.1:12385",
+		ccsocks5.WithAuth(&proxy.Auth{User: "user", Password: "pass"}),
+	)
+	require.NoError(t, err)
+
+	conn, err := client.Dial("udp", lAddr.String())
+	require.NoError(t, err)
+
+	// send ping
+	conn.Write([]byte("ping")) // nolint: errcheck
+
+	// read response
+	out := make([]byte, 4)
+	conn.SetDeadline(time.Now().Add(time.Second)) // nolint: errcheck
+	_, err = io.ReadFull(conn, out)
+	conn.SetDeadline(time.Time{}) // nolint: errcheck
+	require.NoError(t, err)
+	require.Equal(t, []byte("pong"), out)
+	time.Sleep(time.Second * 1)
+}