diff --git a/go.mod b/go.mod
index 8593663..c5cda61 100644
--- a/go.mod
+++ b/go.mod
@@ -12,6 +12,7 @@ require (
 	github.com/mediocregopher/radix/v3 v3.5.0
 	github.com/onsi/ginkgo v1.10.1 // indirect
 	github.com/onsi/gomega v1.7.0 // indirect
+	github.com/patrickmn/go-cache v2.1.0+incompatible
 	github.com/proullon/ramsql v0.0.0-20181213202341-817cee58a244
 	github.com/refraction-networking/utls v0.0.0-20190909200633-43c36d3c1f57
 	github.com/smartystreets/goconvey v1.6.4
diff --git a/go.sum b/go.sum
index cb53be9..9c7d97c 100644
--- a/go.sum
+++ b/go.sum
@@ -225,6 +225,8 @@ github.com/onsi/gomega v1.7.0/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1Cpa
 github.com/openzipkin/zipkin-go v0.1.6/go.mod h1:QgAqvLzwWbR/WpD4A3cGpPtJrZXNIiJc5AZX7/PBEpw=
 github.com/oracle/oci-go-sdk v7.0.0+incompatible/go.mod h1:VQb79nF8Z2cwLkLS35ukwStZIg5F66tcBccjip/j888=
 github.com/ovh/go-ovh v0.0.0-20181109152953-ba5adb4cf014/go.mod h1:joRatxRJaZBsY3JAOEMcoOp05CnZzsx4scTxi95DHyQ=
+github.com/patrickmn/go-cache v2.1.0+incompatible h1:HRMgzkcYKYpi3C8ajMPV8OFXaaRUnok+kx1WdO15EQc=
+github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
 github.com/pierrec/lz4 v2.0.5+incompatible/go.mod h1:pdkljMzZIN41W+lC3N2tnIh5sFi+IEE17M5jbnwPHcY=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
diff --git a/protocol/direct/outbound.go b/protocol/direct/outbound.go
index 66bca87..f5fa774 100644
--- a/protocol/direct/outbound.go
+++ b/protocol/direct/outbound.go
@@ -13,8 +13,11 @@ import (
 	"github.com/p4gefau1t/trojan-go/conf"
 	"github.com/p4gefau1t/trojan-go/log"
 	"github.com/p4gefau1t/trojan-go/protocol"
+	"github.com/patrickmn/go-cache"
 )
 
+var dnsCache = cache.New(5*time.Minute, 1*time.Minute)
+
 type DirectOutboundConnSession struct {
 	protocol.ConnSession
 	conn    io.ReadWriteCloser
@@ -35,8 +38,19 @@ func (o *DirectOutboundConnSession) Close() error {
 
 func NewOutboundConnSession(ctx context.Context, req *protocol.Request, config *conf.GlobalConfig) (protocol.ConnSession, error) {
 	var newConn net.Conn
-	//custom dns server
-	if req.AddressType == common.DomainName && len(config.DNS) != 0 {
+	var err error
+	//look up the domain name in cache first
+	if req.AddressType == common.DomainName && len(config.DNS) != 0 { //customized dns server
+		ip, found := dnsCache.Get(req.DomainName)
+		if found {
+			newConn, err = net.DialTCP("tcp", nil, &net.TCPAddr{
+				IP: ip.(net.IP),
+			})
+			if err != nil {
+				return nil, err
+			}
+			goto done
+		}
 		//find a avaliable dns server
 		for _, s := range config.DNS {
 			var dnsType conf.DNSType
@@ -86,6 +100,7 @@ func NewOutboundConnSession(ctx context.Context, req *protocol.Request, config *
 					if err != nil {
 						return nil, err
 					}
+					dnsCache.Set(req.DomainName, net.ParseIP(ip), cache.DefaultExpiration)
 					break
 				}
 			} else {
@@ -129,6 +144,7 @@ func NewOutboundConnSession(ctx context.Context, req *protocol.Request, config *
 					if err != nil {
 						return nil, err
 					}
+					dnsCache.Set(req.DomainName, ip.IP, cache.DefaultExpiration)
 					break
 				}
 			}
@@ -140,11 +156,12 @@ func NewOutboundConnSession(ctx context.Context, req *protocol.Request, config *
 	} else {
 		//default resolver
 		var err error
-		newConn, err = net.Dial(req.Network(), req.String())
+		newConn, err = net.Dial("tcp", req.String())
 		if err != nil {
 			return nil, err
 		}
 	}
+done:
 	o := &DirectOutboundConnSession{
 		request: req,
 		conn:    newConn,
diff --git a/protocol/direct/outbound_test.go b/protocol/direct/outbound_test.go
index 428ae70..533ff67 100644
--- a/protocol/direct/outbound_test.go
+++ b/protocol/direct/outbound_test.go
@@ -42,7 +42,6 @@ func TestUDPDirectOutbound(t *testing.T) {
 
 func TestDNS(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
-	go test.RunEchoTCPServer(ctx)
 	config := &conf.GlobalConfig{
 		DNS: []string{"114.114.114.114:53"},
 	}
@@ -67,7 +66,6 @@ func TestDNS(t *testing.T) {
 
 func TestDOT(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
-	go test.RunEchoTCPServer(ctx)
 	config := &conf.GlobalConfig{
 		DNS: []string{"dot://223.5.5.5:853"},
 	}
@@ -92,7 +90,6 @@ func TestDOT(t *testing.T) {
 
 func TestDOH(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
-	go test.RunEchoTCPServer(ctx)
 	config := &conf.GlobalConfig{
 		DNS: []string{"https://223.5.5.5:443"},
 	}
@@ -114,3 +111,25 @@ func TestDOH(t *testing.T) {
 	fmt.Println(string(buf[:]))
 	cancel()
 }
+
+func TestCache(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	config := &conf.GlobalConfig{
+		DNS: []string{"223.5.5.5:53"},
+	}
+	req := &protocol.Request{
+		Address: &common.Address{
+			DomainName:  "www.baidu.com",
+			Port:        80,
+			AddressType: common.DomainName,
+			NetworkType: "tcp",
+		},
+	}
+	conn, err := NewOutboundConnSession(ctx, req, config)
+	common.Must(err)
+	conn.Close()
+	conn, err = NewOutboundConnSession(ctx, req, config)
+	common.Must(err)
+	conn.Close()
+	cancel()
+}
diff --git a/protocol/trojan/outbound.go b/protocol/trojan/outbound.go
index d7985d3..20aeeae 100644
--- a/protocol/trojan/outbound.go
+++ b/protocol/trojan/outbound.go
@@ -14,13 +14,14 @@ import (
 type TrojanOutboundConnSession struct {
 	protocol.ConnSession
 
-	config  *conf.GlobalConfig
-	rwc     io.ReadWriteCloser
-	request *protocol.Request
-	sent    uint64
-	recv    uint64
-	auth    stat.Authenticator
-	meter   stat.TrafficMeter
+	config       *conf.GlobalConfig
+	rwc          io.ReadWriteCloser
+	request      *protocol.Request
+	sent         uint64
+	recv         uint64
+	auth         stat.Authenticator
+	meter        stat.TrafficMeter
+	trojanHeader []byte
 }
 
 func (o *TrojanOutboundConnSession) SetMeter(meter stat.TrafficMeter) {
@@ -28,6 +29,19 @@ func (o *TrojanOutboundConnSession) SetMeter(meter stat.TrafficMeter) {
 }
 
 func (o *TrojanOutboundConnSession) Write(p []byte) (int, error) {
+	if o.trojanHeader != nil {
+		//glue the payload with the trojan request header
+		fullRequest := o.trojanHeader
+		fullRequest = append(fullRequest, p...)
+		n, err := o.rwc.Write(fullRequest)
+		if n >= len(o.trojanHeader) {
+			n -= len(o.trojanHeader)
+		}
+		o.meter.Count(n, 0)
+		o.sent += uint64(n)
+		o.trojanHeader = nil
+		return n, err
+	}
 	n, err := o.rwc.Write(p)
 	o.meter.Count(n, 0)
 	o.sent += uint64(n)
@@ -57,8 +71,8 @@ func (o *TrojanOutboundConnSession) writeRequest() error {
 	buf.WriteByte(byte(o.request.Command))
 	protocol.WriteAddress(buf, o.request)
 	buf.Write(crlf)
-	_, err := o.rwc.Write(buf.Bytes())
-	return err
+	o.trojanHeader = buf.Bytes()
+	return nil
 }
 
 func NewOutboundConnSession(req *protocol.Request, rwc io.ReadWriteCloser, config *conf.GlobalConfig, auth stat.Authenticator) (protocol.ConnSession, error) {