diff --git a/internal/transport/conn_tcp.go b/internal/transport/conn_tcp.go
index e261853..e67947d 100644
--- a/internal/transport/conn_tcp.go
+++ b/internal/transport/conn_tcp.go
@@ -17,7 +17,7 @@ type tcpConn struct {
 }
 
 func NewTCP(host string, timeout time.Duration) (Conn, error) {
-	return NewTCPWithCtx(nil, host, timeout)
+	return NewTCPWithCtx(context.Background(), host, timeout)
 }
 
 func NewTCPWithCtx(ctx context.Context, host string, timeout time.Duration) (Conn, error) {
@@ -30,10 +30,6 @@ func NewTCPWithCtx(ctx context.Context, host string, timeout time.Duration) (Con
 		return nil, errors.Wrap(err, "dialing tcp")
 	}
 
-	if ctx == nil {
-		ctx = context.Background()
-	}
-
 	return &tcpConn{
 		cancelReader: ioutil.NewCancelableReader(ctx, conn),
 		conn:         conn,
diff --git a/internal/transport/interfaces.go b/internal/transport/interfaces.go
index 4ed3ca5..2d73282 100644
--- a/internal/transport/interfaces.go
+++ b/internal/transport/interfaces.go
@@ -6,7 +6,7 @@ import (
 
 type Conn io.ReadWriteCloser
 
-type Transport interface {
+type Mode interface {
 	WriteMsg(msg []byte) error // this is not same as the io.Writer
 	ReadMsg() ([]byte, error)
 }
diff --git a/internal/transport/intermediate_mode.go b/internal/transport/intermediate_mode.go
index 4a518dc..ab40c64 100644
--- a/internal/transport/intermediate_mode.go
+++ b/internal/transport/intermediate_mode.go
@@ -15,7 +15,7 @@ type intermediateMode struct {
 
 var transportModeIntermediate = [...]byte{0xee, 0xee, 0xee, 0xee} // meta:immutable
 
-func NewIntermediateMode(conn io.ReadWriter) (Transport, error) {
+func NewIntermediateMode(conn io.ReadWriter) (Mode, error) {
 	if conn == nil {
 		return nil, errors.New("conn is nil")
 	}
diff --git a/internal/transport/mode_test.go b/internal/transport/mode_test.go
new file mode 100644
index 0000000..98b6c7b
--- /dev/null
+++ b/internal/transport/mode_test.go
@@ -0,0 +1,33 @@
+package transport_test
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"github.com/xelaj/mtproto/internal/transport"
+)
+
+func TestMode(t *testing.T) {
+	buf := bytes.NewBuffer(nil)
+
+	tr, err := transport.NewIntermediateMode(buf)
+	require.NoError(t, err)
+
+	require.NoError(t, tr.WriteMsg([]byte("test message")))
+	require.Equal(t, buf.Bytes(), []byte{
+		0xee, 0xee, 0xee, 0xee, 0x0c, 0x00, 0x00, 0x00,
+		0x74, 0x65, 0x73, 0x74, 0x20, 0x6d, 0x65, 0x73,
+		0x73, 0x61, 0x67, 0x65,
+	})
+
+	tr, err = transport.NewIntermediateMode(bytes.NewBuffer([]byte{
+		0x0c, 0x00, 0x00, 0x00, 0x74, 0x65, 0x73, 0x74,
+		0x20, 0x6d, 0x65, 0x73, 0x73, 0x61, 0x67, 0x65,
+	}))
+	require.NoError(t, err)
+
+	res, err := tr.ReadMsg()
+	require.NoError(t, err)
+	require.Equal(t, []byte("test message"), res)
+}
diff --git a/internal/transport/transport_test.go b/internal/transport/transport_test.go
deleted file mode 100644
index bec323d..0000000
--- a/internal/transport/transport_test.go
+++ /dev/null
@@ -1,24 +0,0 @@
-package transport_test
-
-import (
-	"bytes"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-	"github.com/xelaj/mtproto/internal/transport"
-)
-
-func TestMode(t *testing.T) {
-	buf := bytes.NewBuffer(nil)
-
-	transport, err := transport.NewIntermediateMode(buf)
-	require.NoError(t, err)
-
-	require.NoError(t, transport.WriteMsg([]byte("test message")))
-	assert.Equal(t, buf.Bytes(), []byte{
-		0xee, 0xee, 0xee, 0xee, 0x0c, 0x00, 0x00, 0x00,
-		0x74, 0x65, 0x73, 0x74, 0x20, 0x6d, 0x65, 0x73,
-		0x73, 0x61, 0x67, 0x65,
-	})
-}
diff --git a/network.go b/network.go
index 02df760..b297202 100644
--- a/network.go
+++ b/network.go
@@ -8,7 +8,6 @@ package mtproto
 import (
 	"encoding/binary"
 	"fmt"
-	"time"
 
 	"github.com/pkg/errors"
 
@@ -17,11 +16,6 @@ import (
 	"github.com/xelaj/mtproto/internal/mtproto/objects"
 )
 
-const (
-	// если длина пакета больше или равн 127 слов, то кодируем 4 байтами, 1 это магическое число, оставшиеся 3 — дилна
-	magicValueSizeMoreThanSingleByte = 0x7f
-)
-
 // проверяет, надо ли ждать от сервера пинга
 func isNullableResponse(t tl.Object) bool {
 	switch t.(type) {
@@ -32,12 +26,8 @@ func isNullableResponse(t tl.Object) bool {
 	}
 }
 
-const (
-	readTimeout = 2 * time.Second
-)
-
 func CatchResponseErrorCode(data []byte) error {
-	if len(data) == 4 {
+	if len(data) == tl.WordLen {
 		code := int(binary.LittleEndian.Uint32(data))
 		return &ErrResponseCode{Code: code}
 	}
@@ -70,11 +60,9 @@ func (m *MTProto) decodeRecievedData(data []byte) (messages.Common, error) {
 		return nil, errors.Wrap(err, "parsing message")
 	}
 
-	m.msgId = int64(msg.GetMsgID())
-	m.seqNo = int32(msg.GetSeqNo())
-	mod := m.msgId & 3
+	mod := msg.GetMsgID() & 3
 	if mod != 1 && mod != 3 {
-		return nil, fmt.Errorf("Wrong bits of message_id: %d", mod)
+		return nil, fmt.Errorf("wrong bits of message_id: %d", mod)
 	}
 
 	return msg, nil
diff --git a/utils.go b/utils.go
index c5671b4..b3fcd7e 100644
--- a/utils.go
+++ b/utils.go
@@ -6,6 +6,9 @@
 package mtproto
 
 import (
+	"context"
+	"io"
+
 	"github.com/xelaj/mtproto/internal/encoding/tl"
 	"github.com/xelaj/mtproto/internal/mtproto/objects"
 )
@@ -23,14 +26,6 @@ func defaultDCList() map[int]string {
 	}
 }
 
-// https://core.telegram.org/mtproto/mtproto-transports
-var (
-	transportModeAbridged           = [...]byte{0xef}                   // meta:immutable
-	transportModeIntermediate       = [...]byte{0xee, 0xee, 0xee, 0xee} // meta:immutable
-	transportModePaddedIntermediate = [...]byte{0xdd, 0xdd, 0xdd, 0xdd} // meta:immutable
-	transportModeFull               = [...]byte{}                       // meta:immutable
-)
-
 func MessageRequireToAck(msg tl.Object) bool {
 	switch msg.(type) {
 	case /**objects.Ping,*/ *objects.MsgsAck:
@@ -39,3 +34,10 @@ func MessageRequireToAck(msg tl.Object) bool {
 		return true
 	}
 }
+
+func CloseOnCancel(ctx context.Context, c io.Closer) {
+	go func() {
+		<-ctx.Done()
+		c.Close()
+	}()
+}