diff --git a/gold/link/link.go b/gold/link/link.go
index f4b7174..c481af0 100644
--- a/gold/link/link.go
+++ b/gold/link/link.go
@@ -2,11 +2,8 @@ package link
 
 import (
 	"errors"
-	"fmt"
 	"net"
 
-	"github.com/sirupsen/logrus"
-
 	"github.com/fumiama/WireGold/gold/head"
 	"github.com/fumiama/WireGold/helper"
 	base14 "github.com/fumiama/go-base16384"
@@ -16,11 +13,6 @@ import (
 type Link struct {
 	// peer 的公钥
 	pubk *[32]byte
-	// peer 的公网 ip:port
-	pep string
-	// 决定本机是否定时向 peer 发送 hello 保持 NAT。
-	// 以秒为单位，小于等于 0 不发送
-	keepalive int64
 	// 收到的包的队列
 	// 没有下层 nic 时
 	// 包会分发到此
@@ -68,47 +60,6 @@ func (l *Link) Destroy() {
 	l.me.connmapmu.Unlock()
 }
 
-// Read 从 peer 收包
-func (l *Link) Read() *head.Packet {
-	return <-l.pipe
-}
-
-// Write 向 peer 发包
-func (l *Link) Write(p *head.Packet, istransfer bool) (n int, err error) {
-	if len(p.Data) <= int(l.me.mtu) {
-		if !istransfer {
-			p.FillHash()
-			p.Data = l.Encode(p.Data)
-		}
-		return l.write(p, uint32(len(p.Data)), 0, istransfer, false)
-	}
-	if !istransfer {
-		p.FillHash()
-		p.Data = l.Encode(p.Data)
-	}
-	data := p.Data
-	totl := uint32(len(data))
-	i := 0
-	for ; int(totl)-i > int(l.me.mtu); i += int(l.me.mtu) {
-		logrus.Debugln("[link] split frag", i, ":", i+int(l.me.mtu), ", remain:", int(totl)-i-int(l.me.mtu))
-		packet := *p
-		packet.Data = data[:int(l.me.mtu)]
-		cnt, err := l.write(&packet, totl, uint16(uint(i)>>3), istransfer, true)
-		n += cnt
-		if err != nil {
-			return n, err
-		}
-		data = data[int(l.me.mtu):]
-	}
-	p.Data = data
-	cnt, err := l.write(p, totl, uint16(uint(i)>>3), istransfer, false)
-	n += cnt
-	if err != nil {
-		return n, err
-	}
-	return n, nil
-}
-
 func (l *Link) String() (n string) {
 	n = "default"
 	if l.pubk != nil {
@@ -121,30 +72,3 @@ func (l *Link) String() (n string) {
 	}
 	return
 }
-
-// write 向 peer 发一个包
-func (l *Link) write(p *head.Packet, datasz uint32, offset uint16, istransfer, hasmore bool) (n int, err error) {
-	var d []byte
-	var cl func()
-	if istransfer {
-		if p.Flags&0x4000 == 0x4000 && len(p.Data) > int(l.me.mtu) {
-			return len(p.Data), errors.New("drop dont fragmnet big trans packet")
-		}
-		d, cl = p.Marshal(nil, 0, 0, false, false)
-	} else {
-		d, cl = p.Marshal(l.me.me, datasz, offset, false, hasmore)
-	}
-	if d == nil {
-		return 0, errors.New("[link] ttl exceeded")
-	}
-	if err == nil {
-		peerep := l.endpoint
-		if peerep == nil {
-			return 0, errors.New("[link] nil endpoint of " + p.Dst.String())
-		}
-		logrus.Debugln("[link] write", len(d), "bytes data from ep", l.me.myconn.LocalAddr(), "to", peerep, "offset:", fmt.Sprintf("%04x", offset))
-		n, err = l.me.myconn.WriteToUDP(d, peerep)
-		cl()
-	}
-	return
-}
diff --git a/gold/link/link_test.go b/gold/link/link_test.go
deleted file mode 100644
index d3c844b..0000000
--- a/gold/link/link_test.go
+++ /dev/null
@@ -1,31 +0,0 @@
-package link
-
-import (
-	"net"
-	"testing"
-)
-
-func TestUDP(t *testing.T) {
-	t.Log("test start")
-	lconn, err := net.ListenUDP("udp", &net.UDPAddr{Port: 1234})
-	if err == nil {
-		dconn, err := net.DialUDP("udp", &net.UDPAddr{Port: 1235}, &net.UDPAddr{Port: 1234})
-		if err != nil {
-			t.Fatal(err)
-		}
-		_, err = dconn.Write(([]byte)("1234567890"))
-		t.Log("write succ")
-		if err != nil {
-			t.Fatal(err)
-		}
-		d := make([]byte, 10)
-		_, err = lconn.Read(d)
-		t.Log("read succ")
-		if err != nil {
-			t.Fatal(err)
-		}
-		t.Log(d)
-	} else {
-		t.Fatal(err)
-	}
-}
diff --git a/gold/link/listen.go b/gold/link/listen.go
index fca69aa..5d8df85 100644
--- a/gold/link/listen.go
+++ b/gold/link/listen.go
@@ -33,10 +33,9 @@ func (m *Me) listen() (conn *net.UDPConn, err error) {
 						logrus.Debugln("[link] recv from endpoint", addr, "src", packet.Src, "dst", packet.Dst)
 						// logrus.Debugln("[link] recv:", hex.EncodeToString(lbf))
 						if ok {
-							if p.pep == "" || p.pep != addr.String() {
+							if p.peerip == nil || p.peerip.String() != addr.String() {
 								logrus.Infoln("[link] set endpoint of peer", p.peerip, "to", addr.String())
 								p.endpoint = addr
-								p.pep = addr.String()
 							}
 							if p.IsToMe(packet.Dst) {
 								packet.Data = p.Decode(packet.Data)
diff --git a/gold/link/me.go b/gold/link/me.go
index a7a3762..5c543c9 100644
--- a/gold/link/me.go
+++ b/gold/link/me.go
@@ -34,7 +34,7 @@ type Me struct {
 	// 读写同步锁
 	connmapmu sync.RWMutex
 	// 本机监听的 endpoint
-	myconn *net.UDPConn
+	myep *net.UDPConn
 	// 本机网卡
 	nic lower.NICIO
 	// 本机路由表
@@ -43,8 +43,9 @@ type Me struct {
 	writer *helper.Writer
 	// 本机未接收完全分片池
 	recving map[[32]byte]*head.Packet
-	recvmu  sync.Mutex
-	// 超时定时器
+	// 接收锁
+	recvmu sync.Mutex
+	// 收包超时定时器
 	clock map[*head.Packet]uint8
 	// 本机上层配置
 	srcport, dstport, mtu uint16
@@ -64,7 +65,7 @@ func NewMe(privateKey *[32]byte, myipwithmask string, myEndpoint string, nic low
 	}
 	m.me = ip
 	m.subnet = *cidr
-	m.myconn, err = m.listen()
+	m.myep, err = m.listen()
 	if err != nil {
 		panic(err)
 	}
diff --git a/gold/link/nat.go b/gold/link/nat.go
index 6d40fee..45b72f5 100644
--- a/gold/link/nat.go
+++ b/gold/link/nat.go
@@ -1,18 +1,23 @@
 package link
 
 import (
+	"encoding/json"
+	"net"
 	"time"
 
 	"github.com/sirupsen/logrus"
 
 	"github.com/fumiama/WireGold/gold/head"
+	"github.com/fumiama/WireGold/helper"
 )
 
 // 保持 NAT
-func (l *Link) keepAlive() {
-	if l.keepalive > 0 {
+// dur 决定本机是否定时向 peer 发送 hello 保持 NAT
+// 以秒为单位，小于等于 0 不发送
+func (l *Link) keepAlive(dur int64) {
+	if dur > 0 {
 		logrus.Infoln("[link.nat] start to keep alive")
-		t := time.NewTicker(time.Second * time.Duration(l.keepalive))
+		t := time.NewTicker(time.Second * time.Duration(dur))
 		for range t.C {
 			n, err := l.Write(head.NewPacket(head.ProtoHello, l.me.srcport, l.peerip, l.me.dstport, nil), false)
 			if err == nil {
@@ -23,3 +28,85 @@ func (l *Link) keepAlive() {
 		}
 	}
 }
+
+// 收到通告包的处理函数
+func (l *Link) onNotify(packet []byte) {
+	// TODO: 完成data解包与endpoint注册
+	// 1. Data 解包
+	// ---- 使用 head.Notify 解释 packet
+	notify := make(head.Notify, 32)
+	err := json.Unmarshal(packet, &notify)
+	if err != nil {
+		logrus.Errorln("[notify] json unmarshal err:", err)
+		return
+	}
+	// 2. endpoint注册
+	// ---- 遍历 Notify，注册对方的 endpoint 到
+	// ---- connections，注意使用读写锁connmapmu
+	for peer, ep := range notify {
+		addr, err := net.ResolveUDPAddr("udp", ep)
+		if err == nil {
+			p, ok := l.me.IsInPeer(peer)
+			if ok {
+				if p.endpoint.String() != ep {
+					p.endpoint = addr
+					logrus.Infoln("[notify] set ep of peer", peer, "to", ep)
+				}
+				continue
+			}
+		}
+		logrus.Debugln("[notify] drop invalid peer:", peer, "ep:", ep)
+	}
+}
+
+// 收到询问包的处理函数
+func (l *Link) onQuery(packet []byte) {
+	// 完成data解包与notify分发
+
+	// 1. Data 解包
+	// ---- 使用 head.Query 解释 packet
+	// ---- 根据 Query 确定需要封装的 Notify
+	var peers head.Query
+	err := json.Unmarshal(packet, &peers)
+	if err != nil {
+		logrus.Errorln("[qurey] json unmarshal err:", err)
+		return
+	}
+
+	// 2. notify分发
+	// ---- 封装 Notify 到 新的 packet
+	// ---- 调用 l.Send 发送到对方
+	notify := make(head.Notify, len(peers))
+	for _, p := range peers {
+		lnk, ok := l.me.IsInPeer(p)
+		if ok {
+			notify[p] = lnk.endpoint.String()
+		}
+	}
+	if len(notify) > 0 {
+		logrus.Infoln("[query] wrap", len(notify), "notify")
+		w := helper.SelectWriter()
+		json.NewEncoder(w).Encode(&notify)
+		l.Write(head.NewPacket(head.ProtoNotify, l.me.srcport, l.peerip, l.me.dstport, w.Bytes()), false)
+		helper.PutWriter(w)
+	}
+}
+
+// sendquery 主动发起查询，询问对方是否可以到达 peers
+func (l *Link) sendquery(tick time.Duration, peers ...string) {
+	if len(peers) == 0 {
+		return
+	}
+	data, err := json.Marshal(peers)
+	if err != nil {
+		panic(err)
+	}
+	t := time.NewTicker(tick)
+	for range t.C {
+		logrus.Infoln("[query] send query to", l.peerip)
+		_, err = l.Write(head.NewPacket(head.ProtoQuery, l.me.srcport, l.peerip, l.me.dstport, data), false)
+		if err != nil {
+			logrus.Errorln("[query] write err:", err)
+		}
+	}
+}
diff --git a/gold/link/notify.go b/gold/link/notify.go
deleted file mode 100644
index 53784e1..0000000
--- a/gold/link/notify.go
+++ /dev/null
@@ -1,39 +0,0 @@
-package link
-
-import (
-	"encoding/json"
-	"net"
-
-	"github.com/fumiama/WireGold/gold/head"
-	"github.com/sirupsen/logrus"
-)
-
-// 收到通告包的处理函数
-func (l *Link) onNotify(packet []byte) {
-	// TODO: 完成data解包与endpoint注册
-	// 1. Data 解包
-	// ---- 使用 head.Notify 解释 packet
-	notify := make(head.Notify, 32)
-	err := json.Unmarshal(packet, &notify)
-	if err != nil {
-		logrus.Errorln("[notify] json unmarshal err:", err)
-		return
-	}
-	// 2. endpoint注册
-	// ---- 遍历 Notify，注册对方的 endpoint 到
-	// ---- connections，注意使用读写锁connmapmu
-	for peer, ep := range notify {
-		addr, err := net.ResolveUDPAddr("udp", ep)
-		if err == nil {
-			p, ok := l.me.IsInPeer(peer)
-			if ok {
-				if p.endpoint.String() != ep {
-					p.endpoint = addr
-					logrus.Infoln("[notify] set ep of peer", peer, "to", ep)
-				}
-				continue
-			}
-		}
-		logrus.Debugln("[notify] drop invalid peer:", peer, "ep:", ep)
-	}
-}
diff --git a/gold/link/peer.go b/gold/link/peer.go
index 35c84a6..7626cbc 100644
--- a/gold/link/peer.go
+++ b/gold/link/peer.go
@@ -11,7 +11,7 @@ import (
 )
 
 // AddPeer 添加一个 peer
-func (m *Me) AddPeer(peerip string, pubicKey *[32]byte, endPoint string, allowedIPs, querys []string, keepAlive, queryTick int64, allowTrans, nopipe bool) (l *Link) {
+func (m *Me) AddPeer(peerip string, pubicKey *[32]byte, endPoint string, allowedIPs, querys []string, keepAliveDur, queryTick int64, allowTrans, nopipe bool) (l *Link) {
 	peerip = net.ParseIP(peerip).String()
 	var ok bool
 	l, ok = m.IsInPeer(peerip)
@@ -20,7 +20,6 @@ func (m *Me) AddPeer(peerip string, pubicKey *[32]byte, endPoint string, allowed
 	}
 	l = &Link{
 		pubk:       pubicKey,
-		keepalive:  keepAlive,
 		peerip:     net.ParseIP(peerip),
 		allowtrans: allowTrans,
 		me:         m,
@@ -41,7 +40,6 @@ func (m *Me) AddPeer(peerip string, pubicKey *[32]byte, endPoint string, allowed
 		if err != nil {
 			panic(err)
 		}
-		l.pep = endPoint
 		l.endpoint = e
 	}
 	if allowedIPs != nil {
@@ -60,7 +58,7 @@ func (m *Me) AddPeer(peerip string, pubicKey *[32]byte, endPoint string, allowed
 		}
 	}
 	logrus.Infoln("[peer] add peer:", peerip, "allow:", allowedIPs)
-	go l.keepAlive()
+	go l.keepAlive(keepAliveDur)
 	go l.sendquery(time.Second*time.Duration(queryTick), querys...)
 	return
 }
diff --git a/gold/link/query.go b/gold/link/query.go
deleted file mode 100644
index c76cd9b..0000000
--- a/gold/link/query.go
+++ /dev/null
@@ -1,63 +0,0 @@
-package link
-
-import (
-	"encoding/json"
-	"time"
-
-	"github.com/sirupsen/logrus"
-
-	"github.com/fumiama/WireGold/gold/head"
-	"github.com/fumiama/WireGold/helper"
-)
-
-// 收到询问包的处理函数
-func (l *Link) onQuery(packet []byte) {
-	// 完成data解包与notify分发
-
-	// 1. Data 解包
-	// ---- 使用 head.Query 解释 packet
-	// ---- 根据 Query 确定需要封装的 Notify
-	var peers head.Query
-	err := json.Unmarshal(packet, &peers)
-	if err != nil {
-		logrus.Errorln("[qurey] json unmarshal err:", err)
-		return
-	}
-
-	// 2. notify分发
-	// ---- 封装 Notify 到 新的 packet
-	// ---- 调用 l.Send 发送到对方
-	notify := make(head.Notify, len(peers))
-	for _, p := range peers {
-		lnk, ok := l.me.IsInPeer(p)
-		if ok {
-			notify[p] = lnk.endpoint.String()
-		}
-	}
-	if len(notify) > 0 {
-		logrus.Infoln("[query] wrap", len(notify), "notify")
-		w := helper.SelectWriter()
-		json.NewEncoder(w).Encode(&notify)
-		l.Write(head.NewPacket(head.ProtoNotify, l.me.srcport, l.peerip, l.me.dstport, w.Bytes()), false)
-		helper.PutWriter(w)
-	}
-}
-
-// sendquery 主动发起查询，询问对方是否可以到达 peers
-func (l *Link) sendquery(tick time.Duration, peers ...string) {
-	if len(peers) == 0 {
-		return
-	}
-	data, err := json.Marshal(peers)
-	if err != nil {
-		panic(err)
-	}
-	t := time.NewTicker(tick)
-	for range t.C {
-		logrus.Infoln("[query] send query to", l.peerip)
-		_, err = l.Write(head.NewPacket(head.ProtoQuery, l.me.srcport, l.peerip, l.me.dstport, data), false)
-		if err != nil {
-			logrus.Errorln("[query] write err:", err)
-		}
-	}
-}
diff --git a/gold/link/recv.go b/gold/link/recv.go
index 8efb185..74c7be3 100644
--- a/gold/link/recv.go
+++ b/gold/link/recv.go
@@ -10,6 +10,11 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+// Read 从 peer 收包
+func (l *Link) Read() *head.Packet {
+	return <-l.pipe
+}
+
 func (m *Me) initrecvpool() {
 	if m.recving == nil {
 		m.recving = make(map[[32]byte]*head.Packet, 128)
diff --git a/gold/link/send.go b/gold/link/send.go
new file mode 100644
index 0000000..556c40b
--- /dev/null
+++ b/gold/link/send.go
@@ -0,0 +1,72 @@
+package link
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/fumiama/WireGold/gold/head"
+	"github.com/sirupsen/logrus"
+)
+
+// Write 向 peer 发包
+func (l *Link) Write(p *head.Packet, istransfer bool) (n int, err error) {
+	if len(p.Data) <= int(l.me.mtu) {
+		if !istransfer {
+			p.FillHash()
+			p.Data = l.Encode(p.Data)
+		}
+		return l.write(p, uint32(len(p.Data)), 0, istransfer, false)
+	}
+	if !istransfer {
+		p.FillHash()
+		p.Data = l.Encode(p.Data)
+	}
+	data := p.Data
+	totl := uint32(len(data))
+	i := 0
+	for ; int(totl)-i > int(l.me.mtu); i += int(l.me.mtu) {
+		logrus.Debugln("[link] split frag", i, ":", i+int(l.me.mtu), ", remain:", int(totl)-i-int(l.me.mtu))
+		packet := *p
+		packet.Data = data[:int(l.me.mtu)]
+		cnt, err := l.write(&packet, totl, uint16(uint(i)>>3), istransfer, true)
+		n += cnt
+		if err != nil {
+			return n, err
+		}
+		data = data[int(l.me.mtu):]
+	}
+	p.Data = data
+	cnt, err := l.write(p, totl, uint16(uint(i)>>3), istransfer, false)
+	n += cnt
+	if err != nil {
+		return n, err
+	}
+	return n, nil
+}
+
+// write 向 peer 发一个包
+func (l *Link) write(p *head.Packet, datasz uint32, offset uint16, istransfer, hasmore bool) (n int, err error) {
+	var d []byte
+	var cl func()
+	if istransfer {
+		if p.Flags&0x4000 == 0x4000 && len(p.Data) > int(l.me.mtu) {
+			return len(p.Data), errors.New("drop dont fragmnet big trans packet")
+		}
+		d, cl = p.Marshal(nil, 0, 0, false, false)
+	} else {
+		d, cl = p.Marshal(l.me.me, datasz, offset, false, hasmore)
+	}
+	if d == nil {
+		return 0, errors.New("[link] ttl exceeded")
+	}
+	if err == nil {
+		peerep := l.endpoint
+		if peerep == nil {
+			return 0, errors.New("[link] nil endpoint of " + p.Dst.String())
+		}
+		logrus.Debugln("[link] write", len(d), "bytes data from ep", l.me.myep.LocalAddr(), "to", peerep, "offset:", fmt.Sprintf("%04x", offset))
+		n, err = l.me.myep.WriteToUDP(d, peerep)
+		cl()
+	}
+	return
+}